diff options
| author | Tom Smeding <tom.smeding@gmail.com> | 2020-05-05 17:41:14 +0200 |
|---|---|---|
| committer | Tom Smeding <tom.smeding@gmail.com> | 2020-05-05 17:41:14 +0200 |
| commit | c4d58222e0c396585ae19301796097fde4d3f19d (patch) | |
| tree | 4b888aa3412ad2e3adfa25fe7a88c358597c86a5 | |
| parent | 6878d573e50cca6ad917b67d596e5bb38c93b42a (diff) | |
Upgrade lodepng
| -rw-r--r-- | lodepng.cpp | 5535 | ||||
| -rw-r--r-- | lodepng.h | 456 |
2 files changed, 3162 insertions, 2829 deletions
diff --git a/lodepng.cpp b/lodepng.cpp index 1854b4f..1130afe 100644 --- a/lodepng.cpp +++ b/lodepng.cpp @@ -1,7 +1,7 @@ /* -LodePNG version 20180326 +LodePNG version 20200306 -Copyright (c) 2005-2018 Lode Vandevenne +Copyright (c) 2005-2020 Lode Vandevenne This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages @@ -30,16 +30,21 @@ Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for #include "lodepng.h" -#include <limits.h> -#include <stdio.h> -#include <stdlib.h> +#ifdef LODEPNG_COMPILE_DISK +#include <limits.h> /* LONG_MAX */ +#include <stdio.h> /* file handling */ +#endif /* LODEPNG_COMPILE_DISK */ + +#ifdef LODEPNG_COMPILE_ALLOCATORS +#include <stdlib.h> /* allocations */ +#endif /* LODEPNG_COMPILE_ALLOCATORS */ #if defined(_MSC_VER) && (_MSC_VER >= 1310) /*Visual Studio: A few warning types are not desired here.*/ #pragma warning( disable : 4244 ) /*implicit conversions: not warned by gcc -Wall -Wextra and requires too much casts*/ #pragma warning( disable : 4996 ) /*VS does not like fopen, but fopen_s is not standard C so unusable here*/ #endif /*_MSC_VER */ -const char* LODEPNG_VERSION_STRING = "20180326"; +const char* LODEPNG_VERSION_STRING = "20200306"; /* This source file is built up in the following large parts. The code sections @@ -50,6 +55,12 @@ with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way -The C++ wrapper around all of the above */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* // Tools for C, and common code for PNG and Zlib. // */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ + /*The malloc, realloc and free functions defined here with "lodepng_" in front of the name, so that you can easily change them to others related to your platform if needed. Everything else in the code calls these. Pass @@ -60,41 +71,113 @@ lodepng source code. Don't forget to remove "static" if you copypaste them from here.*/ #ifdef LODEPNG_COMPILE_ALLOCATORS -static void* lodepng_malloc(size_t size) -{ +static void* lodepng_malloc(size_t size) { +#ifdef LODEPNG_MAX_ALLOC + if(size > LODEPNG_MAX_ALLOC) return 0; +#endif return malloc(size); } -static void* lodepng_realloc(void* ptr, size_t new_size) -{ +/* NOTE: when realloc returns NULL, it leaves the original memory untouched */ +static void* lodepng_realloc(void* ptr, size_t new_size) { +#ifdef LODEPNG_MAX_ALLOC + if(new_size > LODEPNG_MAX_ALLOC) return 0; +#endif return realloc(ptr, new_size); } -static void lodepng_free(void* ptr) -{ +static void lodepng_free(void* ptr) { free(ptr); } #else /*LODEPNG_COMPILE_ALLOCATORS*/ +/* TODO: support giving additional void* payload to the custom allocators */ void* lodepng_malloc(size_t size); void* lodepng_realloc(void* ptr, size_t new_size); void lodepng_free(void* ptr); #endif /*LODEPNG_COMPILE_ALLOCATORS*/ -/* ////////////////////////////////////////////////////////////////////////// */ -/* ////////////////////////////////////////////////////////////////////////// */ -/* // Tools for C, and common code for PNG and Zlib. // */ -/* ////////////////////////////////////////////////////////////////////////// */ -/* ////////////////////////////////////////////////////////////////////////// */ +/* convince the compiler to inline a function, for use when this measurably improves performance */ +/* inline is not available in C90, but use it when supported by the compiler */ +#if (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)) || (defined(__cplusplus) && (__cplusplus >= 199711L)) +#define LODEPNG_INLINE inline +#else +#define LODEPNG_INLINE /* not available */ +#endif + +/* restrict is not available in C90, but use it when supported by the compiler */ +#if (defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))) ||\ + (defined(_MSC_VER) && (_MSC_VER >= 1400)) || \ + (defined(__WATCOMC__) && (__WATCOMC__ >= 1250) && !defined(__cplusplus)) +#define LODEPNG_RESTRICT __restrict +#else +#define LODEPNG_RESTRICT /* not available */ +#endif + +/* Replacements for C library functions such as memcpy and strlen, to support platforms +where a full C library is not available. The compiler can recognize them and compile +to something as fast. */ + +static void lodepng_memcpy(void* LODEPNG_RESTRICT dst, + const void* LODEPNG_RESTRICT src, size_t size) { + size_t i; + for(i = 0; i < size; i++) ((char*)dst)[i] = ((const char*)src)[i]; +} + +static void lodepng_memset(void* LODEPNG_RESTRICT dst, + int value, size_t num) { + size_t i; + for(i = 0; i < num; i++) ((char*)dst)[i] = (char)value; +} + +/* does not check memory out of bounds, do not use on untrusted data */ +static size_t lodepng_strlen(const char* a) { + const char* orig = a; + /* avoid warning about unused function in case of disabled COMPILE... macros */ + (void)(&lodepng_strlen); + while(*a) a++; + return (size_t)(a - orig); +} + +#define LODEPNG_MAX(a, b) (((a) > (b)) ? (a) : (b)) +#define LODEPNG_MIN(a, b) (((a) < (b)) ? (a) : (b)) +#define LODEPNG_ABS(x) ((x) < 0 ? -(x) : (x)) + +#if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_DECODER) +/* Safely check if adding two integers will overflow (no undefined +behavior, compiler removing the code, etc...) and output result. */ +static int lodepng_addofl(size_t a, size_t b, size_t* result) { + *result = a + b; /* Unsigned addition is well defined and safe in C90 */ + return *result < a; +} +#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_DECODER)*/ + +#ifdef LODEPNG_COMPILE_DECODER +/* Safely check if multiplying two integers will overflow (no undefined +behavior, compiler removing the code, etc...) and output result. */ +static int lodepng_mulofl(size_t a, size_t b, size_t* result) { + *result = a * b; /* Unsigned multiplication is well defined and safe in C90 */ + return (a != 0 && *result / a != b); +} + +#ifdef LODEPNG_COMPILE_ZLIB +/* Safely check if a + b > c, even if overflow could happen. */ +static int lodepng_gtofl(size_t a, size_t b, size_t c) { + size_t d; + if(lodepng_addofl(a, b, &d)) return 1; + return d > c; +} +#endif /*LODEPNG_COMPILE_ZLIB*/ +#endif /*LODEPNG_COMPILE_DECODER*/ + /* Often in case of an error a value is assigned to a variable and then it breaks out of a loop (to go to the cleanup phase of a function). This macro does that. It makes the error handling code shorter and more readable. -Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83); +Example: if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83); */ -#define CERROR_BREAK(errorvar, code)\ -{\ +#define CERROR_BREAK(errorvar, code){\ errorvar = code;\ break;\ } @@ -103,22 +186,19 @@ Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83); #define ERROR_BREAK(code) CERROR_BREAK(error, code) /*Set error var to the error code, and return it.*/ -#define CERROR_RETURN_ERROR(errorvar, code)\ -{\ +#define CERROR_RETURN_ERROR(errorvar, code){\ errorvar = code;\ return code;\ } /*Try the code, if it returns error, also return the error.*/ -#define CERROR_TRY_RETURN(call)\ -{\ +#define CERROR_TRY_RETURN(call){\ unsigned error = call;\ if(error) return error;\ } /*Set error var to the error code, and return from the void function.*/ -#define CERROR_RETURN(errorvar, code)\ -{\ +#define CERROR_RETURN(errorvar, code){\ errorvar = code;\ return;\ } @@ -133,65 +213,43 @@ About uivector, ucvector and string: */ #ifdef LODEPNG_COMPILE_ZLIB +#ifdef LODEPNG_COMPILE_ENCODER /*dynamic vector of unsigned ints*/ -typedef struct uivector -{ +typedef struct uivector { unsigned* data; size_t size; /*size in number of unsigned longs*/ size_t allocsize; /*allocated size in bytes*/ } uivector; -static void uivector_cleanup(void* p) -{ +static void uivector_cleanup(void* p) { ((uivector*)p)->size = ((uivector*)p)->allocsize = 0; lodepng_free(((uivector*)p)->data); ((uivector*)p)->data = NULL; } /*returns 1 if success, 0 if failure ==> nothing done*/ -static unsigned uivector_reserve(uivector* p, size_t allocsize) -{ - if(allocsize > p->allocsize) - { - size_t newsize = (allocsize > p->allocsize * 2) ? allocsize : (allocsize * 3 / 2); +static unsigned uivector_resize(uivector* p, size_t size) { + size_t allocsize = size * sizeof(unsigned); + if(allocsize > p->allocsize) { + size_t newsize = allocsize + (p->allocsize >> 1u); void* data = lodepng_realloc(p->data, newsize); - if(data) - { + if(data) { p->allocsize = newsize; p->data = (unsigned*)data; } else return 0; /*error: not enough memory*/ } - return 1; -} - -/*returns 1 if success, 0 if failure ==> nothing done*/ -static unsigned uivector_resize(uivector* p, size_t size) -{ - if(!uivector_reserve(p, size * sizeof(unsigned))) return 0; p->size = size; return 1; /*success*/ } -/*resize and give all new elements the value*/ -static unsigned uivector_resizev(uivector* p, size_t size, unsigned value) -{ - size_t oldsize = p->size, i; - if(!uivector_resize(p, size)) return 0; - for(i = oldsize; i < size; ++i) p->data[i] = value; - return 1; -} - -static void uivector_init(uivector* p) -{ +static void uivector_init(uivector* p) { p->data = NULL; p->size = p->allocsize = 0; } -#ifdef LODEPNG_COMPILE_ENCODER /*returns 1 if success, 0 if failure ==> nothing done*/ -static unsigned uivector_push_back(uivector* p, unsigned c) -{ +static unsigned uivector_push_back(uivector* p, unsigned c) { if(!uivector_resize(p, p->size + 1)) return 0; p->data[p->size - 1] = c; return 1; @@ -202,130 +260,73 @@ static unsigned uivector_push_back(uivector* p, unsigned c) /* /////////////////////////////////////////////////////////////////////////// */ /*dynamic vector of unsigned chars*/ -typedef struct ucvector -{ +typedef struct ucvector { unsigned char* data; size_t size; /*used size*/ size_t allocsize; /*allocated size*/ } ucvector; /*returns 1 if success, 0 if failure ==> nothing done*/ -static unsigned ucvector_reserve(ucvector* p, size_t allocsize) -{ - if(allocsize > p->allocsize) - { - size_t newsize = (allocsize > p->allocsize * 2) ? allocsize : (allocsize * 3 / 2); +static unsigned ucvector_resize(ucvector* p, size_t size) { + if(size > p->allocsize) { + size_t newsize = size + (p->allocsize >> 1u); void* data = lodepng_realloc(p->data, newsize); - if(data) - { + if(data) { p->allocsize = newsize; p->data = (unsigned char*)data; } else return 0; /*error: not enough memory*/ } - return 1; -} - -/*returns 1 if success, 0 if failure ==> nothing done*/ -static unsigned ucvector_resize(ucvector* p, size_t size) -{ - if(!ucvector_reserve(p, size * sizeof(unsigned char))) return 0; p->size = size; return 1; /*success*/ } -#ifdef LODEPNG_COMPILE_PNG - -static void ucvector_cleanup(void* p) -{ - ((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0; - lodepng_free(((ucvector*)p)->data); - ((ucvector*)p)->data = NULL; -} - -static void ucvector_init(ucvector* p) -{ - p->data = NULL; - p->size = p->allocsize = 0; -} -#endif /*LODEPNG_COMPILE_PNG*/ - -#ifdef LODEPNG_COMPILE_ZLIB -/*you can both convert from vector to buffer&size and vica versa. If you use -init_buffer to take over a buffer and size, it is not needed to use cleanup*/ -static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size) -{ - p->data = buffer; - p->allocsize = p->size = size; -} -#endif /*LODEPNG_COMPILE_ZLIB*/ - -#if (defined(LODEPNG_COMPILE_PNG) && defined(LODEPNG_COMPILE_ANCILLARY_CHUNKS)) || defined(LODEPNG_COMPILE_ENCODER) -/*returns 1 if success, 0 if failure ==> nothing done*/ -static unsigned ucvector_push_back(ucvector* p, unsigned char c) -{ - if(!ucvector_resize(p, p->size + 1)) return 0; - p->data[p->size - 1] = c; - return 1; +static ucvector ucvector_init(unsigned char* buffer, size_t size) { + ucvector v; + v.data = buffer; + v.allocsize = v.size = size; + return v; } -#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/ - /* ////////////////////////////////////////////////////////////////////////// */ #ifdef LODEPNG_COMPILE_PNG #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -/*returns 1 if success, 0 if failure ==> nothing done*/ -static unsigned string_resize(char** out, size_t size) -{ - char* data = (char*)lodepng_realloc(*out, size + 1); - if(data) - { - data[size] = 0; /*null termination char*/ - *out = data; - } - return data != 0; -} -/*init a {char*, size_t} pair for use as string*/ -static void string_init(char** out) -{ - *out = NULL; - string_resize(out, 0); -} - -/*free the above pair again*/ -static void string_cleanup(char** out) -{ +/*free string pointer and set it to NULL*/ +static void string_cleanup(char** out) { lodepng_free(*out); *out = NULL; } -static void string_set(char** out, const char* in) -{ - size_t insize = strlen(in), i; - if(string_resize(out, insize)) - { - for(i = 0; i != insize; ++i) - { - (*out)[i] = in[i]; - } +static char* alloc_string_sized(const char* in, size_t insize) { + char* out = (char*)lodepng_malloc(insize + 1); + if(out) { + lodepng_memcpy(out, in, insize); + out[insize] = 0; } + return out; +} + +/* dynamically allocates a new string with a copy of the null terminated input text */ +static char* alloc_string(const char* in) { + return alloc_string_sized(in, lodepng_strlen(in)); } #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ #endif /*LODEPNG_COMPILE_PNG*/ /* ////////////////////////////////////////////////////////////////////////// */ -unsigned lodepng_read32bitInt(const unsigned char* buffer) -{ - return (unsigned)((buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]); +#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_PNG) +static unsigned lodepng_read32bitInt(const unsigned char* buffer) { + return (((unsigned)buffer[0] << 24u) | ((unsigned)buffer[1] << 16u) | + ((unsigned)buffer[2] << 8u) | (unsigned)buffer[3]); } +#endif /*defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_PNG)*/ #if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER) /*buffer must have at least 4 allocated bytes available*/ -static void lodepng_set32bitInt(unsigned char* buffer, unsigned value) -{ +static void lodepng_set32bitInt(unsigned char* buffer, unsigned value) { buffer[0] = (unsigned char)((value >> 24) & 0xff); buffer[1] = (unsigned char)((value >> 16) & 0xff); buffer[2] = (unsigned char)((value >> 8) & 0xff); @@ -333,14 +334,6 @@ static void lodepng_set32bitInt(unsigned char* buffer, unsigned value) } #endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/ -#ifdef LODEPNG_COMPILE_ENCODER -static void lodepng_add32bitInt(ucvector* buffer, unsigned value) -{ - ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/ - lodepng_set32bitInt(&buffer->data[buffer->size - 4], value); -} -#endif /*LODEPNG_COMPILE_ENCODER*/ - /* ////////////////////////////////////////////////////////////////////////// */ /* / File IO / */ /* ////////////////////////////////////////////////////////////////////////// */ @@ -348,15 +341,13 @@ static void lodepng_add32bitInt(ucvector* buffer, unsigned value) #ifdef LODEPNG_COMPILE_DISK /* returns negative value on error. This should be pure C compatible, so no fstat. */ -static long lodepng_filesize(const char* filename) -{ +static long lodepng_filesize(const char* filename) { FILE* file; long size; file = fopen(filename, "rb"); if(!file) return -1; - if(fseek(file, 0, SEEK_END) != 0) - { + if(fseek(file, 0, SEEK_END) != 0) { fclose(file); return -1; } @@ -370,8 +361,7 @@ static long lodepng_filesize(const char* filename) } /* load file into buffer that already has the correct allocated size. Returns error code.*/ -static unsigned lodepng_buffer_file(unsigned char* out, size_t size, const char* filename) -{ +static unsigned lodepng_buffer_file(unsigned char* out, size_t size, const char* filename) { FILE* file; size_t readsize; file = fopen(filename, "rb"); @@ -380,14 +370,13 @@ static unsigned lodepng_buffer_file(unsigned char* out, size_t size, const char* readsize = fread(out, 1, size, file); fclose(file); - if (readsize != size) return 78; + if(readsize != size) return 78; return 0; } -unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename) -{ +unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename) { long size = lodepng_filesize(filename); - if (size < 0) return 78; + if(size < 0) return 78; *outsize = (size_t)size; *out = (unsigned char*)lodepng_malloc((size_t)size); @@ -397,12 +386,11 @@ unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* fil } /*write given buffer to the file, overwriting the file, it doesn't append to it.*/ -unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename) -{ +unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename) { FILE* file; file = fopen(filename, "wb" ); if(!file) return 79; - fwrite((char*)buffer , 1 , buffersize, file); + fwrite(buffer, 1, buffersize, file); fclose(file); return 0; } @@ -417,52 +405,211 @@ unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const #ifdef LODEPNG_COMPILE_ZLIB #ifdef LODEPNG_COMPILE_ENCODER -/*TODO: this ignores potential out of memory errors*/ -#define addBitToStream(/*size_t**/ bitpointer, /*ucvector**/ bitstream, /*unsigned char*/ bit)\ -{\ - /*add a new byte at the end*/\ - if(((*bitpointer) & 7) == 0) ucvector_push_back(bitstream, (unsigned char)0);\ - /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/\ - (bitstream->data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7));\ - ++(*bitpointer);\ + +typedef struct { + ucvector* data; + unsigned char bp; /*ok to overflow, indicates bit pos inside byte*/ +} LodePNGBitWriter; + +static void LodePNGBitWriter_init(LodePNGBitWriter* writer, ucvector* data) { + writer->data = data; + writer->bp = 0; } -static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits) -{ - size_t i; - for(i = 0; i != nbits; ++i) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> i) & 1)); +/*TODO: this ignores potential out of memory errors*/ +#define WRITEBIT(writer, bit){\ + /* append new byte */\ + if(((writer->bp) & 7u) == 0) {\ + if(!ucvector_resize(writer->data, writer->data->size + 1)) return;\ + writer->data->data[writer->data->size - 1] = 0;\ + }\ + (writer->data->data[writer->data->size - 1]) |= (bit << ((writer->bp) & 7u));\ + ++writer->bp;\ +} + +/* LSB of value is written first, and LSB of bytes is used first */ +static void writeBits(LodePNGBitWriter* writer, unsigned value, size_t nbits) { + if(nbits == 1) { /* compiler should statically compile this case if nbits == 1 */ + WRITEBIT(writer, value); + } else { + /* TODO: increase output size only once here rather than in each WRITEBIT */ + size_t i; + for(i = 0; i != nbits; ++i) { + WRITEBIT(writer, (unsigned char)((value >> i) & 1)); + } + } } -static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits) -{ +/* This one is to use for adding huffman symbol, the value bits are written MSB first */ +static void writeBitsReversed(LodePNGBitWriter* writer, unsigned value, size_t nbits) { size_t i; - for(i = 0; i != nbits; ++i) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> (nbits - 1 - i)) & 1)); + for(i = 0; i != nbits; ++i) { + /* TODO: increase output size only once here rather than in each WRITEBIT */ + WRITEBIT(writer, (unsigned char)((value >> (nbits - 1u - i)) & 1u)); + } } #endif /*LODEPNG_COMPILE_ENCODER*/ #ifdef LODEPNG_COMPILE_DECODER -#define READBIT(bitpointer, bitstream) ((bitstream[bitpointer >> 3] >> (bitpointer & 0x7)) & (unsigned char)1) +typedef struct { + const unsigned char* data; + size_t size; /*size of data in bytes*/ + size_t bitsize; /*size of data in bits, end of valid bp values, should be 8*size*/ + size_t bp; + unsigned buffer; /*buffer for reading bits. NOTE: 'unsigned' must support at least 32 bits*/ +} LodePNGBitReader; + +/* data size argument is in bytes. Returns error if size too large causing overflow */ +static unsigned LodePNGBitReader_init(LodePNGBitReader* reader, const unsigned char* data, size_t size) { + size_t temp; + reader->data = data; + reader->size = size; + /* size in bits, return error if overflow (if size_t is 32 bit this supports up to 500MB) */ + if(lodepng_mulofl(size, 8u, &reader->bitsize)) return 105; + /*ensure incremented bp can be compared to bitsize without overflow even when it would be incremented 32 too much and + trying to ensure 32 more bits*/ + if(lodepng_addofl(reader->bitsize, 64u, &temp)) return 105; + reader->bp = 0; + reader->buffer = 0; + return 0; /*ok*/ +} + +/* +ensureBits functions: +Ensures the reader can at least read nbits bits in one or more readBits calls, +safely even if not enough bits are available. +Returns 1 if there are enough bits available, 0 if not. +*/ -static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream) -{ - unsigned char result = (unsigned char)(READBIT(*bitpointer, bitstream)); - ++(*bitpointer); +/*See ensureBits documentation above. This one ensures exactly 1 bit */ +/*static unsigned ensureBits1(LodePNGBitReader* reader) { + if(reader->bp >= reader->bitsize) return 0; + reader->buffer = (unsigned)reader->data[reader->bp >> 3u] >> (reader->bp & 7u); + return 1; +}*/ + +/*See ensureBits documentation above. This one ensures up to 9 bits */ +static unsigned ensureBits9(LodePNGBitReader* reader, size_t nbits) { + size_t start = reader->bp >> 3u; + size_t size = reader->size; + if(start + 1u < size) { + reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u); + reader->buffer >>= (reader->bp & 7u); + return 1; + } else { + reader->buffer = 0; + if(start + 0u < size) reader->buffer |= reader->data[start + 0]; + reader->buffer >>= (reader->bp & 7u); + return reader->bp + nbits <= reader->bitsize; + } +} + +/*See ensureBits documentation above. This one ensures up to 17 bits */ +static unsigned ensureBits17(LodePNGBitReader* reader, size_t nbits) { + size_t start = reader->bp >> 3u; + size_t size = reader->size; + if(start + 2u < size) { + reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) | + ((unsigned)reader->data[start + 2] << 16u); + reader->buffer >>= (reader->bp & 7u); + return 1; + } else { + reader->buffer = 0; + if(start + 0u < size) reader->buffer |= reader->data[start + 0]; + if(start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u); + reader->buffer >>= (reader->bp & 7u); + return reader->bp + nbits <= reader->bitsize; + } +} + +/*See ensureBits documentation above. This one ensures up to 25 bits */ +static LODEPNG_INLINE unsigned ensureBits25(LodePNGBitReader* reader, size_t nbits) { + size_t start = reader->bp >> 3u; + size_t size = reader->size; + if(start + 3u < size) { + reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) | + ((unsigned)reader->data[start + 2] << 16u) | ((unsigned)reader->data[start + 3] << 24u); + reader->buffer >>= (reader->bp & 7u); + return 1; + } else { + reader->buffer = 0; + if(start + 0u < size) reader->buffer |= reader->data[start + 0]; + if(start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u); + if(start + 2u < size) reader->buffer |= ((unsigned)reader->data[start + 2] << 16u); + reader->buffer >>= (reader->bp & 7u); + return reader->bp + nbits <= reader->bitsize; + } +} + +/*See ensureBits documentation above. This one ensures up to 32 bits */ +static LODEPNG_INLINE unsigned ensureBits32(LodePNGBitReader* reader, size_t nbits) { + size_t start = reader->bp >> 3u; + size_t size = reader->size; + if(start + 4u < size) { + reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) | + ((unsigned)reader->data[start + 2] << 16u) | ((unsigned)reader->data[start + 3] << 24u); + reader->buffer >>= (reader->bp & 7u); + reader->buffer |= (((unsigned)reader->data[start + 4] << 24u) << (8u - (reader->bp & 7u))); + return 1; + } else { + reader->buffer = 0; + if(start + 0u < size) reader->buffer |= reader->data[start + 0]; + if(start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u); + if(start + 2u < size) reader->buffer |= ((unsigned)reader->data[start + 2] << 16u); + if(start + 3u < size) reader->buffer |= ((unsigned)reader->data[start + 3] << 24u); + reader->buffer >>= (reader->bp & 7u); + return reader->bp + nbits <= reader->bitsize; + } +} + +/* Get bits without advancing the bit pointer. Must have enough bits available with ensureBits. Max nbits is 31. */ +static unsigned peekBits(LodePNGBitReader* reader, size_t nbits) { + /* The shift allows nbits to be only up to 31. */ + return reader->buffer & ((1u << nbits) - 1u); +} + +/* Must have enough bits available with ensureBits */ +static void advanceBits(LodePNGBitReader* reader, size_t nbits) { + reader->buffer >>= nbits; + reader->bp += nbits; +} + +/* Must have enough bits available with ensureBits */ +static unsigned readBits(LodePNGBitReader* reader, size_t nbits) { + unsigned result = peekBits(reader, nbits); + advanceBits(reader, nbits); return result; } -static unsigned readBitsFromStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits) -{ - unsigned result = 0, i; - for(i = 0; i != nbits; ++i) - { - result += ((unsigned)READBIT(*bitpointer, bitstream)) << i; - ++(*bitpointer); +/* Public for testing only. steps and result must have numsteps values. */ +unsigned lode_png_test_bitreader(const unsigned char* data, size_t size, + size_t numsteps, const size_t* steps, unsigned* result) { + size_t i; + LodePNGBitReader reader; + unsigned error = LodePNGBitReader_init(&reader, data, size); + if(error) return 0; + for(i = 0; i < numsteps; i++) { + size_t step = steps[i]; + unsigned ok; + if(step > 25) ok = ensureBits32(&reader, step); + else if(step > 17) ok = ensureBits25(&reader, step); + else if(step > 9) ok = ensureBits17(&reader, step); + else ok = ensureBits9(&reader, step); + if(!ok) return 0; + result[i] = readBits(&reader, step); } - return result; + return 1; } #endif /*LODEPNG_COMPILE_DECODER*/ +static unsigned reverseBits(unsigned bits, unsigned num) { + /*TODO: implement faster lookup table based version when needed*/ + unsigned i, result = 0; + for(i = 0; i < num; i++) result |= ((bits >> (num - i - 1u)) & 1u) << i; + return result; +} + /* ////////////////////////////////////////////////////////////////////////// */ /* / Deflate - Huffman / */ /* ////////////////////////////////////////////////////////////////////////// */ @@ -496,8 +643,8 @@ static const unsigned DISTANCEEXTRA[30] = {0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13}; -/*the order in which "code length alphabet code lengths" are stored, out of this -the huffman tree of the dynamic huffman tree lengths is generated*/ +/*the order in which "code length alphabet code lengths" are stored as specified by deflate, out of this the huffman +tree of the dynamic huffman tree lengths is generated*/ static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES] = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15}; @@ -506,98 +653,149 @@ static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES] /* Huffman tree struct, containing multiple representations of the tree */ -typedef struct HuffmanTree -{ - unsigned* tree2d; - unsigned* tree1d; - unsigned* lengths; /*the lengths of the codes of the 1d-tree*/ +typedef struct HuffmanTree { + unsigned* codes; /*the huffman codes (bit patterns representing the symbols)*/ + unsigned* lengths; /*the lengths of the huffman codes*/ unsigned maxbitlen; /*maximum number of bits a single code can get*/ unsigned numcodes; /*number of symbols in the alphabet = number of codes*/ + /* for reading only */ + unsigned char* table_len; /*length of symbol from lookup table, or max length if secondary lookup needed*/ + unsigned short* table_value; /*value of symbol from lookup table, or pointer to secondary table if needed*/ } HuffmanTree; -/*function used for debug purposes to draw the tree in ascii art with C++*/ -/* -static void HuffmanTree_draw(HuffmanTree* tree) -{ - std::cout << "tree. length: " << tree->numcodes << " maxbitlen: " << tree->maxbitlen << std::endl; - for(size_t i = 0; i != tree->tree1d.size; ++i) - { - if(tree->lengths.data[i]) - std::cout << i << " " << tree->tree1d.data[i] << " " << tree->lengths.data[i] << std::endl; - } - std::cout << std::endl; -}*/ - -static void HuffmanTree_init(HuffmanTree* tree) -{ - tree->tree2d = 0; - tree->tree1d = 0; +static void HuffmanTree_init(HuffmanTree* tree) { + tree->codes = 0; tree->lengths = 0; + tree->table_len = 0; + tree->table_value = 0; } -static void HuffmanTree_cleanup(HuffmanTree* tree) -{ - lodepng_free(tree->tree2d); - lodepng_free(tree->tree1d); +static void HuffmanTree_cleanup(HuffmanTree* tree) { + lodepng_free(tree->codes); lodepng_free(tree->lengths); -} - -/*the tree representation used by the decoder. return value is error*/ -static unsigned HuffmanTree_make2DTree(HuffmanTree* tree) -{ - unsigned nodefilled = 0; /*up to which node it is filled*/ - unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/ - unsigned n, i; - - tree->tree2d = (unsigned*)lodepng_malloc(tree->numcodes * 2 * sizeof(unsigned)); - if(!tree->tree2d) return 83; /*alloc fail*/ - - /* - convert tree1d[] to tree2d[][]. In the 2D array, a value of 32767 means - uninited, a value >= numcodes is an address to another bit, a value < numcodes - is a code. The 2 rows are the 2 possible bit values (0 or 1), there are as - many columns as codes - 1. - A good huffman tree has N * 2 - 1 nodes, of which N - 1 are internal nodes. - Here, the internal nodes are stored (what their 0 and 1 option point to). - There is only memory for such good tree currently, if there are more nodes - (due to too long length codes), error 55 will happen - */ - for(n = 0; n < tree->numcodes * 2; ++n) - { - tree->tree2d[n] = 32767; /*32767 here means the tree2d isn't filled there yet*/ - } - - for(n = 0; n < tree->numcodes; ++n) /*the codes*/ - { - for(i = 0; i != tree->lengths[n]; ++i) /*the bits for this code*/ - { - unsigned char bit = (unsigned char)((tree->tree1d[n] >> (tree->lengths[n] - i - 1)) & 1); - /*oversubscribed, see comment in lodepng_error_text*/ - if(treepos > 2147483647 || treepos + 2 > tree->numcodes) return 55; - if(tree->tree2d[2 * treepos + bit] == 32767) /*not yet filled in*/ - { - if(i + 1 == tree->lengths[n]) /*last bit*/ - { - tree->tree2d[2 * treepos + bit] = n; /*put the current code in it*/ - treepos = 0; - } - else - { - /*put address of the next step in here, first that address has to be found of course - (it's just nodefilled + 1)...*/ - ++nodefilled; - /*addresses encoded with numcodes added to it*/ - tree->tree2d[2 * treepos + bit] = nodefilled + tree->numcodes; - treepos = nodefilled; - } + lodepng_free(tree->table_len); + lodepng_free(tree->table_value); +} + +/* amount of bits for first huffman table lookup (aka root bits), see HuffmanTree_makeTable and huffmanDecodeSymbol.*/ +/* values 8u and 9u work the fastest */ +#define FIRSTBITS 9u + +/* a symbol value too big to represent any valid symbol, to indicate reading disallowed huffman bits combination, +which is possible in case of only 0 or 1 present symbols. */ +#define INVALIDSYMBOL 65535u + +/* make table for huffman decoding */ +static unsigned HuffmanTree_makeTable(HuffmanTree* tree) { + static const unsigned headsize = 1u << FIRSTBITS; /*size of the first table*/ + static const unsigned mask = (1u << FIRSTBITS) /*headsize*/ - 1u; + size_t i, numpresent, pointer, size; /*total table size*/ + unsigned* maxlens = (unsigned*)lodepng_malloc(headsize * sizeof(unsigned)); + if(!maxlens) return 83; /*alloc fail*/ + + /* compute maxlens: max total bit length of symbols sharing prefix in the first table*/ + lodepng_memset(maxlens, 0, headsize * sizeof(*maxlens)); + for(i = 0; i < tree->numcodes; i++) { + unsigned symbol = tree->codes[i]; + unsigned l = tree->lengths[i]; + unsigned index; + if(l <= FIRSTBITS) continue; /*symbols that fit in first table don't increase secondary table size*/ + /*get the FIRSTBITS MSBs, the MSBs of the symbol are encoded first. See later comment about the reversing*/ + index = reverseBits(symbol >> (l - FIRSTBITS), FIRSTBITS); + maxlens[index] = LODEPNG_MAX(maxlens[index], l); + } + /* compute total table size: size of first table plus all secondary tables for symbols longer than FIRSTBITS */ + size = headsize; + for(i = 0; i < headsize; ++i) { + unsigned l = maxlens[i]; + if(l > FIRSTBITS) size += (1u << (l - FIRSTBITS)); + } + tree->table_len = (unsigned char*)lodepng_malloc(size * sizeof(*tree->table_len)); + tree->table_value = (unsigned short*)lodepng_malloc(size * sizeof(*tree->table_value)); + if(!tree->table_len || !tree->table_value) { + lodepng_free(maxlens); + /* freeing tree->table values is done at a higher scope */ + return 83; /*alloc fail*/ + } + /*initialize with an invalid length to indicate unused entries*/ + for(i = 0; i < size; ++i) tree->table_len[i] = 16; + + /*fill in the first table for long symbols: max prefix size and pointer to secondary tables*/ + pointer = headsize; + for(i = 0; i < headsize; ++i) { + unsigned l = maxlens[i]; + if(l <= FIRSTBITS) continue; + tree->table_len[i] = l; + tree->table_value[i] = pointer; + pointer += (1u << (l - FIRSTBITS)); + } + lodepng_free(maxlens); + + /*fill in the first table for short symbols, or secondary table for long symbols*/ + numpresent = 0; + for(i = 0; i < tree->numcodes; ++i) { + unsigned l = tree->lengths[i]; + unsigned symbol = tree->codes[i]; /*the huffman bit pattern. i itself is the value.*/ + /*reverse bits, because the huffman bits are given in MSB first order but the bit reader reads LSB first*/ + unsigned reverse = reverseBits(symbol, l); + if(l == 0) continue; + numpresent++; + + if(l <= FIRSTBITS) { + /*short symbol, fully in first table, replicated num times if l < FIRSTBITS*/ + unsigned num = 1u << (FIRSTBITS - l); + unsigned j; + for(j = 0; j < num; ++j) { + /*bit reader will read the l bits of symbol first, the remaining FIRSTBITS - l bits go to the MSB's*/ + unsigned index = reverse | (j << l); + if(tree->table_len[index] != 16) return 55; /*invalid tree: long symbol shares prefix with short symbol*/ + tree->table_len[index] = l; + tree->table_value[index] = i; + } + } else { + /*long symbol, shares prefix with other long symbols in first lookup table, needs second lookup*/ + /*the FIRSTBITS MSBs of the symbol are the first table index*/ + unsigned index = reverse & mask; + unsigned maxlen = tree->table_len[index]; + /*log2 of secondary table length, should be >= l - FIRSTBITS*/ + unsigned tablelen = maxlen - FIRSTBITS; + unsigned start = tree->table_value[index]; /*starting index in secondary table*/ + unsigned num = 1u << (tablelen - (l - FIRSTBITS)); /*amount of entries of this symbol in secondary table*/ + unsigned j; + if(maxlen < l) return 55; /*invalid tree: long symbol shares prefix with short symbol*/ + for(j = 0; j < num; ++j) { + unsigned reverse2 = reverse >> FIRSTBITS; /* l - FIRSTBITS bits */ + unsigned index2 = start + (reverse2 | (j << (l - FIRSTBITS))); + tree->table_len[index2] = l; + tree->table_value[index2] = i; } - else treepos = tree->tree2d[2 * treepos + bit] - tree->numcodes; } } - for(n = 0; n < tree->numcodes * 2; ++n) - { - if(tree->tree2d[n] == 32767) tree->tree2d[n] = 0; /*remove possible remaining 32767's*/ + if(numpresent < 2) { + /* In case of exactly 1 symbol, in theory the huffman symbol needs 0 bits, + but deflate uses 1 bit instead. In case of 0 symbols, no symbols can + appear at all, but such huffman tree could still exist (e.g. if distance + codes are never used). In both cases, not all symbols of the table will be + filled in. Fill them in with an invalid symbol value so returning them from + huffmanDecodeSymbol will cause error. */ + for(i = 0; i < size; ++i) { + if(tree->table_len[i] == 16) { + /* As length, use a value smaller than FIRSTBITS for the head table, + and a value larger than FIRSTBITS for the secondary table, to ensure + valid behavior for advanceBits when reading this symbol. */ + tree->table_len[i] = (i < headsize) ? 1 : (FIRSTBITS + 1); + tree->table_value[i] = INVALIDSYMBOL; + } + } + } else { + /* A good huffman tree has N * 2 - 1 nodes, of which N - 1 are internal nodes. + If that is not the case (due to too long length codes), the table will not + have been fully used, and this is an error (not all bit combinations can be + decoded): an oversubscribed huffman tree, indicated by error 55. */ + for(i = 0; i < size; ++i) { + if(tree->table_len[i] == 16) return 55; + } } return 0; @@ -608,44 +806,40 @@ Second step for the ...makeFromLengths and ...makeFromFrequencies functions. numcodes, lengths and maxbitlen must already be filled in correctly. return value is error. */ -static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree) -{ - uivector blcount; - uivector nextcode; +static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree) { + unsigned* blcount; + unsigned* nextcode; unsigned error = 0; unsigned bits, n; - uivector_init(&blcount); - uivector_init(&nextcode); - - tree->tree1d = (unsigned*)lodepng_malloc(tree->numcodes * sizeof(unsigned)); - if(!tree->tree1d) error = 83; /*alloc fail*/ + tree->codes = (unsigned*)lodepng_malloc(tree->numcodes * sizeof(unsigned)); + blcount = (unsigned*)lodepng_malloc((tree->maxbitlen + 1) * sizeof(unsigned)); + nextcode = (unsigned*)lodepng_malloc((tree->maxbitlen + 1) * sizeof(unsigned)); + if(!tree->codes || !blcount || !nextcode) error = 83; /*alloc fail*/ - if(!uivector_resizev(&blcount, tree->maxbitlen + 1, 0) - || !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0)) - error = 83; /*alloc fail*/ - - if(!error) - { + if(!error) { + for(n = 0; n != tree->maxbitlen + 1; n++) blcount[n] = nextcode[n] = 0; /*step 1: count number of instances of each code length*/ - for(bits = 0; bits != tree->numcodes; ++bits) ++blcount.data[tree->lengths[bits]]; + for(bits = 0; bits != tree->numcodes; ++bits) ++blcount[tree->lengths[bits]]; /*step 2: generate the nextcode values*/ - for(bits = 1; bits <= tree->maxbitlen; ++bits) - { - nextcode.data[bits] = (nextcode.data[bits - 1] + blcount.data[bits - 1]) << 1; + for(bits = 1; bits <= tree->maxbitlen; ++bits) { + nextcode[bits] = (nextcode[bits - 1] + blcount[bits - 1]) << 1u; } /*step 3: generate all the codes*/ - for(n = 0; n != tree->numcodes; ++n) - { - if(tree->lengths[n] != 0) tree->tree1d[n] = nextcode.data[tree->lengths[n]]++; + for(n = 0; n != tree->numcodes; ++n) { + if(tree->lengths[n] != 0) { + tree->codes[n] = nextcode[tree->lengths[n]]++; + /*remove superfluous bits from the code*/ + tree->codes[n] &= ((1u << tree->lengths[n]) - 1u); + } } } - uivector_cleanup(&blcount); - uivector_cleanup(&nextcode); + lodepng_free(blcount); + lodepng_free(nextcode); - if(!error) return HuffmanTree_make2DTree(tree); - else return error; + if(!error) error = HuffmanTree_makeTable(tree); + return error; } /* @@ -654,8 +848,7 @@ by Deflate. maxbitlen is the maximum bits that a code in the tree can have. return value is error. */ static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen, - size_t numcodes, unsigned maxbitlen) -{ + size_t numcodes, unsigned maxbitlen) { unsigned i; tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned)); if(!tree->lengths) return 83; /*alloc fail*/ @@ -671,8 +864,7 @@ static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* b Jyrki Katajainen, Alistair Moffat, Andrew Turpin, 1995.*/ /*chain node for boundary package merge*/ -typedef struct BPMNode -{ +typedef struct BPMNode { int weight; /*the sum of all weights in this chain*/ unsigned index; /*index of this leaf node (called "count" in the paper)*/ struct BPMNode* tail; /*the next nodes in this chain (null if last)*/ @@ -680,8 +872,7 @@ typedef struct BPMNode } BPMNode; /*lists of chains*/ -typedef struct BPMLists -{ +typedef struct BPMLists { /*memory pool*/ unsigned memsize; BPMNode* memory; @@ -695,26 +886,22 @@ typedef struct BPMLists } BPMLists; /*creates a new chain node with the given parameters, from the memory in the lists */ -static BPMNode* bpmnode_create(BPMLists* lists, int weight, unsigned index, BPMNode* tail) -{ +static BPMNode* bpmnode_create(BPMLists* lists, int weight, unsigned index, BPMNode* tail) { unsigned i; BPMNode* result; /*memory full, so garbage collect*/ - if(lists->nextfree >= lists->numfree) - { + if(lists->nextfree >= lists->numfree) { /*mark only those that are in use*/ for(i = 0; i != lists->memsize; ++i) lists->memory[i].in_use = 0; - for(i = 0; i != lists->listsize; ++i) - { + for(i = 0; i != lists->listsize; ++i) { BPMNode* node; for(node = lists->chains0[i]; node != 0; node = node->tail) node->in_use = 1; for(node = lists->chains1[i]; node != 0; node = node->tail) node->in_use = 1; } /*collect those that are free*/ lists->numfree = 0; - for(i = 0; i != lists->memsize; ++i) - { + for(i = 0; i != lists->memsize; ++i) { if(!lists->memory[i].in_use) lists->freelist[lists->numfree++] = &lists->memory[i]; } lists->nextfree = 0; @@ -728,58 +915,48 @@ static BPMNode* bpmnode_create(BPMLists* lists, int weight, unsigned index, BPMN } /*sort the leaves with stable mergesort*/ -static void bpmnode_sort(BPMNode* leaves, size_t num) -{ +static void bpmnode_sort(BPMNode* leaves, size_t num) { BPMNode* mem = (BPMNode*)lodepng_malloc(sizeof(*leaves) * num); size_t width, counter = 0; - for(width = 1; width < num; width *= 2) - { + for(width = 1; width < num; width *= 2) { BPMNode* a = (counter & 1) ? mem : leaves; BPMNode* b = (counter & 1) ? leaves : mem; size_t p; - for(p = 0; p < num; p += 2 * width) - { + for(p = 0; p < num; p += 2 * width) { size_t q = (p + width > num) ? num : (p + width); size_t r = (p + 2 * width > num) ? num : (p + 2 * width); size_t i = p, j = q, k; - for(k = p; k < r; k++) - { + for(k = p; k < r; k++) { if(i < q && (j >= r || a[i].weight <= a[j].weight)) b[k] = a[i++]; else b[k] = a[j++]; } } counter++; } - if(counter & 1) memcpy(leaves, mem, sizeof(*leaves) * num); + if(counter & 1) lodepng_memcpy(leaves, mem, sizeof(*leaves) * num); lodepng_free(mem); } /*Boundary Package Merge step, numpresent is the amount of leaves, and c is the current chain.*/ -static void boundaryPM(BPMLists* lists, BPMNode* leaves, size_t numpresent, int c, int num) -{ +static void boundaryPM(BPMLists* lists, BPMNode* leaves, size_t numpresent, int c, int num) { unsigned lastindex = lists->chains1[c]->index; - if(c == 0) - { + if(c == 0) { if(lastindex >= numpresent) return; lists->chains0[c] = lists->chains1[c]; lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, 0); - } - else - { + } else { /*sum of the weights of the head nodes of the previous lookahead chains.*/ int sum = lists->chains0[c - 1]->weight + lists->chains1[c - 1]->weight; lists->chains0[c] = lists->chains1[c]; - if(lastindex < numpresent && sum > leaves[lastindex].weight) - { + if(lastindex < numpresent && sum > leaves[lastindex].weight) { lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, lists->chains1[c]->tail); return; } lists->chains1[c] = bpmnode_create(lists, sum, lastindex, lists->chains1[c - 1]); /*in the end we are only interested in the chain of the last list, so no need to recurse if we're at the last one (this gives measurable speedup)*/ - if(num + 1 < (int)(2 * numpresent - 2)) - { + if(num + 1 < (int)(2 * numpresent - 2)) { boundaryPM(lists, leaves, numpresent, c - 1, num); boundaryPM(lists, leaves, numpresent, c - 1, num); } @@ -787,8 +964,7 @@ static void boundaryPM(BPMLists* lists, BPMNode* leaves, size_t numpresent, int } unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies, - size_t numcodes, unsigned maxbitlen) -{ + size_t numcodes, unsigned maxbitlen) { unsigned error = 0; unsigned i; size_t numpresent = 0; /*number of symbols with non-zero frequency*/ @@ -800,34 +976,27 @@ unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequen leaves = (BPMNode*)lodepng_malloc(numcodes * sizeof(*leaves)); if(!leaves) return 83; /*alloc fail*/ - for(i = 0; i != numcodes; ++i) - { - if(frequencies[i] > 0) - { + for(i = 0; i != numcodes; ++i) { + if(frequencies[i] > 0) { leaves[numpresent].weight = (int)frequencies[i]; leaves[numpresent].index = i; ++numpresent; } } - for(i = 0; i != numcodes; ++i) lengths[i] = 0; + lodepng_memset(lengths, 0, numcodes * sizeof(*lengths)); /*ensure at least two present symbols. There should be at least one symbol according to RFC 1951 section 3.2.7. Some decoders incorrectly require two. To make these work as well ensure there are at least two symbols. The Package-Merge code below also doesn't work correctly if there's only one - symbol, it'd give it the theoritical 0 bits but in practice zlib wants 1 bit*/ - if(numpresent == 0) - { + symbol, it'd give it the theoretical 0 bits but in practice zlib wants 1 bit*/ + if(numpresent == 0) { lengths[0] = lengths[1] = 1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/ - } - else if(numpresent == 1) - { + } else if(numpresent == 1) { lengths[leaves[0].index] = 1; lengths[leaves[0].index == 0 ? 1 : 0] = 1; - } - else - { + } else { BPMLists lists; BPMNode* node; @@ -843,15 +1012,13 @@ unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequen lists.chains1 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*)); if(!lists.memory || !lists.freelist || !lists.chains0 || !lists.chains1) error = 83; /*alloc fail*/ - if(!error) - { + if(!error) { for(i = 0; i != lists.memsize; ++i) lists.freelist[i] = &lists.memory[i]; bpmnode_create(&lists, leaves[0].weight, 1, 0); bpmnode_create(&lists, leaves[1].weight, 2, 0); - for(i = 0; i != lists.listsize; ++i) - { + for(i = 0; i != lists.listsize; ++i) { lists.chains0[i] = &lists.memory[0]; lists.chains1[i] = &lists.memory[1]; } @@ -859,8 +1026,7 @@ unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequen /*each boundaryPM call adds one chain to the last list, and we need 2 * numpresent - 2 chains.*/ for(i = 2; i != 2 * numpresent - 2; ++i) boundaryPM(&lists, leaves, numpresent, (int)maxbitlen - 1, (int)i); - for(node = lists.chains1[maxbitlen - 1]; node; node = node->tail) - { + for(node = lists.chains1[maxbitlen - 1]; node; node = node->tail) { for(i = 0; i != node->index; ++i) ++lengths[leaves[i].index]; } } @@ -877,36 +1043,22 @@ unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequen /*Create the Huffman tree given the symbol frequencies*/ static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies, - size_t mincodes, size_t numcodes, unsigned maxbitlen) -{ + size_t mincodes, size_t numcodes, unsigned maxbitlen) { unsigned error = 0; while(!frequencies[numcodes - 1] && numcodes > mincodes) --numcodes; /*trim zeroes*/ + tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned)); + if(!tree->lengths) return 83; /*alloc fail*/ tree->maxbitlen = maxbitlen; tree->numcodes = (unsigned)numcodes; /*number of symbols*/ - tree->lengths = (unsigned*)lodepng_realloc(tree->lengths, numcodes * sizeof(unsigned)); - if(!tree->lengths) return 83; /*alloc fail*/ - /*initialize all lengths to 0*/ - memset(tree->lengths, 0, numcodes * sizeof(unsigned)); error = lodepng_huffman_code_lengths(tree->lengths, frequencies, numcodes, maxbitlen); if(!error) error = HuffmanTree_makeFromLengths2(tree); return error; } - -static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index) -{ - return tree->tree1d[index]; -} - -static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index) -{ - return tree->lengths[index]; -} #endif /*LODEPNG_COMPILE_ENCODER*/ /*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/ -static unsigned generateFixedLitLenTree(HuffmanTree* tree) -{ +static unsigned generateFixedLitLenTree(HuffmanTree* tree) { unsigned i, error = 0; unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned)); if(!bitlen) return 83; /*alloc fail*/ @@ -924,8 +1076,7 @@ static unsigned generateFixedLitLenTree(HuffmanTree* tree) } /*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/ -static unsigned generateFixedDistanceTree(HuffmanTree* tree) -{ +static unsigned generateFixedDistanceTree(HuffmanTree* tree) { unsigned i, error = 0; unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned)); if(!bitlen) return 83; /*alloc fail*/ @@ -941,26 +1092,21 @@ static unsigned generateFixedDistanceTree(HuffmanTree* tree) #ifdef LODEPNG_COMPILE_DECODER /* -returns the code, or (unsigned)(-1) if error happened -inbitlength is the length of the complete buffer, in bits (so its byte length times 8) +returns the code. The bit reader must already have been ensured at least 15 bits */ -static unsigned huffmanDecodeSymbol(const unsigned char* in, size_t* bp, - const HuffmanTree* codetree, size_t inbitlength) -{ - unsigned treepos = 0, ct; - for(;;) - { - if(*bp >= inbitlength) return (unsigned)(-1); /*error: end of input memory reached without endcode*/ - /* - decode the symbol from the tree. The "readBitFromStream" code is inlined in - the expression below because this is the biggest bottleneck while decoding - */ - ct = codetree->tree2d[(treepos << 1) + READBIT(*bp, in)]; - ++(*bp); - if(ct < codetree->numcodes) return ct; /*the symbol is decoded, return it*/ - else treepos = ct - codetree->numcodes; /*symbol not yet decoded, instead move tree position*/ - - if(treepos >= codetree->numcodes) return (unsigned)(-1); /*error: it appeared outside the codetree*/ +static unsigned huffmanDecodeSymbol(LodePNGBitReader* reader, const HuffmanTree* codetree) { + unsigned short code = peekBits(reader, FIRSTBITS); + unsigned short l = codetree->table_len[code]; + unsigned short value = codetree->table_value[code]; + if(l <= FIRSTBITS) { + advanceBits(reader, l); + return value; + } else { + unsigned index2; + advanceBits(reader, FIRSTBITS); + index2 = value + peekBits(reader, l - FIRSTBITS); + advanceBits(reader, codetree->table_len[index2] - FIRSTBITS); + return codetree->table_value[index2]; } } #endif /*LODEPNG_COMPILE_DECODER*/ @@ -971,22 +1117,20 @@ static unsigned huffmanDecodeSymbol(const unsigned char* in, size_t* bp, /* / Inflator (Decompressor) / */ /* ////////////////////////////////////////////////////////////////////////// */ -/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/ -static void getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d) -{ - /*TODO: check for out of memory errors*/ - generateFixedLitLenTree(tree_ll); - generateFixedDistanceTree(tree_d); +/*get the tree of a deflated block with fixed tree, as specified in the deflate specification +Returns error code.*/ +static unsigned getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d) { + unsigned error = generateFixedLitLenTree(tree_ll); + if(error) return error; + return generateFixedDistanceTree(tree_d); } /*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/ static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d, - const unsigned char* in, size_t* bp, size_t inlength) -{ + LodePNGBitReader* reader) { /*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/ unsigned error = 0; unsigned n, HLIT, HDIST, HCLEN, i; - size_t inbitlength = inlength * 8; /*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/ unsigned* bitlen_ll = 0; /*lit,len code lengths*/ @@ -995,30 +1139,31 @@ static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d, unsigned* bitlen_cl = 0; HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/ - if((*bp) + 14 > (inlength << 3)) return 49; /*error: the bit pointer is or will go past the memory*/ + if(!ensureBits17(reader, 14)) return 49; /*error: the bit pointer is or will go past the memory*/ /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/ - HLIT = readBitsFromStream(bp, in, 5) + 257; + HLIT = readBits(reader, 5) + 257; /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/ - HDIST = readBitsFromStream(bp, in, 5) + 1; + HDIST = readBits(reader, 5) + 1; /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/ - HCLEN = readBitsFromStream(bp, in, 4) + 4; + HCLEN = readBits(reader, 4) + 4; - if((*bp) + HCLEN * 3 > (inlength << 3)) return 50; /*error: the bit pointer is or will go past the memory*/ + bitlen_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned)); + if(!bitlen_cl) return 83 /*alloc fail*/; HuffmanTree_init(&tree_cl); - while(!error) - { + while(!error) { /*read the code length codes out of 3 * (amount of code length codes) bits*/ - - bitlen_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned)); - if(!bitlen_cl) ERROR_BREAK(83 /*alloc fail*/); - - for(i = 0; i != NUM_CODE_LENGTH_CODES; ++i) - { - if(i < HCLEN) bitlen_cl[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3); - else bitlen_cl[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/ + if(lodepng_gtofl(reader->bp, HCLEN * 3, reader->bitsize)) { + ERROR_BREAK(50); /*error: the bit pointer is or will go past the memory*/ + } + for(i = 0; i != HCLEN; ++i) { + ensureBits9(reader, 3); /*out of bounds already checked above */ + bitlen_cl[CLCL_ORDER[i]] = readBits(reader, 3); + } + for(i = HCLEN; i != NUM_CODE_LENGTH_CODES; ++i) { + bitlen_cl[CLCL_ORDER[i]] = 0; } error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7); @@ -1028,83 +1173,69 @@ static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d, bitlen_ll = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned)); bitlen_d = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned)); if(!bitlen_ll || !bitlen_d) ERROR_BREAK(83 /*alloc fail*/); - for(i = 0; i != NUM_DEFLATE_CODE_SYMBOLS; ++i) bitlen_ll[i] = 0; - for(i = 0; i != NUM_DISTANCE_SYMBOLS; ++i) bitlen_d[i] = 0; + lodepng_memset(bitlen_ll, 0, NUM_DEFLATE_CODE_SYMBOLS * sizeof(*bitlen_ll)); + lodepng_memset(bitlen_d, 0, NUM_DISTANCE_SYMBOLS * sizeof(*bitlen_d)); /*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/ i = 0; - while(i < HLIT + HDIST) - { - unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength); - if(code <= 15) /*a length code*/ - { + while(i < HLIT + HDIST) { + unsigned code; + ensureBits25(reader, 22); /* up to 15 bits for huffman code, up to 7 extra bits below*/ + code = huffmanDecodeSymbol(reader, &tree_cl); + if(code <= 15) /*a length code*/ { if(i < HLIT) bitlen_ll[i] = code; else bitlen_d[i - HLIT] = code; ++i; - } - else if(code == 16) /*repeat previous*/ - { + } else if(code == 16) /*repeat previous*/ { unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/ unsigned value; /*set value to the previous code*/ if(i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/ - if((*bp + 2) > inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ - replength += readBitsFromStream(bp, in, 2); + replength += readBits(reader, 2); if(i < HLIT + 1) value = bitlen_ll[i - 1]; else value = bitlen_d[i - HLIT - 1]; /*repeat this value in the next lengths*/ - for(n = 0; n < replength; ++n) - { + for(n = 0; n < replength; ++n) { if(i >= HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/ if(i < HLIT) bitlen_ll[i] = value; else bitlen_d[i - HLIT] = value; ++i; } - } - else if(code == 17) /*repeat "0" 3-10 times*/ - { + } else if(code == 17) /*repeat "0" 3-10 times*/ { unsigned replength = 3; /*read in the bits that indicate repeat length*/ - if((*bp + 3) > inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ - replength += readBitsFromStream(bp, in, 3); + replength += readBits(reader, 3); /*repeat this value in the next lengths*/ - for(n = 0; n < replength; ++n) - { + for(n = 0; n < replength; ++n) { if(i >= HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/ if(i < HLIT) bitlen_ll[i] = 0; else bitlen_d[i - HLIT] = 0; ++i; } - } - else if(code == 18) /*repeat "0" 11-138 times*/ - { + } else if(code == 18) /*repeat "0" 11-138 times*/ { unsigned replength = 11; /*read in the bits that indicate repeat length*/ - if((*bp + 7) > inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ - replength += readBitsFromStream(bp, in, 7); + replength += readBits(reader, 7); /*repeat this value in the next lengths*/ - for(n = 0; n < replength; ++n) - { + for(n = 0; n < replength; ++n) { if(i >= HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/ if(i < HLIT) bitlen_ll[i] = 0; else bitlen_d[i - HLIT] = 0; ++i; } + } else /*if(code == INVALIDSYMBOL)*/ { + ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/ } - else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/ - { - if(code == (unsigned)(-1)) - { - /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol - (10=no endcode, 11=wrong jump outside of tree)*/ - error = (*bp) > inbitlength ? 10 : 11; - } - else error = 16; /*unexisting code, this can never happen*/ - break; + /*check if any of the ensureBits above went out of bounds*/ + if(reader->bp > reader->bitsize) { + /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol + (10=no endcode, 11=wrong jump outside of tree)*/ + /* TODO: revise error codes 10,11,50: the above comment is no longer valid */ + ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ } } if(error) break; @@ -1127,92 +1258,88 @@ static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d, return error; } -/*inflate a block with dynamic of fixed Huffman tree*/ -static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size_t* bp, - size_t* pos, size_t inlength, unsigned btype) -{ +/*inflate a block with dynamic of fixed Huffman tree. btype must be 1 or 2.*/ +static unsigned inflateHuffmanBlock(ucvector* out, LodePNGBitReader* reader, + unsigned btype) { unsigned error = 0; HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/ HuffmanTree tree_d; /*the huffman tree for distance codes*/ - size_t inbitlength = inlength * 8; HuffmanTree_init(&tree_ll); HuffmanTree_init(&tree_d); - if(btype == 1) getTreeInflateFixed(&tree_ll, &tree_d); - else if(btype == 2) error = getTreeInflateDynamic(&tree_ll, &tree_d, in, bp, inlength); + if(btype == 1) error = getTreeInflateFixed(&tree_ll, &tree_d); + else /*if(btype == 2)*/ error = getTreeInflateDynamic(&tree_ll, &tree_d, reader); - while(!error) /*decode all symbols until end reached, breaks at end code*/ - { + while(!error) /*decode all symbols until end reached, breaks at end code*/ { /*code_ll is literal, length or end code*/ - unsigned code_ll = huffmanDecodeSymbol(in, bp, &tree_ll, inbitlength); - if(code_ll <= 255) /*literal symbol*/ - { - /*ucvector_push_back would do the same, but for some reason the two lines below run 10% faster*/ - if(!ucvector_resize(out, (*pos) + 1)) ERROR_BREAK(83 /*alloc fail*/); - out->data[*pos] = (unsigned char)code_ll; - ++(*pos); - } - else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/ - { + unsigned code_ll; + ensureBits25(reader, 20); /* up to 15 for the huffman symbol, up to 5 for the length extra bits */ + code_ll = huffmanDecodeSymbol(reader, &tree_ll); + if(code_ll <= 255) /*literal symbol*/ { + if(!ucvector_resize(out, out->size + 1)) ERROR_BREAK(83 /*alloc fail*/); + out->data[out->size - 1] = (unsigned char)code_ll; + } else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/ { unsigned code_d, distance; unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/ - size_t start, forward, backward, length; + size_t start, backward, length; /*part 1: get length base*/ length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX]; /*part 2: get extra bits and add the value of that to length*/ numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX]; - if((*bp + numextrabits_l) > inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/ - length += readBitsFromStream(bp, in, numextrabits_l); + if(numextrabits_l != 0) { + /* bits already ensured above */ + length += readBits(reader, numextrabits_l); + } /*part 3: get distance code*/ - code_d = huffmanDecodeSymbol(in, bp, &tree_d, inbitlength); - if(code_d > 29) - { - if(code_d == (unsigned)(-1)) /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/ - { - /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol - (10=no endcode, 11=wrong jump outside of tree)*/ - error = (*bp) > inlength * 8 ? 10 : 11; + ensureBits32(reader, 28); /* up to 15 for the huffman symbol, up to 13 for the extra bits */ + code_d = huffmanDecodeSymbol(reader, &tree_d); + if(code_d > 29) { + if(code_d <= 31) { + ERROR_BREAK(18); /*error: invalid distance code (30-31 are never used)*/ + } else /* if(code_d == INVALIDSYMBOL) */{ + ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/ } - else error = 18; /*error: invalid distance code (30-31 are never used)*/ - break; } distance = DISTANCEBASE[code_d]; /*part 4: get extra bits from distance*/ numextrabits_d = DISTANCEEXTRA[code_d]; - if((*bp + numextrabits_d) > inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/ - distance += readBitsFromStream(bp, in, numextrabits_d); + if(numextrabits_d != 0) { + /* bits already ensured above */ + distance += readBits(reader, numextrabits_d); + } /*part 5: fill in all the out[n] values based on the length and dist*/ - start = (*pos); + start = out->size; if(distance > start) ERROR_BREAK(52); /*too long backward distance*/ backward = start - distance; - if(!ucvector_resize(out, (*pos) + length)) ERROR_BREAK(83 /*alloc fail*/); - if (distance < length) { - for(forward = 0; forward < length; ++forward) - { - out->data[(*pos)++] = out->data[backward++]; + if(!ucvector_resize(out, out->size + length)) ERROR_BREAK(83 /*alloc fail*/); + if(distance < length) { + size_t forward; + lodepng_memcpy(out->data + start, out->data + backward, distance); + start += distance; + for(forward = distance; forward < length; ++forward) { + out->data[start++] = out->data[backward++]; } } else { - memcpy(out->data + *pos, out->data + backward, length); - *pos += length; + lodepng_memcpy(out->data + start, out->data + backward, length); } - } - else if(code_ll == 256) - { + } else if(code_ll == 256) { break; /*end code, break the loop*/ + } else /*if(code_ll == INVALIDSYMBOL)*/ { + ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/ } - else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/ - { + /*check if any of the ensureBits above went out of bounds*/ + if(reader->bp > reader->bitsize) { /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol (10=no endcode, 11=wrong jump outside of tree)*/ - error = ((*bp) > inlength * 8) ? 10 : 11; - break; + /* TODO: revise error codes 10,11,50: the above comment is no longer valid */ + ERROR_BREAK(51); /*error, bit pointer jumps past memory*/ } } @@ -1222,57 +1349,56 @@ static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size return error; } -static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength) -{ - size_t p; - unsigned LEN, NLEN, n, error = 0; +static unsigned inflateNoCompression(ucvector* out, LodePNGBitReader* reader, + const LodePNGDecompressSettings* settings) { + size_t bytepos; + size_t size = reader->size; + unsigned LEN, NLEN, error = 0; /*go to first boundary of byte*/ - while(((*bp) & 0x7) != 0) ++(*bp); - p = (*bp) / 8; /*byte position*/ + bytepos = (reader->bp + 7u) >> 3u; /*read LEN (2 bytes) and NLEN (2 bytes)*/ - if(p + 4 >= inlength) return 52; /*error, bit pointer will jump past memory*/ - LEN = in[p] + 256u * in[p + 1]; p += 2; - NLEN = in[p] + 256u * in[p + 1]; p += 2; + if(bytepos + 4 >= size) return 52; /*error, bit pointer will jump past memory*/ + LEN = (unsigned)reader->data[bytepos] + ((unsigned)reader->data[bytepos + 1] << 8u); bytepos += 2; + NLEN = (unsigned)reader->data[bytepos] + ((unsigned)reader->data[bytepos + 1] << 8u); bytepos += 2; /*check if 16-bit NLEN is really the one's complement of LEN*/ - if(LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/ + if(!settings->ignore_nlen && LEN + NLEN != 65535) { + return 21; /*error: NLEN is not one's complement of LEN*/ + } - if(!ucvector_resize(out, (*pos) + LEN)) return 83; /*alloc fail*/ + if(!ucvector_resize(out, out->size + LEN)) return 83; /*alloc fail*/ /*read the literal data: LEN bytes are now stored in the out buffer*/ - if(p + LEN > inlength) return 23; /*error: reading outside of in buffer*/ - for(n = 0; n < LEN; ++n) out->data[(*pos)++] = in[p++]; + if(bytepos + LEN > size) return 23; /*error: reading outside of in buffer*/ - (*bp) = p * 8; + lodepng_memcpy(out->data + out->size - LEN, reader->data + bytepos, LEN); + bytepos += LEN; + + reader->bp = bytepos << 3u; return error; } static unsigned lodepng_inflatev(ucvector* out, const unsigned char* in, size_t insize, - const LodePNGDecompressSettings* settings) -{ - /*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/ - size_t bp = 0; + const LodePNGDecompressSettings* settings) { unsigned BFINAL = 0; - size_t pos = 0; /*byte position in the out buffer*/ - unsigned error = 0; + LodePNGBitReader reader; + unsigned error = LodePNGBitReader_init(&reader, in, insize); - (void)settings; + if(error) return error; - while(!BFINAL) - { + while(!BFINAL) { unsigned BTYPE; - if(bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/ - BFINAL = readBitFromStream(&bp, in); - BTYPE = 1u * readBitFromStream(&bp, in); - BTYPE += 2u * readBitFromStream(&bp, in); + if(!ensureBits9(&reader, 3)) return 52; /*error, bit pointer will jump past memory*/ + BFINAL = readBits(&reader, 1); + BTYPE = readBits(&reader, 2); if(BTYPE == 3) return 20; /*error: invalid BTYPE*/ - else if(BTYPE == 0) error = inflateNoCompression(out, in, &bp, &pos, insize); /*no compression*/ - else error = inflateHuffmanBlock(out, in, &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/ + else if(BTYPE == 0) error = inflateNoCompression(out, &reader, settings); /*no compression*/ + else error = inflateHuffmanBlock(out, &reader, BTYPE); /*compression, BTYPE 01 or 10*/ if(error) return error; } @@ -1282,28 +1408,22 @@ static unsigned lodepng_inflatev(ucvector* out, unsigned lodepng_inflate(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, - const LodePNGDecompressSettings* settings) -{ - unsigned error; - ucvector v; - ucvector_init_buffer(&v, *out, *outsize); - error = lodepng_inflatev(&v, in, insize, settings); + const LodePNGDecompressSettings* settings) { + ucvector v = ucvector_init(*out, *outsize); + unsigned error = lodepng_inflatev(&v, in, insize, settings); *out = v.data; *outsize = v.size; return error; } -static unsigned inflate(unsigned char** out, size_t* outsize, - const unsigned char* in, size_t insize, - const LodePNGDecompressSettings* settings) -{ - if(settings->custom_inflate) - { - return settings->custom_inflate(out, outsize, in, insize, settings); - } - else - { - return lodepng_inflate(out, outsize, in, insize, settings); +static unsigned inflatev(ucvector* out, const unsigned char* in, size_t insize, + const LodePNGDecompressSettings* settings) { + if(settings->custom_inflate) { + unsigned error = settings->custom_inflate(&out->data, &out->size, in, insize, settings); + out->allocsize = out->size; + return error; + } else { + return lodepng_inflatev(out, in, insize, settings); } } @@ -1317,31 +1437,23 @@ static unsigned inflate(unsigned char** out, size_t* outsize, static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258; -/*bitlen is the size in bits of the code*/ -static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen) -{ - addBitsToStreamReversed(bp, compressed, code, bitlen); -} - /*search the index in the array, that has the largest value smaller than or equal to the given value, given array must be sorted (if no value is smaller, it returns the size of the given array)*/ -static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value) -{ +static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value) { /*binary search (only small gain over linear). TODO: use CPU log2 instruction for getting symbols instead*/ size_t left = 1; size_t right = array_size - 1; while(left <= right) { size_t mid = (left + right) >> 1; - if (array[mid] >= value) right = mid - 1; + if(array[mid] >= value) right = mid - 1; else left = mid + 1; } if(left >= array_size || array[left] > value) left--; return left; } -static void addLengthDistance(uivector* values, size_t length, size_t distance) -{ +static void addLengthDistance(uivector* values, size_t length, size_t distance) { /*values in encoded vector are those used by deflate: 0-255: literal bytes 256: end @@ -1353,10 +1465,15 @@ static void addLengthDistance(uivector* values, size_t length, size_t distance) unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance); unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]); - uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX); - uivector_push_back(values, extra_length); - uivector_push_back(values, dist_code); - uivector_push_back(values, extra_distance); + size_t pos = values->size; + /*TODO: return error when this fails (out of memory)*/ + unsigned ok = uivector_resize(values, values->size + 4); + if(ok) { + values->data[pos + 0] = length_code + FIRST_LENGTH_CODE_INDEX; + values->data[pos + 1] = extra_length; + values->data[pos + 2] = dist_code; + values->data[pos + 3] = extra_distance; + } } /*3 bytes of data get encoded into two bytes. The hash cannot use more than 3 @@ -1364,8 +1481,7 @@ bytes as input because 3 is the minimum match length for deflate*/ static const unsigned HASH_NUM_VALUES = 65536; static const unsigned HASH_BIT_MASK = 65535; /*HASH_NUM_VALUES - 1, but C90 does not like that as initializer*/ -typedef struct Hash -{ +typedef struct Hash { int* head; /*hash value to head circular pos - can be outdated if went around window*/ /*circular pos to prev circular pos*/ unsigned short* chain; @@ -1378,8 +1494,7 @@ typedef struct Hash unsigned short* zeros; /*length of zeros streak, used as a second hash chain*/ } Hash; -static unsigned hash_init(Hash* hash, unsigned windowsize) -{ +static unsigned hash_init(Hash* hash, unsigned windowsize) { unsigned i; hash->head = (int*)lodepng_malloc(sizeof(int) * HASH_NUM_VALUES); hash->val = (int*)lodepng_malloc(sizeof(int) * windowsize); @@ -1389,8 +1504,7 @@ static unsigned hash_init(Hash* hash, unsigned windowsize) hash->headz = (int*)lodepng_malloc(sizeof(int) * (MAX_SUPPORTED_DEFLATE_LENGTH + 1)); hash->chainz = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize); - if(!hash->head || !hash->chain || !hash->val || !hash->headz|| !hash->chainz || !hash->zeros) - { + if(!hash->head || !hash->chain || !hash->val || !hash->headz|| !hash->chainz || !hash->zeros) { return 83; /*alloc fail*/ } @@ -1405,8 +1519,7 @@ static unsigned hash_init(Hash* hash, unsigned windowsize) return 0; } -static void hash_cleanup(Hash* hash) -{ +static void hash_cleanup(Hash* hash) { lodepng_free(hash->head); lodepng_free(hash->val); lodepng_free(hash->chain); @@ -1418,29 +1531,26 @@ static void hash_cleanup(Hash* hash) -static unsigned getHash(const unsigned char* data, size_t size, size_t pos) -{ +static unsigned getHash(const unsigned char* data, size_t size, size_t pos) { unsigned result = 0; - if(pos + 2 < size) - { + if(pos + 2 < size) { /*A simple shift and xor hash is used. Since the data of PNGs is dominated by zeroes due to the filters, a better hash does not have a significant effect on speed in traversing the chain, and causes more time spend on calculating the hash.*/ - result ^= (unsigned)(data[pos + 0] << 0u); - result ^= (unsigned)(data[pos + 1] << 4u); - result ^= (unsigned)(data[pos + 2] << 8u); + result ^= ((unsigned)data[pos + 0] << 0u); + result ^= ((unsigned)data[pos + 1] << 4u); + result ^= ((unsigned)data[pos + 2] << 8u); } else { size_t amount, i; if(pos >= size) return 0; amount = size - pos; - for(i = 0; i != amount; ++i) result ^= (unsigned)(data[pos + i] << (i * 8u)); + for(i = 0; i != amount; ++i) result ^= ((unsigned)data[pos + i] << (i * 8u)); } return result & HASH_BIT_MASK; } -static unsigned countZeros(const unsigned char* data, size_t size, size_t pos) -{ +static unsigned countZeros(const unsigned char* data, size_t size, size_t pos) { const unsigned char* start = data + pos; const unsigned char* end = start + MAX_SUPPORTED_DEFLATE_LENGTH; if(end > data + size) end = data + size; @@ -1451,15 +1561,14 @@ static unsigned countZeros(const unsigned char* data, size_t size, size_t pos) } /*wpos = pos & (windowsize - 1)*/ -static void updateHashChain(Hash* hash, size_t wpos, unsigned hashval, unsigned short numzeros) -{ +static void updateHashChain(Hash* hash, size_t wpos, unsigned hashval, unsigned short numzeros) { hash->val[wpos] = (int)hashval; if(hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval]; - hash->head[hashval] = (unsigned)wpos; + hash->head[hashval] = (int)wpos; hash->zeros[wpos] = numzeros; if(hash->headz[numzeros] != -1) hash->chainz[wpos] = hash->headz[numzeros]; - hash->headz[numzeros] = (unsigned)wpos; + hash->headz[numzeros] = (int)wpos; } /* @@ -1473,12 +1582,11 @@ this hash technique is one out of several ways to speed this up. */ static unsigned encodeLZ77(uivector* out, Hash* hash, const unsigned char* in, size_t inpos, size_t insize, unsigned windowsize, - unsigned minmatch, unsigned nicematch, unsigned lazymatching) -{ + unsigned minmatch, unsigned nicematch, unsigned lazymatching) { size_t pos; unsigned i, error = 0; /*for large window lengths, assume the user wants no compression loss. Otherwise, max hash chain length speedup.*/ - unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8; + unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8u; unsigned maxlazymatch = windowsize >= 8192 ? MAX_SUPPORTED_DEFLATE_LENGTH : 64; unsigned usezeros = 1; /*not sure if setting it to false for windowsize < 8192 is better or worse*/ @@ -1499,20 +1607,16 @@ static unsigned encodeLZ77(uivector* out, Hash* hash, if(nicematch > MAX_SUPPORTED_DEFLATE_LENGTH) nicematch = MAX_SUPPORTED_DEFLATE_LENGTH; - for(pos = inpos; pos < insize; ++pos) - { + for(pos = inpos; pos < insize; ++pos) { size_t wpos = pos & (windowsize - 1); /*position for in 'circular' hash buffers*/ unsigned chainlength = 0; hashval = getHash(in, insize, pos); - if(usezeros && hashval == 0) - { + if(usezeros && hashval == 0) { if(numzeros == 0) numzeros = countZeros(in, insize, pos); else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros; - } - else - { + } else { numzeros = 0; } @@ -1528,37 +1632,32 @@ static unsigned encodeLZ77(uivector* out, Hash* hash, /*search for the longest string*/ prev_offset = 0; - for(;;) - { + for(;;) { if(chainlength++ >= maxchainlength) break; current_offset = (unsigned)(hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize); if(current_offset < prev_offset) break; /*stop when went completely around the circular buffer*/ prev_offset = current_offset; - if(current_offset > 0) - { + if(current_offset > 0) { /*test the next characters*/ foreptr = &in[pos]; backptr = &in[pos - current_offset]; /*common case in PNGs is lots of zeros. Quickly skip over them as a speedup*/ - if(numzeros >= 3) - { + if(numzeros >= 3) { unsigned skip = hash->zeros[hashpos]; if(skip > numzeros) skip = numzeros; backptr += skip; foreptr += skip; } - while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/ - { + while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/ { ++backptr; ++foreptr; } current_length = (unsigned)(foreptr - &in[pos]); - if(current_length > length) - { + if(current_length > length) { length = current_length; /*the longest length*/ offset = current_offset; /*the offset that is related to this longest length*/ /*jump out once a length of max length is found (speed gain). This also jumps @@ -1569,39 +1668,30 @@ static unsigned encodeLZ77(uivector* out, Hash* hash, if(hashpos == hash->chain[hashpos]) break; - if(numzeros >= 3 && length > numzeros) - { + if(numzeros >= 3 && length > numzeros) { hashpos = hash->chainz[hashpos]; if(hash->zeros[hashpos] != numzeros) break; - } - else - { + } else { hashpos = hash->chain[hashpos]; /*outdated hash value, happens if particular value was not encountered in whole last window*/ if(hash->val[hashpos] != (int)hashval) break; } } - if(lazymatching) - { - if(!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH) - { + if(lazymatching) { + if(!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH) { lazy = 1; lazylength = length; lazyoffset = offset; continue; /*try the next byte*/ } - if(lazy) - { + if(lazy) { lazy = 0; if(pos == 0) ERROR_BREAK(81); - if(length > lazylength + 1) - { + if(length > lazylength + 1) { /*push the previous character as literal*/ if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(83 /*alloc fail*/); - } - else - { + } else { length = lazylength; offset = lazyoffset; hash->head[hashval] = -1; /*the same hashchain update will be done, this ensures no wrong alteration*/ @@ -1613,31 +1703,22 @@ static unsigned encodeLZ77(uivector* out, Hash* hash, if(length >= 3 && offset > windowsize) ERROR_BREAK(86 /*too big (or overflown negative) offset*/); /*encode it as length/distance pair or literal value*/ - if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/ - { + if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/ { if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/); - } - else if(length < minmatch || (length == 3 && offset > 4096)) - { + } else if(length < minmatch || (length == 3 && offset > 4096)) { /*compensate for the fact that longer offsets have more extra bits, a length of only 3 may be not worth it then*/ if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/); - } - else - { + } else { addLengthDistance(out, length, offset); - for(i = 1; i < length; ++i) - { + for(i = 1; i < length; ++i) { ++pos; wpos = pos & (windowsize - 1); hashval = getHash(in, insize, pos); - if(usezeros && hashval == 0) - { + if(usezeros && hashval == 0) { if(numzeros == 0) numzeros = countZeros(in, insize, pos); else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros; - } - else - { + } else { numzeros = 0; } updateHashChain(hash, wpos, hashval, numzeros); @@ -1650,38 +1731,34 @@ static unsigned encodeLZ77(uivector* out, Hash* hash, /* /////////////////////////////////////////////////////////////////////////// */ -static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize) -{ +static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize) { /*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte, 2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/ - size_t i, j, numdeflateblocks = (datasize + 65534) / 65535; + size_t i, numdeflateblocks = (datasize + 65534u) / 65535u; unsigned datapos = 0; - for(i = 0; i != numdeflateblocks; ++i) - { + for(i = 0; i != numdeflateblocks; ++i) { unsigned BFINAL, BTYPE, LEN, NLEN; unsigned char firstbyte; + size_t pos = out->size; BFINAL = (i == numdeflateblocks - 1); BTYPE = 0; - firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1)); - ucvector_push_back(out, firstbyte); - LEN = 65535; - if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos; + if(datasize - datapos < 65535u) LEN = (unsigned)datasize - datapos; NLEN = 65535 - LEN; - ucvector_push_back(out, (unsigned char)(LEN & 255)); - ucvector_push_back(out, (unsigned char)(LEN >> 8)); - ucvector_push_back(out, (unsigned char)(NLEN & 255)); - ucvector_push_back(out, (unsigned char)(NLEN >> 8)); + if(!ucvector_resize(out, out->size + LEN + 5)) return 83; /*alloc fail*/ - /*Decompressed data*/ - for(j = 0; j < 65535 && datapos < datasize; ++j) - { - ucvector_push_back(out, data[datapos++]); - } + firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1u) << 1u) + ((BTYPE & 2u) << 1u)); + out->data[pos + 0] = firstbyte; + out->data[pos + 1] = (unsigned char)(LEN & 255); + out->data[pos + 2] = (unsigned char)(LEN >> 8u); + out->data[pos + 3] = (unsigned char)(NLEN & 255); + out->data[pos + 4] = (unsigned char)(NLEN >> 8u); + lodepng_memcpy(out->data + pos + 5, data + datapos, LEN); + datapos += LEN; } return 0; @@ -1692,16 +1769,13 @@ write the lz77-encoded data, which has lit, len and dist codes, to compressed st tree_ll: the tree for lit and len codes. tree_d: the tree for distance codes. */ -static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded, - const HuffmanTree* tree_ll, const HuffmanTree* tree_d) -{ +static void writeLZ77data(LodePNGBitWriter* writer, const uivector* lz77_encoded, + const HuffmanTree* tree_ll, const HuffmanTree* tree_d) { size_t i = 0; - for(i = 0; i != lz77_encoded->size; ++i) - { + for(i = 0; i != lz77_encoded->size; ++i) { unsigned val = lz77_encoded->data[i]; - addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_ll, val), HuffmanTree_getLength(tree_ll, val)); - if(val > 256) /*for a length code, 3 more things have to be added*/ - { + writeBitsReversed(writer, tree_ll->codes[val], tree_ll->lengths[val]); + if(val > 256) /*for a length code, 3 more things have to be added*/ { unsigned length_index = val - FIRST_LENGTH_CODE_INDEX; unsigned n_length_extra_bits = LENGTHEXTRA[length_index]; unsigned length_extra_bits = lz77_encoded->data[++i]; @@ -1712,19 +1786,17 @@ static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encode unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index]; unsigned distance_extra_bits = lz77_encoded->data[++i]; - addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits); - addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_d, distance_code), - HuffmanTree_getLength(tree_d, distance_code)); - addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits); + writeBits(writer, length_extra_bits, n_length_extra_bits); + writeBitsReversed(writer, tree_d->codes[distance_code], tree_d->lengths[distance_code]); + writeBits(writer, distance_extra_bits, n_distance_extra_bits); } } } /*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/ -static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash, +static unsigned deflateDynamic(LodePNGBitWriter* writer, Hash* hash, const unsigned char* data, size_t datapos, size_t dataend, - const LodePNGCompressSettings* settings, unsigned final) -{ + const LodePNGCompressSettings* settings, unsigned final) { unsigned error = 0; /* @@ -1734,7 +1806,7 @@ static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash, another huffman tree is used for the dist values ("d"). These two trees are stored using their code lengths, and to compress even more these code lengths are also run-length encoded and huffman compressed. This gives a huffman tree - of code lengths "cl". The code lenghts used to describe this third tree are + of code lengths "cl". The code lengths used to describe this third tree are the code length code lengths ("clcl"). */ @@ -1743,159 +1815,140 @@ static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash, HuffmanTree tree_ll; /*tree for lit,len values*/ HuffmanTree tree_d; /*tree for distance codes*/ HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/ - uivector frequencies_ll; /*frequency of lit,len codes*/ - uivector frequencies_d; /*frequency of dist codes*/ - uivector frequencies_cl; /*frequency of code length codes*/ - uivector bitlen_lld; /*lit,len,dist code lenghts (int bits), literally (without repeat codes).*/ - uivector bitlen_lld_e; /*bitlen_lld encoded with repeat codes (this is a rudemtary run length compression)*/ - /*bitlen_cl is the code length code lengths ("clcl"). The bit lengths of codes to represent tree_cl - (these are written as is in the file, it would be crazy to compress these using yet another huffman - tree that needs to be represented by yet another set of code lengths)*/ - uivector bitlen_cl; + unsigned* frequencies_ll = 0; /*frequency of lit,len codes*/ + unsigned* frequencies_d = 0; /*frequency of dist codes*/ + unsigned* frequencies_cl = 0; /*frequency of code length codes*/ + unsigned* bitlen_lld = 0; /*lit,len,dist code lengths (int bits), literally (without repeat codes).*/ + unsigned* bitlen_lld_e = 0; /*bitlen_lld encoded with repeat codes (this is a rudimentary run length compression)*/ size_t datasize = dataend - datapos; /* - Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies: + If we could call "bitlen_cl" the the code length code lengths ("clcl"), that is the bit lengths of codes to represent + tree_cl in CLCL_ORDER, then due to the huffman compression of huffman tree representations ("two levels"), there are + some analogies: bitlen_lld is to tree_cl what data is to tree_ll and tree_d. bitlen_lld_e is to bitlen_lld what lz77_encoded is to data. bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded. */ unsigned BFINAL = final; - size_t numcodes_ll, numcodes_d, i; + size_t i; + size_t numcodes_ll, numcodes_d, numcodes_lld, numcodes_lld_e, numcodes_cl; unsigned HLIT, HDIST, HCLEN; uivector_init(&lz77_encoded); HuffmanTree_init(&tree_ll); HuffmanTree_init(&tree_d); HuffmanTree_init(&tree_cl); - uivector_init(&frequencies_ll); - uivector_init(&frequencies_d); - uivector_init(&frequencies_cl); - uivector_init(&bitlen_lld); - uivector_init(&bitlen_lld_e); - uivector_init(&bitlen_cl); + /* could fit on stack, but >1KB is on the larger side so allocate instead */ + frequencies_ll = (unsigned*)lodepng_malloc(286 * sizeof(*frequencies_ll)); + frequencies_d = (unsigned*)lodepng_malloc(30 * sizeof(*frequencies_d)); + frequencies_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(*frequencies_cl)); + + if(!frequencies_ll || !frequencies_d || !frequencies_cl) error = 83; /*alloc fail*/ /*This while loop never loops due to a break at the end, it is here to allow breaking out of it to the cleanup phase on error conditions.*/ - while(!error) - { - if(settings->use_lz77) - { + while(!error) { + lodepng_memset(frequencies_ll, 0, 286 * sizeof(*frequencies_ll)); + lodepng_memset(frequencies_d, 0, 30 * sizeof(*frequencies_d)); + lodepng_memset(frequencies_cl, 0, NUM_CODE_LENGTH_CODES * sizeof(*frequencies_cl)); + + if(settings->use_lz77) { error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize, settings->minmatch, settings->nicematch, settings->lazymatching); if(error) break; - } - else - { + } else { if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83 /*alloc fail*/); for(i = datapos; i < dataend; ++i) lz77_encoded.data[i - datapos] = data[i]; /*no LZ77, but still will be Huffman compressed*/ } - if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83 /*alloc fail*/); - if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(83 /*alloc fail*/); - /*Count the frequencies of lit, len and dist codes*/ - for(i = 0; i != lz77_encoded.size; ++i) - { + for(i = 0; i != lz77_encoded.size; ++i) { unsigned symbol = lz77_encoded.data[i]; - ++frequencies_ll.data[symbol]; - if(symbol > 256) - { + ++frequencies_ll[symbol]; + if(symbol > 256) { unsigned dist = lz77_encoded.data[i + 2]; - ++frequencies_d.data[dist]; + ++frequencies_d[dist]; i += 3; } } - frequencies_ll.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/ + frequencies_ll[256] = 1; /*there will be exactly 1 end code, at the end of the block*/ /*Make both huffman trees, one for the lit and len codes, one for the dist codes*/ - error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll.data, 257, frequencies_ll.size, 15); + error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll, 257, 286, 15); if(error) break; /*2, not 1, is chosen for mincodes: some buggy PNG decoders require at least 2 symbols in the dist tree*/ - error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, 2, frequencies_d.size, 15); + error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d, 2, 30, 15); if(error) break; - numcodes_ll = tree_ll.numcodes; if(numcodes_ll > 286) numcodes_ll = 286; - numcodes_d = tree_d.numcodes; if(numcodes_d > 30) numcodes_d = 30; + numcodes_ll = LODEPNG_MIN(tree_ll.numcodes, 286); + numcodes_d = LODEPNG_MIN(tree_d.numcodes, 30); /*store the code lengths of both generated trees in bitlen_lld*/ - for(i = 0; i != numcodes_ll; ++i) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_ll, (unsigned)i)); - for(i = 0; i != numcodes_d; ++i) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_d, (unsigned)i)); + numcodes_lld = numcodes_ll + numcodes_d; + bitlen_lld = (unsigned*)lodepng_malloc(numcodes_lld * sizeof(*bitlen_lld)); + /*numcodes_lld_e never needs more size than bitlen_lld*/ + bitlen_lld_e = (unsigned*)lodepng_malloc(numcodes_lld * sizeof(*bitlen_lld_e)); + if(!bitlen_lld || !bitlen_lld_e) ERROR_BREAK(83); /*alloc fail*/ + numcodes_lld_e = 0; + + for(i = 0; i != numcodes_ll; ++i) bitlen_lld[i] = tree_ll.lengths[i]; + for(i = 0; i != numcodes_d; ++i) bitlen_lld[numcodes_ll + i] = tree_d.lengths[i]; /*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times), 17 (3-10 zeroes), 18 (11-138 zeroes)*/ - for(i = 0; i != (unsigned)bitlen_lld.size; ++i) - { - unsigned j = 0; /*amount of repititions*/ - while(i + j + 1 < (unsigned)bitlen_lld.size && bitlen_lld.data[i + j + 1] == bitlen_lld.data[i]) ++j; + for(i = 0; i != numcodes_lld; ++i) { + unsigned j = 0; /*amount of repetitions*/ + while(i + j + 1 < numcodes_lld && bitlen_lld[i + j + 1] == bitlen_lld[i]) ++j; - if(bitlen_lld.data[i] == 0 && j >= 2) /*repeat code for zeroes*/ - { + if(bitlen_lld[i] == 0 && j >= 2) /*repeat code for zeroes*/ { ++j; /*include the first zero*/ - if(j <= 10) /*repeat code 17 supports max 10 zeroes*/ - { - uivector_push_back(&bitlen_lld_e, 17); - uivector_push_back(&bitlen_lld_e, j - 3); - } - else /*repeat code 18 supports max 138 zeroes*/ - { + if(j <= 10) /*repeat code 17 supports max 10 zeroes*/ { + bitlen_lld_e[numcodes_lld_e++] = 17; + bitlen_lld_e[numcodes_lld_e++] = j - 3; + } else /*repeat code 18 supports max 138 zeroes*/ { if(j > 138) j = 138; - uivector_push_back(&bitlen_lld_e, 18); - uivector_push_back(&bitlen_lld_e, j - 11); + bitlen_lld_e[numcodes_lld_e++] = 18; + bitlen_lld_e[numcodes_lld_e++] = j - 11; } i += (j - 1); - } - else if(j >= 3) /*repeat code for value other than zero*/ - { + } else if(j >= 3) /*repeat code for value other than zero*/ { size_t k; - unsigned num = j / 6, rest = j % 6; - uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]); - for(k = 0; k < num; ++k) - { - uivector_push_back(&bitlen_lld_e, 16); - uivector_push_back(&bitlen_lld_e, 6 - 3); + unsigned num = j / 6u, rest = j % 6u; + bitlen_lld_e[numcodes_lld_e++] = bitlen_lld[i]; + for(k = 0; k < num; ++k) { + bitlen_lld_e[numcodes_lld_e++] = 16; + bitlen_lld_e[numcodes_lld_e++] = 6 - 3; } - if(rest >= 3) - { - uivector_push_back(&bitlen_lld_e, 16); - uivector_push_back(&bitlen_lld_e, rest - 3); + if(rest >= 3) { + bitlen_lld_e[numcodes_lld_e++] = 16; + bitlen_lld_e[numcodes_lld_e++] = rest - 3; } else j -= rest; i += j; - } - else /*too short to benefit from repeat code*/ - { - uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]); + } else /*too short to benefit from repeat code*/ { + bitlen_lld_e[numcodes_lld_e++] = bitlen_lld[i]; } } /*generate tree_cl, the huffmantree of huffmantrees*/ - - if(!uivector_resizev(&frequencies_cl, NUM_CODE_LENGTH_CODES, 0)) ERROR_BREAK(83 /*alloc fail*/); - for(i = 0; i != bitlen_lld_e.size; ++i) - { - ++frequencies_cl.data[bitlen_lld_e.data[i]]; + for(i = 0; i != numcodes_lld_e; ++i) { + ++frequencies_cl[bitlen_lld_e[i]]; /*after a repeat code come the bits that specify the number of repetitions, those don't need to be in the frequencies_cl calculation*/ - if(bitlen_lld_e.data[i] >= 16) ++i; + if(bitlen_lld_e[i] >= 16) ++i; } - error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data, - frequencies_cl.size, frequencies_cl.size, 7); + error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl, + NUM_CODE_LENGTH_CODES, NUM_CODE_LENGTH_CODES, 7); if(error) break; - if(!uivector_resize(&bitlen_cl, tree_cl.numcodes)) ERROR_BREAK(83 /*alloc fail*/); - for(i = 0; i != tree_cl.numcodes; ++i) - { - /*lenghts of code length tree is in the order as specified by deflate*/ - bitlen_cl.data[i] = HuffmanTree_getLength(&tree_cl, CLCL_ORDER[i]); - } - while(bitlen_cl.data[bitlen_cl.size - 1] == 0 && bitlen_cl.size > 4) - { - /*remove zeros at the end, but minimum size must be 4*/ - if(!uivector_resize(&bitlen_cl, bitlen_cl.size - 1)) ERROR_BREAK(83 /*alloc fail*/); + /*compute amount of code-length-code-lengths to output*/ + numcodes_cl = NUM_CODE_LENGTH_CODES; + /*trim zeros at the end (using CLCL_ORDER), but minimum size must be 4 (see HCLEN below)*/ + while(numcodes_cl > 4u && tree_cl.lengths[CLCL_ORDER[numcodes_cl - 1u]] == 0) { + numcodes_cl--; } - if(error) break; /* Write everything into the output @@ -1903,7 +1956,7 @@ static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash, After the BFINAL and BTYPE, the dynamic block consists out of the following: - 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN - (HCLEN+4)*3 bits code lengths of code length alphabet - - HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length + - HLIT + 257 code lengths of lit/length alphabet (encoded using the code length alphabet, + possible repetition codes 16, 17, 18) - HDIST + 1 code lengths of distance alphabet (encoded using the code length alphabet, + possible repetition codes 16, 17, 18) @@ -1912,41 +1965,39 @@ static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash, */ /*Write block type*/ - addBitToStream(bp, out, BFINAL); - addBitToStream(bp, out, 0); /*first bit of BTYPE "dynamic"*/ - addBitToStream(bp, out, 1); /*second bit of BTYPE "dynamic"*/ + writeBits(writer, BFINAL, 1); + writeBits(writer, 0, 1); /*first bit of BTYPE "dynamic"*/ + writeBits(writer, 1, 1); /*second bit of BTYPE "dynamic"*/ /*write the HLIT, HDIST and HCLEN values*/ + /*all three sizes take trimmed ending zeroes into account, done either by HuffmanTree_makeFromFrequencies + or in the loop for numcodes_cl above, which saves space. */ HLIT = (unsigned)(numcodes_ll - 257); HDIST = (unsigned)(numcodes_d - 1); - HCLEN = (unsigned)bitlen_cl.size - 4; - /*trim zeroes for HCLEN. HLIT and HDIST were already trimmed at tree creation*/ - while(!bitlen_cl.data[HCLEN + 4 - 1] && HCLEN > 0) --HCLEN; - addBitsToStream(bp, out, HLIT, 5); - addBitsToStream(bp, out, HDIST, 5); - addBitsToStream(bp, out, HCLEN, 4); - - /*write the code lenghts of the code length alphabet*/ - for(i = 0; i != HCLEN + 4; ++i) addBitsToStream(bp, out, bitlen_cl.data[i], 3); - - /*write the lenghts of the lit/len AND the dist alphabet*/ - for(i = 0; i != bitlen_lld_e.size; ++i) - { - addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_cl, bitlen_lld_e.data[i]), - HuffmanTree_getLength(&tree_cl, bitlen_lld_e.data[i])); + HCLEN = (unsigned)(numcodes_cl - 4); + writeBits(writer, HLIT, 5); + writeBits(writer, HDIST, 5); + writeBits(writer, HCLEN, 4); + + /*write the code lengths of the code length alphabet ("bitlen_cl")*/ + for(i = 0; i != numcodes_cl; ++i) writeBits(writer, tree_cl.lengths[CLCL_ORDER[i]], 3); + + /*write the lengths of the lit/len AND the dist alphabet*/ + for(i = 0; i != numcodes_lld_e; ++i) { + writeBitsReversed(writer, tree_cl.codes[bitlen_lld_e[i]], tree_cl.lengths[bitlen_lld_e[i]]); /*extra bits of repeat codes*/ - if(bitlen_lld_e.data[i] == 16) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 2); - else if(bitlen_lld_e.data[i] == 17) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 3); - else if(bitlen_lld_e.data[i] == 18) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 7); + if(bitlen_lld_e[i] == 16) writeBits(writer, bitlen_lld_e[++i], 2); + else if(bitlen_lld_e[i] == 17) writeBits(writer, bitlen_lld_e[++i], 3); + else if(bitlen_lld_e[i] == 18) writeBits(writer, bitlen_lld_e[++i], 7); } /*write the compressed data symbols*/ - writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d); + writeLZ77data(writer, &lz77_encoded, &tree_ll, &tree_d); /*error: the length of the end code 256 must be larger than 0*/ - if(HuffmanTree_getLength(&tree_ll, 256) == 0) ERROR_BREAK(64); + if(tree_ll.lengths[256] == 0) ERROR_BREAK(64); /*write the end code*/ - addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256)); + writeBitsReversed(writer, tree_ll.codes[256], tree_ll.lengths[256]); break; /*end of error-while*/ } @@ -1956,21 +2007,19 @@ static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash, HuffmanTree_cleanup(&tree_ll); HuffmanTree_cleanup(&tree_d); HuffmanTree_cleanup(&tree_cl); - uivector_cleanup(&frequencies_ll); - uivector_cleanup(&frequencies_d); - uivector_cleanup(&frequencies_cl); - uivector_cleanup(&bitlen_lld_e); - uivector_cleanup(&bitlen_lld); - uivector_cleanup(&bitlen_cl); + lodepng_free(frequencies_ll); + lodepng_free(frequencies_d); + lodepng_free(frequencies_cl); + lodepng_free(bitlen_lld); + lodepng_free(bitlen_lld_e); return error; } -static unsigned deflateFixed(ucvector* out, size_t* bp, Hash* hash, +static unsigned deflateFixed(LodePNGBitWriter* writer, Hash* hash, const unsigned char* data, size_t datapos, size_t dataend, - const LodePNGCompressSettings* settings, unsigned final) -{ + const LodePNGCompressSettings* settings, unsigned final) { HuffmanTree tree_ll; /*tree for literal values and length codes*/ HuffmanTree tree_d; /*tree for distance codes*/ @@ -1981,31 +2030,29 @@ static unsigned deflateFixed(ucvector* out, size_t* bp, Hash* hash, HuffmanTree_init(&tree_ll); HuffmanTree_init(&tree_d); - generateFixedLitLenTree(&tree_ll); - generateFixedDistanceTree(&tree_d); - - addBitToStream(bp, out, BFINAL); - addBitToStream(bp, out, 1); /*first bit of BTYPE*/ - addBitToStream(bp, out, 0); /*second bit of BTYPE*/ - - if(settings->use_lz77) /*LZ77 encoded*/ - { - uivector lz77_encoded; - uivector_init(&lz77_encoded); - error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize, - settings->minmatch, settings->nicematch, settings->lazymatching); - if(!error) writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d); - uivector_cleanup(&lz77_encoded); - } - else /*no LZ77, but still will be Huffman compressed*/ - { - for(i = datapos; i < dataend; ++i) - { - addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, data[i]), HuffmanTree_getLength(&tree_ll, data[i])); + error = generateFixedLitLenTree(&tree_ll); + if(!error) error = generateFixedDistanceTree(&tree_d); + + if(!error) { + writeBits(writer, BFINAL, 1); + writeBits(writer, 1, 1); /*first bit of BTYPE*/ + writeBits(writer, 0, 1); /*second bit of BTYPE*/ + + if(settings->use_lz77) /*LZ77 encoded*/ { + uivector lz77_encoded; + uivector_init(&lz77_encoded); + error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize, + settings->minmatch, settings->nicematch, settings->lazymatching); + if(!error) writeLZ77data(writer, &lz77_encoded, &tree_ll, &tree_d); + uivector_cleanup(&lz77_encoded); + } else /*no LZ77, but still will be Huffman compressed*/ { + for(i = datapos; i < dataend; ++i) { + writeBitsReversed(writer, tree_ll.codes[data[i]], tree_ll.lengths[data[i]]); + } } + /*add END code*/ + if(!error) writeBitsReversed(writer,tree_ll.codes[256], tree_ll.lengths[256]); } - /*add END code*/ - if(!error) addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256)); /*cleanup*/ HuffmanTree_cleanup(&tree_ll); @@ -2015,20 +2062,20 @@ static unsigned deflateFixed(ucvector* out, size_t* bp, Hash* hash, } static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t insize, - const LodePNGCompressSettings* settings) -{ + const LodePNGCompressSettings* settings) { unsigned error = 0; size_t i, blocksize, numdeflateblocks; - size_t bp = 0; /*the bit pointer*/ Hash hash; + LodePNGBitWriter writer; + + LodePNGBitWriter_init(&writer, out); if(settings->btype > 2) return 61; else if(settings->btype == 0) return deflateNoCompression(out, in, insize); else if(settings->btype == 1) blocksize = insize; - else /*if(settings->btype == 2)*/ - { + else /*if(settings->btype == 2)*/ { /*on PNGs, deflate blocks of 65-262k seem to give most dense encoding*/ - blocksize = insize / 8 + 8; + blocksize = insize / 8u + 8; if(blocksize < 65536) blocksize = 65536; if(blocksize > 262144) blocksize = 262144; } @@ -2037,17 +2084,17 @@ static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t if(numdeflateblocks == 0) numdeflateblocks = 1; error = hash_init(&hash, settings->windowsize); - if(error) return error; - for(i = 0; i != numdeflateblocks && !error; ++i) - { - unsigned final = (i == numdeflateblocks - 1); - size_t start = i * blocksize; - size_t end = start + blocksize; - if(end > insize) end = insize; + if(!error) { + for(i = 0; i != numdeflateblocks && !error; ++i) { + unsigned final = (i == numdeflateblocks - 1); + size_t start = i * blocksize; + size_t end = start + blocksize; + if(end > insize) end = insize; - if(settings->btype == 1) error = deflateFixed(out, &bp, &hash, in, start, end, settings, final); - else if(settings->btype == 2) error = deflateDynamic(out, &bp, &hash, in, start, end, settings, final); + if(settings->btype == 1) error = deflateFixed(&writer, &hash, in, start, end, settings, final); + else if(settings->btype == 2) error = deflateDynamic(&writer, &hash, in, start, end, settings, final); + } } hash_cleanup(&hash); @@ -2057,12 +2104,9 @@ static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t unsigned lodepng_deflate(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, - const LodePNGCompressSettings* settings) -{ - unsigned error; - ucvector v; - ucvector_init_buffer(&v, *out, *outsize); - error = lodepng_deflatev(&v, in, insize, settings); + const LodePNGCompressSettings* settings) { + ucvector v = ucvector_init(*out, *outsize); + unsigned error = lodepng_deflatev(&v, in, insize, settings); *out = v.data; *outsize = v.size; return error; @@ -2070,14 +2114,10 @@ unsigned lodepng_deflate(unsigned char** out, size_t* outsize, static unsigned deflate(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, - const LodePNGCompressSettings* settings) -{ - if(settings->custom_deflate) - { + const LodePNGCompressSettings* settings) { + if(settings->custom_deflate) { return settings->custom_deflate(out, outsize, in, insize, settings); - } - else - { + } else { return lodepng_deflate(out, outsize, in, insize, settings); } } @@ -2085,36 +2125,32 @@ static unsigned deflate(unsigned char** out, size_t* outsize, #endif /*LODEPNG_COMPILE_DECODER*/ /* ////////////////////////////////////////////////////////////////////////// */ -/* / Adler32 */ +/* / Adler32 / */ /* ////////////////////////////////////////////////////////////////////////// */ -static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len) -{ - unsigned s1 = adler & 0xffff; - unsigned s2 = (adler >> 16) & 0xffff; +static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len) { + unsigned s1 = adler & 0xffffu; + unsigned s2 = (adler >> 16u) & 0xffffu; - while(len > 0) - { - /*at least 5550 sums can be done before the sums overflow, saving a lot of module divisions*/ - unsigned amount = len > 5550 ? 5550 : len; + while(len != 0u) { + unsigned i; + /*at least 5552 sums can be done before the sums overflow, saving a lot of module divisions*/ + unsigned amount = len > 5552u ? 5552u : len; len -= amount; - while(amount > 0) - { + for(i = 0; i != amount; ++i) { s1 += (*data++); s2 += s1; - --amount; } - s1 %= 65521; - s2 %= 65521; + s1 %= 65521u; + s2 %= 65521u; } - return (s2 << 16) | s1; + return (s2 << 16u) | s1; } /*Return the adler32 of the bytes data[0..len-1]*/ -static unsigned adler32(const unsigned char* data, unsigned len) -{ - return update_adler32(1L, data, len); +static unsigned adler32(const unsigned char* data, unsigned len) { + return update_adler32(1u, data, len); } /* ////////////////////////////////////////////////////////////////////////// */ @@ -2123,16 +2159,15 @@ static unsigned adler32(const unsigned char* data, unsigned len) #ifdef LODEPNG_COMPILE_DECODER -unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGDecompressSettings* settings) -{ +static unsigned lodepng_zlib_decompressv(ucvector* out, + const unsigned char* in, size_t insize, + const LodePNGDecompressSettings* settings) { unsigned error = 0; unsigned CM, CINFO, FDICT; if(insize < 2) return 53; /*error, size of zlib data too small*/ /*read information from zlib header*/ - if((in[0] * 256 + in[1]) % 31 != 0) - { + if((in[0] * 256 + in[1]) % 31 != 0) { /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/ return 24; } @@ -2143,41 +2178,55 @@ unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const uns FDICT = (in[1] >> 5) & 1; /*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/ - if(CM != 8 || CINFO > 7) - { + if(CM != 8 || CINFO > 7) { /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/ return 25; } - if(FDICT != 0) - { + if(FDICT != 0) { /*error: the specification of PNG says about the zlib stream: "The additional flags shall not specify a preset dictionary."*/ return 26; } - error = inflate(out, outsize, in + 2, insize - 2, settings); + error = inflatev(out, in + 2, insize - 2, settings); if(error) return error; - if(!settings->ignore_adler32) - { + if(!settings->ignore_adler32) { unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]); - unsigned checksum = adler32(*out, (unsigned)(*outsize)); + unsigned checksum = adler32(out->data, (unsigned)(out->size)); if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/ } return 0; /*no error*/ } -static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGDecompressSettings* settings) -{ - if(settings->custom_zlib) - { + +unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNGDecompressSettings* settings) { + ucvector v = ucvector_init(*out, *outsize); + unsigned error = lodepng_zlib_decompressv(&v, in, insize, settings); + *out = v.data; + *outsize = v.size; + return error; +} + +/*expected_size is expected output size, to avoid intermediate allocations. Set to 0 if not known. */ +static unsigned zlib_decompress(unsigned char** out, size_t* outsize, size_t expected_size, + const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings) { + if(settings->custom_zlib) { return settings->custom_zlib(out, outsize, in, insize, settings); - } - else - { - return lodepng_zlib_decompress(out, outsize, in, insize, settings); + } else { + unsigned error; + ucvector v = ucvector_init(*out, *outsize); + if(expected_size) { + /*reserve the memory to avoid intermediate reallocations*/ + ucvector_resize(&v, *outsize + expected_size); + v.size = *outsize; + } + error = lodepng_zlib_decompressv(&v, in, insize, settings); + *out = v.data; + *outsize = v.size; + return error; } } @@ -2186,56 +2235,48 @@ static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsi #ifdef LODEPNG_COMPILE_ENCODER unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGCompressSettings* settings) -{ - /*initially, *out must be NULL and outsize 0, if you just give some random *out - that's pointing to a non allocated buffer, this'll crash*/ - ucvector outv; + size_t insize, const LodePNGCompressSettings* settings) { size_t i; unsigned error; unsigned char* deflatedata = 0; size_t deflatesize = 0; - /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/ - unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/ - unsigned FLEVEL = 0; - unsigned FDICT = 0; - unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64; - unsigned FCHECK = 31 - CMFFLG % 31; - CMFFLG += FCHECK; - - /*ucvector-controlled version of the output buffer, for dynamic array*/ - ucvector_init_buffer(&outv, *out, *outsize); - - ucvector_push_back(&outv, (unsigned char)(CMFFLG >> 8)); - ucvector_push_back(&outv, (unsigned char)(CMFFLG & 255)); - error = deflate(&deflatedata, &deflatesize, in, insize, settings); - if(!error) - { - unsigned ADLER32 = adler32(in, (unsigned)insize); - for(i = 0; i != deflatesize; ++i) ucvector_push_back(&outv, deflatedata[i]); - lodepng_free(deflatedata); - lodepng_add32bitInt(&outv, ADLER32); + *out = NULL; + *outsize = 0; + if(!error) { + *outsize = deflatesize + 6; + *out = (unsigned char*)lodepng_malloc(*outsize); + if(!*out) error = 83; /*alloc fail*/ } - *out = outv.data; - *outsize = outv.size; + if(!error) { + unsigned ADLER32 = adler32(in, (unsigned)insize); + /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/ + unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/ + unsigned FLEVEL = 0; + unsigned FDICT = 0; + unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64; + unsigned FCHECK = 31 - CMFFLG % 31; + CMFFLG += FCHECK; + (*out)[0] = (unsigned char)(CMFFLG >> 8); + (*out)[1] = (unsigned char)(CMFFLG & 255); + for(i = 0; i != deflatesize; ++i) (*out)[i + 2] = deflatedata[i]; + lodepng_set32bitInt(&(*out)[*outsize - 4], ADLER32); + } + + lodepng_free(deflatedata); return error; } /* compress using the default or custom zlib function */ static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGCompressSettings* settings) -{ - if(settings->custom_zlib) - { + size_t insize, const LodePNGCompressSettings* settings) { + if(settings->custom_zlib) { return settings->custom_zlib(out, outsize, in, insize, settings); - } - else - { + } else { return lodepng_zlib_compress(out, outsize, in, insize, settings); } } @@ -2245,17 +2286,16 @@ static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsign #else /*no LODEPNG_COMPILE_ZLIB*/ #ifdef LODEPNG_COMPILE_DECODER -static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGDecompressSettings* settings) -{ +static unsigned zlib_decompress(unsigned char** out, size_t* outsize, size_t expected_size, + const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings) { if(!settings->custom_zlib) return 87; /*no custom zlib function provided */ + (void)expected_size; return settings->custom_zlib(out, outsize, in, insize, settings); } #endif /*LODEPNG_COMPILE_DECODER*/ #ifdef LODEPNG_COMPILE_ENCODER static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGCompressSettings* settings) -{ + size_t insize, const LodePNGCompressSettings* settings) { if(!settings->custom_zlib) return 87; /*no custom zlib function provided */ return settings->custom_zlib(out, outsize, in, insize, settings); } @@ -2270,8 +2310,7 @@ static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsign /*this is a good tradeoff between speed and compression ratio*/ #define DEFAULT_WINDOWSIZE 2048 -void lodepng_compress_settings_init(LodePNGCompressSettings* settings) -{ +void lodepng_compress_settings_init(LodePNGCompressSettings* settings) { /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/ settings->btype = 2; settings->use_lz77 = 1; @@ -2292,16 +2331,16 @@ const LodePNGCompressSettings lodepng_default_compress_settings = {2, 1, DEFAULT #ifdef LODEPNG_COMPILE_DECODER -void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings) -{ +void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings) { settings->ignore_adler32 = 0; + settings->ignore_nlen = 0; settings->custom_zlib = 0; settings->custom_inflate = 0; settings->custom_context = 0; } -const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0}; +const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0, 0}; #endif /*LODEPNG_COMPILE_DECODER*/ @@ -2356,13 +2395,11 @@ static unsigned lodepng_crc32_table[256] = { }; /*Return the CRC of the bytes buf[0..len-1].*/ -unsigned lodepng_crc32(const unsigned char* data, size_t length) -{ +unsigned lodepng_crc32(const unsigned char* data, size_t length) { unsigned r = 0xffffffffu; size_t i; - for(i = 0; i < length; ++i) - { - r = lodepng_crc32_table[(r ^ data[i]) & 0xff] ^ (r >> 8); + for(i = 0; i < length; ++i) { + r = lodepng_crc32_table[(r ^ data[i]) & 0xffu] ^ (r >> 8u); } return r ^ 0xffffffffu; } @@ -2371,46 +2408,33 @@ unsigned lodepng_crc32(const unsigned char* data, size_t length); #endif /* !LODEPNG_NO_COMPILE_CRC */ /* ////////////////////////////////////////////////////////////////////////// */ -/* / Reading and writing single bits and bytes from/to stream for LodePNG / */ +/* / Reading and writing PNG color channel bits / */ /* ////////////////////////////////////////////////////////////////////////// */ -static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream) -{ +/* The color channel bits of less-than-8-bit pixels are read with the MSB of bytes first, +so LodePNGBitWriter and LodePNGBitReader can't be used for those. */ + +static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream) { unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1); ++(*bitpointer); return result; } -static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits) -{ +/* TODO: make this faster */ +static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits) { unsigned result = 0; size_t i; - for(i = 0 ; i < nbits; ++i) - { - result <<= 1; + for(i = 0 ; i < nbits; ++i) { + result <<= 1u; result |= (unsigned)readBitFromReversedStream(bitpointer, bitstream); } return result; } -#ifdef LODEPNG_COMPILE_DECODER -static void setBitOfReversedStream0(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) -{ - /*the current bit in bitstream must be 0 for this to work*/ - if(bit) - { - /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/ - bitstream[(*bitpointer) >> 3] |= (bit << (7 - ((*bitpointer) & 0x7))); - } - ++(*bitpointer); -} -#endif /*LODEPNG_COMPILE_DECODER*/ - -static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) -{ +static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) { /*the current bit in bitstream may be 0 or 1 for this to work*/ - if(bit == 0) bitstream[(*bitpointer) >> 3] &= (unsigned char)(~(1 << (7 - ((*bitpointer) & 0x7)))); - else bitstream[(*bitpointer) >> 3] |= (1 << (7 - ((*bitpointer) & 0x7))); + if(bit == 0) bitstream[(*bitpointer) >> 3u] &= (unsigned char)(~(1u << (7u - ((*bitpointer) & 7u)))); + else bitstream[(*bitpointer) >> 3u] |= (1u << (7u - ((*bitpointer) & 7u))); ++(*bitpointer); } @@ -2418,51 +2442,42 @@ static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, /* / PNG chunks / */ /* ////////////////////////////////////////////////////////////////////////// */ -unsigned lodepng_chunk_length(const unsigned char* chunk) -{ +unsigned lodepng_chunk_length(const unsigned char* chunk) { return lodepng_read32bitInt(&chunk[0]); } -void lodepng_chunk_type(char type[5], const unsigned char* chunk) -{ +void lodepng_chunk_type(char type[5], const unsigned char* chunk) { unsigned i; for(i = 0; i != 4; ++i) type[i] = (char)chunk[4 + i]; type[4] = 0; /*null termination char*/ } -unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type) -{ - if(strlen(type) != 4) return 0; +unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type) { + if(lodepng_strlen(type) != 4) return 0; return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]); } -unsigned char lodepng_chunk_ancillary(const unsigned char* chunk) -{ +unsigned char lodepng_chunk_ancillary(const unsigned char* chunk) { return((chunk[4] & 32) != 0); } -unsigned char lodepng_chunk_private(const unsigned char* chunk) -{ +unsigned char lodepng_chunk_private(const unsigned char* chunk) { return((chunk[6] & 32) != 0); } -unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk) -{ +unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk) { return((chunk[7] & 32) != 0); } -unsigned char* lodepng_chunk_data(unsigned char* chunk) -{ +unsigned char* lodepng_chunk_data(unsigned char* chunk) { return &chunk[8]; } -const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk) -{ +const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk) { return &chunk[8]; } -unsigned lodepng_chunk_check_crc(const unsigned char* chunk) -{ +unsigned lodepng_chunk_check_crc(const unsigned char* chunk) { unsigned length = lodepng_chunk_length(chunk); unsigned CRC = lodepng_read32bitInt(&chunk[length + 8]); /*the CRC is taken of the data and the 4 chunk type letters, not the length*/ @@ -2471,37 +2486,72 @@ unsigned lodepng_chunk_check_crc(const unsigned char* chunk) else return 0; } -void lodepng_chunk_generate_crc(unsigned char* chunk) -{ +void lodepng_chunk_generate_crc(unsigned char* chunk) { unsigned length = lodepng_chunk_length(chunk); unsigned CRC = lodepng_crc32(&chunk[4], length + 4); lodepng_set32bitInt(chunk + 8 + length, CRC); } -unsigned char* lodepng_chunk_next(unsigned char* chunk) -{ - unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; - return &chunk[total_chunk_length]; +unsigned char* lodepng_chunk_next(unsigned char* chunk, unsigned char* end) { + if(chunk >= end || end - chunk < 12) return end; /*too small to contain a chunk*/ + if(chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47 + && chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) { + /* Is PNG magic header at start of PNG file. Jump to first actual chunk. */ + return chunk + 8; + } else { + size_t total_chunk_length; + unsigned char* result; + if(lodepng_addofl(lodepng_chunk_length(chunk), 12, &total_chunk_length)) return end; + result = chunk + total_chunk_length; + if(result < chunk) return end; /*pointer overflow*/ + return result; + } } -const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk) -{ - unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; - return &chunk[total_chunk_length]; +const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk, const unsigned char* end) { + if(chunk >= end || end - chunk < 12) return end; /*too small to contain a chunk*/ + if(chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47 + && chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) { + /* Is PNG magic header at start of PNG file. Jump to first actual chunk. */ + return chunk + 8; + } else { + size_t total_chunk_length; + const unsigned char* result; + if(lodepng_addofl(lodepng_chunk_length(chunk), 12, &total_chunk_length)) return end; + result = chunk + total_chunk_length; + if(result < chunk) return end; /*pointer overflow*/ + return result; + } } -unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk) -{ +unsigned char* lodepng_chunk_find(unsigned char* chunk, unsigned char* end, const char type[5]) { + for(;;) { + if(chunk >= end || end - chunk < 12) return 0; /* past file end: chunk + 12 > end */ + if(lodepng_chunk_type_equals(chunk, type)) return chunk; + chunk = lodepng_chunk_next(chunk, end); + } +} + +const unsigned char* lodepng_chunk_find_const(const unsigned char* chunk, const unsigned char* end, const char type[5]) { + for(;;) { + if(chunk >= end || end - chunk < 12) return 0; /* past file end: chunk + 12 > end */ + if(lodepng_chunk_type_equals(chunk, type)) return chunk; + chunk = lodepng_chunk_next_const(chunk, end); + } +} + +unsigned lodepng_chunk_append(unsigned char** out, size_t* outsize, const unsigned char* chunk) { unsigned i; - unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; + size_t total_chunk_length, new_length; unsigned char *chunk_start, *new_buffer; - size_t new_length = (*outlength) + total_chunk_length; - if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/ + + if(lodepng_addofl(lodepng_chunk_length(chunk), 12, &total_chunk_length)) return 77; + if(lodepng_addofl(*outsize, total_chunk_length, &new_length)) return 77; new_buffer = (unsigned char*)lodepng_realloc(*out, new_length); if(!new_buffer) return 83; /*alloc fail*/ (*out) = new_buffer; - (*outlength) = new_length; + (*outsize) = new_length; chunk_start = &(*out)[new_length - total_chunk_length]; for(i = 0; i != total_chunk_length; ++i) chunk_start[i] = chunk[i]; @@ -2509,30 +2559,36 @@ unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsi return 0; } -unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length, - const char* type, const unsigned char* data) -{ - unsigned i; - unsigned char *chunk, *new_buffer; - size_t new_length = (*outlength) + length + 12; - if(new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/ - new_buffer = (unsigned char*)lodepng_realloc(*out, new_length); - if(!new_buffer) return 83; /*alloc fail*/ - (*out) = new_buffer; - (*outlength) = new_length; - chunk = &(*out)[(*outlength) - length - 12]; +/*Sets length and name and allocates the space for data and crc but does not +set data or crc yet. Returns the start of the chunk in chunk. The start of +the data is at chunk + 8. To finalize chunk, add the data, then use +lodepng_chunk_generate_crc */ +static unsigned lodepng_chunk_init(unsigned char** chunk, + ucvector* out, + unsigned length, const char* type) { + size_t new_length = out->size; + if(lodepng_addofl(new_length, length, &new_length)) return 77; + if(lodepng_addofl(new_length, 12, &new_length)) return 77; + if(!ucvector_resize(out, new_length)) return 83; /*alloc fail*/ + *chunk = out->data + new_length - length - 12u; /*1: length*/ - lodepng_set32bitInt(chunk, (unsigned)length); + lodepng_set32bitInt(*chunk, length); /*2: chunk name (4 letters)*/ - chunk[4] = (unsigned char)type[0]; - chunk[5] = (unsigned char)type[1]; - chunk[6] = (unsigned char)type[2]; - chunk[7] = (unsigned char)type[3]; + lodepng_memcpy(*chunk + 4, type, 4); + + return 0; +} + +/* like lodepng_chunk_create but with custom allocsize */ +static unsigned lodepng_chunk_createv(ucvector* out, + unsigned length, const char* type, const unsigned char* data) { + unsigned char* chunk; + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, length, type)); /*3: the data*/ - for(i = 0; i != length; ++i) chunk[8 + i] = data[i]; + lodepng_memcpy(chunk + 8, data, length); /*4: CRC (of the chunkname characters and the data)*/ lodepng_chunk_generate_crc(chunk); @@ -2540,48 +2596,54 @@ unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned l return 0; } +unsigned lodepng_chunk_create(unsigned char** out, size_t* outsize, + unsigned length, const char* type, const unsigned char* data) { + ucvector v = ucvector_init(*out, *outsize); + unsigned error = lodepng_chunk_createv(&v, length, type, data); + *out = v.data; + *outsize = v.size; + return error; +} + /* ////////////////////////////////////////////////////////////////////////// */ -/* / Color types and such / */ +/* / Color types, channels, bits / */ /* ////////////////////////////////////////////////////////////////////////// */ -/*return type is a LodePNG error code*/ -static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) /*bd = bitdepth*/ -{ - switch(colortype) - { - case 0: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/ - case 2: if(!( bd == 8 || bd == 16)) return 37; break; /*RGB*/ - case 3: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 )) return 37; break; /*palette*/ - case 4: if(!( bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/ - case 6: if(!( bd == 8 || bd == 16)) return 37; break; /*RGBA*/ - default: return 31; +/*checks if the colortype is valid and the bitdepth bd is allowed for this colortype. +Return value is a LodePNG error code.*/ +static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) { + switch(colortype) { + case LCT_GREY: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; + case LCT_RGB: if(!( bd == 8 || bd == 16)) return 37; break; + case LCT_PALETTE: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 )) return 37; break; + case LCT_GREY_ALPHA: if(!( bd == 8 || bd == 16)) return 37; break; + case LCT_RGBA: if(!( bd == 8 || bd == 16)) return 37; break; + case LCT_MAX_OCTET_VALUE: return 31; /* invalid color type */ + default: return 31; /* invalid color type */ } return 0; /*allowed color type / bits combination*/ } -static unsigned getNumColorChannels(LodePNGColorType colortype) -{ - switch(colortype) - { - case 0: return 1; /*grey*/ - case 2: return 3; /*RGB*/ - case 3: return 1; /*palette*/ - case 4: return 2; /*grey + alpha*/ - case 6: return 4; /*RGBA*/ +static unsigned getNumColorChannels(LodePNGColorType colortype) { + switch(colortype) { + case LCT_GREY: return 1; + case LCT_RGB: return 3; + case LCT_PALETTE: return 1; + case LCT_GREY_ALPHA: return 2; + case LCT_RGBA: return 4; + case LCT_MAX_OCTET_VALUE: return 0; /* invalid color type */ + default: return 0; /*invalid color type*/ } - return 0; /*unexisting color type*/ } -static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth) -{ +static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth) { /*bits per pixel is amount of channels * bits per channel*/ return getNumColorChannels(colortype) * bitdepth; } /* ////////////////////////////////////////////////////////////////////////// */ -void lodepng_color_mode_init(LodePNGColorMode* info) -{ +void lodepng_color_mode_init(LodePNGColorMode* info) { info->key_defined = 0; info->key_r = info->key_g = info->key_b = 0; info->colortype = LCT_RGBA; @@ -2590,64 +2652,78 @@ void lodepng_color_mode_init(LodePNGColorMode* info) info->palettesize = 0; } -void lodepng_color_mode_cleanup(LodePNGColorMode* info) -{ +/*allocates palette memory if needed, and initializes all colors to black*/ +static void lodepng_color_mode_alloc_palette(LodePNGColorMode* info) { + size_t i; + /*if the palette is already allocated, it will have size 1024 so no reallocation needed in that case*/ + /*the palette must have room for up to 256 colors with 4 bytes each.*/ + if(!info->palette) info->palette = (unsigned char*)lodepng_malloc(1024); + if(!info->palette) return; /*alloc fail*/ + for(i = 0; i != 256; ++i) { + /*Initialize all unused colors with black, the value used for invalid palette indices. + This is an error according to the PNG spec, but common PNG decoders make it black instead. + That makes color conversion slightly faster due to no error handling needed.*/ + info->palette[i * 4 + 0] = 0; + info->palette[i * 4 + 1] = 0; + info->palette[i * 4 + 2] = 0; + info->palette[i * 4 + 3] = 255; + } +} + +void lodepng_color_mode_cleanup(LodePNGColorMode* info) { lodepng_palette_clear(info); } -unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source) -{ - size_t i; +unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source) { lodepng_color_mode_cleanup(dest); - *dest = *source; - if(source->palette) - { + lodepng_memcpy(dest, source, sizeof(LodePNGColorMode)); + if(source->palette) { dest->palette = (unsigned char*)lodepng_malloc(1024); if(!dest->palette && source->palettesize) return 83; /*alloc fail*/ - for(i = 0; i != source->palettesize * 4; ++i) dest->palette[i] = source->palette[i]; + lodepng_memcpy(dest->palette, source->palette, source->palettesize * 4); } return 0; } -static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b) -{ +LodePNGColorMode lodepng_color_mode_make(LodePNGColorType colortype, unsigned bitdepth) { + LodePNGColorMode result; + lodepng_color_mode_init(&result); + result.colortype = colortype; + result.bitdepth = bitdepth; + return result; +} + +static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b) { size_t i; if(a->colortype != b->colortype) return 0; if(a->bitdepth != b->bitdepth) return 0; if(a->key_defined != b->key_defined) return 0; - if(a->key_defined) - { + if(a->key_defined) { if(a->key_r != b->key_r) return 0; if(a->key_g != b->key_g) return 0; if(a->key_b != b->key_b) return 0; } if(a->palettesize != b->palettesize) return 0; - for(i = 0; i != a->palettesize * 4; ++i) - { + for(i = 0; i != a->palettesize * 4; ++i) { if(a->palette[i] != b->palette[i]) return 0; } return 1; } -void lodepng_palette_clear(LodePNGColorMode* info) -{ +void lodepng_palette_clear(LodePNGColorMode* info) { if(info->palette) lodepng_free(info->palette); info->palette = 0; info->palettesize = 0; } unsigned lodepng_palette_add(LodePNGColorMode* info, - unsigned char r, unsigned char g, unsigned char b, unsigned char a) -{ - unsigned char* data; - /*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with - the max of 256 colors, it'll have the exact alloc size*/ - if(!info->palette) /*allocate palette if empty*/ - { - /*room for 256 colors with 4 bytes each*/ - data = (unsigned char*)lodepng_realloc(info->palette, 1024); - if(!data) return 83; /*alloc fail*/ - else info->palette = data; + unsigned char r, unsigned char g, unsigned char b, unsigned char a) { + if(!info->palette) /*allocate palette if empty*/ { + lodepng_color_mode_alloc_palette(info); + if(!info->palette) return 83; /*alloc fail*/ + } + if(info->palettesize >= 256) { + return 108; /*too many palette values*/ } info->palette[4 * info->palettesize + 0] = r; info->palette[4 * info->palettesize + 1] = g; @@ -2657,108 +2733,118 @@ unsigned lodepng_palette_add(LodePNGColorMode* info, return 0; } -unsigned lodepng_get_bpp(const LodePNGColorMode* info) -{ - /*calculate bits per pixel out of colortype and bitdepth*/ +/*calculate bits per pixel out of colortype and bitdepth*/ +unsigned lodepng_get_bpp(const LodePNGColorMode* info) { return lodepng_get_bpp_lct(info->colortype, info->bitdepth); } -unsigned lodepng_get_channels(const LodePNGColorMode* info) -{ +unsigned lodepng_get_channels(const LodePNGColorMode* info) { return getNumColorChannels(info->colortype); } -unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info) -{ +unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info) { return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA; } -unsigned lodepng_is_alpha_type(const LodePNGColorMode* info) -{ +unsigned lodepng_is_alpha_type(const LodePNGColorMode* info) { return (info->colortype & 4) != 0; /*4 or 6*/ } -unsigned lodepng_is_palette_type(const LodePNGColorMode* info) -{ +unsigned lodepng_is_palette_type(const LodePNGColorMode* info) { return info->colortype == LCT_PALETTE; } -unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info) -{ +unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info) { size_t i; - for(i = 0; i != info->palettesize; ++i) - { + for(i = 0; i != info->palettesize; ++i) { if(info->palette[i * 4 + 3] < 255) return 1; } return 0; } -unsigned lodepng_can_have_alpha(const LodePNGColorMode* info) -{ +unsigned lodepng_can_have_alpha(const LodePNGColorMode* info) { return info->key_defined || lodepng_is_alpha_type(info) || lodepng_has_palette_alpha(info); } -size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color) -{ - /*will not overflow for any color type if roughly w * h < 268435455*/ - size_t bpp = lodepng_get_bpp(color); - size_t n = w * h; - return ((n / 8) * bpp) + ((n & 7) * bpp + 7) / 8; +static size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) { + size_t bpp = lodepng_get_bpp_lct(colortype, bitdepth); + size_t n = (size_t)w * (size_t)h; + return ((n / 8u) * bpp) + ((n & 7u) * bpp + 7u) / 8u; } -size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) -{ - /*will not overflow for any color type if roughly w * h < 268435455*/ - size_t bpp = lodepng_get_bpp_lct(colortype, bitdepth); - size_t n = w * h; - return ((n / 8) * bpp) + ((n & 7) * bpp + 7) / 8; +size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color) { + return lodepng_get_raw_size_lct(w, h, color->colortype, color->bitdepth); } #ifdef LODEPNG_COMPILE_PNG + +/*in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer, +and in addition has one extra byte per line: the filter byte. So this gives a larger +result than lodepng_get_raw_size. Set h to 1 to get the size of 1 row including filter byte. */ +static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, unsigned bpp) { + /* + 1 for the filter byte, and possibly plus padding bits per line. */ + /* Ignoring casts, the expression is equal to (w * bpp + 7) / 8 + 1, but avoids overflow of w * bpp */ + size_t line = ((size_t)(w / 8u) * bpp) + 1u + ((w & 7u) * bpp + 7u) / 8u; + return (size_t)h * line; +} + #ifdef LODEPNG_COMPILE_DECODER -/*in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer*/ -static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, const LodePNGColorMode* color) -{ - /*will not overflow for any color type if roughly w * h < 268435455*/ - size_t bpp = lodepng_get_bpp(color); - size_t line = ((w / 8) * bpp) + ((w & 7) * bpp + 7) / 8; - return h * line; +/*Safely checks whether size_t overflow can be caused due to amount of pixels. +This check is overcautious rather than precise. If this check indicates no overflow, +you can safely compute in a size_t (but not an unsigned): +-(size_t)w * (size_t)h * 8 +-amount of bytes in IDAT (including filter, padding and Adam7 bytes) +-amount of bytes in raw color model +Returns 1 if overflow possible, 0 if not. +*/ +static int lodepng_pixel_overflow(unsigned w, unsigned h, + const LodePNGColorMode* pngcolor, const LodePNGColorMode* rawcolor) { + size_t bpp = LODEPNG_MAX(lodepng_get_bpp(pngcolor), lodepng_get_bpp(rawcolor)); + size_t numpixels, total; + size_t line; /* bytes per line in worst case */ + + if(lodepng_mulofl((size_t)w, (size_t)h, &numpixels)) return 1; + if(lodepng_mulofl(numpixels, 8, &total)) return 1; /* bit pointer with 8-bit color, or 8 bytes per channel color */ + + /* Bytes per scanline with the expression "(w / 8u) * bpp) + ((w & 7u) * bpp + 7u) / 8u" */ + if(lodepng_mulofl((size_t)(w / 8u), bpp, &line)) return 1; + if(lodepng_addofl(line, ((w & 7u) * bpp + 7u) / 8u, &line)) return 1; + + if(lodepng_addofl(line, 5, &line)) return 1; /* 5 bytes overhead per line: 1 filterbyte, 4 for Adam7 worst case */ + if(lodepng_mulofl(line, h, &total)) return 1; /* Total bytes in worst case */ + + return 0; /* no overflow */ } #endif /*LODEPNG_COMPILE_DECODER*/ #endif /*LODEPNG_COMPILE_PNG*/ #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -static void LodePNGUnknownChunks_init(LodePNGInfo* info) -{ +static void LodePNGUnknownChunks_init(LodePNGInfo* info) { unsigned i; for(i = 0; i != 3; ++i) info->unknown_chunks_data[i] = 0; for(i = 0; i != 3; ++i) info->unknown_chunks_size[i] = 0; } -static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info) -{ +static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info) { unsigned i; for(i = 0; i != 3; ++i) lodepng_free(info->unknown_chunks_data[i]); } -static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src) -{ +static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src) { unsigned i; LodePNGUnknownChunks_cleanup(dest); - for(i = 0; i != 3; ++i) - { + for(i = 0; i != 3; ++i) { size_t j; dest->unknown_chunks_size[i] = src->unknown_chunks_size[i]; dest->unknown_chunks_data[i] = (unsigned char*)lodepng_malloc(src->unknown_chunks_size[i]); if(!dest->unknown_chunks_data[i] && dest->unknown_chunks_size[i]) return 83; /*alloc fail*/ - for(j = 0; j < src->unknown_chunks_size[i]; ++j) - { + for(j = 0; j < src->unknown_chunks_size[i]; ++j) { dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j]; } } @@ -2768,18 +2854,15 @@ static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* /******************************************************************************/ -static void LodePNGText_init(LodePNGInfo* info) -{ +static void LodePNGText_init(LodePNGInfo* info) { info->text_num = 0; info->text_keys = NULL; info->text_strings = NULL; } -static void LodePNGText_cleanup(LodePNGInfo* info) -{ +static void LodePNGText_cleanup(LodePNGInfo* info) { size_t i; - for(i = 0; i != info->text_num; ++i) - { + for(i = 0; i != info->text_num; ++i) { string_cleanup(&info->text_keys[i]); string_cleanup(&info->text_strings[i]); } @@ -2787,52 +2870,45 @@ static void LodePNGText_cleanup(LodePNGInfo* info) lodepng_free(info->text_strings); } -static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source) -{ +static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source) { size_t i = 0; dest->text_keys = 0; dest->text_strings = 0; dest->text_num = 0; - for(i = 0; i != source->text_num; ++i) - { + for(i = 0; i != source->text_num; ++i) { CERROR_TRY_RETURN(lodepng_add_text(dest, source->text_keys[i], source->text_strings[i])); } return 0; } -void lodepng_clear_text(LodePNGInfo* info) -{ - LodePNGText_cleanup(info); -} - -unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str) -{ +static unsigned lodepng_add_text_sized(LodePNGInfo* info, const char* key, const char* str, size_t size) { char** new_keys = (char**)(lodepng_realloc(info->text_keys, sizeof(char*) * (info->text_num + 1))); char** new_strings = (char**)(lodepng_realloc(info->text_strings, sizeof(char*) * (info->text_num + 1))); - if(!new_keys || !new_strings) - { - lodepng_free(new_keys); - lodepng_free(new_strings); - return 83; /*alloc fail*/ - } - ++info->text_num; - info->text_keys = new_keys; - info->text_strings = new_strings; + if(new_keys) info->text_keys = new_keys; + if(new_strings) info->text_strings = new_strings; - string_init(&info->text_keys[info->text_num - 1]); - string_set(&info->text_keys[info->text_num - 1], key); + if(!new_keys || !new_strings) return 83; /*alloc fail*/ - string_init(&info->text_strings[info->text_num - 1]); - string_set(&info->text_strings[info->text_num - 1], str); + ++info->text_num; + info->text_keys[info->text_num - 1] = alloc_string(key); + info->text_strings[info->text_num - 1] = alloc_string_sized(str, size); + if(!info->text_keys[info->text_num - 1] || !info->text_strings[info->text_num - 1]) return 83; /*alloc fail*/ return 0; } +unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str) { + return lodepng_add_text_sized(info, key, str, lodepng_strlen(str)); +} + +void lodepng_clear_text(LodePNGInfo* info) { + LodePNGText_cleanup(info); +} + /******************************************************************************/ -static void LodePNGIText_init(LodePNGInfo* info) -{ +static void LodePNGIText_init(LodePNGInfo* info) { info->itext_num = 0; info->itext_keys = NULL; info->itext_langtags = NULL; @@ -2840,11 +2916,9 @@ static void LodePNGIText_init(LodePNGInfo* info) info->itext_strings = NULL; } -static void LodePNGIText_cleanup(LodePNGInfo* info) -{ +static void LodePNGIText_cleanup(LodePNGInfo* info) { size_t i; - for(i = 0; i != info->itext_num; ++i) - { + for(i = 0; i != info->itext_num; ++i) { string_cleanup(&info->itext_keys[i]); string_cleanup(&info->itext_langtags[i]); string_cleanup(&info->itext_transkeys[i]); @@ -2856,67 +2930,85 @@ static void LodePNGIText_cleanup(LodePNGInfo* info) lodepng_free(info->itext_strings); } -static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source) -{ +static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source) { size_t i = 0; dest->itext_keys = 0; dest->itext_langtags = 0; dest->itext_transkeys = 0; dest->itext_strings = 0; dest->itext_num = 0; - for(i = 0; i != source->itext_num; ++i) - { + for(i = 0; i != source->itext_num; ++i) { CERROR_TRY_RETURN(lodepng_add_itext(dest, source->itext_keys[i], source->itext_langtags[i], source->itext_transkeys[i], source->itext_strings[i])); } return 0; } -void lodepng_clear_itext(LodePNGInfo* info) -{ +void lodepng_clear_itext(LodePNGInfo* info) { LodePNGIText_cleanup(info); } -unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag, - const char* transkey, const char* str) -{ +static unsigned lodepng_add_itext_sized(LodePNGInfo* info, const char* key, const char* langtag, + const char* transkey, const char* str, size_t size) { char** new_keys = (char**)(lodepng_realloc(info->itext_keys, sizeof(char*) * (info->itext_num + 1))); char** new_langtags = (char**)(lodepng_realloc(info->itext_langtags, sizeof(char*) * (info->itext_num + 1))); char** new_transkeys = (char**)(lodepng_realloc(info->itext_transkeys, sizeof(char*) * (info->itext_num + 1))); char** new_strings = (char**)(lodepng_realloc(info->itext_strings, sizeof(char*) * (info->itext_num + 1))); - if(!new_keys || !new_langtags || !new_transkeys || !new_strings) - { - lodepng_free(new_keys); - lodepng_free(new_langtags); - lodepng_free(new_transkeys); - lodepng_free(new_strings); - return 83; /*alloc fail*/ - } + + if(new_keys) info->itext_keys = new_keys; + if(new_langtags) info->itext_langtags = new_langtags; + if(new_transkeys) info->itext_transkeys = new_transkeys; + if(new_strings) info->itext_strings = new_strings; + + if(!new_keys || !new_langtags || !new_transkeys || !new_strings) return 83; /*alloc fail*/ ++info->itext_num; - info->itext_keys = new_keys; - info->itext_langtags = new_langtags; - info->itext_transkeys = new_transkeys; - info->itext_strings = new_strings; - string_init(&info->itext_keys[info->itext_num - 1]); - string_set(&info->itext_keys[info->itext_num - 1], key); + info->itext_keys[info->itext_num - 1] = alloc_string(key); + info->itext_langtags[info->itext_num - 1] = alloc_string(langtag); + info->itext_transkeys[info->itext_num - 1] = alloc_string(transkey); + info->itext_strings[info->itext_num - 1] = alloc_string_sized(str, size); - string_init(&info->itext_langtags[info->itext_num - 1]); - string_set(&info->itext_langtags[info->itext_num - 1], langtag); + return 0; +} - string_init(&info->itext_transkeys[info->itext_num - 1]); - string_set(&info->itext_transkeys[info->itext_num - 1], transkey); +unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag, + const char* transkey, const char* str) { + return lodepng_add_itext_sized(info, key, langtag, transkey, str, lodepng_strlen(str)); +} - string_init(&info->itext_strings[info->itext_num - 1]); - string_set(&info->itext_strings[info->itext_num - 1], str); +/* same as set but does not delete */ +static unsigned lodepng_assign_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size) { + if(profile_size == 0) return 100; /*invalid ICC profile size*/ - return 0; + info->iccp_name = alloc_string(name); + info->iccp_profile = (unsigned char*)lodepng_malloc(profile_size); + + if(!info->iccp_name || !info->iccp_profile) return 83; /*alloc fail*/ + + lodepng_memcpy(info->iccp_profile, profile, profile_size); + info->iccp_profile_size = profile_size; + + return 0; /*ok*/ +} + +unsigned lodepng_set_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size) { + if(info->iccp_name) lodepng_clear_icc(info); + info->iccp_defined = 1; + + return lodepng_assign_icc(info, name, profile, profile_size); +} + +void lodepng_clear_icc(LodePNGInfo* info) { + string_cleanup(&info->iccp_name); + lodepng_free(info->iccp_profile); + info->iccp_profile = NULL; + info->iccp_profile_size = 0; + info->iccp_defined = 0; } #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -void lodepng_info_init(LodePNGInfo* info) -{ +void lodepng_info_init(LodePNGInfo* info) { lodepng_color_mode_init(&info->color); info->interlace_method = 0; info->compression_method = 0; @@ -2931,31 +3023,41 @@ void lodepng_info_init(LodePNGInfo* info) info->time_defined = 0; info->phys_defined = 0; + info->gama_defined = 0; + info->chrm_defined = 0; + info->srgb_defined = 0; + info->iccp_defined = 0; + info->iccp_name = NULL; + info->iccp_profile = NULL; + LodePNGUnknownChunks_init(info); #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ } -void lodepng_info_cleanup(LodePNGInfo* info) -{ +void lodepng_info_cleanup(LodePNGInfo* info) { lodepng_color_mode_cleanup(&info->color); #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS LodePNGText_cleanup(info); LodePNGIText_cleanup(info); + lodepng_clear_icc(info); + LodePNGUnknownChunks_cleanup(info); #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ } -unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) -{ +unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) { lodepng_info_cleanup(dest); - *dest = *source; + lodepng_memcpy(dest, source, sizeof(LodePNGInfo)); lodepng_color_mode_init(&dest->color); CERROR_TRY_RETURN(lodepng_color_mode_copy(&dest->color, &source->color)); #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS CERROR_TRY_RETURN(LodePNGText_copy(dest, source)); CERROR_TRY_RETURN(LodePNGIText_copy(dest, source)); + if(source->iccp_defined) { + CERROR_TRY_RETURN(lodepng_assign_icc(dest, source->iccp_name, source->iccp_profile, source->iccp_profile_size)); + } LodePNGUnknownChunks_init(dest); CERROR_TRY_RETURN(LodePNGUnknownChunks_copy(dest, source)); @@ -2963,25 +3065,17 @@ unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) return 0; } -void lodepng_info_swap(LodePNGInfo* a, LodePNGInfo* b) -{ - LodePNGInfo temp = *a; - *a = *b; - *b = temp; -} - /* ////////////////////////////////////////////////////////////////////////// */ /*index: bitgroup index, bits: bitgroup size(1, 2 or 4), in: bitgroup value, out: octet array to add bits to*/ -static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in) -{ +static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in) { unsigned m = bits == 1 ? 7 : bits == 2 ? 3 : 1; /*8 / bits - 1*/ /*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/ unsigned p = index & m; in &= (1u << bits) - 1u; /*filter out any other bits of the input value*/ in = in << (bits * (m - p)); - if(p == 0) out[index * bits / 8] = in; - else out[index * bits / 8] |= in; + if(p == 0) out[index * bits / 8u] = in; + else out[index * bits / 8u] |= in; } typedef struct ColorTree ColorTree; @@ -2992,26 +3086,20 @@ This is the data structure used to count the number of unique colors and to get index for a color. It's like an octree, but because the alpha channel is used too, each node has 16 instead of 8 children. */ -struct ColorTree -{ +struct ColorTree { ColorTree* children[16]; /*up to 16 pointers to ColorTree of next level*/ int index; /*the payload. Only has a meaningful value if this is in the last level*/ }; -static void color_tree_init(ColorTree* tree) -{ - int i; - for(i = 0; i != 16; ++i) tree->children[i] = 0; +static void color_tree_init(ColorTree* tree) { + lodepng_memset(tree->children, 0, 16 * sizeof(*tree->children)); tree->index = -1; } -static void color_tree_cleanup(ColorTree* tree) -{ +static void color_tree_cleanup(ColorTree* tree) { int i; - for(i = 0; i != 16; ++i) - { - if(tree->children[i]) - { + for(i = 0; i != 16; ++i) { + if(tree->children[i]) { color_tree_cleanup(tree->children[i]); lodepng_free(tree->children[i]); } @@ -3019,11 +3107,9 @@ static void color_tree_cleanup(ColorTree* tree) } /*returns -1 if color not present, its index otherwise*/ -static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) -{ +static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) { int bit = 0; - for(bit = 0; bit < 8; ++bit) - { + for(bit = 0; bit < 8; ++bit) { int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1); if(!tree->children[i]) return -1; else tree = tree->children[i]; @@ -3032,95 +3118,74 @@ static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, uns } #ifdef LODEPNG_COMPILE_ENCODER -static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) -{ +static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) { return color_tree_get(tree, r, g, b, a) >= 0; } #endif /*LODEPNG_COMPILE_ENCODER*/ /*color is not allowed to already exist. -Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")*/ -static void color_tree_add(ColorTree* tree, - unsigned char r, unsigned char g, unsigned char b, unsigned char a, unsigned index) -{ +Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist") +Returns error code, or 0 if ok*/ +static unsigned color_tree_add(ColorTree* tree, + unsigned char r, unsigned char g, unsigned char b, unsigned char a, unsigned index) { int bit; - for(bit = 0; bit < 8; ++bit) - { + for(bit = 0; bit < 8; ++bit) { int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1); - if(!tree->children[i]) - { + if(!tree->children[i]) { tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree)); + if(!tree->children[i]) return 83; /*alloc fail*/ color_tree_init(tree->children[i]); } tree = tree->children[i]; } tree->index = (int)index; + return 0; } /*put a pixel, given its RGBA color, into image of any color type*/ static unsigned rgba8ToPixel(unsigned char* out, size_t i, const LodePNGColorMode* mode, ColorTree* tree /*for palette*/, - unsigned char r, unsigned char g, unsigned char b, unsigned char a) -{ - if(mode->colortype == LCT_GREY) - { - unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/; - if(mode->bitdepth == 8) out[i] = grey; - else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = grey; - else - { - /*take the most significant bits of grey*/ - grey = (grey >> (8 - mode->bitdepth)) & ((1 << mode->bitdepth) - 1); - addColorBits(out, i, mode->bitdepth, grey); - } - } - else if(mode->colortype == LCT_RGB) - { - if(mode->bitdepth == 8) - { + unsigned char r, unsigned char g, unsigned char b, unsigned char a) { + if(mode->colortype == LCT_GREY) { + unsigned char gray = r; /*((unsigned short)r + g + b) / 3u;*/ + if(mode->bitdepth == 8) out[i] = gray; + else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = gray; + else { + /*take the most significant bits of gray*/ + gray = ((unsigned)gray >> (8u - mode->bitdepth)) & ((1u << mode->bitdepth) - 1u); + addColorBits(out, i, mode->bitdepth, gray); + } + } else if(mode->colortype == LCT_RGB) { + if(mode->bitdepth == 8) { out[i * 3 + 0] = r; out[i * 3 + 1] = g; out[i * 3 + 2] = b; - } - else - { + } else { out[i * 6 + 0] = out[i * 6 + 1] = r; out[i * 6 + 2] = out[i * 6 + 3] = g; out[i * 6 + 4] = out[i * 6 + 5] = b; } - } - else if(mode->colortype == LCT_PALETTE) - { + } else if(mode->colortype == LCT_PALETTE) { int index = color_tree_get(tree, r, g, b, a); if(index < 0) return 82; /*color not in palette*/ if(mode->bitdepth == 8) out[i] = index; else addColorBits(out, i, mode->bitdepth, (unsigned)index); - } - else if(mode->colortype == LCT_GREY_ALPHA) - { - unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/; - if(mode->bitdepth == 8) - { - out[i * 2 + 0] = grey; + } else if(mode->colortype == LCT_GREY_ALPHA) { + unsigned char gray = r; /*((unsigned short)r + g + b) / 3u;*/ + if(mode->bitdepth == 8) { + out[i * 2 + 0] = gray; out[i * 2 + 1] = a; - } - else if(mode->bitdepth == 16) - { - out[i * 4 + 0] = out[i * 4 + 1] = grey; + } else if(mode->bitdepth == 16) { + out[i * 4 + 0] = out[i * 4 + 1] = gray; out[i * 4 + 2] = out[i * 4 + 3] = a; } - } - else if(mode->colortype == LCT_RGBA) - { - if(mode->bitdepth == 8) - { + } else if(mode->colortype == LCT_RGBA) { + if(mode->bitdepth == 8) { out[i * 4 + 0] = r; out[i * 4 + 1] = g; out[i * 4 + 2] = b; out[i * 4 + 3] = a; - } - else - { + } else { out[i * 8 + 0] = out[i * 8 + 1] = r; out[i * 8 + 2] = out[i * 8 + 3] = g; out[i * 8 + 4] = out[i * 8 + 5] = b; @@ -3134,33 +3199,25 @@ static unsigned rgba8ToPixel(unsigned char* out, size_t i, /*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/ static void rgba16ToPixel(unsigned char* out, size_t i, const LodePNGColorMode* mode, - unsigned short r, unsigned short g, unsigned short b, unsigned short a) -{ - if(mode->colortype == LCT_GREY) - { - unsigned short grey = r; /*((unsigned)r + g + b) / 3*/; - out[i * 2 + 0] = (grey >> 8) & 255; - out[i * 2 + 1] = grey & 255; - } - else if(mode->colortype == LCT_RGB) - { + unsigned short r, unsigned short g, unsigned short b, unsigned short a) { + if(mode->colortype == LCT_GREY) { + unsigned short gray = r; /*((unsigned)r + g + b) / 3u;*/ + out[i * 2 + 0] = (gray >> 8) & 255; + out[i * 2 + 1] = gray & 255; + } else if(mode->colortype == LCT_RGB) { out[i * 6 + 0] = (r >> 8) & 255; out[i * 6 + 1] = r & 255; out[i * 6 + 2] = (g >> 8) & 255; out[i * 6 + 3] = g & 255; out[i * 6 + 4] = (b >> 8) & 255; out[i * 6 + 5] = b & 255; - } - else if(mode->colortype == LCT_GREY_ALPHA) - { - unsigned short grey = r; /*((unsigned)r + g + b) / 3*/; - out[i * 4 + 0] = (grey >> 8) & 255; - out[i * 4 + 1] = grey & 255; + } else if(mode->colortype == LCT_GREY_ALPHA) { + unsigned short gray = r; /*((unsigned)r + g + b) / 3u;*/ + out[i * 4 + 0] = (gray >> 8) & 255; + out[i * 4 + 1] = gray & 255; out[i * 4 + 2] = (a >> 8) & 255; out[i * 4 + 3] = a & 255; - } - else if(mode->colortype == LCT_RGBA) - { + } else if(mode->colortype == LCT_RGBA) { out[i * 8 + 0] = (r >> 8) & 255; out[i * 8 + 1] = r & 255; out[i * 8 + 2] = (g >> 8) & 255; @@ -3176,24 +3233,17 @@ static void rgba16ToPixel(unsigned char* out, size_t i, static void getPixelColorRGBA8(unsigned char* r, unsigned char* g, unsigned char* b, unsigned char* a, const unsigned char* in, size_t i, - const LodePNGColorMode* mode) -{ - if(mode->colortype == LCT_GREY) - { - if(mode->bitdepth == 8) - { + const LodePNGColorMode* mode) { + if(mode->colortype == LCT_GREY) { + if(mode->bitdepth == 8) { *r = *g = *b = in[i]; if(mode->key_defined && *r == mode->key_r) *a = 0; else *a = 255; - } - else if(mode->bitdepth == 16) - { + } else if(mode->bitdepth == 16) { *r = *g = *b = in[i * 2 + 0]; if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0; else *a = 255; - } - else - { + } else { unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ size_t j = i * mode->bitdepth; unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); @@ -3201,17 +3251,12 @@ static void getPixelColorRGBA8(unsigned char* r, unsigned char* g, if(mode->key_defined && value == mode->key_r) *a = 0; else *a = 255; } - } - else if(mode->colortype == LCT_RGB) - { - if(mode->bitdepth == 8) - { + } else if(mode->colortype == LCT_RGB) { + if(mode->bitdepth == 8) { *r = in[i * 3 + 0]; *g = in[i * 3 + 1]; *b = in[i * 3 + 2]; if(mode->key_defined && *r == mode->key_r && *g == mode->key_g && *b == mode->key_b) *a = 0; else *a = 255; - } - else - { + } else { *r = in[i * 6 + 0]; *g = in[i * 6 + 2]; *b = in[i * 6 + 4]; @@ -3220,56 +3265,33 @@ static void getPixelColorRGBA8(unsigned char* r, unsigned char* g, && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0; else *a = 255; } - } - else if(mode->colortype == LCT_PALETTE) - { + } else if(mode->colortype == LCT_PALETTE) { unsigned index; if(mode->bitdepth == 8) index = in[i]; - else - { + else { size_t j = i * mode->bitdepth; index = readBitsFromReversedStream(&j, in, mode->bitdepth); } - - if(index >= mode->palettesize) - { - /*This is an error according to the PNG spec, but common PNG decoders make it black instead. - Done here too, slightly faster due to no error handling needed.*/ - *r = *g = *b = 0; - *a = 255; - } - else - { - *r = mode->palette[index * 4 + 0]; - *g = mode->palette[index * 4 + 1]; - *b = mode->palette[index * 4 + 2]; - *a = mode->palette[index * 4 + 3]; - } - } - else if(mode->colortype == LCT_GREY_ALPHA) - { - if(mode->bitdepth == 8) - { + /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/ + *r = mode->palette[index * 4 + 0]; + *g = mode->palette[index * 4 + 1]; + *b = mode->palette[index * 4 + 2]; + *a = mode->palette[index * 4 + 3]; + } else if(mode->colortype == LCT_GREY_ALPHA) { + if(mode->bitdepth == 8) { *r = *g = *b = in[i * 2 + 0]; *a = in[i * 2 + 1]; - } - else - { + } else { *r = *g = *b = in[i * 4 + 0]; *a = in[i * 4 + 2]; } - } - else if(mode->colortype == LCT_RGBA) - { - if(mode->bitdepth == 8) - { + } else if(mode->colortype == LCT_RGBA) { + if(mode->bitdepth == 8) { *r = in[i * 4 + 0]; *g = in[i * 4 + 1]; *b = in[i * 4 + 2]; *a = in[i * 4 + 3]; - } - else - { + } else { *r = in[i * 8 + 0]; *g = in[i * 8 + 2]; *b = in[i * 8 + 4]; @@ -3280,136 +3302,171 @@ static void getPixelColorRGBA8(unsigned char* r, unsigned char* g, /*Similar to getPixelColorRGBA8, but with all the for loops inside of the color mode test cases, optimized to convert the colors much faster, when converting -to RGBA or RGB with 8 bit per cannel. buffer must be RGBA or RGB output with -enough memory, if has_alpha is true the output is RGBA. mode has the color mode -of the input buffer.*/ -static void getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels, - unsigned has_alpha, const unsigned char* in, - const LodePNGColorMode* mode) -{ - unsigned num_channels = has_alpha ? 4 : 3; +to the common case of RGBA with 8 bit per channel. buffer must be RGBA with +enough memory.*/ +static void getPixelColorsRGBA8(unsigned char* LODEPNG_RESTRICT buffer, size_t numpixels, + const unsigned char* LODEPNG_RESTRICT in, + const LodePNGColorMode* mode) { + unsigned num_channels = 4; size_t i; - if(mode->colortype == LCT_GREY) - { - if(mode->bitdepth == 8) - { - for(i = 0; i != numpixels; ++i, buffer += num_channels) - { + if(mode->colortype == LCT_GREY) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { buffer[0] = buffer[1] = buffer[2] = in[i]; - if(has_alpha) buffer[3] = mode->key_defined && in[i] == mode->key_r ? 0 : 255; + buffer[3] = 255; } - } - else if(mode->bitdepth == 16) - { - for(i = 0; i != numpixels; ++i, buffer += num_channels) - { + if(mode->key_defined) { + buffer -= numpixels * num_channels; + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + if(buffer[0] == mode->key_r) buffer[3] = 0; + } + } + } else if(mode->bitdepth == 16) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { buffer[0] = buffer[1] = buffer[2] = in[i * 2]; - if(has_alpha) buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255; + buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255; } - } - else - { + } else { unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ size_t j = 0; - for(i = 0; i != numpixels; ++i, buffer += num_channels) - { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest; - if(has_alpha) buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255; + buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255; } } - } - else if(mode->colortype == LCT_RGB) - { - if(mode->bitdepth == 8) - { - for(i = 0; i != numpixels; ++i, buffer += num_channels) - { - buffer[0] = in[i * 3 + 0]; - buffer[1] = in[i * 3 + 1]; - buffer[2] = in[i * 3 + 2]; - if(has_alpha) buffer[3] = mode->key_defined && buffer[0] == mode->key_r - && buffer[1]== mode->key_g && buffer[2] == mode->key_b ? 0 : 255; + } else if(mode->colortype == LCT_RGB) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + lodepng_memcpy(buffer, &in[i * 3], 3); + buffer[3] = 255; } - } - else - { - for(i = 0; i != numpixels; ++i, buffer += num_channels) - { + if(mode->key_defined) { + buffer -= numpixels * num_channels; + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + if(buffer[0] == mode->key_r && buffer[1]== mode->key_g && buffer[2] == mode->key_b) buffer[3] = 0; + } + } + } else { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { buffer[0] = in[i * 6 + 0]; buffer[1] = in[i * 6 + 2]; buffer[2] = in[i * 6 + 4]; - if(has_alpha) buffer[3] = mode->key_defined + buffer[3] = mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b ? 0 : 255; } } - } - else if(mode->colortype == LCT_PALETTE) - { - unsigned index; - size_t j = 0; - for(i = 0; i != numpixels; ++i, buffer += num_channels) - { - if(mode->bitdepth == 8) index = in[i]; - else index = readBitsFromReversedStream(&j, in, mode->bitdepth); - - if(index >= mode->palettesize) - { - /*This is an error according to the PNG spec, but most PNG decoders make it black instead. - Done here too, slightly faster due to no error handling needed.*/ - buffer[0] = buffer[1] = buffer[2] = 0; - if(has_alpha) buffer[3] = 255; + } else if(mode->colortype == LCT_PALETTE) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + unsigned index = in[i]; + /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/ + lodepng_memcpy(buffer, &mode->palette[index * 4], 4); } - else - { - buffer[0] = mode->palette[index * 4 + 0]; - buffer[1] = mode->palette[index * 4 + 1]; - buffer[2] = mode->palette[index * 4 + 2]; - if(has_alpha) buffer[3] = mode->palette[index * 4 + 3]; + } else { + size_t j = 0; + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + unsigned index = readBitsFromReversedStream(&j, in, mode->bitdepth); + /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/ + lodepng_memcpy(buffer, &mode->palette[index * 4], 4); } } - } - else if(mode->colortype == LCT_GREY_ALPHA) - { - if(mode->bitdepth == 8) - { - for(i = 0; i != numpixels; ++i, buffer += num_channels) - { + } else if(mode->colortype == LCT_GREY_ALPHA) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0]; - if(has_alpha) buffer[3] = in[i * 2 + 1]; + buffer[3] = in[i * 2 + 1]; } - } - else - { - for(i = 0; i != numpixels; ++i, buffer += num_channels) - { + } else { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0]; - if(has_alpha) buffer[3] = in[i * 4 + 2]; + buffer[3] = in[i * 4 + 2]; + } + } + } else if(mode->colortype == LCT_RGBA) { + if(mode->bitdepth == 8) { + lodepng_memcpy(buffer, in, numpixels * 4); + } else { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = in[i * 8 + 0]; + buffer[1] = in[i * 8 + 2]; + buffer[2] = in[i * 8 + 4]; + buffer[3] = in[i * 8 + 6]; } } } - else if(mode->colortype == LCT_RGBA) - { - if(mode->bitdepth == 8) - { - for(i = 0; i != numpixels; ++i, buffer += num_channels) - { - buffer[0] = in[i * 4 + 0]; - buffer[1] = in[i * 4 + 1]; - buffer[2] = in[i * 4 + 2]; - if(has_alpha) buffer[3] = in[i * 4 + 3]; +} + +/*Similar to getPixelColorsRGBA8, but with 3-channel RGB output.*/ +static void getPixelColorsRGB8(unsigned char* LODEPNG_RESTRICT buffer, size_t numpixels, + const unsigned char* LODEPNG_RESTRICT in, + const LodePNGColorMode* mode) { + const unsigned num_channels = 3; + size_t i; + if(mode->colortype == LCT_GREY) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = buffer[1] = buffer[2] = in[i]; + } + } else if(mode->bitdepth == 16) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = buffer[1] = buffer[2] = in[i * 2]; + } + } else { + unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ + size_t j = 0; + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); + buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest; + } + } + } else if(mode->colortype == LCT_RGB) { + if(mode->bitdepth == 8) { + lodepng_memcpy(buffer, in, numpixels * 3); + } else { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = in[i * 6 + 0]; + buffer[1] = in[i * 6 + 2]; + buffer[2] = in[i * 6 + 4]; + } + } + } else if(mode->colortype == LCT_PALETTE) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + unsigned index = in[i]; + /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/ + lodepng_memcpy(buffer, &mode->palette[index * 4], 3); + } + } else { + size_t j = 0; + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + unsigned index = readBitsFromReversedStream(&j, in, mode->bitdepth); + /*out of bounds of palette not checked: see lodepng_color_mode_alloc_palette.*/ + lodepng_memcpy(buffer, &mode->palette[index * 4], 3); + } + } + } else if(mode->colortype == LCT_GREY_ALPHA) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0]; + } + } else { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0]; } } - else - { - for(i = 0; i != numpixels; ++i, buffer += num_channels) - { + } else if(mode->colortype == LCT_RGBA) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + lodepng_memcpy(buffer, &in[i * 4], 3); + } + } else { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { buffer[0] = in[i * 8 + 0]; buffer[1] = in[i * 8 + 2]; buffer[2] = in[i * 8 + 4]; - if(has_alpha) buffer[3] = in[i * 8 + 6]; } } } @@ -3418,16 +3475,12 @@ static void getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels, /*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with given color type, but the given color type must be 16-bit itself.*/ static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a, - const unsigned char* in, size_t i, const LodePNGColorMode* mode) -{ - if(mode->colortype == LCT_GREY) - { + const unsigned char* in, size_t i, const LodePNGColorMode* mode) { + if(mode->colortype == LCT_GREY) { *r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1]; if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0; else *a = 65535; - } - else if(mode->colortype == LCT_RGB) - { + } else if(mode->colortype == LCT_RGB) { *r = 256u * in[i * 6 + 0] + in[i * 6 + 1]; *g = 256u * in[i * 6 + 2] + in[i * 6 + 3]; *b = 256u * in[i * 6 + 4] + in[i * 6 + 5]; @@ -3436,14 +3489,10 @@ static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned s && 256u * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g && 256u * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0; else *a = 65535; - } - else if(mode->colortype == LCT_GREY_ALPHA) - { + } else if(mode->colortype == LCT_GREY_ALPHA) { *r = *g = *b = 256u * in[i * 4 + 0] + in[i * 4 + 1]; *a = 256u * in[i * 4 + 2] + in[i * 4 + 3]; - } - else if(mode->colortype == LCT_RGBA) - { + } else if(mode->colortype == LCT_RGBA) { *r = 256u * in[i * 8 + 0] + in[i * 8 + 1]; *g = 256u * in[i * 8 + 2] + in[i * 8 + 3]; *b = 256u * in[i * 8 + 4] + in[i * 8 + 5]; @@ -3453,102 +3502,153 @@ static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned s unsigned lodepng_convert(unsigned char* out, const unsigned char* in, const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in, - unsigned w, unsigned h) -{ + unsigned w, unsigned h) { size_t i; ColorTree tree; - size_t numpixels = w * h; + size_t numpixels = (size_t)w * (size_t)h; unsigned error = 0; - if(lodepng_color_mode_equal(mode_out, mode_in)) - { + if(mode_in->colortype == LCT_PALETTE && !mode_in->palette) { + return 107; /* error: must provide palette if input mode is palette */ + } + + if(lodepng_color_mode_equal(mode_out, mode_in)) { size_t numbytes = lodepng_get_raw_size(w, h, mode_in); - for(i = 0; i != numbytes; ++i) out[i] = in[i]; + lodepng_memcpy(out, in, numbytes); return 0; } - if(mode_out->colortype == LCT_PALETTE) - { + if(mode_out->colortype == LCT_PALETTE) { size_t palettesize = mode_out->palettesize; const unsigned char* palette = mode_out->palette; size_t palsize = (size_t)1u << mode_out->bitdepth; /*if the user specified output palette but did not give the values, assume they want the values of the input color type (assuming that one is palette). Note that we never create a new palette ourselves.*/ - if(palettesize == 0) - { + if(palettesize == 0) { palettesize = mode_in->palettesize; palette = mode_in->palette; /*if the input was also palette with same bitdepth, then the color types are also equal, so copy literally. This to preserve the exact indices that were in the PNG even in case there are duplicate colors in the palette.*/ - if (mode_in->colortype == LCT_PALETTE && mode_in->bitdepth == mode_out->bitdepth) - { + if(mode_in->colortype == LCT_PALETTE && mode_in->bitdepth == mode_out->bitdepth) { size_t numbytes = lodepng_get_raw_size(w, h, mode_in); - for(i = 0; i != numbytes; ++i) out[i] = in[i]; + lodepng_memcpy(out, in, numbytes); return 0; } } if(palettesize < palsize) palsize = palettesize; color_tree_init(&tree); - for(i = 0; i != palsize; ++i) - { + for(i = 0; i != palsize; ++i) { const unsigned char* p = &palette[i * 4]; - color_tree_add(&tree, p[0], p[1], p[2], p[3], (unsigned)i); + error = color_tree_add(&tree, p[0], p[1], p[2], p[3], (unsigned)i); + if(error) break; } } - if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16) - { - for(i = 0; i != numpixels; ++i) - { - unsigned short r = 0, g = 0, b = 0, a = 0; - getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); - rgba16ToPixel(out, i, mode_out, r, g, b, a); - } - } - else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA) - { - getPixelColorsRGBA8(out, numpixels, 1, in, mode_in); - } - else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) - { - getPixelColorsRGBA8(out, numpixels, 0, in, mode_in); - } - else - { - unsigned char r = 0, g = 0, b = 0, a = 0; - for(i = 0; i != numpixels; ++i) - { - getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in); - error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a); - if (error) break; + if(!error) { + if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16) { + for(i = 0; i != numpixels; ++i) { + unsigned short r = 0, g = 0, b = 0, a = 0; + getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); + rgba16ToPixel(out, i, mode_out, r, g, b, a); + } + } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA) { + getPixelColorsRGBA8(out, numpixels, in, mode_in); + } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) { + getPixelColorsRGB8(out, numpixels, in, mode_in); + } else { + unsigned char r = 0, g = 0, b = 0, a = 0; + for(i = 0; i != numpixels; ++i) { + getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in); + error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a); + if(error) break; + } } } - if(mode_out->colortype == LCT_PALETTE) - { + if(mode_out->colortype == LCT_PALETTE) { color_tree_cleanup(&tree); } return error; } + +/* Converts a single rgb color without alpha from one type to another, color bits truncated to +their bitdepth. In case of single channel (gray or palette), only the r channel is used. Slow +function, do not use to process all pixels of an image. Alpha channel not supported on purpose: +this is for bKGD, supporting alpha may prevent it from finding a color in the palette, from the +specification it looks like bKGD should ignore the alpha values of the palette since it can use +any palette index but doesn't have an alpha channel. Idem with ignoring color key. */ +unsigned lodepng_convert_rgb( + unsigned* r_out, unsigned* g_out, unsigned* b_out, + unsigned r_in, unsigned g_in, unsigned b_in, + const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in) { + unsigned r = 0, g = 0, b = 0; + unsigned mul = 65535 / ((1u << mode_in->bitdepth) - 1u); /*65535, 21845, 4369, 257, 1*/ + unsigned shift = 16 - mode_out->bitdepth; + + if(mode_in->colortype == LCT_GREY || mode_in->colortype == LCT_GREY_ALPHA) { + r = g = b = r_in * mul; + } else if(mode_in->colortype == LCT_RGB || mode_in->colortype == LCT_RGBA) { + r = r_in * mul; + g = g_in * mul; + b = b_in * mul; + } else if(mode_in->colortype == LCT_PALETTE) { + if(r_in >= mode_in->palettesize) return 82; + r = mode_in->palette[r_in * 4 + 0] * 257u; + g = mode_in->palette[r_in * 4 + 1] * 257u; + b = mode_in->palette[r_in * 4 + 2] * 257u; + } else { + return 31; + } + + /* now convert to output format */ + if(mode_out->colortype == LCT_GREY || mode_out->colortype == LCT_GREY_ALPHA) { + *r_out = r >> shift ; + } else if(mode_out->colortype == LCT_RGB || mode_out->colortype == LCT_RGBA) { + *r_out = r >> shift ; + *g_out = g >> shift ; + *b_out = b >> shift ; + } else if(mode_out->colortype == LCT_PALETTE) { + unsigned i; + /* a 16-bit color cannot be in the palette */ + if((r >> 8) != (r & 255) || (g >> 8) != (g & 255) || (b >> 8) != (b & 255)) return 82; + for(i = 0; i < mode_out->palettesize; i++) { + unsigned j = i * 4; + if((r >> 8) == mode_out->palette[j + 0] && (g >> 8) == mode_out->palette[j + 1] && + (b >> 8) == mode_out->palette[j + 2]) { + *r_out = i; + return 0; + } + } + return 82; + } else { + return 31; + } + + return 0; +} + #ifdef LODEPNG_COMPILE_ENCODER -void lodepng_color_profile_init(LodePNGColorProfile* profile) -{ - profile->colored = 0; - profile->key = 0; - profile->key_r = profile->key_g = profile->key_b = 0; - profile->alpha = 0; - profile->numcolors = 0; - profile->bits = 1; +void lodepng_color_stats_init(LodePNGColorStats* stats) { + /*stats*/ + stats->colored = 0; + stats->key = 0; + stats->key_r = stats->key_g = stats->key_b = 0; + stats->alpha = 0; + stats->numcolors = 0; + stats->bits = 1; + stats->numpixels = 0; + /*settings*/ + stats->allow_palette = 1; + stats->allow_greyscale = 1; } /*function used for debug purposes with C++*/ -/*void printColorProfile(LodePNGColorProfile* p) -{ +/*void printColorStats(LodePNGColorStats* p) { std::cout << "colored: " << (int)p->colored << ", "; std::cout << "key: " << (int)p->key << ", "; std::cout << "key_r: " << (int)p->key_r << ", "; @@ -3560,243 +3660,260 @@ void lodepng_color_profile_init(LodePNGColorProfile* profile) }*/ /*Returns how many bits needed to represent given value (max 8 bit)*/ -static unsigned getValueRequiredBits(unsigned char value) -{ +static unsigned getValueRequiredBits(unsigned char value) { if(value == 0 || value == 255) return 1; /*The scaling of 2-bit and 4-bit values uses multiples of 85 and 17*/ if(value % 17 == 0) return value % 85 == 0 ? 2 : 4; return 8; } -/*profile must already have been inited with mode. -It's ok to set some parameters of profile to done already.*/ -unsigned lodepng_get_color_profile(LodePNGColorProfile* profile, - const unsigned char* in, unsigned w, unsigned h, - const LodePNGColorMode* mode) -{ - unsigned error = 0; +/*stats must already have been inited. */ +unsigned lodepng_compute_color_stats(LodePNGColorStats* stats, + const unsigned char* in, unsigned w, unsigned h, + const LodePNGColorMode* mode_in) { size_t i; ColorTree tree; - size_t numpixels = w * h; + size_t numpixels = (size_t)w * (size_t)h; + unsigned error = 0; - unsigned colored_done = lodepng_is_greyscale_type(mode) ? 1 : 0; - unsigned alpha_done = lodepng_can_have_alpha(mode) ? 0 : 1; + /* mark things as done already if it would be impossible to have a more expensive case */ + unsigned colored_done = lodepng_is_greyscale_type(mode_in) ? 1 : 0; + unsigned alpha_done = lodepng_can_have_alpha(mode_in) ? 0 : 1; unsigned numcolors_done = 0; - unsigned bpp = lodepng_get_bpp(mode); - unsigned bits_done = bpp == 1 ? 1 : 0; + unsigned bpp = lodepng_get_bpp(mode_in); + unsigned bits_done = (stats->bits == 1 && bpp == 1) ? 1 : 0; + unsigned sixteen = 0; /* whether the input image is 16 bit */ unsigned maxnumcolors = 257; - unsigned sixteen = 0; - if(bpp <= 8) maxnumcolors = bpp == 1 ? 2 : (bpp == 2 ? 4 : (bpp == 4 ? 16 : 256)); + if(bpp <= 8) maxnumcolors = LODEPNG_MIN(257, stats->numcolors + (1u << bpp)); + + stats->numpixels += numpixels; + + /*if palette not allowed, no need to compute numcolors*/ + if(!stats->allow_palette) numcolors_done = 1; color_tree_init(&tree); + /*If the stats was already filled in from previous data, fill its palette in tree + and mark things as done already if we know they are the most expensive case already*/ + if(stats->alpha) alpha_done = 1; + if(stats->colored) colored_done = 1; + if(stats->bits == 16) numcolors_done = 1; + if(stats->bits >= bpp) bits_done = 1; + if(stats->numcolors >= maxnumcolors) numcolors_done = 1; + + if(!numcolors_done) { + for(i = 0; i < stats->numcolors; i++) { + const unsigned char* color = &stats->palette[i * 4]; + error = color_tree_add(&tree, color[0], color[1], color[2], color[3], i); + if(error) goto cleanup; + } + } + /*Check if the 16-bit input is truly 16-bit*/ - if(mode->bitdepth == 16) - { - unsigned short r, g, b, a; - for(i = 0; i != numpixels; ++i) - { - getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode); + if(mode_in->bitdepth == 16 && !sixteen) { + unsigned short r = 0, g = 0, b = 0, a = 0; + for(i = 0; i != numpixels; ++i) { + getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); if((r & 255) != ((r >> 8) & 255) || (g & 255) != ((g >> 8) & 255) || - (b & 255) != ((b >> 8) & 255) || (a & 255) != ((a >> 8) & 255)) /*first and second byte differ*/ - { + (b & 255) != ((b >> 8) & 255) || (a & 255) != ((a >> 8) & 255)) /*first and second byte differ*/ { + stats->bits = 16; sixteen = 1; + bits_done = 1; + numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/ break; } } } - if(sixteen) - { + if(sixteen) { unsigned short r = 0, g = 0, b = 0, a = 0; - profile->bits = 16; - bits_done = numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/ - for(i = 0; i != numpixels; ++i) - { - getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode); + for(i = 0; i != numpixels; ++i) { + getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); - if(!colored_done && (r != g || r != b)) - { - profile->colored = 1; + if(!colored_done && (r != g || r != b)) { + stats->colored = 1; colored_done = 1; } - if(!alpha_done) - { - unsigned matchkey = (r == profile->key_r && g == profile->key_g && b == profile->key_b); - if(a != 65535 && (a != 0 || (profile->key && !matchkey))) - { - profile->alpha = 1; - profile->key = 0; + if(!alpha_done) { + unsigned matchkey = (r == stats->key_r && g == stats->key_g && b == stats->key_b); + if(a != 65535 && (a != 0 || (stats->key && !matchkey))) { + stats->alpha = 1; + stats->key = 0; alpha_done = 1; - } - else if(a == 0 && !profile->alpha && !profile->key) - { - profile->key = 1; - profile->key_r = r; - profile->key_g = g; - profile->key_b = b; - } - else if(a == 65535 && profile->key && matchkey) - { + } else if(a == 0 && !stats->alpha && !stats->key) { + stats->key = 1; + stats->key_r = r; + stats->key_g = g; + stats->key_b = b; + } else if(a == 65535 && stats->key && matchkey) { /* Color key cannot be used if an opaque pixel also has that RGB color. */ - profile->alpha = 1; - profile->key = 0; + stats->alpha = 1; + stats->key = 0; alpha_done = 1; } } if(alpha_done && numcolors_done && colored_done && bits_done) break; } - if(profile->key && !profile->alpha) - { - for(i = 0; i != numpixels; ++i) - { - getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode); - if(a != 0 && r == profile->key_r && g == profile->key_g && b == profile->key_b) - { + if(stats->key && !stats->alpha) { + for(i = 0; i != numpixels; ++i) { + getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); + if(a != 0 && r == stats->key_r && g == stats->key_g && b == stats->key_b) { /* Color key cannot be used if an opaque pixel also has that RGB color. */ - profile->alpha = 1; - profile->key = 0; + stats->alpha = 1; + stats->key = 0; alpha_done = 1; } } } - } - else /* < 16-bit */ - { + } else /* < 16-bit */ { unsigned char r = 0, g = 0, b = 0, a = 0; - for(i = 0; i != numpixels; ++i) - { - getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode); + for(i = 0; i != numpixels; ++i) { + getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in); - if(!bits_done && profile->bits < 8) - { - /*only r is checked, < 8 bits is only relevant for greyscale*/ + if(!bits_done && stats->bits < 8) { + /*only r is checked, < 8 bits is only relevant for grayscale*/ unsigned bits = getValueRequiredBits(r); - if(bits > profile->bits) profile->bits = bits; + if(bits > stats->bits) stats->bits = bits; } - bits_done = (profile->bits >= bpp); + bits_done = (stats->bits >= bpp); - if(!colored_done && (r != g || r != b)) - { - profile->colored = 1; + if(!colored_done && (r != g || r != b)) { + stats->colored = 1; colored_done = 1; - if(profile->bits < 8) profile->bits = 8; /*PNG has no colored modes with less than 8-bit per channel*/ + if(stats->bits < 8) stats->bits = 8; /*PNG has no colored modes with less than 8-bit per channel*/ } - if(!alpha_done) - { - unsigned matchkey = (r == profile->key_r && g == profile->key_g && b == profile->key_b); - if(a != 255 && (a != 0 || (profile->key && !matchkey))) - { - profile->alpha = 1; - profile->key = 0; + if(!alpha_done) { + unsigned matchkey = (r == stats->key_r && g == stats->key_g && b == stats->key_b); + if(a != 255 && (a != 0 || (stats->key && !matchkey))) { + stats->alpha = 1; + stats->key = 0; alpha_done = 1; - if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ - } - else if(a == 0 && !profile->alpha && !profile->key) - { - profile->key = 1; - profile->key_r = r; - profile->key_g = g; - profile->key_b = b; - } - else if(a == 255 && profile->key && matchkey) - { + if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ + } else if(a == 0 && !stats->alpha && !stats->key) { + stats->key = 1; + stats->key_r = r; + stats->key_g = g; + stats->key_b = b; + } else if(a == 255 && stats->key && matchkey) { /* Color key cannot be used if an opaque pixel also has that RGB color. */ - profile->alpha = 1; - profile->key = 0; + stats->alpha = 1; + stats->key = 0; alpha_done = 1; - if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ + if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ } } - if(!numcolors_done) - { - if(!color_tree_has(&tree, r, g, b, a)) - { - color_tree_add(&tree, r, g, b, a, profile->numcolors); - if(profile->numcolors < 256) - { - unsigned char* p = profile->palette; - unsigned n = profile->numcolors; + if(!numcolors_done) { + if(!color_tree_has(&tree, r, g, b, a)) { + error = color_tree_add(&tree, r, g, b, a, stats->numcolors); + if(error) goto cleanup; + if(stats->numcolors < 256) { + unsigned char* p = stats->palette; + unsigned n = stats->numcolors; p[n * 4 + 0] = r; p[n * 4 + 1] = g; p[n * 4 + 2] = b; p[n * 4 + 3] = a; } - ++profile->numcolors; - numcolors_done = profile->numcolors >= maxnumcolors; + ++stats->numcolors; + numcolors_done = stats->numcolors >= maxnumcolors; } } if(alpha_done && numcolors_done && colored_done && bits_done) break; } - if(profile->key && !profile->alpha) - { - for(i = 0; i != numpixels; ++i) - { - getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode); - if(a != 0 && r == profile->key_r && g == profile->key_g && b == profile->key_b) - { + if(stats->key && !stats->alpha) { + for(i = 0; i != numpixels; ++i) { + getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in); + if(a != 0 && r == stats->key_r && g == stats->key_g && b == stats->key_b) { /* Color key cannot be used if an opaque pixel also has that RGB color. */ - profile->alpha = 1; - profile->key = 0; + stats->alpha = 1; + stats->key = 0; alpha_done = 1; - if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ + if(stats->bits < 8) stats->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ } } } - /*make the profile's key always 16-bit for consistency - repeat each byte twice*/ - profile->key_r += (profile->key_r << 8); - profile->key_g += (profile->key_g << 8); - profile->key_b += (profile->key_b << 8); + /*make the stats's key always 16-bit for consistency - repeat each byte twice*/ + stats->key_r += (stats->key_r << 8); + stats->key_g += (stats->key_g << 8); + stats->key_b += (stats->key_b << 8); } +cleanup: color_tree_cleanup(&tree); return error; } -/*Automatically chooses color type that gives smallest amount of bits in the -output image, e.g. grey if there are only greyscale pixels, palette if there -are less than 256 colors, ... -Updates values of mode with a potentially smaller color model. mode_out should -contain the user chosen color model, but will be overwritten with the new chosen one.*/ -unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out, - const unsigned char* image, unsigned w, unsigned h, - const LodePNGColorMode* mode_in) -{ - LodePNGColorProfile prof; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS +/*Adds a single color to the color stats. The stats must already have been inited. The color must be given as 16-bit +(with 2 bytes repeating for 8-bit and 65535 for opaque alpha channel). This function is expensive, do not call it for +all pixels of an image but only for a few additional values. */ +static unsigned lodepng_color_stats_add(LodePNGColorStats* stats, + unsigned r, unsigned g, unsigned b, unsigned a) { unsigned error = 0; - unsigned i, n, palettebits, palette_ok; + unsigned char image[8]; + LodePNGColorMode mode; + lodepng_color_mode_init(&mode); + image[0] = r >> 8; image[1] = r; image[2] = g >> 8; image[3] = g; + image[4] = b >> 8; image[5] = b; image[6] = a >> 8; image[7] = a; + mode.bitdepth = 16; + mode.colortype = LCT_RGBA; + error = lodepng_compute_color_stats(stats, image, 1, 1, &mode); + lodepng_color_mode_cleanup(&mode); + return error; +} +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +/*Computes a minimal PNG color model that can contain all colors as indicated by the stats. +The stats should be computed with lodepng_compute_color_stats. +mode_in is raw color profile of the image the stats were computed on, to copy palette order from when relevant. +Minimal PNG color model means the color type and bit depth that gives smallest amount of bits in the output image, +e.g. gray if only grayscale pixels, palette if less than 256 colors, color key if only single transparent color, ... +This is used if auto_convert is enabled (it is by default). +*/ +static unsigned auto_choose_color(LodePNGColorMode* mode_out, + const LodePNGColorMode* mode_in, + const LodePNGColorStats* stats) { + unsigned error = 0; + unsigned palettebits; + size_t i, n; + size_t numpixels = stats->numpixels; + unsigned palette_ok, gray_ok; + + unsigned alpha = stats->alpha; + unsigned key = stats->key; + unsigned bits = stats->bits; - lodepng_color_profile_init(&prof); - error = lodepng_get_color_profile(&prof, image, w, h, mode_in); - if(error) return error; mode_out->key_defined = 0; - if(prof.key && w * h <= 16) - { - prof.alpha = 1; /*too few pixels to justify tRNS chunk overhead*/ - prof.key = 0; - if(prof.bits < 8) prof.bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ + if(key && numpixels <= 16) { + alpha = 1; /*too few pixels to justify tRNS chunk overhead*/ + key = 0; + if(bits < 8) bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ } - n = prof.numcolors; + + gray_ok = !stats->colored; + if(!stats->allow_greyscale) gray_ok = 0; + if(!gray_ok && bits < 8) bits = 8; + + n = stats->numcolors; palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8)); - palette_ok = n <= 256 && prof.bits <= 8; - if(w * h < n * 2) palette_ok = 0; /*don't add palette overhead if image has only a few pixels*/ - if(!prof.colored && prof.bits <= palettebits) palette_ok = 0; /*grey is less overhead*/ + palette_ok = n <= 256 && bits <= 8 && n != 0; /*n==0 means likely numcolors wasn't computed*/ + if(numpixels < n * 2) palette_ok = 0; /*don't add palette overhead if image has only a few pixels*/ + if(gray_ok && !alpha && bits <= palettebits) palette_ok = 0; /*gray is less overhead*/ + if(!stats->allow_palette) palette_ok = 0; - if(palette_ok) - { - unsigned char* p = prof.palette; + if(palette_ok) { + const unsigned char* p = stats->palette; lodepng_palette_clear(mode_out); /*remove potential earlier palette*/ - for(i = 0; i != prof.numcolors; ++i) - { + for(i = 0; i != stats->numcolors; ++i) { error = lodepng_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2], p[i * 4 + 3]); if(error) break; } @@ -3805,25 +3922,20 @@ unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out, mode_out->bitdepth = palettebits; if(mode_in->colortype == LCT_PALETTE && mode_in->palettesize >= mode_out->palettesize - && mode_in->bitdepth == mode_out->bitdepth) - { + && mode_in->bitdepth == mode_out->bitdepth) { /*If input should have same palette colors, keep original to preserve its order and prevent conversion*/ lodepng_color_mode_cleanup(mode_out); lodepng_color_mode_copy(mode_out, mode_in); } - } - else /*8-bit or 16-bit per channel*/ - { - mode_out->bitdepth = prof.bits; - mode_out->colortype = prof.alpha ? (prof.colored ? LCT_RGBA : LCT_GREY_ALPHA) - : (prof.colored ? LCT_RGB : LCT_GREY); - - if(prof.key) - { - unsigned mask = (1u << mode_out->bitdepth) - 1u; /*profile always uses 16-bit, mask converts it*/ - mode_out->key_r = prof.key_r & mask; - mode_out->key_g = prof.key_g & mask; - mode_out->key_b = prof.key_b & mask; + } else /*8-bit or 16-bit per channel*/ { + mode_out->bitdepth = bits; + mode_out->colortype = alpha ? (gray_ok ? LCT_GREY_ALPHA : LCT_RGBA) + : (gray_ok ? LCT_GREY : LCT_RGB); + if(key) { + unsigned mask = (1u << mode_out->bitdepth) - 1u; /*stats always uses 16-bit, mask converts it*/ + mode_out->key_r = stats->key_r & mask; + mode_out->key_g = stats->key_g & mask; + mode_out->key_b = stats->key_b & mask; mode_out->key_defined = 1; } } @@ -3834,19 +3946,17 @@ unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out, #endif /* #ifdef LODEPNG_COMPILE_ENCODER */ /* -Paeth predicter, used by PNG filter type 4 +Paeth predictor, used by PNG filter type 4 The parameters are of type short, but should come from unsigned chars, the shorts are only needed to make the paeth calculation correct. */ -static unsigned char paethPredictor(short a, short b, short c) -{ - short pa = abs(b - c); - short pb = abs(a - c); - short pc = abs(a + b - c - c); - - if(pc < pa && pc < pb) return (unsigned char)c; - else if(pb < pa) return (unsigned char)b; - else return (unsigned char)a; +static unsigned char paethPredictor(short a, short b, short c) { + short pa = LODEPNG_ABS(b - c); + short pb = LODEPNG_ABS(a - c); + short pc = LODEPNG_ABS(a + b - c - c); + /* return input value associated with smallest of pa, pb, pc (with certain priority if equal) */ + if(pb < pa) { a = b; pa = pb; } + return (pc < pa) ? c : a; } /*shared values used by multiple Adam7 related functions*/ @@ -3872,14 +3982,12 @@ bpp: bits per pixel end at a full byte */ static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8], - size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp) -{ + size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp) { /*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/ unsigned i; /*calculate width and height in pixels of each pass*/ - for(i = 0; i != 7; ++i) - { + for(i = 0; i != 7; ++i) { passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i]; passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i]; if(passw[i] == 0) passh[i] = 0; @@ -3887,15 +3995,14 @@ static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t fil } filter_passstart[0] = padded_passstart[0] = passstart[0] = 0; - for(i = 0; i != 7; ++i) - { + for(i = 0; i != 7; ++i) { /*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/ filter_passstart[i + 1] = filter_passstart[i] - + ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0); + + ((passw[i] && passh[i]) ? passh[i] * (1u + (passw[i] * bpp + 7u) / 8u) : 0); /*bits padded if needed to fill full byte at end of each scanline*/ - padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8); + padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7u) / 8u); /*only padded at end of reduced image*/ - passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8; + passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7u) / 8u; } } @@ -3907,60 +4014,51 @@ static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t fil /*read the information from the header and store it in the LodePNGInfo. return value is error*/ unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state, - const unsigned char* in, size_t insize) -{ + const unsigned char* in, size_t insize) { + unsigned width, height; LodePNGInfo* info = &state->info_png; - if(insize == 0 || in == 0) - { + if(insize == 0 || in == 0) { CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/ } - if(insize < 33) - { + if(insize < 33) { CERROR_RETURN_ERROR(state->error, 27); /*error: the data length is smaller than the length of a PNG header*/ } /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/ + /* TODO: remove this. One should use a new LodePNGState for new sessions */ lodepng_info_cleanup(info); lodepng_info_init(info); if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71 - || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) - { + || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) { CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/ } - if(lodepng_chunk_length(in + 8) != 13) - { + if(lodepng_chunk_length(in + 8) != 13) { CERROR_RETURN_ERROR(state->error, 94); /*error: header size must be 13 bytes*/ } - if(!lodepng_chunk_type_equals(in + 8, "IHDR")) - { + if(!lodepng_chunk_type_equals(in + 8, "IHDR")) { CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/ } /*read the values given in the header*/ - *w = lodepng_read32bitInt(&in[16]); - *h = lodepng_read32bitInt(&in[20]); + width = lodepng_read32bitInt(&in[16]); + height = lodepng_read32bitInt(&in[20]); + /*TODO: remove the undocumented feature that allows to give null pointers to width or height*/ + if(w) *w = width; + if(h) *h = height; info->color.bitdepth = in[24]; info->color.colortype = (LodePNGColorType)in[25]; info->compression_method = in[26]; info->filter_method = in[27]; info->interlace_method = in[28]; - if(*w == 0 || *h == 0) - { - CERROR_RETURN_ERROR(state->error, 93); - } - - if(!state->decoder.ignore_crc) - { - unsigned CRC = lodepng_read32bitInt(&in[29]); - unsigned checksum = lodepng_crc32(&in[12], 17); - if(CRC != checksum) - { - CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/ - } - } + /*errors returned only after the parsing so other values are still output*/ + /*error: invalid image size*/ + if(width == 0 || height == 0) CERROR_RETURN_ERROR(state->error, 93); + /*error: invalid colortype or bitdepth combination*/ + state->error = checkColorValidity(info->color.colortype, info->color.bitdepth); + if(state->error) return state->error; /*error: only compression method 0 is allowed in the specification*/ if(info->compression_method != 0) CERROR_RETURN_ERROR(state->error, 32); /*error: only filter method 0 is allowed in the specification*/ @@ -3968,13 +4066,19 @@ unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state, /*error: only interlace methods 0 and 1 exist in the specification*/ if(info->interlace_method > 1) CERROR_RETURN_ERROR(state->error, 34); - state->error = checkColorValidity(info->color.colortype, info->color.bitdepth); + if(!state->decoder.ignore_crc) { + unsigned CRC = lodepng_read32bitInt(&in[29]); + unsigned checksum = lodepng_crc32(&in[12], 17); + if(CRC != checksum) { + CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/ + } + } + return state->error; } static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon, - size_t bytewidth, unsigned char filterType, size_t length) -{ + size_t bytewidth, unsigned char filterType, size_t length) { /* For PNG filter method 0 unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte, @@ -3985,8 +4089,7 @@ static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scan */ size_t i; - switch(filterType) - { + switch(filterType) { case 0: for(i = 0; i != length; ++i) recon[i] = scanline[i]; break; @@ -3995,59 +4098,83 @@ static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scan for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + recon[i - bytewidth]; break; case 2: - if(precon) - { + if(precon) { for(i = 0; i != length; ++i) recon[i] = scanline[i] + precon[i]; - } - else - { + } else { for(i = 0; i != length; ++i) recon[i] = scanline[i]; } break; case 3: - if(precon) - { - for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i] + (precon[i] >> 1); - for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) >> 1); - } - else - { + if(precon) { + for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i] + (precon[i] >> 1u); + for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) >> 1u); + } else { for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i]; - for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + (recon[i - bytewidth] >> 1); + for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + (recon[i - bytewidth] >> 1u); } break; case 4: - if(precon) - { - for(i = 0; i != bytewidth; ++i) - { + if(precon) { + for(i = 0; i != bytewidth; ++i) { recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/ } - for(i = bytewidth; i < length; ++i) - { + + /* Unroll independent paths of the paeth predictor. A 6x and 8x version would also be possible but that + adds too much code. Whether this actually speeds anything up at all depends on compiler and settings. */ + if(bytewidth >= 4) { + for(; i + 3 < length; i += 4) { + size_t j = i - bytewidth; + unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1], s2 = scanline[i + 2], s3 = scanline[i + 3]; + unsigned char r0 = recon[j + 0], r1 = recon[j + 1], r2 = recon[j + 2], r3 = recon[j + 3]; + unsigned char p0 = precon[i + 0], p1 = precon[i + 1], p2 = precon[i + 2], p3 = precon[i + 3]; + unsigned char q0 = precon[j + 0], q1 = precon[j + 1], q2 = precon[j + 2], q3 = precon[j + 3]; + recon[i + 0] = s0 + paethPredictor(r0, p0, q0); + recon[i + 1] = s1 + paethPredictor(r1, p1, q1); + recon[i + 2] = s2 + paethPredictor(r2, p2, q2); + recon[i + 3] = s3 + paethPredictor(r3, p3, q3); + } + } else if(bytewidth >= 3) { + for(; i + 2 < length; i += 3) { + size_t j = i - bytewidth; + unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1], s2 = scanline[i + 2]; + unsigned char r0 = recon[j + 0], r1 = recon[j + 1], r2 = recon[j + 2]; + unsigned char p0 = precon[i + 0], p1 = precon[i + 1], p2 = precon[i + 2]; + unsigned char q0 = precon[j + 0], q1 = precon[j + 1], q2 = precon[j + 2]; + recon[i + 0] = s0 + paethPredictor(r0, p0, q0); + recon[i + 1] = s1 + paethPredictor(r1, p1, q1); + recon[i + 2] = s2 + paethPredictor(r2, p2, q2); + } + } else if(bytewidth >= 2) { + for(; i + 1 < length; i += 2) { + size_t j = i - bytewidth; + unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1]; + unsigned char r0 = recon[j + 0], r1 = recon[j + 1]; + unsigned char p0 = precon[i + 0], p1 = precon[i + 1]; + unsigned char q0 = precon[j + 0], q1 = precon[j + 1]; + recon[i + 0] = s0 + paethPredictor(r0, p0, q0); + recon[i + 1] = s1 + paethPredictor(r1, p1, q1); + } + } + + for(; i != length; ++i) { recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth])); } - } - else - { - for(i = 0; i != bytewidth; ++i) - { + } else { + for(i = 0; i != bytewidth; ++i) { recon[i] = scanline[i]; } - for(i = bytewidth; i < length; ++i) - { + for(i = bytewidth; i < length; ++i) { /*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/ recon[i] = (scanline[i] + recon[i - bytewidth]); } } break; - default: return 36; /*error: unexisting filter type given*/ + default: return 36; /*error: invalid filter type given*/ } return 0; } -static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) -{ +static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) { /* For PNG filter method 0 this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times) @@ -4060,11 +4187,11 @@ static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w unsigned char* prevline = 0; /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ - size_t bytewidth = (bpp + 7) / 8; - size_t linebytes = (w * bpp + 7) / 8; + size_t bytewidth = (bpp + 7u) / 8u; + /*the width of a scanline in bytes, not including the filter type*/ + size_t linebytes = lodepng_get_raw_size_idat(w, 1, bpp) - 1u; - for(y = 0; y < h; ++y) - { + for(y = 0; y < h; ++y) { size_t outindex = linebytes * y; size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ unsigned char filterType = in[inindex]; @@ -4088,50 +4215,40 @@ out must be big enough AND must be 0 everywhere if bpp < 8 in the current implem (because that's likely a little bit faster) NOTE: comments about padding bits are only relevant if bpp < 8 */ -static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) -{ +static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) { unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; unsigned i; Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); - if(bpp >= 8) - { - for(i = 0; i != 7; ++i) - { + if(bpp >= 8) { + for(i = 0; i != 7; ++i) { unsigned x, y, b; - size_t bytewidth = bpp / 8; + size_t bytewidth = bpp / 8u; for(y = 0; y < passh[i]; ++y) - for(x = 0; x < passw[i]; ++x) - { + for(x = 0; x < passw[i]; ++x) { size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth; - size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth; - for(b = 0; b < bytewidth; ++b) - { + size_t pixeloutstart = ((ADAM7_IY[i] + (size_t)y * ADAM7_DY[i]) * (size_t)w + + ADAM7_IX[i] + (size_t)x * ADAM7_DX[i]) * bytewidth; + for(b = 0; b < bytewidth; ++b) { out[pixeloutstart + b] = in[pixelinstart + b]; } } } - } - else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ - { - for(i = 0; i != 7; ++i) - { + } else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ { + for(i = 0; i != 7; ++i) { unsigned x, y, b; unsigned ilinebits = bpp * passw[i]; unsigned olinebits = bpp * w; size_t obp, ibp; /*bit pointers (for out and in buffer)*/ for(y = 0; y < passh[i]; ++y) - for(x = 0; x < passw[i]; ++x) - { + for(x = 0; x < passw[i]; ++x) { ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp); - obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp; - for(b = 0; b < bpp; ++b) - { + obp = (ADAM7_IY[i] + (size_t)y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + (size_t)x * ADAM7_DX[i]) * bpp; + for(b = 0; b < bpp; ++b) { unsigned char bit = readBitFromReversedStream(&ibp, in); - /*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/ - setBitOfReversedStream0(&obp, out, bit); + setBitOfReversedStream(&obp, out, bit); } } } @@ -4139,8 +4256,7 @@ static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsig } static void removePaddingBits(unsigned char* out, const unsigned char* in, - size_t olinebits, size_t ilinebits, unsigned h) -{ + size_t olinebits, size_t ilinebits, unsigned h) { /* After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers @@ -4153,11 +4269,9 @@ static void removePaddingBits(unsigned char* out, const unsigned char* in, unsigned y; size_t diff = ilinebits - olinebits; size_t ibp = 0, obp = 0; /*input and output bit pointers*/ - for(y = 0; y < h; ++y) - { + for(y = 0; y < h; ++y) { size_t x; - for(x = 0; x < olinebits; ++x) - { + for(x = 0; x < olinebits; ++x) { unsigned char bit = readBitFromReversedStream(&ibp, in); setBitOfReversedStream(&obp, out, bit); } @@ -4169,46 +4283,39 @@ static void removePaddingBits(unsigned char* out, const unsigned char* in, the IDAT chunks (with filter index bytes and possible padding bits) return value is error*/ static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, - unsigned w, unsigned h, const LodePNGInfo* info_png) -{ + unsigned w, unsigned h, const LodePNGInfo* info_png) { /* This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype. Steps: - *) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8) + *) if no Adam7: 1) unfilter 2) remove padding bits (= possible extra bits per scanline if bpp < 8) *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace NOTE: the in buffer will be overwritten with intermediate data! */ unsigned bpp = lodepng_get_bpp(&info_png->color); if(bpp == 0) return 31; /*error: invalid colortype*/ - if(info_png->interlace_method == 0) - { - if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) - { + if(info_png->interlace_method == 0) { + if(bpp < 8 && w * bpp != ((w * bpp + 7u) / 8u) * 8u) { CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp)); - removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h); + removePaddingBits(out, in, w * bpp, ((w * bpp + 7u) / 8u) * 8u, h); } /*we can immediately filter into the out buffer, no other steps needed*/ else CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp)); - } - else /*interlace_method is 1 (Adam7)*/ - { + } else /*interlace_method is 1 (Adam7)*/ { unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; unsigned i; Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); - for(i = 0; i != 7; ++i) - { + for(i = 0; i != 7; ++i) { CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp)); /*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline, move bytes instead of bits or move not at all*/ - if(bpp < 8) - { + if(bpp < 8) { /*remove padding bits in scanlines; after this there still may be padding bits between the different reduced images: each reduced image still starts nicely at a byte*/ removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp, - ((passw[i] * bpp + 7) / 8) * 8, passh[i]); + ((passw[i] * bpp + 7u) / 8u) * 8u, passh[i]); } } @@ -4218,21 +4325,17 @@ static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, return 0; } -static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) -{ +static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) { unsigned pos = 0, i; - if(color->palette) lodepng_free(color->palette); - color->palettesize = chunkLength / 3; - color->palette = (unsigned char*)lodepng_malloc(4 * color->palettesize); - if(!color->palette && color->palettesize) - { + color->palettesize = chunkLength / 3u; + if(color->palettesize == 0 || color->palettesize > 256) return 38; /*error: palette too small or big*/ + lodepng_color_mode_alloc_palette(color); + if(!color->palette && color->palettesize) { color->palettesize = 0; return 83; /*alloc fail*/ } - if(color->palettesize > 256) return 38; /*error: palette too big*/ - for(i = 0; i != color->palettesize; ++i) - { + for(i = 0; i != color->palettesize; ++i) { color->palette[4 * i + 0] = data[pos++]; /*R*/ color->palette[4 * i + 1] = data[pos++]; /*G*/ color->palette[4 * i + 2] = data[pos++]; /*B*/ @@ -4242,26 +4345,20 @@ static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* dat return 0; /* OK */ } -static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) -{ +static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) { unsigned i; - if(color->colortype == LCT_PALETTE) - { + if(color->colortype == LCT_PALETTE) { /*error: more alpha values given than there are palette entries*/ - if(chunkLength > color->palettesize) return 38; + if(chunkLength > color->palettesize) return 39; for(i = 0; i != chunkLength; ++i) color->palette[4 * i + 3] = data[i]; - } - else if(color->colortype == LCT_GREY) - { - /*error: this chunk must be 2 bytes for greyscale image*/ + } else if(color->colortype == LCT_GREY) { + /*error: this chunk must be 2 bytes for grayscale image*/ if(chunkLength != 2) return 30; color->key_defined = 1; color->key_r = color->key_g = color->key_b = 256u * data[0] + data[1]; - } - else if(color->colortype == LCT_RGB) - { + } else if(color->colortype == LCT_RGB) { /*error: this chunk must be 6 bytes for RGB image*/ if(chunkLength != 6) return 41; @@ -4278,29 +4375,28 @@ static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* dat #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS /*background color chunk (bKGD)*/ -static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) -{ - if(info->color.colortype == LCT_PALETTE) - { +static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { + if(info->color.colortype == LCT_PALETTE) { /*error: this chunk must be 1 byte for indexed color image*/ if(chunkLength != 1) return 43; + /*error: invalid palette index, or maybe this chunk appeared before PLTE*/ + if(data[0] >= info->color.palettesize) return 103; + info->background_defined = 1; info->background_r = info->background_g = info->background_b = data[0]; - } - else if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) - { - /*error: this chunk must be 2 bytes for greyscale image*/ + } else if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) { + /*error: this chunk must be 2 bytes for grayscale image*/ if(chunkLength != 2) return 44; + /*the values are truncated to bitdepth in the PNG file*/ info->background_defined = 1; info->background_r = info->background_g = info->background_b = 256u * data[0] + data[1]; - } - else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) - { - /*error: this chunk must be 6 bytes for greyscale image*/ + } else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) { + /*error: this chunk must be 6 bytes for grayscale image*/ if(chunkLength != 6) return 45; + /*the values are truncated to bitdepth in the PNG file*/ info->background_defined = 1; info->background_r = 256u * data[0] + data[1]; info->background_g = 256u * data[2] + data[3]; @@ -4311,14 +4407,11 @@ static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, siz } /*text chunk (tEXt)*/ -static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) -{ +static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { unsigned error = 0; char *key = 0, *str = 0; - unsigned i; - while(!error) /*not really a while loop, only used to break on error*/ - { + while(!error) /*not really a while loop, only used to break on error*/ { unsigned length, string2_begin; length = 0; @@ -4330,8 +4423,8 @@ static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, siz key = (char*)lodepng_malloc(length + 1); if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ + lodepng_memcpy(key, data, length); key[length] = 0; - for(i = 0; i != length; ++i) key[i] = (char)data[i]; string2_begin = length + 1; /*skip keyword null terminator*/ @@ -4339,8 +4432,8 @@ static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, siz str = (char*)lodepng_malloc(length + 1); if(!str) CERROR_BREAK(error, 83); /*alloc fail*/ + lodepng_memcpy(str, data + string2_begin, length); str[length] = 0; - for(i = 0; i != length; ++i) str[i] = (char)data[string2_begin + i]; error = lodepng_add_text(info, key, str); @@ -4355,19 +4448,15 @@ static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, siz /*compressed text chunk (zTXt)*/ static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, - const unsigned char* data, size_t chunkLength) -{ + const unsigned char* data, size_t chunkLength) { unsigned error = 0; - unsigned i; unsigned length, string2_begin; char *key = 0; - ucvector decoded; - - ucvector_init(&decoded); + unsigned char* str = 0; + size_t size = 0; - while(!error) /*not really a while loop, only used to break on error*/ - { + while(!error) /*not really a while loop, only used to break on error*/ { for(length = 0; length < chunkLength && data[length] != 0; ++length) ; if(length + 2 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/ if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ @@ -4375,8 +4464,8 @@ static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSetting key = (char*)lodepng_malloc(length + 1); if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ + lodepng_memcpy(key, data, length); key[length] = 0; - for(i = 0; i != length; ++i) key[i] = (char)data[i]; if(data[length + 1] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/ @@ -4385,37 +4474,30 @@ static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSetting length = (unsigned)chunkLength - string2_begin; /*will fail if zlib error, e.g. if length is too small*/ - error = zlib_decompress(&decoded.data, &decoded.size, - (unsigned char*)(&data[string2_begin]), + error = zlib_decompress(&str, &size, 0, &data[string2_begin], length, zlibsettings); if(error) break; - ucvector_push_back(&decoded, 0); - - error = lodepng_add_text(info, key, (char*)decoded.data); + error = lodepng_add_text_sized(info, key, (char*)str, size); break; } lodepng_free(key); - ucvector_cleanup(&decoded); + lodepng_free(str); return error; } /*international text chunk (iTXt)*/ static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, - const unsigned char* data, size_t chunkLength) -{ + const unsigned char* data, size_t chunkLength) { unsigned error = 0; unsigned i; unsigned length, begin, compressed; char *key = 0, *langtag = 0, *transkey = 0; - ucvector decoded; - ucvector_init(&decoded); - while(!error) /*not really a while loop, only used to break on error*/ - { + while(!error) /*not really a while loop, only used to break on error*/ { /*Quick check if the chunk length isn't too small. Even without check it'd still fail with other error checks below if it's too short. This just gives a different error code.*/ if(chunkLength < 5) CERROR_BREAK(error, 30); /*iTXt chunk too short*/ @@ -4428,8 +4510,8 @@ static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSetting key = (char*)lodepng_malloc(length + 1); if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ + lodepng_memcpy(key, data, length); key[length] = 0; - for(i = 0; i != length; ++i) key[i] = (char)data[i]; /*read the compression method*/ compressed = data[length + 1]; @@ -4446,8 +4528,8 @@ static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSetting langtag = (char*)lodepng_malloc(length + 1); if(!langtag) CERROR_BREAK(error, 83); /*alloc fail*/ + lodepng_memcpy(langtag, data + begin, length); langtag[length] = 0; - for(i = 0; i != length; ++i) langtag[i] = (char)data[begin + i]; /*read the transkey*/ begin += length + 1; @@ -4457,47 +4539,37 @@ static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSetting transkey = (char*)lodepng_malloc(length + 1); if(!transkey) CERROR_BREAK(error, 83); /*alloc fail*/ + lodepng_memcpy(transkey, data + begin, length); transkey[length] = 0; - for(i = 0; i != length; ++i) transkey[i] = (char)data[begin + i]; /*read the actual text*/ begin += length + 1; length = (unsigned)chunkLength < begin ? 0 : (unsigned)chunkLength - begin; - if(compressed) - { + if(compressed) { + unsigned char* str = 0; + size_t size = 0; /*will fail if zlib error, e.g. if length is too small*/ - error = zlib_decompress(&decoded.data, &decoded.size, - (unsigned char*)(&data[begin]), + error = zlib_decompress(&str, &size, 0, &data[begin], length, zlibsettings); - if(error) break; - if(decoded.allocsize < decoded.size) decoded.allocsize = decoded.size; - ucvector_push_back(&decoded, 0); - } - else - { - if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(error, 83 /*alloc fail*/); - - decoded.data[length] = 0; - for(i = 0; i != length; ++i) decoded.data[i] = data[begin + i]; + if(!error) error = lodepng_add_itext_sized(info, key, langtag, transkey, (char*)str, size); + lodepng_free(str); + } else { + error = lodepng_add_itext_sized(info, key, langtag, transkey, (char*)(data + begin), length); } - error = lodepng_add_itext(info, key, langtag, transkey, (char*)decoded.data); - break; } lodepng_free(key); lodepng_free(langtag); lodepng_free(transkey); - ucvector_cleanup(&decoded); return error; } -static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) -{ +static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { if(chunkLength != 7) return 73; /*invalid tIME chunk size*/ info->time_defined = 1; @@ -4511,8 +4583,7 @@ static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, siz return 0; /* OK */ } -static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) -{ +static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { if(chunkLength != 9) return 74; /*invalid pHYs chunk size*/ info->phys_defined = 1; @@ -4522,20 +4593,139 @@ static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, siz return 0; /* OK */ } + +static unsigned readChunk_gAMA(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { + if(chunkLength != 4) return 96; /*invalid gAMA chunk size*/ + + info->gama_defined = 1; + info->gama_gamma = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3]; + + return 0; /* OK */ +} + +static unsigned readChunk_cHRM(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { + if(chunkLength != 32) return 97; /*invalid cHRM chunk size*/ + + info->chrm_defined = 1; + info->chrm_white_x = 16777216u * data[ 0] + 65536u * data[ 1] + 256u * data[ 2] + data[ 3]; + info->chrm_white_y = 16777216u * data[ 4] + 65536u * data[ 5] + 256u * data[ 6] + data[ 7]; + info->chrm_red_x = 16777216u * data[ 8] + 65536u * data[ 9] + 256u * data[10] + data[11]; + info->chrm_red_y = 16777216u * data[12] + 65536u * data[13] + 256u * data[14] + data[15]; + info->chrm_green_x = 16777216u * data[16] + 65536u * data[17] + 256u * data[18] + data[19]; + info->chrm_green_y = 16777216u * data[20] + 65536u * data[21] + 256u * data[22] + data[23]; + info->chrm_blue_x = 16777216u * data[24] + 65536u * data[25] + 256u * data[26] + data[27]; + info->chrm_blue_y = 16777216u * data[28] + 65536u * data[29] + 256u * data[30] + data[31]; + + return 0; /* OK */ +} + +static unsigned readChunk_sRGB(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { + if(chunkLength != 1) return 98; /*invalid sRGB chunk size (this one is never ignored)*/ + + info->srgb_defined = 1; + info->srgb_intent = data[0]; + + return 0; /* OK */ +} + +static unsigned readChunk_iCCP(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, + const unsigned char* data, size_t chunkLength) { + unsigned error = 0; + unsigned i; + size_t size = 0; + + unsigned length, string2_begin; + + info->iccp_defined = 1; + if(info->iccp_name) lodepng_clear_icc(info); + + for(length = 0; length < chunkLength && data[length] != 0; ++length) ; + if(length + 2 >= chunkLength) return 75; /*no null termination, corrupt?*/ + if(length < 1 || length > 79) return 89; /*keyword too short or long*/ + + info->iccp_name = (char*)lodepng_malloc(length + 1); + if(!info->iccp_name) return 83; /*alloc fail*/ + + info->iccp_name[length] = 0; + for(i = 0; i != length; ++i) info->iccp_name[i] = (char)data[i]; + + if(data[length + 1] != 0) return 72; /*the 0 byte indicating compression must be 0*/ + + string2_begin = length + 2; + if(string2_begin > chunkLength) return 75; /*no null termination, corrupt?*/ + + length = (unsigned)chunkLength - string2_begin; + error = zlib_decompress(&info->iccp_profile, &size, 0, + &data[string2_begin], + length, zlibsettings); + info->iccp_profile_size = size; + if(!error && !info->iccp_profile_size) error = 100; /*invalid ICC profile size*/ + return error; +} +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +unsigned lodepng_inspect_chunk(LodePNGState* state, size_t pos, + const unsigned char* in, size_t insize) { + const unsigned char* chunk = in + pos; + unsigned chunkLength; + const unsigned char* data; + unsigned unhandled = 0; + unsigned error = 0; + + if(pos + 4 > insize) return 30; + chunkLength = lodepng_chunk_length(chunk); + if(chunkLength > 2147483647) return 63; + data = lodepng_chunk_data_const(chunk); + if(data + chunkLength + 4 > in + insize) return 30; + + if(lodepng_chunk_type_equals(chunk, "PLTE")) { + error = readChunk_PLTE(&state->info_png.color, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "tRNS")) { + error = readChunk_tRNS(&state->info_png.color, data, chunkLength); +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + } else if(lodepng_chunk_type_equals(chunk, "bKGD")) { + error = readChunk_bKGD(&state->info_png, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "tEXt")) { + error = readChunk_tEXt(&state->info_png, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "zTXt")) { + error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "iTXt")) { + error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "tIME")) { + error = readChunk_tIME(&state->info_png, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "pHYs")) { + error = readChunk_pHYs(&state->info_png, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "gAMA")) { + error = readChunk_gAMA(&state->info_png, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "cHRM")) { + error = readChunk_cHRM(&state->info_png, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "sRGB")) { + error = readChunk_sRGB(&state->info_png, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "iCCP")) { + error = readChunk_iCCP(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + } else { + /* unhandled chunk is ok (is not an error) */ + unhandled = 1; + } + + if(!error && !unhandled && !state->decoder.ignore_crc) { + if(lodepng_chunk_check_crc(chunk)) return 57; /*invalid CRC*/ + } + + return error; +} /*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/ static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h, LodePNGState* state, - const unsigned char* in, size_t insize) -{ + const unsigned char* in, size_t insize) { unsigned char IEND = 0; const unsigned char* chunk; - size_t i; - ucvector idat; /*the data from idat chunks*/ - ucvector scanlines; - size_t predict; - size_t numpixels; + unsigned char* idat; /*the data from idat chunks, zlib compressed*/ + size_t idatsize = 0; + unsigned char* scanlines = 0; + size_t scanlines_size = 0, expected_size = 0; size_t outsize = 0; /*for unknown chunk order*/ @@ -4544,33 +4734,32 @@ static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h, unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/ #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - /*provide some proper output values if error will happen*/ + + /* safe output values in case error happens */ *out = 0; + *w = *h = 0; state->error = lodepng_inspect(w, h, state, in, insize); /*reads header and resets other parameters in state->info_png*/ if(state->error) return; - numpixels = *w * *h; + if(lodepng_pixel_overflow(*w, *h, &state->info_png.color, &state->info_raw)) { + CERROR_RETURN(state->error, 92); /*overflow possible due to amount of pixels*/ + } - /*multiplication overflow*/ - if(*h != 0 && numpixels / *h != *w) CERROR_RETURN(state->error, 92); - /*multiplication overflow possible further below. Allows up to 2^31-1 pixel - bytes with 16-bit RGBA, the rest is room for filter bytes.*/ - if(numpixels > 268435455) CERROR_RETURN(state->error, 92); + /*the input filesize is a safe upper bound for the sum of idat chunks size*/ + idat = (unsigned char*)lodepng_malloc(insize); + if(!idat) CERROR_RETURN(state->error, 83); /*alloc fail*/ - ucvector_init(&idat); chunk = &in[33]; /*first byte of the first chunk after the header*/ /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk. IDAT data is put at the start of the in buffer*/ - while(!IEND && !state->error) - { + while(!IEND && !state->error) { unsigned chunkLength; const unsigned char* data; /*the data in the chunk*/ /*error: size of the in buffer too small to contain next chunk*/ - if((size_t)((chunk - in) + 12) > insize || chunk < in) - { + if((size_t)((chunk - in) + 12) > insize || chunk < in) { if(state->decoder.ignore_end) break; /*other errors may still happen though*/ CERROR_BREAK(state->error, 30); } @@ -4578,106 +4767,96 @@ static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h, /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/ chunkLength = lodepng_chunk_length(chunk); /*error: chunk length larger than the max PNG chunk size*/ - if(chunkLength > 2147483647) - { + if(chunkLength > 2147483647) { if(state->decoder.ignore_end) break; /*other errors may still happen though*/ CERROR_BREAK(state->error, 63); } - if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in) - { + if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in) { CERROR_BREAK(state->error, 64); /*error: size of the in buffer too small to contain next chunk*/ } data = lodepng_chunk_data_const(chunk); + unknown = 0; + /*IDAT chunk, containing compressed image data*/ - if(lodepng_chunk_type_equals(chunk, "IDAT")) - { - size_t oldsize = idat.size; - if(!ucvector_resize(&idat, oldsize + chunkLength)) CERROR_BREAK(state->error, 83 /*alloc fail*/); - for(i = 0; i != chunkLength; ++i) idat.data[oldsize + i] = data[i]; + if(lodepng_chunk_type_equals(chunk, "IDAT")) { + size_t newsize; + if(lodepng_addofl(idatsize, chunkLength, &newsize)) CERROR_BREAK(state->error, 95); + if(newsize > insize) CERROR_BREAK(state->error, 95); + lodepng_memcpy(idat + idatsize, data, chunkLength); + idatsize += chunkLength; #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS critical_pos = 3; #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - } - /*IEND chunk*/ - else if(lodepng_chunk_type_equals(chunk, "IEND")) - { + } else if(lodepng_chunk_type_equals(chunk, "IEND")) { + /*IEND chunk*/ IEND = 1; - } - /*palette chunk (PLTE)*/ - else if(lodepng_chunk_type_equals(chunk, "PLTE")) - { + } else if(lodepng_chunk_type_equals(chunk, "PLTE")) { + /*palette chunk (PLTE)*/ state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength); if(state->error) break; #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS critical_pos = 2; #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - } - /*palette transparency chunk (tRNS)*/ - else if(lodepng_chunk_type_equals(chunk, "tRNS")) - { + } else if(lodepng_chunk_type_equals(chunk, "tRNS")) { + /*palette transparency chunk (tRNS). Even though this one is an ancillary chunk , it is still compiled + in without 'LODEPNG_COMPILE_ANCILLARY_CHUNKS' because it contains essential color information that + affects the alpha channel of pixels. */ state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength); if(state->error) break; - } #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /*background color chunk (bKGD)*/ - else if(lodepng_chunk_type_equals(chunk, "bKGD")) - { + /*background color chunk (bKGD)*/ + } else if(lodepng_chunk_type_equals(chunk, "bKGD")) { state->error = readChunk_bKGD(&state->info_png, data, chunkLength); if(state->error) break; - } - /*text chunk (tEXt)*/ - else if(lodepng_chunk_type_equals(chunk, "tEXt")) - { - if(state->decoder.read_text_chunks) - { + } else if(lodepng_chunk_type_equals(chunk, "tEXt")) { + /*text chunk (tEXt)*/ + if(state->decoder.read_text_chunks) { state->error = readChunk_tEXt(&state->info_png, data, chunkLength); if(state->error) break; } - } - /*compressed text chunk (zTXt)*/ - else if(lodepng_chunk_type_equals(chunk, "zTXt")) - { - if(state->decoder.read_text_chunks) - { + } else if(lodepng_chunk_type_equals(chunk, "zTXt")) { + /*compressed text chunk (zTXt)*/ + if(state->decoder.read_text_chunks) { state->error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); if(state->error) break; } - } - /*international text chunk (iTXt)*/ - else if(lodepng_chunk_type_equals(chunk, "iTXt")) - { - if(state->decoder.read_text_chunks) - { + } else if(lodepng_chunk_type_equals(chunk, "iTXt")) { + /*international text chunk (iTXt)*/ + if(state->decoder.read_text_chunks) { state->error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); if(state->error) break; } - } - else if(lodepng_chunk_type_equals(chunk, "tIME")) - { + } else if(lodepng_chunk_type_equals(chunk, "tIME")) { state->error = readChunk_tIME(&state->info_png, data, chunkLength); if(state->error) break; - } - else if(lodepng_chunk_type_equals(chunk, "pHYs")) - { + } else if(lodepng_chunk_type_equals(chunk, "pHYs")) { state->error = readChunk_pHYs(&state->info_png, data, chunkLength); if(state->error) break; - } + } else if(lodepng_chunk_type_equals(chunk, "gAMA")) { + state->error = readChunk_gAMA(&state->info_png, data, chunkLength); + if(state->error) break; + } else if(lodepng_chunk_type_equals(chunk, "cHRM")) { + state->error = readChunk_cHRM(&state->info_png, data, chunkLength); + if(state->error) break; + } else if(lodepng_chunk_type_equals(chunk, "sRGB")) { + state->error = readChunk_sRGB(&state->info_png, data, chunkLength); + if(state->error) break; + } else if(lodepng_chunk_type_equals(chunk, "iCCP")) { + state->error = readChunk_iCCP(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); + if(state->error) break; #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - else /*it's not an implemented chunk type, so ignore it: skip over the data*/ - { + } else /*it's not an implemented chunk type, so ignore it: skip over the data*/ { /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/ - if(!state->decoder.ignore_critical && !lodepng_chunk_ancillary(chunk)) - { + if(!state->decoder.ignore_critical && !lodepng_chunk_ancillary(chunk)) { CERROR_BREAK(state->error, 69); } unknown = 1; #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - if(state->decoder.remember_unknown_chunks) - { + if(state->decoder.remember_unknown_chunks) { state->error = lodepng_chunk_append(&state->info_png.unknown_chunks_data[critical_pos - 1], &state->info_png.unknown_chunks_size[critical_pos - 1], chunk); if(state->error) break; @@ -4685,94 +4864,81 @@ static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h, #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ } - if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/ - { + if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/ { if(lodepng_chunk_check_crc(chunk)) CERROR_BREAK(state->error, 57); /*invalid CRC*/ } - if(!IEND) chunk = lodepng_chunk_next_const(chunk); - } - - ucvector_init(&scanlines); - /*predict output size, to allocate exact size for output buffer to avoid more dynamic allocation. - If the decompressed size does not match the prediction, the image must be corrupt.*/ - if(state->info_png.interlace_method == 0) - { - /*The extra *h is added because this are the filter bytes every scanline starts with*/ - predict = lodepng_get_raw_size_idat(*w, *h, &state->info_png.color) + *h; - } - else - { - /*Adam-7 interlaced: predicted size is the sum of the 7 sub-images sizes*/ - const LodePNGColorMode* color = &state->info_png.color; - predict = 0; - predict += lodepng_get_raw_size_idat((*w + 7) >> 3, (*h + 7) >> 3, color) + ((*h + 7) >> 3); - if(*w > 4) predict += lodepng_get_raw_size_idat((*w + 3) >> 3, (*h + 7) >> 3, color) + ((*h + 7) >> 3); - predict += lodepng_get_raw_size_idat((*w + 3) >> 2, (*h + 3) >> 3, color) + ((*h + 3) >> 3); - if(*w > 2) predict += lodepng_get_raw_size_idat((*w + 1) >> 2, (*h + 3) >> 2, color) + ((*h + 3) >> 2); - predict += lodepng_get_raw_size_idat((*w + 1) >> 1, (*h + 1) >> 2, color) + ((*h + 1) >> 2); - if(*w > 1) predict += lodepng_get_raw_size_idat((*w + 0) >> 1, (*h + 1) >> 1, color) + ((*h + 1) >> 1); - predict += lodepng_get_raw_size_idat((*w + 0), (*h + 0) >> 1, color) + ((*h + 0) >> 1); - } - if(!state->error && !ucvector_reserve(&scanlines, predict)) state->error = 83; /*alloc fail*/ - if(!state->error) - { - state->error = zlib_decompress(&scanlines.data, &scanlines.size, idat.data, - idat.size, &state->decoder.zlibsettings); - if(!state->error && scanlines.size != predict) state->error = 91; /*decompressed size doesn't match prediction*/ - } - ucvector_cleanup(&idat); - - if(!state->error) - { + if(!IEND) chunk = lodepng_chunk_next_const(chunk, in + insize); + } + + if(state->info_png.color.colortype == LCT_PALETTE && !state->info_png.color.palette) { + state->error = 106; /* error: PNG file must have PLTE chunk if color type is palette */ + } + + if(!state->error) { + /*predict output size, to allocate exact size for output buffer to avoid more dynamic allocation. + If the decompressed size does not match the prediction, the image must be corrupt.*/ + if(state->info_png.interlace_method == 0) { + size_t bpp = lodepng_get_bpp(&state->info_png.color); + expected_size = lodepng_get_raw_size_idat(*w, *h, bpp); + } else { + size_t bpp = lodepng_get_bpp(&state->info_png.color); + /*Adam-7 interlaced: expected size is the sum of the 7 sub-images sizes*/ + expected_size = 0; + expected_size += lodepng_get_raw_size_idat((*w + 7) >> 3, (*h + 7) >> 3, bpp); + if(*w > 4) expected_size += lodepng_get_raw_size_idat((*w + 3) >> 3, (*h + 7) >> 3, bpp); + expected_size += lodepng_get_raw_size_idat((*w + 3) >> 2, (*h + 3) >> 3, bpp); + if(*w > 2) expected_size += lodepng_get_raw_size_idat((*w + 1) >> 2, (*h + 3) >> 2, bpp); + expected_size += lodepng_get_raw_size_idat((*w + 1) >> 1, (*h + 1) >> 2, bpp); + if(*w > 1) expected_size += lodepng_get_raw_size_idat((*w + 0) >> 1, (*h + 1) >> 1, bpp); + expected_size += lodepng_get_raw_size_idat((*w + 0), (*h + 0) >> 1, bpp); + } + + state->error = zlib_decompress(&scanlines, &scanlines_size, expected_size, idat, idatsize, &state->decoder.zlibsettings); + } + if(!state->error && scanlines_size != expected_size) state->error = 91; /*decompressed size doesn't match prediction*/ + lodepng_free(idat); + + if(!state->error) { outsize = lodepng_get_raw_size(*w, *h, &state->info_png.color); *out = (unsigned char*)lodepng_malloc(outsize); if(!*out) state->error = 83; /*alloc fail*/ } - if(!state->error) - { - for(i = 0; i < outsize; i++) (*out)[i] = 0; - state->error = postProcessScanlines(*out, scanlines.data, *w, *h, &state->info_png); + if(!state->error) { + lodepng_memset(*out, 0, outsize); + state->error = postProcessScanlines(*out, scanlines, *w, *h, &state->info_png); } - ucvector_cleanup(&scanlines); + lodepng_free(scanlines); } unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h, LodePNGState* state, - const unsigned char* in, size_t insize) -{ + const unsigned char* in, size_t insize) { *out = 0; decodeGeneric(out, w, h, state, in, insize); if(state->error) return state->error; - if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color)) - { + if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color)) { /*same color type, no copying or converting of data needed*/ /*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype the raw image has to the end user*/ - if(!state->decoder.color_convert) - { + if(!state->decoder.color_convert) { state->error = lodepng_color_mode_copy(&state->info_raw, &state->info_png.color); if(state->error) return state->error; } - } - else - { - /*color conversion needed; sort of copy of the data*/ + } else { /*color conversion needed*/ unsigned char* data = *out; size_t outsize; /*TODO: check if this works according to the statement in the documentation: "The converter can convert - from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/ + from grayscale input color type, to 8-bit grayscale or grayscale with alpha"*/ if(!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA) - && !(state->info_raw.bitdepth == 8)) - { + && !(state->info_raw.bitdepth == 8)) { return 56; /*unsupported color mode conversion*/ } outsize = lodepng_get_raw_size(*w, *h, &state->info_raw); *out = (unsigned char*)lodepng_malloc(outsize); - if(!(*out)) - { + if(!(*out)) { state->error = 83; /*alloc fail*/ } else state->error = lodepng_convert(*out, data, &state->info_raw, @@ -4783,8 +4949,7 @@ unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h, } unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, - size_t insize, LodePNGColorType colortype, unsigned bitdepth) -{ + size_t insize, LodePNGColorType colortype, unsigned bitdepth) { unsigned error; LodePNGState state; lodepng_state_init(&state); @@ -4795,42 +4960,39 @@ unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, co return error; } -unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) -{ +unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) { return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8); } -unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) -{ +unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) { return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8); } #ifdef LODEPNG_COMPILE_DISK unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename, - LodePNGColorType colortype, unsigned bitdepth) -{ + LodePNGColorType colortype, unsigned bitdepth) { unsigned char* buffer = 0; size_t buffersize; unsigned error; + /* safe output values in case error happens */ + *out = 0; + *w = *h = 0; error = lodepng_load_file(&buffer, &buffersize, filename); if(!error) error = lodepng_decode_memory(out, w, h, buffer, buffersize, colortype, bitdepth); lodepng_free(buffer); return error; } -unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) -{ +unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) { return lodepng_decode_file(out, w, h, filename, LCT_RGBA, 8); } -unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) -{ +unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) { return lodepng_decode_file(out, w, h, filename, LCT_RGB, 8); } #endif /*LODEPNG_COMPILE_DISK*/ -void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) -{ +void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) { settings->color_convert = 1; #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS settings->read_text_chunks = 1; @@ -4846,8 +5008,7 @@ void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) #if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) -void lodepng_state_init(LodePNGState* state) -{ +void lodepng_state_init(LodePNGState* state) { #ifdef LODEPNG_COMPILE_DECODER lodepng_decoder_settings_init(&state->decoder); #endif /*LODEPNG_COMPILE_DECODER*/ @@ -4859,14 +5020,12 @@ void lodepng_state_init(LodePNGState* state) state->error = 1; } -void lodepng_state_cleanup(LodePNGState* state) -{ +void lodepng_state_cleanup(LodePNGState* state) { lodepng_color_mode_cleanup(&state->info_raw); lodepng_info_cleanup(&state->info_png); } -void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source) -{ +void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source) { lodepng_state_cleanup(dest); *dest = *source; lodepng_color_mode_init(&dest->info_raw); @@ -4883,289 +5042,300 @@ void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source) /* / PNG Encoder / */ /* ////////////////////////////////////////////////////////////////////////// */ -/*chunkName must be string of 4 characters*/ -static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length) -{ - CERROR_TRY_RETURN(lodepng_chunk_create(&out->data, &out->size, (unsigned)length, chunkName, data)); - out->allocsize = out->size; /*fix the allocsize again*/ - return 0; -} -static void writeSignature(ucvector* out) -{ +static unsigned writeSignature(ucvector* out) { + size_t pos = out->size; + const unsigned char signature[] = {137, 80, 78, 71, 13, 10, 26, 10}; /*8 bytes PNG signature, aka the magic bytes*/ - ucvector_push_back(out, 137); - ucvector_push_back(out, 80); - ucvector_push_back(out, 78); - ucvector_push_back(out, 71); - ucvector_push_back(out, 13); - ucvector_push_back(out, 10); - ucvector_push_back(out, 26); - ucvector_push_back(out, 10); + if(!ucvector_resize(out, out->size + 8)) return 83; /*alloc fail*/ + lodepng_memcpy(out->data + pos, signature, 8); + return 0; } static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method) -{ - unsigned error = 0; - ucvector header; - ucvector_init(&header); + LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method) { + unsigned char *chunk, *data; + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 13, "IHDR")); + data = chunk + 8; + + lodepng_set32bitInt(data + 0, w); /*width*/ + lodepng_set32bitInt(data + 4, h); /*height*/ + data[8] = (unsigned char)bitdepth; /*bit depth*/ + data[9] = (unsigned char)colortype; /*color type*/ + data[10] = 0; /*compression method*/ + data[11] = 0; /*filter method*/ + data[12] = interlace_method; /*interlace method*/ - lodepng_add32bitInt(&header, w); /*width*/ - lodepng_add32bitInt(&header, h); /*height*/ - ucvector_push_back(&header, (unsigned char)bitdepth); /*bit depth*/ - ucvector_push_back(&header, (unsigned char)colortype); /*color type*/ - ucvector_push_back(&header, 0); /*compression method*/ - ucvector_push_back(&header, 0); /*filter method*/ - ucvector_push_back(&header, interlace_method); /*interlace method*/ + lodepng_chunk_generate_crc(chunk); + return 0; +} - error = addChunk(out, "IHDR", header.data, header.size); - ucvector_cleanup(&header); +/* only adds the chunk if needed (there is a key or palette with alpha) */ +static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* info) { + unsigned char* chunk; + size_t i, j = 8; - return error; -} + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, info->palettesize * 3, "PLTE")); -static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* info) -{ - unsigned error = 0; - size_t i; - ucvector PLTE; - ucvector_init(&PLTE); - for(i = 0; i != info->palettesize * 4; ++i) - { + for(i = 0; i != info->palettesize; ++i) { /*add all channels except alpha channel*/ - if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]); + chunk[j++] = info->palette[i * 4 + 0]; + chunk[j++] = info->palette[i * 4 + 1]; + chunk[j++] = info->palette[i * 4 + 2]; } - error = addChunk(out, "PLTE", PLTE.data, PLTE.size); - ucvector_cleanup(&PLTE); - return error; + lodepng_chunk_generate_crc(chunk); + return 0; } -static unsigned addChunk_tRNS(ucvector* out, const LodePNGColorMode* info) -{ - unsigned error = 0; - size_t i; - ucvector tRNS; - ucvector_init(&tRNS); - if(info->colortype == LCT_PALETTE) - { - size_t amount = info->palettesize; +static unsigned addChunk_tRNS(ucvector* out, const LodePNGColorMode* info) { + unsigned char* chunk = 0; + + if(info->colortype == LCT_PALETTE) { + size_t i, amount = info->palettesize; /*the tail of palette values that all have 255 as alpha, does not have to be encoded*/ - for(i = info->palettesize; i != 0; --i) - { - if(info->palette[4 * (i - 1) + 3] == 255) --amount; - else break; + for(i = info->palettesize; i != 0; --i) { + if(info->palette[4 * (i - 1) + 3] != 255) break; + --amount; } - /*add only alpha channel*/ - for(i = 0; i != amount; ++i) ucvector_push_back(&tRNS, info->palette[4 * i + 3]); - } - else if(info->colortype == LCT_GREY) - { - if(info->key_defined) - { - ucvector_push_back(&tRNS, (unsigned char)(info->key_r >> 8)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_r & 255)); + if(amount) { + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, amount, "tRNS")); + /*add the alpha channel values from the palette*/ + for(i = 0; i != amount; ++i) chunk[8 + i] = info->palette[4 * i + 3]; } - } - else if(info->colortype == LCT_RGB) - { - if(info->key_defined) - { - ucvector_push_back(&tRNS, (unsigned char)(info->key_r >> 8)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_r & 255)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_g >> 8)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_g & 255)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_b >> 8)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_b & 255)); + } else if(info->colortype == LCT_GREY) { + if(info->key_defined) { + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 2, "tRNS")); + chunk[8] = (unsigned char)(info->key_r >> 8); + chunk[9] = (unsigned char)(info->key_r & 255); + } + } else if(info->colortype == LCT_RGB) { + if(info->key_defined) { + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 6, "tRNS")); + chunk[8] = (unsigned char)(info->key_r >> 8); + chunk[9] = (unsigned char)(info->key_r & 255); + chunk[10] = (unsigned char)(info->key_g >> 8); + chunk[11] = (unsigned char)(info->key_g & 255); + chunk[12] = (unsigned char)(info->key_b >> 8); + chunk[13] = (unsigned char)(info->key_b & 255); } } - error = addChunk(out, "tRNS", tRNS.data, tRNS.size); - ucvector_cleanup(&tRNS); - - return error; + if(chunk) lodepng_chunk_generate_crc(chunk); + return 0; } static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize, - LodePNGCompressSettings* zlibsettings) -{ - ucvector zlibdata; + LodePNGCompressSettings* zlibsettings) { unsigned error = 0; + unsigned char* zlib = 0; + size_t zlibsize = 0; - /*compress with the Zlib compressor*/ - ucvector_init(&zlibdata); - error = zlib_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings); - if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size); - ucvector_cleanup(&zlibdata); - + error = zlib_compress(&zlib, &zlibsize, data, datasize, zlibsettings); + if(!error) { + error = lodepng_chunk_createv(out, zlibsize, "IDAT", zlib); + } + lodepng_free(zlib); return error; } -static unsigned addChunk_IEND(ucvector* out) -{ - unsigned error = 0; - error = addChunk(out, "IEND", 0, 0); - return error; +static unsigned addChunk_IEND(ucvector* out) { + return lodepng_chunk_createv(out, 0, "IEND", 0); } #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring) -{ - unsigned error = 0; - size_t i; - ucvector text; - ucvector_init(&text); - for(i = 0; keyword[i] != 0; ++i) ucvector_push_back(&text, (unsigned char)keyword[i]); - if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/ - ucvector_push_back(&text, 0); /*0 termination char*/ - for(i = 0; textstring[i] != 0; ++i) ucvector_push_back(&text, (unsigned char)textstring[i]); - error = addChunk(out, "tEXt", text.data, text.size); - ucvector_cleanup(&text); - - return error; +static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring) { + unsigned char* chunk = 0; + size_t keysize = lodepng_strlen(keyword), textsize = lodepng_strlen(textstring); + size_t size = keysize + 1 + textsize; + if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/ + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, size, "tEXt")); + lodepng_memcpy(chunk + 8, keyword, keysize); + chunk[8 + keysize] = 0; /*null termination char*/ + lodepng_memcpy(chunk + 9 + keysize, textstring, textsize); + lodepng_chunk_generate_crc(chunk); + return 0; } static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring, - LodePNGCompressSettings* zlibsettings) -{ + LodePNGCompressSettings* zlibsettings) { unsigned error = 0; - ucvector data, compressed; - size_t i, textsize = strlen(textstring); - - ucvector_init(&data); - ucvector_init(&compressed); - for(i = 0; keyword[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)keyword[i]); - if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/ - ucvector_push_back(&data, 0); /*0 termination char*/ - ucvector_push_back(&data, 0); /*compression method: 0*/ - - error = zlib_compress(&compressed.data, &compressed.size, - (unsigned char*)textstring, textsize, zlibsettings); - if(!error) - { - for(i = 0; i != compressed.size; ++i) ucvector_push_back(&data, compressed.data[i]); - error = addChunk(out, "zTXt", data.data, data.size); - } - - ucvector_cleanup(&compressed); - ucvector_cleanup(&data); + unsigned char* chunk = 0; + unsigned char* compressed = 0; + size_t compressedsize = 0; + size_t textsize = lodepng_strlen(textstring); + size_t keysize = lodepng_strlen(keyword); + if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/ + + error = zlib_compress(&compressed, &compressedsize, + (const unsigned char*)textstring, textsize, zlibsettings); + if(!error) { + size_t size = keysize + 2 + compressedsize; + error = lodepng_chunk_init(&chunk, out, size, "zTXt"); + } + if(!error) { + lodepng_memcpy(chunk + 8, keyword, keysize); + chunk[8 + keysize] = 0; /*null termination char*/ + chunk[9 + keysize] = 0; /*compression method: 0*/ + lodepng_memcpy(chunk + 10 + keysize, compressed, compressedsize); + lodepng_chunk_generate_crc(chunk); + } + + lodepng_free(compressed); return error; } -static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag, - const char* transkey, const char* textstring, LodePNGCompressSettings* zlibsettings) -{ +static unsigned addChunk_iTXt(ucvector* out, unsigned compress, const char* keyword, const char* langtag, + const char* transkey, const char* textstring, LodePNGCompressSettings* zlibsettings) { unsigned error = 0; - ucvector data; - size_t i, textsize = strlen(textstring); - - ucvector_init(&data); - - for(i = 0; keyword[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)keyword[i]); - if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/ - ucvector_push_back(&data, 0); /*null termination char*/ - ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/ - ucvector_push_back(&data, 0); /*compression method*/ - for(i = 0; langtag[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)langtag[i]); - ucvector_push_back(&data, 0); /*null termination char*/ - for(i = 0; transkey[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)transkey[i]); - ucvector_push_back(&data, 0); /*null termination char*/ - - if(compressed) - { - ucvector compressed_data; - ucvector_init(&compressed_data); - error = zlib_compress(&compressed_data.data, &compressed_data.size, - (unsigned char*)textstring, textsize, zlibsettings); - if(!error) - { - for(i = 0; i != compressed_data.size; ++i) ucvector_push_back(&data, compressed_data.data[i]); - } - ucvector_cleanup(&compressed_data); - } - else /*not compressed*/ - { - for(i = 0; textstring[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)textstring[i]); - } - - if(!error) error = addChunk(out, "iTXt", data.data, data.size); - ucvector_cleanup(&data); + unsigned char* chunk = 0; + unsigned char* compressed = 0; + size_t compressedsize = 0; + size_t textsize = lodepng_strlen(textstring); + size_t keysize = lodepng_strlen(keyword), langsize = lodepng_strlen(langtag), transsize = lodepng_strlen(transkey); + + if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/ + + if(compress) { + error = zlib_compress(&compressed, &compressedsize, + (const unsigned char*)textstring, textsize, zlibsettings); + } + if(!error) { + size_t size = keysize + 3 + langsize + 1 + transsize + 1 + (compress ? compressedsize : textsize); + error = lodepng_chunk_init(&chunk, out, size, "iTXt"); + } + if(!error) { + size_t pos = 8; + lodepng_memcpy(chunk + pos, keyword, keysize); + pos += keysize; + chunk[pos++] = 0; /*null termination char*/ + chunk[pos++] = (compress ? 1 : 0); /*compression flag*/ + chunk[pos++] = 0; /*compression method: 0*/ + lodepng_memcpy(chunk + pos, langtag, langsize); + pos += langsize; + chunk[pos++] = 0; /*null termination char*/ + lodepng_memcpy(chunk + pos, transkey, transsize); + pos += transsize; + chunk[pos++] = 0; /*null termination char*/ + if(compress) { + lodepng_memcpy(chunk + pos, compressed, compressedsize); + } else { + lodepng_memcpy(chunk + pos, textstring, textsize); + } + lodepng_chunk_generate_crc(chunk); + } + + lodepng_free(compressed); return error; } -static unsigned addChunk_bKGD(ucvector* out, const LodePNGInfo* info) -{ - unsigned error = 0; - ucvector bKGD; - ucvector_init(&bKGD); - if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) - { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r >> 8)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_r & 255)); - } - else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) - { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r >> 8)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_r & 255)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_g >> 8)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_g & 255)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_b >> 8)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_b & 255)); - } - else if(info->color.colortype == LCT_PALETTE) - { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r & 255)); /*palette index*/ - } - - error = addChunk(out, "bKGD", bKGD.data, bKGD.size); - ucvector_cleanup(&bKGD); +static unsigned addChunk_bKGD(ucvector* out, const LodePNGInfo* info) { + unsigned char* chunk = 0; + if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) { + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 2, "bKGD")); + chunk[8] = (unsigned char)(info->background_r >> 8); + chunk[9] = (unsigned char)(info->background_r & 255); + } else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) { + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 6, "bKGD")); + chunk[8] = (unsigned char)(info->background_r >> 8); + chunk[9] = (unsigned char)(info->background_r & 255); + chunk[10] = (unsigned char)(info->background_g >> 8); + chunk[11] = (unsigned char)(info->background_g & 255); + chunk[12] = (unsigned char)(info->background_b >> 8); + chunk[13] = (unsigned char)(info->background_b & 255); + } else if(info->color.colortype == LCT_PALETTE) { + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 1, "bKGD")); + chunk[8] = (unsigned char)(info->background_r & 255); /*palette index*/ + } + if(chunk) lodepng_chunk_generate_crc(chunk); + return 0; +} - return error; +static unsigned addChunk_tIME(ucvector* out, const LodePNGTime* time) { + unsigned char* chunk; + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 7, "tIME")); + chunk[8] = (unsigned char)(time->year >> 8); + chunk[9] = (unsigned char)(time->year & 255); + chunk[10] = (unsigned char)time->month; + chunk[11] = (unsigned char)time->day; + chunk[12] = (unsigned char)time->hour; + chunk[13] = (unsigned char)time->minute; + chunk[14] = (unsigned char)time->second; + lodepng_chunk_generate_crc(chunk); + return 0; } -static unsigned addChunk_tIME(ucvector* out, const LodePNGTime* time) -{ - unsigned error = 0; - unsigned char* data = (unsigned char*)lodepng_malloc(7); - if(!data) return 83; /*alloc fail*/ - data[0] = (unsigned char)(time->year >> 8); - data[1] = (unsigned char)(time->year & 255); - data[2] = (unsigned char)time->month; - data[3] = (unsigned char)time->day; - data[4] = (unsigned char)time->hour; - data[5] = (unsigned char)time->minute; - data[6] = (unsigned char)time->second; - error = addChunk(out, "tIME", data, 7); - lodepng_free(data); - return error; +static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* info) { + unsigned char* chunk; + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 9, "pHYs")); + lodepng_set32bitInt(chunk + 8, info->phys_x); + lodepng_set32bitInt(chunk + 12, info->phys_y); + chunk[16] = info->phys_unit; + lodepng_chunk_generate_crc(chunk); + return 0; } -static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* info) -{ - unsigned error = 0; - ucvector data; - ucvector_init(&data); +static unsigned addChunk_gAMA(ucvector* out, const LodePNGInfo* info) { + unsigned char* chunk; + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 4, "gAMA")); + lodepng_set32bitInt(chunk + 8, info->gama_gamma); + lodepng_chunk_generate_crc(chunk); + return 0; +} - lodepng_add32bitInt(&data, info->phys_x); - lodepng_add32bitInt(&data, info->phys_y); - ucvector_push_back(&data, info->phys_unit); +static unsigned addChunk_cHRM(ucvector* out, const LodePNGInfo* info) { + unsigned char* chunk; + CERROR_TRY_RETURN(lodepng_chunk_init(&chunk, out, 32, "cHRM")); + lodepng_set32bitInt(chunk + 8, info->chrm_white_x); + lodepng_set32bitInt(chunk + 12, info->chrm_white_y); + lodepng_set32bitInt(chunk + 16, info->chrm_red_x); + lodepng_set32bitInt(chunk + 20, info->chrm_red_y); + lodepng_set32bitInt(chunk + 24, info->chrm_green_x); + lodepng_set32bitInt(chunk + 28, info->chrm_green_y); + lodepng_set32bitInt(chunk + 32, info->chrm_blue_x); + lodepng_set32bitInt(chunk + 36, info->chrm_blue_y); + lodepng_chunk_generate_crc(chunk); + return 0; +} - error = addChunk(out, "pHYs", data.data, data.size); - ucvector_cleanup(&data); +static unsigned addChunk_sRGB(ucvector* out, const LodePNGInfo* info) { + unsigned char data = info->srgb_intent; + return lodepng_chunk_createv(out, 1, "sRGB", &data); +} +static unsigned addChunk_iCCP(ucvector* out, const LodePNGInfo* info, LodePNGCompressSettings* zlibsettings) { + unsigned error = 0; + unsigned char* chunk = 0; + unsigned char* compressed = 0; + size_t compressedsize = 0; + size_t keysize = lodepng_strlen(info->iccp_name); + + if(keysize < 1 || keysize > 79) return 89; /*error: invalid keyword size*/ + error = zlib_compress(&compressed, &compressedsize, + info->iccp_profile, info->iccp_profile_size, zlibsettings); + if(!error) { + size_t size = keysize + 2 + compressedsize; + error = lodepng_chunk_init(&chunk, out, size, "iCCP"); + } + if(!error) { + lodepng_memcpy(chunk + 8, info->iccp_name, keysize); + chunk[8 + keysize] = 0; /*null termination char*/ + chunk[9 + keysize] = 0; /*compression method: 0*/ + lodepng_memcpy(chunk + 10 + keysize, compressed, compressedsize); + lodepng_chunk_generate_crc(chunk); + } + + lodepng_free(compressed); return error; } #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline, - size_t length, size_t bytewidth, unsigned char filterType) -{ + size_t length, size_t bytewidth, unsigned char filterType) { size_t i; - switch(filterType) - { + switch(filterType) { case 0: /*None*/ for(i = 0; i != length; ++i) out[i] = scanline[i]; break; @@ -5174,71 +5344,73 @@ static void filterScanline(unsigned char* out, const unsigned char* scanline, co for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - scanline[i - bytewidth]; break; case 2: /*Up*/ - if(prevline) - { + if(prevline) { for(i = 0; i != length; ++i) out[i] = scanline[i] - prevline[i]; - } - else - { + } else { for(i = 0; i != length; ++i) out[i] = scanline[i]; } break; case 3: /*Average*/ - if(prevline) - { + if(prevline) { for(i = 0; i != bytewidth; ++i) out[i] = scanline[i] - (prevline[i] >> 1); for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) >> 1); - } - else - { + } else { for(i = 0; i != bytewidth; ++i) out[i] = scanline[i]; for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - (scanline[i - bytewidth] >> 1); } break; case 4: /*Paeth*/ - if(prevline) - { + if(prevline) { /*paethPredictor(0, prevline[i], 0) is always prevline[i]*/ for(i = 0; i != bytewidth; ++i) out[i] = (scanline[i] - prevline[i]); - for(i = bytewidth; i < length; ++i) - { + for(i = bytewidth; i < length; ++i) { out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth])); } - } - else - { + } else { for(i = 0; i != bytewidth; ++i) out[i] = scanline[i]; /*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/ for(i = bytewidth; i < length; ++i) out[i] = (scanline[i] - scanline[i - bytewidth]); } break; - default: return; /*unexisting filter type given*/ + default: return; /*invalid filter type given*/ } } -/* log2 approximation. A slight bit faster than std::log. */ -static float flog2(float f) -{ - float result = 0; - while(f > 32) { result += 4; f /= 16; } - while(f > 2) { ++result; f /= 2; } - return result + 1.442695f * (f * f * f / 3 - 3 * f * f / 2 + 3 * f - 1.83333f); +/* integer binary logarithm, max return value is 31 */ +static size_t ilog2(size_t i) { + size_t result = 0; + if(i >= 65536) { result += 16; i >>= 16; } + if(i >= 256) { result += 8; i >>= 8; } + if(i >= 16) { result += 4; i >>= 4; } + if(i >= 4) { result += 2; i >>= 2; } + if(i >= 2) { result += 1; /*i >>= 1;*/ } + return result; +} + +/* integer approximation for i * log2(i), helper function for LFS_ENTROPY */ +static size_t ilog2i(size_t i) { + size_t l; + if(i == 0) return 0; + l = ilog2(i); + /* approximate i*log2(i): l is integer logarithm, ((i - (1u << l)) << 1u) + linearly approximates the missing fractional part multiplied by i */ + return i * l + ((i - (1u << l)) << 1u); } static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, - const LodePNGColorMode* info, const LodePNGEncoderSettings* settings) -{ + const LodePNGColorMode* color, const LodePNGEncoderSettings* settings) { /* For PNG filter method 0 - out must be a buffer with as size: h + (w * h * bpp + 7) / 8, because there are + out must be a buffer with as size: h + (w * h * bpp + 7u) / 8u, because there are the scanlines with 1 extra byte per scanline */ - unsigned bpp = lodepng_get_bpp(info); + unsigned bpp = lodepng_get_bpp(color); /*the width of a scanline in bytes, not including the filter type*/ - size_t linebytes = (w * bpp + 7) / 8; + size_t linebytes = lodepng_get_raw_size_idat(w, 1, bpp) - 1u; + /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ - size_t bytewidth = (bpp + 7) / 8; + size_t bytewidth = (bpp + 7u) / 8u; const unsigned char* prevline = 0; unsigned x, y; unsigned error = 0; @@ -5258,67 +5430,54 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, heuristic is used. */ if(settings->filter_palette_zero && - (info->colortype == LCT_PALETTE || info->bitdepth < 8)) strategy = LFS_ZERO; + (color->colortype == LCT_PALETTE || color->bitdepth < 8)) strategy = LFS_ZERO; if(bpp == 0) return 31; /*error: invalid color type*/ - if(strategy == LFS_ZERO) - { - for(y = 0; y != h; ++y) - { + if(strategy >= LFS_ZERO && strategy <= LFS_FOUR) { + unsigned char type = (unsigned char)strategy; + for(y = 0; y != h; ++y) { size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ size_t inindex = linebytes * y; - out[outindex] = 0; /*filter type byte*/ - filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, 0); + out[outindex] = type; /*filter type byte*/ + filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type); prevline = &in[inindex]; } - } - else if(strategy == LFS_MINSUM) - { + } else if(strategy == LFS_MINSUM) { /*adaptive filtering*/ - size_t sum[5]; unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/ size_t smallest = 0; unsigned char type, bestType = 0; - for(type = 0; type != 5; ++type) - { + for(type = 0; type != 5; ++type) { attempt[type] = (unsigned char*)lodepng_malloc(linebytes); - if(!attempt[type]) return 83; /*alloc fail*/ + if(!attempt[type]) error = 83; /*alloc fail*/ } - if(!error) - { - for(y = 0; y != h; ++y) - { + if(!error) { + for(y = 0; y != h; ++y) { /*try the 5 filter types*/ - for(type = 0; type != 5; ++type) - { + for(type = 0; type != 5; ++type) { + size_t sum = 0; filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); /*calculate the sum of the result*/ - sum[type] = 0; - if(type == 0) - { - for(x = 0; x != linebytes; ++x) sum[type] += (unsigned char)(attempt[type][x]); - } - else - { - for(x = 0; x != linebytes; ++x) - { + if(type == 0) { + for(x = 0; x != linebytes; ++x) sum += (unsigned char)(attempt[type][x]); + } else { + for(x = 0; x != linebytes; ++x) { /*For differences, each byte should be treated as signed, values above 127 are negative (converted to signed char). Filtertype 0 isn't a difference though, so use unsigned there. This means filtertype 0 is almost never chosen, but that is justified.*/ unsigned char s = attempt[type][x]; - sum[type] += s < 128 ? s : (255U - s); + sum += s < 128 ? s : (255U - s); } } /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/ - if(type == 0 || sum[type] < smallest) - { + if(type == 0 || sum < smallest) { bestType = type; - smallest = sum[type]; + smallest = sum; } } @@ -5331,57 +5490,47 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, } for(type = 0; type != 5; ++type) lodepng_free(attempt[type]); - } - else if(strategy == LFS_ENTROPY) - { - float sum[5]; + } else if(strategy == LFS_ENTROPY) { unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/ - float smallest = 0; + size_t bestSum = 0; unsigned type, bestType = 0; unsigned count[256]; - for(type = 0; type != 5; ++type) - { + for(type = 0; type != 5; ++type) { attempt[type] = (unsigned char*)lodepng_malloc(linebytes); - if(!attempt[type]) return 83; /*alloc fail*/ + if(!attempt[type]) error = 83; /*alloc fail*/ } - for(y = 0; y != h; ++y) - { - /*try the 5 filter types*/ - for(type = 0; type != 5; ++type) - { - filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); - for(x = 0; x != 256; ++x) count[x] = 0; - for(x = 0; x != linebytes; ++x) ++count[attempt[type][x]]; - ++count[type]; /*the filter type itself is part of the scanline*/ - sum[type] = 0; - for(x = 0; x != 256; ++x) - { - float p = count[x] / (float)(linebytes + 1); - sum[type] += count[x] == 0 ? 0 : flog2(1 / p) * p; - } - /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/ - if(type == 0 || sum[type] < smallest) - { - bestType = type; - smallest = sum[type]; + if(!error) { + for(y = 0; y != h; ++y) { + /*try the 5 filter types*/ + for(type = 0; type != 5; ++type) { + size_t sum = 0; + filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); + lodepng_memset(count, 0, 256 * sizeof(*count)); + for(x = 0; x != linebytes; ++x) ++count[attempt[type][x]]; + ++count[type]; /*the filter type itself is part of the scanline*/ + for(x = 0; x != 256; ++x) { + sum += ilog2i(count[x]); + } + /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/ + if(type == 0 || sum > bestSum) { + bestType = type; + bestSum = sum; + } } - } - prevline = &in[y * linebytes]; + prevline = &in[y * linebytes]; - /*now fill the out values*/ - out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ - for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x]; + /*now fill the out values*/ + out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ + for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x]; + } } for(type = 0; type != 5; ++type) lodepng_free(attempt[type]); - } - else if(strategy == LFS_PREDEFINED) - { - for(y = 0; y != h; ++y) - { + } else if(strategy == LFS_PREDEFINED) { + for(y = 0; y != h; ++y) { size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ size_t inindex = linebytes * y; unsigned char type = settings->predefined_filters[y]; @@ -5389,9 +5538,7 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type); prevline = &in[inindex]; } - } - else if(strategy == LFS_BRUTE_FORCE) - { + } else if(strategy == LFS_BRUTE_FORCE) { /*brute force filter chooser. deflate the scanline after every filter attempt to see which one deflates best. This is very slow and gives only slightly smaller, sometimes even larger, result*/ @@ -5400,7 +5547,8 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, size_t smallest = 0; unsigned type = 0, bestType = 0; unsigned char* dummy; - LodePNGCompressSettings zlibsettings = settings->zlibsettings; + LodePNGCompressSettings zlibsettings; + lodepng_memcpy(&zlibsettings, &settings->zlibsettings, sizeof(LodePNGCompressSettings)); /*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose, to simulate the true case where the tree is the same for the whole image. Sometimes it gives better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare @@ -5410,33 +5558,31 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, images only, so disable it*/ zlibsettings.custom_zlib = 0; zlibsettings.custom_deflate = 0; - for(type = 0; type != 5; ++type) - { + for(type = 0; type != 5; ++type) { attempt[type] = (unsigned char*)lodepng_malloc(linebytes); - if(!attempt[type]) return 83; /*alloc fail*/ + if(!attempt[type]) error = 83; /*alloc fail*/ } - for(y = 0; y != h; ++y) /*try the 5 filter types*/ - { - for(type = 0; type != 5; ++type) - { - unsigned testsize = (unsigned)linebytes; - /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/ - - filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); - size[type] = 0; - dummy = 0; - zlib_compress(&dummy, &size[type], attempt[type], testsize, &zlibsettings); - lodepng_free(dummy); - /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/ - if(type == 0 || size[type] < smallest) - { - bestType = type; - smallest = size[type]; + if(!error) { + for(y = 0; y != h; ++y) /*try the 5 filter types*/ { + for(type = 0; type != 5; ++type) { + unsigned testsize = (unsigned)linebytes; + /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/ + + filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); + size[type] = 0; + dummy = 0; + zlib_compress(&dummy, &size[type], attempt[type], testsize, &zlibsettings); + lodepng_free(dummy); + /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/ + if(type == 0 || size[type] < smallest) { + bestType = type; + smallest = size[type]; + } } + prevline = &in[y * linebytes]; + out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ + for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x]; } - prevline = &in[y * linebytes]; - out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ - for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x]; } for(type = 0; type != 5; ++type) lodepng_free(attempt[type]); } @@ -5446,18 +5592,15 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, } static void addPaddingBits(unsigned char* out, const unsigned char* in, - size_t olinebits, size_t ilinebits, unsigned h) -{ + size_t olinebits, size_t ilinebits, unsigned h) { /*The opposite of the removePaddingBits function olinebits must be >= ilinebits*/ unsigned y; size_t diff = olinebits - ilinebits; size_t obp = 0, ibp = 0; /*bit pointers*/ - for(y = 0; y != h; ++y) - { + for(y = 0; y != h; ++y) { size_t x; - for(x = 0; x < ilinebits; ++x) - { + for(x = 0; x < ilinebits; ++x) { unsigned char bit = readBitFromReversedStream(&ibp, in); setBitOfReversedStream(&obp, out, bit); } @@ -5478,47 +5621,37 @@ in has the following size in bits: w * h * bpp. out is possibly bigger due to padding bits between reduced images NOTE: comments about padding bits are only relevant if bpp < 8 */ -static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) -{ +static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) { unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; unsigned i; Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); - if(bpp >= 8) - { - for(i = 0; i != 7; ++i) - { + if(bpp >= 8) { + for(i = 0; i != 7; ++i) { unsigned x, y, b; - size_t bytewidth = bpp / 8; + size_t bytewidth = bpp / 8u; for(y = 0; y < passh[i]; ++y) - for(x = 0; x < passw[i]; ++x) - { + for(x = 0; x < passw[i]; ++x) { size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth; size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth; - for(b = 0; b < bytewidth; ++b) - { + for(b = 0; b < bytewidth; ++b) { out[pixeloutstart + b] = in[pixelinstart + b]; } } } - } - else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ - { - for(i = 0; i != 7; ++i) - { + } else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ { + for(i = 0; i != 7; ++i) { unsigned x, y, b; unsigned ilinebits = bpp * passw[i]; unsigned olinebits = bpp * w; size_t obp, ibp; /*bit pointers (for out and in buffer)*/ for(y = 0; y < passh[i]; ++y) - for(x = 0; x < passw[i]; ++x) - { + for(x = 0; x < passw[i]; ++x) { ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp; obp = (8 * passstart[i]) + (y * ilinebits + x * bpp); - for(b = 0; b < bpp; ++b) - { + for(b = 0; b < bpp; ++b) { unsigned char bit = readBitFromReversedStream(&ibp, in); setBitOfReversedStream(&obp, out, bit); } @@ -5531,45 +5664,36 @@ static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigne return value is error**/ static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in, unsigned w, unsigned h, - const LodePNGInfo* info_png, const LodePNGEncoderSettings* settings) -{ + const LodePNGInfo* info_png, const LodePNGEncoderSettings* settings) { /* This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps: - *) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp < 8) 2) filter + *) if no Adam7: 1) add padding bits (= possible extra bits per scanline if bpp < 8) 2) filter *) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter */ unsigned bpp = lodepng_get_bpp(&info_png->color); unsigned error = 0; - if(info_png->interlace_method == 0) - { - *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/ + if(info_png->interlace_method == 0) { + *outsize = h + (h * ((w * bpp + 7u) / 8u)); /*image size plus an extra byte per scanline + possible padding bits*/ *out = (unsigned char*)lodepng_malloc(*outsize); if(!(*out) && (*outsize)) error = 83; /*alloc fail*/ - if(!error) - { + if(!error) { /*non multiple of 8 bits per scanline, padding bits needed per scanline*/ - if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) - { - unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7) / 8)); + if(bpp < 8 && w * bpp != ((w * bpp + 7u) / 8u) * 8u) { + unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7u) / 8u)); if(!padded) error = 83; /*alloc fail*/ - if(!error) - { - addPaddingBits(padded, in, ((w * bpp + 7) / 8) * 8, w * bpp, h); + if(!error) { + addPaddingBits(padded, in, ((w * bpp + 7u) / 8u) * 8u, w * bpp, h); error = filter(*out, padded, w, h, &info_png->color, settings); } lodepng_free(padded); - } - else - { + } else { /*we can immediately filter into the out buffer, no other steps needed*/ error = filter(*out, in, w, h, &info_png->color, settings); } } - } - else /*interlace_method is 1 (Adam7)*/ - { + } else /*interlace_method is 1 (Adam7)*/ { unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; unsigned char* adam7; @@ -5583,25 +5707,20 @@ static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const adam7 = (unsigned char*)lodepng_malloc(passstart[7]); if(!adam7 && passstart[7]) error = 83; /*alloc fail*/ - if(!error) - { + if(!error) { unsigned i; Adam7_interlace(adam7, in, w, h, bpp); - for(i = 0; i != 7; ++i) - { - if(bpp < 8) - { + for(i = 0; i != 7; ++i) { + if(bpp < 8) { unsigned char* padded = (unsigned char*)lodepng_malloc(padded_passstart[i + 1] - padded_passstart[i]); if(!padded) ERROR_BREAK(83); /*alloc fail*/ addPaddingBits(padded, &adam7[passstart[i]], - ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]); + ((passw[i] * bpp + 7u) / 8u) * 8u, passw[i] * bpp, passh[i]); error = filter(&(*out)[filter_passstart[i]], padded, passw[i], passh[i], &info_png->color, settings); lodepng_free(padded); - } - else - { + } else { error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]], passw[i], passh[i], &info_png->color, settings); } @@ -5616,54 +5735,48 @@ static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const return error; } -/* -palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA... -returns 0 if the palette is opaque, -returns 1 if the palette has a single color with alpha 0 ==> color key -returns 2 if the palette is semi-translucent. -*/ -static unsigned getPaletteTranslucency(const unsigned char* palette, size_t palettesize) -{ - size_t i; - unsigned key = 0; - unsigned r = 0, g = 0, b = 0; /*the value of the color with alpha 0, so long as color keying is possible*/ - for(i = 0; i != palettesize; ++i) - { - if(!key && palette[4 * i + 3] == 0) - { - r = palette[4 * i + 0]; g = palette[4 * i + 1]; b = palette[4 * i + 2]; - key = 1; - i = (size_t)(-1); /*restart from beginning, to detect earlier opaque colors with key's value*/ - } - else if(palette[4 * i + 3] != 255) return 2; - /*when key, no opaque RGB may have key's RGB*/ - else if(key && r == palette[i * 4 + 0] && g == palette[i * 4 + 1] && b == palette[i * 4 + 2]) return 2; - } - return key; -} - #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize) -{ +static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize) { unsigned char* inchunk = data; - while((size_t)(inchunk - data) < datasize) - { + while((size_t)(inchunk - data) < datasize) { CERROR_TRY_RETURN(lodepng_chunk_append(&out->data, &out->size, inchunk)); out->allocsize = out->size; /*fix the allocsize again*/ - inchunk = lodepng_chunk_next(inchunk); + inchunk = lodepng_chunk_next(inchunk, data + datasize); } return 0; } + +static unsigned isGrayICCProfile(const unsigned char* profile, unsigned size) { + /* + It is a gray profile if bytes 16-19 are "GRAY", rgb profile if bytes 16-19 + are "RGB ". We do not perform any full parsing of the ICC profile here, other + than check those 4 bytes to grayscale profile. Other than that, validity of + the profile is not checked. This is needed only because the PNG specification + requires using a non-gray color model if there is an ICC profile with "RGB " + (sadly limiting compression opportunities if the input data is grayscale RGB + data), and requires using a gray color model if it is "GRAY". + */ + if(size < 20) return 0; + return profile[16] == 'G' && profile[17] == 'R' && profile[18] == 'A' && profile[19] == 'Y'; +} + +static unsigned isRGBICCProfile(const unsigned char* profile, unsigned size) { + /* See comment in isGrayICCProfile*/ + if(size < 20) return 0; + return profile[16] == 'R' && profile[17] == 'G' && profile[18] == 'B' && profile[19] == ' '; +} #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ unsigned lodepng_encode(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h, - LodePNGState* state) -{ - LodePNGInfo info; - ucvector outv; + LodePNGState* state) { unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/ size_t datasize = 0; + ucvector outv = ucvector_init(NULL, 0); + LodePNGInfo info; + const LodePNGInfo* info_png = &state->info_png; + + lodepng_info_init(&info); /*provide some proper output values if error will happen*/ *out = 0; @@ -5671,177 +5784,239 @@ unsigned lodepng_encode(unsigned char** out, size_t* outsize, state->error = 0; /*check input values validity*/ - if((state->info_png.color.colortype == LCT_PALETTE || state->encoder.force_palette) - && (state->info_png.color.palettesize == 0 || state->info_png.color.palettesize > 256)) - { - CERROR_RETURN_ERROR(state->error, 68); /*invalid palette size, it is only allowed to be 1-256*/ + if((info_png->color.colortype == LCT_PALETTE || state->encoder.force_palette) + && (info_png->color.palettesize == 0 || info_png->color.palettesize > 256)) { + state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/ + goto cleanup; } - if(state->encoder.zlibsettings.btype > 2) - { - CERROR_RETURN_ERROR(state->error, 61); /*error: unexisting btype*/ + if(state->encoder.zlibsettings.btype > 2) { + state->error = 61; /*error: invalid btype*/ + goto cleanup; } - if(state->info_png.interlace_method > 1) - { - CERROR_RETURN_ERROR(state->error, 71); /*error: unexisting interlace mode*/ + if(info_png->interlace_method > 1) { + state->error = 71; /*error: invalid interlace mode*/ + goto cleanup; } - state->error = checkColorValidity(state->info_png.color.colortype, state->info_png.color.bitdepth); - if(state->error) return state->error; /*error: unexisting color type given*/ + state->error = checkColorValidity(info_png->color.colortype, info_png->color.bitdepth); + if(state->error) goto cleanup; /*error: invalid color type given*/ state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth); - if(state->error) return state->error; /*error: unexisting color type given*/ + if(state->error) goto cleanup; /*error: invalid color type given*/ /* color convert and compute scanline filter types */ - lodepng_info_init(&info); lodepng_info_copy(&info, &state->info_png); - if(state->encoder.auto_convert) - { - state->error = lodepng_auto_choose_color(&info.color, image, w, h, &state->info_raw); - } - if (!state->error) - { - if(!lodepng_color_mode_equal(&state->info_raw, &info.color)) - { - unsigned char* converted; - size_t size = (w * h * (size_t)lodepng_get_bpp(&info.color) + 7) / 8; - - converted = (unsigned char*)lodepng_malloc(size); - if(!converted && size) state->error = 83; /*alloc fail*/ - if(!state->error) - { - state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h); + if(state->encoder.auto_convert) { + LodePNGColorStats stats; + lodepng_color_stats_init(&stats); +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + if(info_png->iccp_defined && + isGrayICCProfile(info_png->iccp_profile, info_png->iccp_profile_size)) { + /*the PNG specification does not allow to use palette with a GRAY ICC profile, even + if the palette has only gray colors, so disallow it.*/ + stats.allow_palette = 0; + } + if(info_png->iccp_defined && + isRGBICCProfile(info_png->iccp_profile, info_png->iccp_profile_size)) { + /*the PNG specification does not allow to use grayscale color with RGB ICC profile, so disallow gray.*/ + stats.allow_greyscale = 0; + } +#endif /* LODEPNG_COMPILE_ANCILLARY_CHUNKS */ + state->error = lodepng_compute_color_stats(&stats, image, w, h, &state->info_raw); + if(state->error) goto cleanup; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + if(info_png->background_defined) { + /*the background chunk's color must be taken into account as well*/ + unsigned r = 0, g = 0, b = 0; + LodePNGColorMode mode16 = lodepng_color_mode_make(LCT_RGB, 16); + lodepng_convert_rgb(&r, &g, &b, info_png->background_r, info_png->background_g, info_png->background_b, &mode16, &info_png->color); + state->error = lodepng_color_stats_add(&stats, r, g, b, 65535); + if(state->error) goto cleanup; + } +#endif /* LODEPNG_COMPILE_ANCILLARY_CHUNKS */ + state->error = auto_choose_color(&info.color, &state->info_raw, &stats); + if(state->error) goto cleanup; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + /*also convert the background chunk*/ + if(info_png->background_defined) { + if(lodepng_convert_rgb(&info.background_r, &info.background_g, &info.background_b, + info_png->background_r, info_png->background_g, info_png->background_b, &info.color, &info_png->color)) { + state->error = 104; + goto cleanup; } - if(!state->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder); - lodepng_free(converted); } - else preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder); +#endif /* LODEPNG_COMPILE_ANCILLARY_CHUNKS */ + } +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + if(info_png->iccp_defined) { + unsigned gray_icc = isGrayICCProfile(info_png->iccp_profile, info_png->iccp_profile_size); + unsigned rgb_icc = isRGBICCProfile(info_png->iccp_profile, info_png->iccp_profile_size); + unsigned gray_png = info.color.colortype == LCT_GREY || info.color.colortype == LCT_GREY_ALPHA; + if(!gray_icc && !rgb_icc) { + state->error = 100; /* Disallowed profile color type for PNG */ + goto cleanup; + } + if(gray_icc != gray_png) { + /*Not allowed to use RGB/RGBA/palette with GRAY ICC profile or vice versa, + or in case of auto_convert, it wasn't possible to find appropriate model*/ + state->error = state->encoder.auto_convert ? 102 : 101; + goto cleanup; + } } +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + if(!lodepng_color_mode_equal(&state->info_raw, &info.color)) { + unsigned char* converted; + size_t size = ((size_t)w * (size_t)h * (size_t)lodepng_get_bpp(&info.color) + 7u) / 8u; - /* output all PNG chunks */ - ucvector_init(&outv); - while(!state->error) /*while only executed once, to break on error*/ - { + converted = (unsigned char*)lodepng_malloc(size); + if(!converted && size) state->error = 83; /*alloc fail*/ + if(!state->error) { + state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h); + } + if(!state->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder); + lodepng_free(converted); + if(state->error) goto cleanup; + } + else preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder); + + /* output all PNG chunks */ { #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS size_t i; #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ /*write signature and chunks*/ - writeSignature(&outv); + state->error = writeSignature(&outv); + if(state->error) goto cleanup; /*IHDR*/ - addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method); + state->error = addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method); + if(state->error) goto cleanup; #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS /*unknown chunks between IHDR and PLTE*/ - if(info.unknown_chunks_data[0]) - { + if(info.unknown_chunks_data[0]) { state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0], info.unknown_chunks_size[0]); - if(state->error) break; + if(state->error) goto cleanup; } -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - /*PLTE*/ - if(info.color.colortype == LCT_PALETTE) - { - addChunk_PLTE(&outv, &info.color); + /*color profile chunks must come before PLTE */ + if(info.iccp_defined) { + state->error = addChunk_iCCP(&outv, &info, &state->encoder.zlibsettings); + if(state->error) goto cleanup; } - if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA)) - { - addChunk_PLTE(&outv, &info.color); + if(info.srgb_defined) { + state->error = addChunk_sRGB(&outv, &info); + if(state->error) goto cleanup; } - /*tRNS*/ - if(info.color.colortype == LCT_PALETTE && getPaletteTranslucency(info.color.palette, info.color.palettesize) != 0) - { - addChunk_tRNS(&outv, &info.color); + if(info.gama_defined) { + state->error = addChunk_gAMA(&outv, &info); + if(state->error) goto cleanup; } - if((info.color.colortype == LCT_GREY || info.color.colortype == LCT_RGB) && info.color.key_defined) - { - addChunk_tRNS(&outv, &info.color); + if(info.chrm_defined) { + state->error = addChunk_cHRM(&outv, &info); + if(state->error) goto cleanup; } +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + /*PLTE*/ + if(info.color.colortype == LCT_PALETTE) { + state->error = addChunk_PLTE(&outv, &info.color); + if(state->error) goto cleanup; + } + if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA)) { + /*force_palette means: write suggested palette for truecolor in PLTE chunk*/ + state->error = addChunk_PLTE(&outv, &info.color); + if(state->error) goto cleanup; + } + /*tRNS (this will only add if when necessary) */ + state->error = addChunk_tRNS(&outv, &info.color); + if(state->error) goto cleanup; #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS /*bKGD (must come between PLTE and the IDAt chunks*/ - if(info.background_defined) addChunk_bKGD(&outv, &info); + if(info.background_defined) { + state->error = addChunk_bKGD(&outv, &info); + if(state->error) goto cleanup; + } /*pHYs (must come before the IDAT chunks)*/ - if(info.phys_defined) addChunk_pHYs(&outv, &info); + if(info.phys_defined) { + state->error = addChunk_pHYs(&outv, &info); + if(state->error) goto cleanup; + } /*unknown chunks between PLTE and IDAT*/ - if(info.unknown_chunks_data[1]) - { + if(info.unknown_chunks_data[1]) { state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1], info.unknown_chunks_size[1]); - if(state->error) break; + if(state->error) goto cleanup; } #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ /*IDAT (multiple IDAT chunks must be consecutive)*/ state->error = addChunk_IDAT(&outv, data, datasize, &state->encoder.zlibsettings); - if(state->error) break; + if(state->error) goto cleanup; #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS /*tIME*/ - if(info.time_defined) addChunk_tIME(&outv, &info.time); + if(info.time_defined) { + state->error = addChunk_tIME(&outv, &info.time); + if(state->error) goto cleanup; + } /*tEXt and/or zTXt*/ - for(i = 0; i != info.text_num; ++i) - { - if(strlen(info.text_keys[i]) > 79) - { + for(i = 0; i != info.text_num; ++i) { + if(lodepng_strlen(info.text_keys[i]) > 79) { state->error = 66; /*text chunk too large*/ - break; + goto cleanup; } - if(strlen(info.text_keys[i]) < 1) - { + if(lodepng_strlen(info.text_keys[i]) < 1) { state->error = 67; /*text chunk too small*/ - break; - } - if(state->encoder.text_compression) - { - addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings); + goto cleanup; } - else - { - addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]); + if(state->encoder.text_compression) { + state->error = addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings); + if(state->error) goto cleanup; + } else { + state->error = addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]); + if(state->error) goto cleanup; } } /*LodePNG version id in text chunk*/ - if(state->encoder.add_id) - { - unsigned alread_added_id_text = 0; - for(i = 0; i != info.text_num; ++i) - { - if(!strcmp(info.text_keys[i], "LodePNG")) - { - alread_added_id_text = 1; + if(state->encoder.add_id) { + unsigned already_added_id_text = 0; + for(i = 0; i != info.text_num; ++i) { + const char* k = info.text_keys[i]; + /* Could use strcmp, but we're not calling or reimplementing this C library function for this use only */ + if(k[0] == 'L' && k[1] == 'o' && k[2] == 'd' && k[3] == 'e' && + k[4] == 'P' && k[5] == 'N' && k[6] == 'G' && k[7] == '\0') { + already_added_id_text = 1; break; } } - if(alread_added_id_text == 0) - { - addChunk_tEXt(&outv, "LodePNG", LODEPNG_VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/ + if(already_added_id_text == 0) { + state->error = addChunk_tEXt(&outv, "LodePNG", LODEPNG_VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/ + if(state->error) goto cleanup; } } /*iTXt*/ - for(i = 0; i != info.itext_num; ++i) - { - if(strlen(info.itext_keys[i]) > 79) - { + for(i = 0; i != info.itext_num; ++i) { + if(lodepng_strlen(info.itext_keys[i]) > 79) { state->error = 66; /*text chunk too large*/ - break; + goto cleanup; } - if(strlen(info.itext_keys[i]) < 1) - { + if(lodepng_strlen(info.itext_keys[i]) < 1) { state->error = 67; /*text chunk too small*/ - break; + goto cleanup; } - addChunk_iTXt(&outv, state->encoder.text_compression, - info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i], - &state->encoder.zlibsettings); + state->error = addChunk_iTXt( + &outv, state->encoder.text_compression, + info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i], + &state->encoder.zlibsettings); + if(state->error) goto cleanup; } /*unknown chunks between IDAT and IEND*/ - if(info.unknown_chunks_data[2]) - { + if(info.unknown_chunks_data[2]) { state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2], info.unknown_chunks_size[2]); - if(state->error) break; + if(state->error) goto cleanup; } #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - addChunk_IEND(&outv); - - break; /*this isn't really a while loop; no error happened so break out now!*/ + state->error = addChunk_IEND(&outv); + if(state->error) goto cleanup; } +cleanup: lodepng_info_cleanup(&info); lodepng_free(data); + /*instead of cleaning the vector up, give it to the output*/ *out = outv.data; *outsize = outv.size; @@ -5850,8 +6025,7 @@ unsigned lodepng_encode(unsigned char** out, size_t* outsize, } unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsigned char* image, - unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) -{ + unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) { unsigned error; LodePNGState state; lodepng_state_init(&state); @@ -5865,20 +6039,17 @@ unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsig return error; } -unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) -{ +unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) { return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGBA, 8); } -unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) -{ +unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) { return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGB, 8); } #ifdef LODEPNG_COMPILE_DISK unsigned lodepng_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth) -{ + LodePNGColorType colortype, unsigned bitdepth) { unsigned char* buffer; size_t buffersize; unsigned error = lodepng_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth); @@ -5887,19 +6058,16 @@ unsigned lodepng_encode_file(const char* filename, const unsigned char* image, u return error; } -unsigned lodepng_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) -{ +unsigned lodepng_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) { return lodepng_encode_file(filename, image, w, h, LCT_RGBA, 8); } -unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) -{ +unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) { return lodepng_encode_file(filename, image, w, h, LCT_RGB, 8); } #endif /*LODEPNG_COMPILE_DISK*/ -void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings) -{ +void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings) { lodepng_compress_settings_init(&settings->zlibsettings); settings->filter_palette_zero = 1; settings->filter_strategy = LFS_MINSUM; @@ -5920,10 +6088,8 @@ void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings) This returns the description of a numerical error code in English. This is also the documentation of all the error codes. */ -const char* lodepng_error_text(unsigned code) -{ - switch(code) - { +const char* lodepng_error_text(unsigned code) { + switch(code) { case 0: return "no error, everything went ok"; case 1: return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, error checking makes no sense yet*/ case 10: return "end of input memory reached without huffman end code"; /*while huffman decoding*/ @@ -5931,16 +6097,18 @@ const char* lodepng_error_text(unsigned code) case 13: return "problem while processing dynamic deflate block"; case 14: return "problem while processing dynamic deflate block"; case 15: return "problem while processing dynamic deflate block"; - case 16: return "unexisting code while processing dynamic deflate block"; + /*this error could happen if there are only 0 or 1 symbols present in the huffman code:*/ + case 16: return "invalid code while processing dynamic deflate block"; case 17: return "end of out buffer memory reached while inflating"; case 18: return "invalid distance code while inflating"; case 19: return "end of out buffer memory reached while inflating"; case 20: return "invalid deflate block BTYPE encountered while decoding"; case 21: return "NLEN is not ones complement of LEN in a deflate block"; - /*end of out buffer memory reached while inflating: - This can happen if the inflated deflate data is longer than the amount of bytes required to fill up - all the pixels of the image, given the color depth and image dimensions. Something that doesn't - happen in a normal, well encoded, PNG image.*/ + + /*end of out buffer memory reached while inflating: + This can happen if the inflated deflate data is longer than the amount of bytes required to fill up + all the pixels of the image, given the color depth and image dimensions. Something that doesn't + happen in a normal, well encoded, PNG image.*/ case 22: return "end of out buffer memory reached while inflating"; case 23: return "end of in buffer memory reached while inflating"; case 24: return "invalid FCHECK in zlib header"; @@ -5958,13 +6126,13 @@ const char* lodepng_error_text(unsigned code) case 35: return "chunk length of a chunk is too large or the chunk too small"; case 36: return "illegal PNG filter type encountered"; case 37: return "illegal bit depth for this color type given"; - case 38: return "the palette is too big"; /*more than 256 colors*/ - case 39: return "more palette alpha values given in tRNS chunk than there are colors in the palette"; - case 40: return "tRNS chunk has wrong size for greyscale image"; + case 38: return "the palette is too small or too big"; /*0, or more than 256 colors*/ + case 39: return "tRNS chunk before PLTE or has more entries than palette size"; + case 40: return "tRNS chunk has wrong size for grayscale image"; case 41: return "tRNS chunk has wrong size for RGB image"; case 42: return "tRNS chunk appeared while it was not allowed for this color type"; case 43: return "bKGD chunk has wrong size for palette image"; - case 44: return "bKGD chunk has wrong size for greyscale image"; + case 44: return "bKGD chunk has wrong size for grayscale image"; case 45: return "bKGD chunk has wrong size for RGB image"; case 48: return "empty input buffer given to decoder. Maybe caused by non-existing file?"; case 49: return "jumped past memory while generating dynamic huffman tree"; @@ -5975,7 +6143,7 @@ const char* lodepng_error_text(unsigned code) case 54: return "repeat symbol in tree while there was no value symbol yet"; /*jumped past tree while generating huffman tree, this could be when the tree will have more leaves than symbols after generating it out of the - given lenghts. They call this an oversubscribed dynamic bit lengths tree in zlib.*/ + given lengths. They call this an oversubscribed dynamic bit lengths tree in zlib.*/ case 55: return "jumped past tree while generating huffman tree"; case 56: return "given output image colortype or bitdepth not supported for color conversion"; case 57: return "invalid CRC encountered (checking CRC can be disabled)"; @@ -5983,17 +6151,18 @@ const char* lodepng_error_text(unsigned code) case 59: return "requested color conversion not supported"; case 60: return "invalid window size given in the settings of the encoder (must be 0-32768)"; case 61: return "invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed)"; - /*LodePNG leaves the choice of RGB to greyscale conversion formula to the user.*/ - case 62: return "conversion from color to greyscale not supported"; - case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk"; /*(2^31-1)*/ + /*LodePNG leaves the choice of RGB to grayscale conversion formula to the user.*/ + case 62: return "conversion from color to grayscale not supported"; + /*(2^31-1)*/ + case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk"; /*this would result in the inability of a deflated block to ever contain an end code. It must be at least 1.*/ case 64: return "the length of the END symbol 256 in the Huffman tree is 0"; case 66: return "the length of a text chunk keyword given to the encoder is longer than the maximum of 79 bytes"; case 67: return "the length of a text chunk keyword given to the encoder is smaller than the minimum of 1 byte"; case 68: return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors"; case 69: return "unknown chunk type with 'critical' flag encountered by the decoder"; - case 71: return "unexisting interlace mode given to encoder (must be 0 or 1)"; - case 72: return "while decoding, unexisting compression method encountering in zTXt or iTXt chunk (it must be 0)"; + case 71: return "invalid interlace mode given to encoder (must be 0 or 1)"; + case 72: return "while decoding, invalid compression method encountering in zTXt or iTXt chunk (it must be 0)"; case 73: return "invalid tIME chunk size"; case 74: return "invalid pHYs chunk size"; /*length could be wrong, or data chopped off*/ @@ -6004,7 +6173,7 @@ const char* lodepng_error_text(unsigned code) case 79: return "failed to open file for writing"; case 80: return "tried creating a tree of 0 symbols"; case 81: return "lazy matching at pos 0 is impossible"; - case 82: return "color conversion to palette requested while a color isn't in palette"; + case 82: return "color conversion to palette requested while a color isn't in palette, or index out of bounds"; case 83: return "memory allocation failed"; case 84: return "given image too small to contain all pixels to be encoded"; case 86: return "impossible offset in lz77 encoding (internal bug)"; @@ -6014,9 +6183,23 @@ const char* lodepng_error_text(unsigned code) /*the windowsize in the LodePNGCompressSettings. Requiring POT(==> & instead of %) makes encoding 12% faster.*/ case 90: return "windowsize must be a power of two"; case 91: return "invalid decompressed idat size"; - case 92: return "too many pixels, not supported"; + case 92: return "integer overflow due to too many pixels"; case 93: return "zero width or height is invalid"; case 94: return "header chunk must have a size of 13 bytes"; + case 95: return "integer overflow with combined idat chunk size"; + case 96: return "invalid gAMA chunk size"; + case 97: return "invalid cHRM chunk size"; + case 98: return "invalid sRGB chunk size"; + case 99: return "invalid sRGB rendering intent"; + case 100: return "invalid ICC profile color type, the PNG specification only allows RGB or GRAY"; + case 101: return "PNG specification does not allow RGB ICC profile on gray color types and vice versa"; + case 102: return "not allowed to set grayscale ICC profile with colored pixels by PNG specification"; + case 103: return "invalid palette index in bKGD chunk. Maybe it came before PLTE chunk?"; + case 104: return "invalid bKGD color while encoding (e.g. palette index out of range)"; + case 105: return "integer overflow of bitsize"; + case 106: return "PNG file must have PLTE chunk if color type is palette"; + case 107: return "color convert from palette mode requested without setting the palette data in it"; + case 108: return "tried to add more than 256 values to a palette"; } return "unknown error code"; } @@ -6029,12 +6212,10 @@ const char* lodepng_error_text(unsigned code) /* ////////////////////////////////////////////////////////////////////////// */ #ifdef LODEPNG_COMPILE_CPP -namespace lodepng -{ +namespace lodepng { #ifdef LODEPNG_COMPILE_DISK -unsigned load_file(std::vector<unsigned char>& buffer, const std::string& filename) -{ +unsigned load_file(std::vector<unsigned char>& buffer, const std::string& filename) { long size = lodepng_filesize(filename.c_str()); if(size < 0) return 78; buffer.resize((size_t)size); @@ -6042,8 +6223,7 @@ unsigned load_file(std::vector<unsigned char>& buffer, const std::string& filena } /*write given buffer to the file, overwriting the file, it doesn't append to it.*/ -unsigned save_file(const std::vector<unsigned char>& buffer, const std::string& filename) -{ +unsigned save_file(const std::vector<unsigned char>& buffer, const std::string& filename) { return lodepng_save_file(buffer.empty() ? 0 : &buffer[0], buffer.size(), filename.c_str()); } #endif /* LODEPNG_COMPILE_DISK */ @@ -6051,13 +6231,11 @@ unsigned save_file(const std::vector<unsigned char>& buffer, const std::string& #ifdef LODEPNG_COMPILE_ZLIB #ifdef LODEPNG_COMPILE_DECODER unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize, - const LodePNGDecompressSettings& settings) -{ + const LodePNGDecompressSettings& settings) { unsigned char* buffer = 0; size_t buffersize = 0; - unsigned error = zlib_decompress(&buffer, &buffersize, in, insize, &settings); - if(buffer) - { + unsigned error = zlib_decompress(&buffer, &buffersize, 0, in, insize, &settings); + if(buffer) { out.insert(out.end(), &buffer[0], &buffer[buffersize]); lodepng_free(buffer); } @@ -6065,21 +6243,18 @@ unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, si } unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, - const LodePNGDecompressSettings& settings) -{ + const LodePNGDecompressSettings& settings) { return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings); } #endif /* LODEPNG_COMPILE_DECODER */ #ifdef LODEPNG_COMPILE_ENCODER unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize, - const LodePNGCompressSettings& settings) -{ + const LodePNGCompressSettings& settings) { unsigned char* buffer = 0; size_t buffersize = 0; unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings); - if(buffer) - { + if(buffer) { out.insert(out.end(), &buffer[0], &buffer[buffersize]); lodepng_free(buffer); } @@ -6087,8 +6262,7 @@ unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size } unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, - const LodePNGCompressSettings& settings) -{ + const LodePNGCompressSettings& settings) { return compress(out, in.empty() ? 0 : &in[0], in.size(), settings); } #endif /* LODEPNG_COMPILE_ENCODER */ @@ -6097,24 +6271,20 @@ unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned ch #ifdef LODEPNG_COMPILE_PNG -State::State() -{ +State::State() { lodepng_state_init(this); } -State::State(const State& other) -{ +State::State(const State& other) { lodepng_state_init(this); lodepng_state_copy(this, &other); } -State::~State() -{ +State::~State() { lodepng_state_cleanup(this); } -State& State::operator=(const State& other) -{ +State& State::operator=(const State& other) { lodepng_state_copy(this, &other); return *this; } @@ -6122,36 +6292,31 @@ State& State::operator=(const State& other) #ifdef LODEPNG_COMPILE_DECODER unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in, - size_t insize, LodePNGColorType colortype, unsigned bitdepth) -{ - unsigned char* buffer; + size_t insize, LodePNGColorType colortype, unsigned bitdepth) { + unsigned char* buffer = 0; unsigned error = lodepng_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth); - if(buffer && !error) - { + if(buffer && !error) { State state; state.info_raw.colortype = colortype; state.info_raw.bitdepth = bitdepth; size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw); out.insert(out.end(), &buffer[0], &buffer[buffersize]); - lodepng_free(buffer); } + lodepng_free(buffer); return error; } unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - const std::vector<unsigned char>& in, LodePNGColorType colortype, unsigned bitdepth) -{ + const std::vector<unsigned char>& in, LodePNGColorType colortype, unsigned bitdepth) { return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colortype, bitdepth); } unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, State& state, - const unsigned char* in, size_t insize) -{ + const unsigned char* in, size_t insize) { unsigned char* buffer = NULL; unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize); - if(buffer && !error) - { + if(buffer && !error) { size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw); out.insert(out.end(), &buffer[0], &buffer[buffersize]); } @@ -6161,16 +6326,16 @@ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, State& state, - const std::vector<unsigned char>& in) -{ + const std::vector<unsigned char>& in) { return decode(out, w, h, state, in.empty() ? 0 : &in[0], in.size()); } #ifdef LODEPNG_COMPILE_DISK unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename, - LodePNGColorType colortype, unsigned bitdepth) -{ + LodePNGColorType colortype, unsigned bitdepth) { std::vector<unsigned char> buffer; + /* safe output values in case error happens */ + w = h = 0; unsigned error = load_file(buffer, filename); if(error) return error; return decode(out, w, h, buffer, colortype, bitdepth); @@ -6180,13 +6345,11 @@ unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const #ifdef LODEPNG_COMPILE_ENCODER unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth) -{ + LodePNGColorType colortype, unsigned bitdepth) { unsigned char* buffer; size_t buffersize; unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth); - if(buffer) - { + if(buffer) { out.insert(out.end(), &buffer[0], &buffer[buffersize]); lodepng_free(buffer); } @@ -6195,21 +6358,18 @@ unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsign unsigned encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth) -{ + LodePNGColorType colortype, unsigned bitdepth) { if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84; return encode(out, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth); } unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h, - State& state) -{ + State& state) { unsigned char* buffer; size_t buffersize; unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state); - if(buffer) - { + if(buffer) { out.insert(out.end(), &buffer[0], &buffer[buffersize]); lodepng_free(buffer); } @@ -6218,8 +6378,7 @@ unsigned encode(std::vector<unsigned char>& out, unsigned encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, unsigned w, unsigned h, - State& state) -{ + State& state) { if(lodepng_get_raw_size(w, h, &state.info_raw) > in.size()) return 84; return encode(out, in.empty() ? 0 : &in[0], w, h, state); } @@ -6227,8 +6386,7 @@ unsigned encode(std::vector<unsigned char>& out, #ifdef LODEPNG_COMPILE_DISK unsigned encode(const std::string& filename, const unsigned char* in, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth) -{ + LodePNGColorType colortype, unsigned bitdepth) { std::vector<unsigned char> buffer; unsigned error = encode(buffer, in, w, h, colortype, bitdepth); if(!error) error = save_file(buffer, filename); @@ -6237,8 +6395,7 @@ unsigned encode(const std::string& filename, unsigned encode(const std::string& filename, const std::vector<unsigned char>& in, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth) -{ + LodePNGColorType colortype, unsigned bitdepth) { if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84; return encode(filename, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth); } @@ -1,7 +1,7 @@ /* -LodePNG version 20180326 +LodePNG version 20200306 -Copyright (c) 2005-2018 Lode Vandevenne +Copyright (c) 2005-2020 Lode Vandevenne This software is provided 'as-is', without any express or implied warranty. In no event will the authors be held liable for any damages @@ -44,36 +44,44 @@ the custom_zlib field of the compress and decompress settings*/ #ifndef LODEPNG_NO_COMPILE_ZLIB #define LODEPNG_COMPILE_ZLIB #endif + /*png encoder and png decoder*/ #ifndef LODEPNG_NO_COMPILE_PNG #define LODEPNG_COMPILE_PNG #endif + /*deflate&zlib decoder and png decoder*/ #ifndef LODEPNG_NO_COMPILE_DECODER #define LODEPNG_COMPILE_DECODER #endif + /*deflate&zlib encoder and png encoder*/ #ifndef LODEPNG_NO_COMPILE_ENCODER #define LODEPNG_COMPILE_ENCODER #endif + /*the optional built in harddisk file loading and saving functions*/ #ifndef LODEPNG_NO_COMPILE_DISK #define LODEPNG_COMPILE_DISK #endif + /*support for chunks other than IHDR, IDAT, PLTE, tRNS, IEND: ancillary and unknown chunks*/ #ifndef LODEPNG_NO_COMPILE_ANCILLARY_CHUNKS #define LODEPNG_COMPILE_ANCILLARY_CHUNKS #endif + /*ability to convert error numerical codes to English text string*/ #ifndef LODEPNG_NO_COMPILE_ERROR_TEXT #define LODEPNG_COMPILE_ERROR_TEXT #endif + /*Compile the default allocators (C's free, malloc and realloc). If you disable this, you can define the functions lodepng_free, lodepng_malloc and lodepng_realloc in your source files with custom allocators.*/ #ifndef LODEPNG_NO_COMPILE_ALLOCATORS #define LODEPNG_COMPILE_ALLOCATORS #endif + /*compile the C++ version (you can disable the C++ wrapper here even when compiling for C++)*/ #ifdef __cplusplus #ifndef LODEPNG_NO_COMPILE_CPP @@ -87,14 +95,19 @@ source files with custom allocators.*/ #endif /*LODEPNG_COMPILE_CPP*/ #ifdef LODEPNG_COMPILE_PNG -/*The PNG color types (also used for raw).*/ -typedef enum LodePNGColorType -{ - LCT_GREY = 0, /*greyscale: 1,2,4,8,16 bit*/ +/*The PNG color types (also used for raw image).*/ +typedef enum LodePNGColorType { + LCT_GREY = 0, /*grayscale: 1,2,4,8,16 bit*/ LCT_RGB = 2, /*RGB: 8,16 bit*/ LCT_PALETTE = 3, /*palette: 1,2,4,8 bit*/ - LCT_GREY_ALPHA = 4, /*greyscale with alpha: 8,16 bit*/ - LCT_RGBA = 6 /*RGB with alpha: 8,16 bit*/ + LCT_GREY_ALPHA = 4, /*grayscale with alpha: 8,16 bit*/ + LCT_RGBA = 6, /*RGB with alpha: 8,16 bit*/ + /*LCT_MAX_OCTET_VALUE lets the compiler allow this enum to represent any invalid + byte value from 0 to 255 that could be present in an invalid PNG file header. Do + not use, compare with or set the name LCT_MAX_OCTET_VALUE, instead either use + the valid color type names above, or numeric values like 1 or 7 when checking for + particular disallowed color type byte values, or cast to integer to print it.*/ + LCT_MAX_OCTET_VALUE = 255 } LodePNGColorType; #ifdef LODEPNG_COMPILE_DECODER @@ -196,8 +209,7 @@ unsigned lodepng_encode24_file(const char* filename, #ifdef LODEPNG_COMPILE_CPP -namespace lodepng -{ +namespace lodepng { #ifdef LODEPNG_COMPILE_DECODER /*Same as lodepng_decode_memory, but decodes to an std::vector. The colortype is the format to output the pixels to. Default is RGBA 8-bit per channel.*/ @@ -253,18 +265,17 @@ const char* lodepng_error_text(unsigned code); #ifdef LODEPNG_COMPILE_DECODER /*Settings for zlib decompression*/ typedef struct LodePNGDecompressSettings LodePNGDecompressSettings; -struct LodePNGDecompressSettings -{ - /* Check LodePNGDecoderSettings for more ignorable errors */ +struct LodePNGDecompressSettings { + /* Check LodePNGDecoderSettings for more ignorable errors such as ignore_crc */ unsigned ignore_adler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/ + unsigned ignore_nlen; /*ignore complement of len checksum in uncompressed blocks*/ /*use custom zlib decoder instead of built in one (default: null)*/ unsigned (*custom_zlib)(unsigned char**, size_t*, const unsigned char*, size_t, const LodePNGDecompressSettings*); /*use custom deflate decoder instead of built in one (default: null) - if custom_zlib is used, custom_deflate is ignored since only the built in - zlib function will call custom_deflate*/ + if custom_zlib is not null, custom_inflate is ignored (the zlib format uses deflate)*/ unsigned (*custom_inflate)(unsigned char**, size_t*, const unsigned char*, size_t, const LodePNGDecompressSettings*); @@ -282,13 +293,12 @@ Settings for zlib compression. Tweaking these settings tweaks the balance between speed and compression ratio. */ typedef struct LodePNGCompressSettings LodePNGCompressSettings; -struct LodePNGCompressSettings /*deflate = compress*/ -{ +struct LodePNGCompressSettings /*deflate = compress*/ { /*LZ77 related settings*/ unsigned btype; /*the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression.*/ unsigned use_lz77; /*whether or not to use LZ77. Should be 1 for proper compression.*/ unsigned windowsize; /*must be a power of two <= 32768. higher compresses more but is slower. Default value: 2048.*/ - unsigned minmatch; /*mininum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0*/ + unsigned minmatch; /*minimum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0*/ unsigned nicematch; /*stop searching if >= this length found. Set to 258 for best compression. Default: 128*/ unsigned lazymatching; /*use lazy matching: better compression but a bit slower. Default: true*/ @@ -316,8 +326,7 @@ Color mode of an image. Contains all information required to decode the pixel bits to RGBA colors. This information is the same as used in the PNG file format, and is used both for PNG and raw image data in LodePNG. */ -typedef struct LodePNGColorMode -{ +typedef struct LodePNGColorMode { /*header (IHDR)*/ LodePNGColorType colortype; /*color type, see PNG standard or documentation further in this header file*/ unsigned bitdepth; /*bits per sample, see PNG standard or documentation further in this header file*/ @@ -326,23 +335,25 @@ typedef struct LodePNGColorMode palette (PLTE and tRNS) Dynamically allocated with the colors of the palette, including alpha. - When encoding a PNG, to store your colors in the palette of the LodePNGColorMode, first use - lodepng_palette_clear, then for each color use lodepng_palette_add. - If you encode an image without alpha with palette, don't forget to put value 255 in each A byte of the palette. + This field may not be allocated directly, use lodepng_color_mode_init first, + then lodepng_palette_add per color to correctly initialize it (to ensure size + of exactly 1024 bytes). + + The alpha channels must be set as well, set them to 255 for opaque images. When decoding, by default you can ignore this palette, since LodePNG already fills the palette colors in the pixels of the raw RGBA output. The palette is only supported for color type 3. */ - unsigned char* palette; /*palette in RGBARGBA... order. When allocated, must be either 0, or have size 1024*/ - size_t palettesize; /*palette size in number of colors (amount of bytes is 4 * palettesize)*/ + unsigned char* palette; /*palette in RGBARGBA... order. Must be either 0, or when allocated must have 1024 bytes*/ + size_t palettesize; /*palette size in number of colors (amount of used bytes is 4 * palettesize)*/ /* transparent color key (tRNS) This color uses the same bit depth as the bitdepth value in this struct, which can be 1-bit to 16-bit. - For greyscale PNGs, r, g and b will all 3 be set to the same. + For grayscale PNGs, r, g and b will all 3 be set to the same. When decoding, by default you can ignore this information, since LodePNG sets pixels with this key to transparent already in the raw RGBA output. @@ -350,7 +361,7 @@ typedef struct LodePNGColorMode The color key is only supported for color types 0 and 2. */ unsigned key_defined; /*is a transparent color key given? 0 = false, 1 = true*/ - unsigned key_r; /*red/greyscale component of color key*/ + unsigned key_r; /*red/grayscale component of color key*/ unsigned key_g; /*green component of color key*/ unsigned key_b; /*blue component of color key*/ } LodePNGColorMode; @@ -360,6 +371,8 @@ void lodepng_color_mode_init(LodePNGColorMode* info); void lodepng_color_mode_cleanup(LodePNGColorMode* info); /*return value is error code (0 means no error)*/ unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source); +/* Makes a temporary LodePNGColorMode that does not need cleanup (no palette) */ +LodePNGColorMode lodepng_color_mode_make(LodePNGColorType colortype, unsigned bitdepth); void lodepng_palette_clear(LodePNGColorMode* info); /*add 1 color to the palette*/ @@ -371,7 +384,7 @@ unsigned lodepng_get_bpp(const LodePNGColorMode* info); /*get the amount of color channels used, based on colortype in the struct. If a palette is used, it counts as 1 channel.*/ unsigned lodepng_get_channels(const LodePNGColorMode* info); -/*is it a greyscale type? (only colortype 0 or 4)*/ +/*is it a grayscale type? (only colortype 0 or 4)*/ unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info); /*has it got an alpha channel? (only colortype 2 or 6)*/ unsigned lodepng_is_alpha_type(const LodePNGColorMode* info); @@ -393,8 +406,7 @@ size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* colo #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS /*The information of a Time chunk in PNG.*/ -typedef struct LodePNGTime -{ +typedef struct LodePNGTime { unsigned year; /*2 bytes used (0-65535)*/ unsigned month; /*1-12*/ unsigned day; /*1-31*/ @@ -405,28 +417,39 @@ typedef struct LodePNGTime #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ /*Information about the PNG image, except pixels, width and height.*/ -typedef struct LodePNGInfo -{ +typedef struct LodePNGInfo { /*header (IHDR), palette (PLTE) and transparency (tRNS) chunks*/ unsigned compression_method;/*compression method of the original file. Always 0.*/ unsigned filter_method; /*filter method of the original file*/ - unsigned interlace_method; /*interlace method of the original file*/ + unsigned interlace_method; /*interlace method of the original file: 0=none, 1=Adam7*/ LodePNGColorMode color; /*color type and bits, palette and transparency of the PNG file*/ #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS /* - suggested background color chunk (bKGD) - This color uses the same color mode as the PNG (except alpha channel), which can be 1-bit to 16-bit. + Suggested background color chunk (bKGD) + + This uses the same color mode and bit depth as the PNG (except no alpha channel), + with values truncated to the bit depth in the unsigned integer. + + For grayscale and palette PNGs, the value is stored in background_r. The values + in background_g and background_b are then unused. - For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding - the encoder writes the red one. For palette PNGs: When decoding, the RGB value - will be stored, not a palette index. But when encoding, specify the index of - the palette in background_r, the other two are then ignored. + So when decoding, you may get these in a different color mode than the one you requested + for the raw pixels. - The decoder does not use this background color to edit the color of pixels. + When encoding with auto_convert, you must use the color model defined in info_png.color for + these values. The encoder normally ignores info_png.color when auto_convert is on, but will + use it to interpret these values (and convert copies of them to its chosen color model). + + When encoding, avoid setting this to an expensive color, such as a non-gray value + when the image is gray, or the compression will be worse since it will be forced to + write the PNG with a more expensive color mode (when auto_convert is on). + + The decoder does not use this background color to edit the color of pixels. This is a + completely optional metadata feature. */ unsigned background_defined; /*is a suggested background color given?*/ - unsigned background_r; /*red component of suggested background color*/ + unsigned background_r; /*red/gray/palette component of suggested background color*/ unsigned background_g; /*green component of suggested background color*/ unsigned background_b; /*blue component of suggested background color*/ @@ -437,6 +460,10 @@ typedef struct LodePNGInfo text_strings, while text_keys are keywords that give a short description what the actual text represents, e.g. Title, Author, Description, or anything else. + All the string fields below including keys, names and language tags are null terminated. + The PNG specification uses null characters for the keys, names and tags, and forbids null + characters to appear in the main text which is why we can use null termination everywhere here. + A keyword is minimum 1 character and maximum 79 characters long. It's discouraged to use a single line length longer than 79 characters for texts. @@ -469,11 +496,86 @@ typedef struct LodePNGInfo unsigned phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/ /* - unknown chunks - There are 3 buffers, one for each position in the PNG where unknown chunks can appear - each buffer contains all unknown chunks for that position consecutively - The 3 buffers are the unknown chunks between certain critical chunks: - 0: IHDR-PLTE, 1: PLTE-IDAT, 2: IDAT-IEND + Color profile related chunks: gAMA, cHRM, sRGB, iCPP + + LodePNG does not apply any color conversions on pixels in the encoder or decoder and does not interpret these color + profile values. It merely passes on the information. If you wish to use color profiles and convert colors, please + use these values with a color management library. + + See the PNG, ICC and sRGB specifications for more information about the meaning of these values. + */ + + /* gAMA chunk: optional, overridden by sRGB or iCCP if those are present. */ + unsigned gama_defined; /* Whether a gAMA chunk is present (0 = not present, 1 = present). */ + unsigned gama_gamma; /* Gamma exponent times 100000 */ + + /* cHRM chunk: optional, overridden by sRGB or iCCP if those are present. */ + unsigned chrm_defined; /* Whether a cHRM chunk is present (0 = not present, 1 = present). */ + unsigned chrm_white_x; /* White Point x times 100000 */ + unsigned chrm_white_y; /* White Point y times 100000 */ + unsigned chrm_red_x; /* Red x times 100000 */ + unsigned chrm_red_y; /* Red y times 100000 */ + unsigned chrm_green_x; /* Green x times 100000 */ + unsigned chrm_green_y; /* Green y times 100000 */ + unsigned chrm_blue_x; /* Blue x times 100000 */ + unsigned chrm_blue_y; /* Blue y times 100000 */ + + /* + sRGB chunk: optional. May not appear at the same time as iCCP. + If gAMA is also present gAMA must contain value 45455. + If cHRM is also present cHRM must contain respectively 31270,32900,64000,33000,30000,60000,15000,6000. + */ + unsigned srgb_defined; /* Whether an sRGB chunk is present (0 = not present, 1 = present). */ + unsigned srgb_intent; /* Rendering intent: 0=perceptual, 1=rel. colorimetric, 2=saturation, 3=abs. colorimetric */ + + /* + iCCP chunk: optional. May not appear at the same time as sRGB. + + LodePNG does not parse or use the ICC profile (except its color space header field for an edge case), a + separate library to handle the ICC data (not included in LodePNG) format is needed to use it for color + management and conversions. + + For encoding, if iCCP is present, gAMA and cHRM are recommended to be added as well with values that match the ICC + profile as closely as possible, if you wish to do this you should provide the correct values for gAMA and cHRM and + enable their '_defined' flags since LodePNG will not automatically compute them from the ICC profile. + + For encoding, the ICC profile is required by the PNG specification to be an "RGB" profile for non-gray + PNG color types and a "GRAY" profile for gray PNG color types. If you disable auto_convert, you must ensure + the ICC profile type matches your requested color type, else the encoder gives an error. If auto_convert is + enabled (the default), and the ICC profile is not a good match for the pixel data, this will result in an encoder + error if the pixel data has non-gray pixels for a GRAY profile, or a silent less-optimal compression of the pixel + data if the pixels could be encoded as grayscale but the ICC profile is RGB. + + To avoid this do not set an ICC profile in the image unless there is a good reason for it, and when doing so + make sure you compute it carefully to avoid the above problems. + */ + unsigned iccp_defined; /* Whether an iCCP chunk is present (0 = not present, 1 = present). */ + char* iccp_name; /* Null terminated string with profile name, 1-79 bytes */ + /* + The ICC profile in iccp_profile_size bytes. + Don't allocate this buffer yourself. Use the init/cleanup functions + correctly and use lodepng_set_icc and lodepng_clear_icc. + */ + unsigned char* iccp_profile; + unsigned iccp_profile_size; /* The size of iccp_profile in bytes */ + + /* End of color profile related chunks */ + + + /* + unknown chunks: chunks not known by LodePNG, passed on byte for byte. + + There are 3 buffers, one for each position in the PNG where unknown chunks can appear. + Each buffer contains all unknown chunks for that position consecutively. + The 3 positions are: + 0: between IHDR and PLTE, 1: between PLTE and IDAT, 2: between IDAT and IEND. + + For encoding, do not store critical chunks or known chunks that are enabled with a "_defined" flag + above in here, since the encoder will blindly follow this and could then encode an invalid PNG file + (such as one with two IHDR chunks or the disallowed combination of sRGB with iCCP). But do use + this if you wish to store an ancillary chunk that is not supported by LodePNG (such as sPLT or hIST), + or any non-standard PNG chunk. + Do not allocate or traverse this data yourself. Use the chunk traversing functions declared later, such as lodepng_chunk_next and lodepng_chunk_append, to read/write this struct. */ @@ -489,12 +591,16 @@ void lodepng_info_cleanup(LodePNGInfo* info); unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source); #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -void lodepng_clear_text(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/ unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str); /*push back both texts at once*/ +void lodepng_clear_text(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/ -void lodepng_clear_itext(LodePNGInfo* info); /*use this to clear the itexts again after you filled them in*/ unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag, const char* transkey, const char* str); /*push back the 4 texts of 1 chunk at once*/ +void lodepng_clear_itext(LodePNGInfo* info); /*use this to clear the itexts again after you filled them in*/ + +/*replaces if exists*/ +unsigned lodepng_set_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size); +void lodepng_clear_icc(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/ #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ /* @@ -517,14 +623,17 @@ unsigned lodepng_convert(unsigned char* out, const unsigned char* in, Settings for the decoder. This contains settings for the PNG and the Zlib decoder, but not the Info settings from the Info structs. */ -typedef struct LodePNGDecoderSettings -{ +typedef struct LodePNGDecoderSettings { LodePNGDecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/ - /* Check LodePNGDecompressSettings for more ignorable errors */ + /* Check LodePNGDecompressSettings for more ignorable errors such as ignore_adler32 */ unsigned ignore_crc; /*ignore CRC checksums*/ unsigned ignore_critical; /*ignore unknown critical chunks*/ unsigned ignore_end; /*ignore issues at end of file if possible (missing IEND chunk, too large chunk, ...)*/ + /* TODO: make a system involving warnings with levels and a strict mode instead. Other potentially recoverable + errors: srgb rendering intent value, size of content of ancillary chunks, more than 79 characters for some + strings, placement/combination rules for ancillary chunks, crc of unknown chunks, allowed characters + in string keys, etc... */ unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/ @@ -540,10 +649,14 @@ void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings); #ifdef LODEPNG_COMPILE_ENCODER /*automatically use color type with less bits per pixel if losslessly possible. Default: AUTO*/ -typedef enum LodePNGFilterStrategy -{ +typedef enum LodePNGFilterStrategy { /*every filter at zero*/ - LFS_ZERO, + LFS_ZERO = 0, + /*every filter at 1, 2, 3 or 4 (paeth), unlike LFS_ZERO not a good choice, but for testing*/ + LFS_ONE = 1, + LFS_TWO = 2, + LFS_THREE = 3, + LFS_FOUR = 4, /*Use filter that gives minimum sum, as described in the official PNG filter heuristic.*/ LFS_MINSUM, /*Use the filter type that gives smallest Shannon entropy for this scanline. Depending @@ -558,36 +671,36 @@ typedef enum LodePNGFilterStrategy LFS_PREDEFINED } LodePNGFilterStrategy; -/*Gives characteristics about the colors of the image, which helps decide which color model to use for encoding. +/*Gives characteristics about the integer RGBA colors of the image (count, alpha channel usage, bit depth, ...), +which helps decide which color model to use for encoding. Used internally by default if "auto_convert" is enabled. Public because it's useful for custom algorithms.*/ -typedef struct LodePNGColorProfile -{ - unsigned colored; /*not greyscale*/ +typedef struct LodePNGColorStats { + unsigned colored; /*not grayscale*/ unsigned key; /*image is not opaque and color key is possible instead of full alpha*/ unsigned short key_r; /*key values, always as 16-bit, in 8-bit case the byte is duplicated, e.g. 65535 means 255*/ unsigned short key_g; unsigned short key_b; unsigned alpha; /*image is not opaque and alpha channel or alpha palette required*/ - unsigned numcolors; /*amount of colors, up to 257. Not valid if bits == 16.*/ - unsigned char palette[1024]; /*Remembers up to the first 256 RGBA colors, in no particular order*/ - unsigned bits; /*bits per channel (not for palette). 1,2 or 4 for greyscale only. 16 if 16-bit per channel required.*/ -} LodePNGColorProfile; - -void lodepng_color_profile_init(LodePNGColorProfile* profile); - -/*Get a LodePNGColorProfile of the image.*/ -unsigned lodepng_get_color_profile(LodePNGColorProfile* profile, - const unsigned char* image, unsigned w, unsigned h, - const LodePNGColorMode* mode_in); -/*The function LodePNG uses internally to decide the PNG color with auto_convert. -Chooses an optimal color model, e.g. grey if only grey pixels, palette if < 256 colors, ...*/ -unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out, - const unsigned char* image, unsigned w, unsigned h, - const LodePNGColorMode* mode_in); + unsigned numcolors; /*amount of colors, up to 257. Not valid if bits == 16 or allow_palette is disabled.*/ + unsigned char palette[1024]; /*Remembers up to the first 256 RGBA colors, in no particular order, only valid when numcolors is valid*/ + unsigned bits; /*bits per channel (not for palette). 1,2 or 4 for grayscale only. 16 if 16-bit per channel required.*/ + size_t numpixels; + + /*user settings for computing/using the stats*/ + unsigned allow_palette; /*default 1. if 0, disallow choosing palette colortype in auto_choose_color, and don't count numcolors*/ + unsigned allow_greyscale; /*default 1. if 0, choose RGB or RGBA even if the image only has gray colors*/ +} LodePNGColorStats; + +void lodepng_color_stats_init(LodePNGColorStats* stats); + +/*Get a LodePNGColorStats of the image. The stats must already have been inited. +Returns error code (e.g. alloc fail) or 0 if ok.*/ +unsigned lodepng_compute_color_stats(LodePNGColorStats* stats, + const unsigned char* image, unsigned w, unsigned h, + const LodePNGColorMode* mode_in); /*Settings for the encoder.*/ -typedef struct LodePNGEncoderSettings -{ +typedef struct LodePNGEncoderSettings { LodePNGCompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/ unsigned auto_convert; /*automatically choose output PNG color type. Default: true*/ @@ -623,8 +736,7 @@ void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings); #if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) /*The settings, state and information for extended encoding and decoding.*/ -typedef struct LodePNGState -{ +typedef struct LodePNGState { #ifdef LODEPNG_COMPILE_DECODER LodePNGDecoderSettings decoder; /*the decoding settings*/ #endif /*LODEPNG_COMPILE_DECODER*/ @@ -634,10 +746,6 @@ typedef struct LodePNGState LodePNGColorMode info_raw; /*specifies the format in which you would like to get the raw pixel buffer*/ LodePNGInfo info_png; /*info of the PNG image obtained after decoding*/ unsigned error; -#ifdef LODEPNG_COMPILE_CPP - /* For the lodepng::State subclass. */ - virtual ~LodePNGState(){} -#endif } LodePNGState; /*init, cleanup and copy functions to use with this struct*/ @@ -657,7 +765,7 @@ unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h, /* Read the PNG header, but not the actual data. This returns only the information -that is in the header chunk of the PNG, such as width, height and color type. The +that is in the IHDR chunk of the PNG, such as width, height and color type. The information is placed in the info_png field of the LodePNGState. */ unsigned lodepng_inspect(unsigned* w, unsigned* h, @@ -665,6 +773,20 @@ unsigned lodepng_inspect(unsigned* w, unsigned* h, const unsigned char* in, size_t insize); #endif /*LODEPNG_COMPILE_DECODER*/ +/* +Reads one metadata chunk (other than IHDR) of the PNG file and outputs what it +read in the state. Returns error code on failure. +Use lodepng_inspect first with a new state, then e.g. lodepng_chunk_find_const +to find the desired chunk type, and if non null use lodepng_inspect_chunk (with +chunk_pointer - start_of_file as pos). +Supports most metadata chunks from the PNG standard (gAMA, bKGD, tEXt, ...). +Ignores unsupported, unknown, non-metadata or IHDR chunks (without error). +Requirements: &in[pos] must point to start of a chunk, must use regular +lodepng_inspect first since format of most other chunks depends on IHDR, and if +there is a PLTE chunk, that one must be inspected before tRNS or bKGD. +*/ +unsigned lodepng_inspect_chunk(LodePNGState* state, size_t pos, + const unsigned char* in, size_t insize); #ifdef LODEPNG_COMPILE_ENCODER /*This function allocates the out buffer with standard malloc and stores the size in *outsize.*/ @@ -678,11 +800,23 @@ The lodepng_chunk functions are normally not needed, except to traverse the unknown chunks stored in the LodePNGInfo struct, or add new ones to it. It also allows traversing the chunks of an encoded PNG file yourself. -PNG standard chunk naming conventions: -First byte: uppercase = critical, lowercase = ancillary -Second byte: uppercase = public, lowercase = private -Third byte: must be uppercase -Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy +The chunk pointer always points to the beginning of the chunk itself, that is +the first byte of the 4 length bytes. + +In the PNG file format, chunks have the following format: +-4 bytes length: length of the data of the chunk in bytes (chunk itself is 12 bytes longer) +-4 bytes chunk type (ASCII a-z,A-Z only, see below) +-length bytes of data (may be 0 bytes if length was 0) +-4 bytes of CRC, computed on chunk name + data + +The first chunk starts at the 8th byte of the PNG file, the entire rest of the file +exists out of concatenated chunks with the above format. + +PNG standard chunk ASCII naming conventions: +-First byte: uppercase = critical, lowercase = ancillary +-Second byte: uppercase = public, lowercase = private +-Third byte: must be uppercase +-Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy */ /* @@ -717,24 +851,38 @@ unsigned lodepng_chunk_check_crc(const unsigned char* chunk); /*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/ void lodepng_chunk_generate_crc(unsigned char* chunk); -/*iterate to next chunks. don't use on IEND chunk, as there is no next chunk then*/ -unsigned char* lodepng_chunk_next(unsigned char* chunk); -const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk); +/* +Iterate to next chunks, allows iterating through all chunks of the PNG file. +Input must be at the beginning of a chunk (result of a previous lodepng_chunk_next call, +or the 8th byte of a PNG file which always has the first chunk), or alternatively may +point to the first byte of the PNG file (which is not a chunk but the magic header, the +function will then skip over it and return the first real chunk). +Will output pointer to the start of the next chunk, or at or beyond end of the file if there +is no more chunk after this or possibly if the chunk is corrupt. +Start this process at the 8th byte of the PNG file. +In a non-corrupt PNG file, the last chunk should have name "IEND". +*/ +unsigned char* lodepng_chunk_next(unsigned char* chunk, unsigned char* end); +const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk, const unsigned char* end); + +/*Finds the first chunk with the given type in the range [chunk, end), or returns NULL if not found.*/ +unsigned char* lodepng_chunk_find(unsigned char* chunk, unsigned char* end, const char type[5]); +const unsigned char* lodepng_chunk_find_const(const unsigned char* chunk, const unsigned char* end, const char type[5]); /* Appends chunk to the data in out. The given chunk should already have its chunk header. -The out variable and outlength are updated to reflect the new reallocated buffer. +The out variable and outsize are updated to reflect the new reallocated buffer. Returns error code (0 if it went ok) */ -unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk); +unsigned lodepng_chunk_append(unsigned char** out, size_t* outsize, const unsigned char* chunk); /* Appends new chunk to out. The chunk to append is given by giving its length, type and data separately. The type is a 4-letter string. -The out variable and outlength are updated to reflect the new reallocated buffer. +The out variable and outsize are updated to reflect the new reallocated buffer. Returne error code (0 if it went ok) */ -unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length, +unsigned lodepng_chunk_create(unsigned char** out, size_t* outsize, unsigned length, const char* type, const unsigned char* data); @@ -818,15 +966,13 @@ unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const #ifdef LODEPNG_COMPILE_CPP /* The LodePNG C++ wrapper uses std::vectors instead of manually allocated memory buffers. */ -namespace lodepng -{ +namespace lodepng { #ifdef LODEPNG_COMPILE_PNG -class State : public LodePNGState -{ +class State : public LodePNGState { public: State(); State(const State& other); - virtual ~State(); + ~State(); State& operator=(const State& other); }; @@ -894,16 +1040,21 @@ TODO: [.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often [.] check compatibility with various compilers - done but needs to be redone for every newer version [X] converting color to 16-bit per channel types -[ ] read all public PNG chunk types (but never let the color profile and gamma ones touch RGB values) +[X] support color profile chunk types (but never let them touch RGB values by default) +[ ] support all public PNG chunk types (almost done except sBIT, sPLT and hIST) [ ] make sure encoder generates no chunks with size > (2^31)-1 [ ] partial decoding (stream processing) [X] let the "isFullyOpaque" function check color keys and transparent palettes too [X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl" -[ ] don't stop decoding on errors like 69, 57, 58 (make warnings) +[ ] allow treating some errors like warnings, when image is recoverable (e.g. 69, 57, 58) [ ] make warnings like: oob palette, checksum fail, data after iend, wrong/unknown crit chunk, no null terminator in text, ... +[ ] error messages with line numbers (and version) +[ ] errors in state instead of as return code? +[ ] new errors/warnings like suspiciously big decompressed ztxt or iccp chunk [ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes [ ] allow user to provide custom color conversion functions, e.g. for premultiplied alpha, padding bits or not, ... [ ] allow user to give data (void*) to custom allocator +[X] provide alternatives for C library functions not present on some platforms (memcpy, ...) */ #endif /*LODEPNG_H inclusion guard*/ @@ -998,8 +1149,10 @@ The following features are supported by the decoder: *) zlib decompression (inflate) *) zlib compression (deflate) *) CRC32 and ADLER32 checksums +*) colorimetric color profile conversions: currently experimentally available in lodepng_util.cpp only, + plus alternatively ability to pass on chroma/gamma/ICC profile information to other color management system. *) handling of unknown chunks, allowing making a PNG editor that stores custom and unknown chunks. -*) the following chunks are supported (generated/interpreted) by both encoder and decoder: +*) the following chunks are supported by both encoder and decoder: IHDR: header information PLTE: color palette IDAT: pixel data @@ -1011,6 +1164,10 @@ The following features are supported by the decoder: bKGD: suggested background color pHYs: physical dimensions tIME: modification time + cHRM: RGB chromaticities + gAMA: RGB gamma correction + iCCP: ICC color profile + sRGB: rendering intent 1.2. features not supported --------------------------- @@ -1019,10 +1176,10 @@ The following features are _not_ supported: *) some features needed to make a conformant PNG-Editor might be still missing. *) partial loading/stream processing. All data must be available and is processed in one call. -*) The following public chunks are not supported but treated as unknown chunks by LodePNG - cHRM, gAMA, iCCP, sRGB, sBIT, hIST, sPLT - Some of these are not supported on purpose: LodePNG wants to provide the RGB values - stored in the pixels, not values modified by system dependent gamma or color models. +*) The following public chunks are not (yet) supported but treated as unknown chunks by LodePNG: + sBIT + hIST + sPLT 2. C and C++ version @@ -1096,7 +1253,7 @@ LodePNGColorMode info_raw When decoding, here you can specify which color type you want the resulting raw image to be. If this is different from the colortype of the PNG, then the decoder will automatically convert the result. This conversion -always works, except if you want it to convert a color PNG to greyscale or to +always works, except if you want it to convert a color PNG to grayscale or to a palette with missing colors. By default, 32-bit color is used for the result. @@ -1192,7 +1349,7 @@ can encode the colors of all pixels without information loss. An important thing to note about LodePNG, is that the color type of the PNG, and the color type of the raw image, are completely independent. By default, when you decode a PNG, you get the result as a raw image in the color type you want, -no matter whether the PNG was encoded with a palette, greyscale or RGBA color. +no matter whether the PNG was encoded with a palette, grayscale or RGBA color. And if you encode an image, by default LodePNG will automatically choose the PNG color type that gives good compression based on the values of colors and amount of colors in the image. It can be configured to let you control it instead as @@ -1200,10 +1357,10 @@ well, though. To be able to do this, LodePNG does conversions from one color mode to another. It can convert from almost any color type to any other color type, except the -following conversions: RGB to greyscale is not supported, and converting to a +following conversions: RGB to grayscale is not supported, and converting to a palette when the palette doesn't have a required color is not supported. This is not supported on purpose: this is information loss which requires a color -reduction algorithm that is beyong the scope of a PNG encoder (yes, RGB to grey +reduction algorithm that is beyond the scope of a PNG encoder (yes, RGB to gray is easy, but there are multiple ways if you want to give some channels more weight). @@ -1224,10 +1381,10 @@ decoding to have another color type, a conversion is done by LodePNG. The PNG specification gives the following color types: -0: greyscale, bit depths 1, 2, 4, 8, 16 +0: grayscale, bit depths 1, 2, 4, 8, 16 2: RGB, bit depths 8 and 16 3: palette, bit depths 1, 2, 4 and 8 -4: greyscale with alpha, bit depths 8 and 16 +4: grayscale with alpha, bit depths 8 and 16 6: RGBA, bit depths 8 and 16 Bit depth is the amount of bits per pixel per color channel. So the total amount @@ -1276,15 +1433,22 @@ To avoid some confusion: the raw image correctly before encoding. -both encoder and decoder use the same color converter. +The function lodepng_convert does the color conversion. It is available in the +interface but normally isn't needed since the encoder and decoder already call +it. + Non supported color conversions: --color to greyscale: no error is thrown, but the result will look ugly because -only the red channel is taken --anything to palette when that palette does not have that color in it: in this -case an error is thrown +-color to grayscale when non-gray pixels are present: no error is thrown, but +the result will look ugly because only the red channel is taken (it assumes all +three channels are the same in this case so ignores green and blue). The reason +no error is given is to allow converting from three-channel grayscale images to +one-channel even if there are numerical imprecisions. +-anything to palette when the palette does not have an exact match for a from-color +in it: in this case an error is thrown Supported color conversions: -anything to 8-bit RGB, 8-bit RGBA, 16-bit RGB, 16-bit RGBA --any grey or grey+alpha, to grey or grey+alpha +-any gray or gray+alpha, to gray or gray+alpha -anything to a palette, as long as the palette has the requested colors in it -removing alpha channel -higher to smaller bitdepth, and vice versa @@ -1297,10 +1461,6 @@ false. as the PNG has, by setting the color_convert setting to false. Settings in info_raw are then ignored. -The function lodepng_convert does the color conversion. It is available in the -interface but normally isn't needed since the encoder and decoder already call -it. - 6.3. padding bits ----------------- @@ -1309,7 +1469,7 @@ have a bit amount that isn't a multiple of 8, then padding bits are used so that scanline starts at a fresh byte. But that is NOT true for the LodePNG raw input and output. The raw input image you give to the encoder, and the raw output image you get from the decoder will NOT have these padding bits, e.g. in the case of a 1-bit image with a width -of 7 pixels, the first pixel of the second scanline will the the 8th bit of the first byte, +of 7 pixels, the first pixel of the second scanline will the 8th bit of the first byte, not the first bit of a new byte. 6.4. A note about 16-bits per channel and endianness @@ -1410,12 +1570,12 @@ Iterate to the next chunk. This works if you have a buffer with consecutive chun functions do no boundary checking of the allocated data whatsoever, so make sure there is enough data available in the buffer to be able to go to the next chunk. -unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk): -unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length, +unsigned lodepng_chunk_append(unsigned char** out, size_t* outsize, const unsigned char* chunk): +unsigned lodepng_chunk_create(unsigned char** out, size_t* outsize, unsigned length, const char* type, const unsigned char* data): These functions are used to create new chunks that are appended to the data in *out that has -length *outlength. The append function appends an existing chunk to the new data. The create +length *outsize. The append function appends an existing chunk to the new data. The create function creates a new chunk with the given parameters and appends it. Type is the 4-letter name of the chunk. @@ -1426,7 +1586,7 @@ The LodePNGInfo struct contains fields with the unknown chunk in it. It has 3 buffers (each with size) to contain 3 types of unknown chunks: the ones that come before the PLTE chunk, the ones that come between the PLTE and the IDAT chunks, and the ones that come after the IDAT chunks. -It's necessary to make the distionction between these 3 cases because the PNG +It's necessary to make the distinction between these 3 cases because the PNG standard forces to keep the ordering of unknown chunks compared to the critical chunks, but does not force any other ordering rules. @@ -1509,7 +1669,7 @@ C and C++. *) Other Compilers If you encounter problems on any compilers, feel free to let me know and I may -try to fix it if the compiler is modern and standards complient. +try to fix it if the compiler is modern and standards compliant. 10. examples @@ -1524,8 +1684,7 @@ examples can be found on the LodePNG website. #include "lodepng.h" #include <iostream> -int main(int argc, char *argv[]) -{ +int main(int argc, char *argv[]) { const char* filename = argc > 1 ? argv[1] : "test.png"; //load and decode @@ -1544,8 +1703,7 @@ int main(int argc, char *argv[]) #include "lodepng.h" -int main(int argc, char *argv[]) -{ +int main(int argc, char *argv[]) { unsigned error; unsigned char* image; size_t width, height; @@ -1614,6 +1772,23 @@ yyyymmdd. Some changes aren't backwards compatible. Those are indicated with a (!) symbol. +Not all changes are listed here, the commit history in github lists more: +https://github.com/lvandeve/lodepng + +*) 06 mar 2020: simplified some of the dynamic memory allocations. +*) 12 jan 2020: (!) added 'end' argument to lodepng_chunk_next to allow correct + overflow checks. +*) 14 aug 2019: around 25% faster decoding thanks to huffman lookup tables. +*) 15 jun 2019: (!) auto_choose_color API changed (for bugfix: don't use palette + if gray ICC profile) and non-ICC LodePNGColorProfile renamed to + LodePNGColorStats. +*) 30 dec 2018: code style changes only: removed newlines before opening braces. +*) 10 sep 2018: added way to inspect metadata chunks without full decoding. +*) 19 aug 2018: (!) fixed color mode bKGD is encoded with and made it use + palette index in case of palette. +*) 10 aug 2018: (!) added support for gAMA, cHRM, sRGB and iCCP chunks. This + change is backwards compatible unless you relied on unknown_chunks for those. +*) 11 jun 2018: less restrictive check for pixel size integer overflow *) 14 jan 2018: allow optionally ignoring a few more recoverable errors *) 17 sep 2017: fix memory leak for some encoder input error cases *) 27 nov 2016: grey+alpha auto color model detection bugfix @@ -1623,6 +1798,7 @@ symbol. *) 08 dec 2015: Made load_file function return error if file can't be opened. *) 24 okt 2015: Bugfix with decoding to palette output. *) 18 apr 2015: Boundary PM instead of just package-merge for faster encoding. +*) 24 aug 2014: Moved to github *) 23 aug 2014: Reduced needless memory usage of decoder. *) 28 jun 2014: Removed fix_png setting, always support palette OOB for simplicity. Made ColorProfile public. @@ -1630,25 +1806,25 @@ symbol. *) 22 dec 2013: Power of two windowsize required for optimization. *) 15 apr 2013: Fixed bug with LAC_ALPHA and color key. *) 25 mar 2013: Added an optional feature to ignore some PNG errors (fix_png). -*) 11 mar 2013 (!): Bugfix with custom free. Changed from "my" to "lodepng_" +*) 11 mar 2013: (!) Bugfix with custom free. Changed from "my" to "lodepng_" prefix for the custom allocators and made it possible with a new #define to use custom ones in your project without needing to change lodepng's code. *) 28 jan 2013: Bugfix with color key. *) 27 okt 2012: Tweaks in text chunk keyword length error handling. -*) 8 okt 2012 (!): Added new filter strategy (entropy) and new auto color mode. +*) 8 okt 2012: (!) Added new filter strategy (entropy) and new auto color mode. (no palette). Better deflate tree encoding. New compression tweak settings. Faster color conversions while decoding. Some internal cleanups. *) 23 sep 2012: Reduced warnings in Visual Studio a little bit. -*) 1 sep 2012 (!): Removed #define's for giving custom (de)compression functions +*) 1 sep 2012: (!) Removed #define's for giving custom (de)compression functions and made it work with function pointers instead. *) 23 jun 2012: Added more filter strategies. Made it easier to use custom alloc and free functions and toggle #defines from compiler flags. Small fixes. -*) 6 may 2012 (!): Made plugging in custom zlib/deflate functions more flexible. -*) 22 apr 2012 (!): Made interface more consistent, renaming a lot. Removed +*) 6 may 2012: (!) Made plugging in custom zlib/deflate functions more flexible. +*) 22 apr 2012: (!) Made interface more consistent, renaming a lot. Removed redundant C++ codec classes. Reduced amount of structs. Everything changed, but it is cleaner now imho and functionality remains the same. Also fixed several bugs and shrunk the implementation code. Made new samples. -*) 6 nov 2011 (!): By default, the encoder now automatically chooses the best +*) 6 nov 2011: (!) By default, the encoder now automatically chooses the best PNG color model and bit depth, based on the amount and type of colors of the raw image. For this, autoLeaveOutAlphaChannel replaced by auto_choose_color. *) 9 okt 2011: simpler hash chain implementation for the encoder. @@ -1657,7 +1833,7 @@ symbol. A bug with the PNG filtertype heuristic was fixed, so that it chooses much better ones (it's quite significant). A setting to do an experimental, slow, brute force search for PNG filter types is added. -*) 17 aug 2011 (!): changed some C zlib related function names. +*) 17 aug 2011: (!) changed some C zlib related function names. *) 16 aug 2011: made the code less wide (max 120 characters per line). *) 17 apr 2011: code cleanup. Bugfixes. Convert low to 16-bit per sample colors. *) 21 feb 2011: fixed compiling for C90. Fixed compiling with sections disabled. @@ -1765,5 +1941,5 @@ Domain: gmail dot com. Account: lode dot vandevenne. -Copyright (c) 2005-2017 Lode Vandevenne +Copyright (c) 2005-2020 Lode Vandevenne */ |