/* | |
LodePNG version 20161127 | |
Copyright (c) 2005-2016 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 | |
arising from the use of this software. | |
Permission is granted to anyone to use this software for any purpose, | |
including commercial applications, and to alter it and redistribute it | |
freely, subject to the following restrictions: | |
1. The origin of this software must not be misrepresented; you must not | |
claim that you wrote the original software. If you use this software | |
in a product, an acknowledgment in the product documentation would be | |
appreciated but is not required. | |
2. Altered source versions must be plainly marked as such, and must not be | |
misrepresented as being the original software. | |
3. This notice may not be removed or altered from any source | |
distribution. | |
*/ | |
/* | |
The manual and changelog are in the header file "lodepng.h" | |
Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for C. | |
*/ | |
#include "lodepng.h" | |
#include <limits.h> | |
#include <stdio.h> | |
#include <stdlib.h> | |
#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 = "20161127"; | |
/* | |
This source file is built up in the following large parts. The code sections | |
with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way. | |
-Tools for C and common code for PNG and Zlib | |
-C Code for Zlib (huffman, deflate, ...) | |
-C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...) | |
-The C++ wrapper around all of the above | |
*/ | |
/*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 | |
-DLODEPNG_NO_COMPILE_ALLOCATORS to the compiler, or comment out | |
#define LODEPNG_COMPILE_ALLOCATORS in the header, to disable the ones here and | |
define them in your own project's source files without needing to change | |
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) | |
{ | |
return malloc(size); | |
} | |
static void* lodepng_realloc(void* ptr, size_t new_size) | |
{ | |
return realloc(ptr, new_size); | |
} | |
static void lodepng_free(void* ptr) | |
{ | |
free(ptr); | |
} | |
#else /*LODEPNG_COMPILE_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. // */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* | |
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); | |
*/ | |
#define CERROR_BREAK(errorvar, code)\ | |
{\ | |
errorvar = code;\ | |
break;\ | |
} | |
/*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/ | |
#define ERROR_BREAK(code) CERROR_BREAK(error, code) | |
/*Set error var to the error code, and return it.*/ | |
#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)\ | |
{\ | |
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)\ | |
{\ | |
errorvar = code;\ | |
return;\ | |
} | |
/* | |
About uivector, ucvector and string: | |
-All of them wrap dynamic arrays or text strings in a similar way. | |
-LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version. | |
-The string tools are made to avoid problems with compilers that declare things like strncat as deprecated. | |
-They're not used in the interface, only internally in this file as static functions. | |
-As with many other structs in this file, the init and cleanup functions serve as ctor and dtor. | |
*/ | |
#ifdef LODEPNG_COMPILE_ZLIB | |
/*dynamic vector of unsigned ints*/ | |
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) | |
{ | |
((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); | |
void* data = lodepng_realloc(p->data, newsize); | |
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) | |
{ | |
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) | |
{ | |
if(!uivector_resize(p, p->size + 1)) return 0; | |
p->data[p->size - 1] = c; | |
return 1; | |
} | |
#endif /*LODEPNG_COMPILE_ENCODER*/ | |
#endif /*LODEPNG_COMPILE_ZLIB*/ | |
/* /////////////////////////////////////////////////////////////////////////// */ | |
/*dynamic vector of unsigned chars*/ | |
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); | |
void* data = lodepng_realloc(p->data, newsize); | |
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; | |
} | |
#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) | |
{ | |
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]; | |
} | |
} | |
} | |
#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_PNG) || defined(LODEPNG_COMPILE_ENCODER) | |
/*buffer must have at least 4 allocated bytes available*/ | |
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); | |
buffer[3] = (unsigned char)((value ) & 0xff); | |
} | |
#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 / */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
#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) | |
{ | |
FILE* file; | |
long size; | |
file = fopen(filename, "rb"); | |
if(!file) return -1; | |
if(fseek(file, 0, SEEK_END) != 0) | |
{ | |
fclose(file); | |
return -1; | |
} | |
size = ftell(file); | |
/* It may give LONG_MAX as directory size, this is invalid for us. */ | |
if(size == LONG_MAX) size = -1; | |
fclose(file); | |
return size; | |
} | |
/* 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) | |
{ | |
FILE* file; | |
size_t readsize; | |
file = fopen(filename, "rb"); | |
if(!file) return 78; | |
readsize = fread(out, 1, size, file); | |
fclose(file); | |
if (readsize != size) return 78; | |
return 0; | |
} | |
unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename) | |
{ | |
long size = lodepng_filesize(filename); | |
if (size < 0) return 78; | |
*outsize = (size_t)size; | |
*out = (unsigned char*)lodepng_malloc((size_t)size); | |
if(!(*out) && size > 0) return 83; /*the above malloc failed*/ | |
return lodepng_buffer_file(*out, (size_t)size, filename); | |
} | |
/*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) | |
{ | |
FILE* file; | |
file = fopen(filename, "wb" ); | |
if(!file) return 79; | |
fwrite((char*)buffer , 1 , buffersize, file); | |
fclose(file); | |
return 0; | |
} | |
#endif /*LODEPNG_COMPILE_DISK*/ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* // End of common code and tools. Begin of Zlib related code. // */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
#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);\ | |
} | |
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)); | |
} | |
static void addBitsToStreamReversed(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 >> (nbits - 1 - i)) & 1)); | |
} | |
#endif /*LODEPNG_COMPILE_ENCODER*/ | |
#ifdef LODEPNG_COMPILE_DECODER | |
#define READBIT(bitpointer, bitstream) ((bitstream[bitpointer >> 3] >> (bitpointer & 0x7)) & (unsigned char)1) | |
static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream) | |
{ | |
unsigned char result = (unsigned char)(READBIT(*bitpointer, bitstream)); | |
++(*bitpointer); | |
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); | |
} | |
return result; | |
} | |
#endif /*LODEPNG_COMPILE_DECODER*/ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* / Deflate - Huffman / */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
#define FIRST_LENGTH_CODE_INDEX 257 | |
#define LAST_LENGTH_CODE_INDEX 285 | |
/*256 literals, the end code, some length codes, and 2 unused codes*/ | |
#define NUM_DEFLATE_CODE_SYMBOLS 288 | |
/*the distance codes have their own symbols, 30 used, 2 unused*/ | |
#define NUM_DISTANCE_SYMBOLS 32 | |
/*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/ | |
#define NUM_CODE_LENGTH_CODES 19 | |
/*the base lengths represented by codes 257-285*/ | |
static const unsigned LENGTHBASE[29] | |
= {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59, | |
67, 83, 99, 115, 131, 163, 195, 227, 258}; | |
/*the extra bits used by codes 257-285 (added to base length)*/ | |
static const unsigned LENGTHEXTRA[29] | |
= {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, | |
4, 4, 4, 4, 5, 5, 5, 5, 0}; | |
/*the base backwards distances (the bits of distance codes appear after length codes and use their own huffman tree)*/ | |
static const unsigned DISTANCEBASE[30] | |
= {1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513, | |
769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577}; | |
/*the extra bits of backwards distances (added to base)*/ | |
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*/ | |
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}; | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* | |
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*/ | |
unsigned maxbitlen; /*maximum number of bits a single code can get*/ | |
unsigned numcodes; /*number of symbols in the alphabet = number of codes*/ | |
} 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; | |
tree->lengths = 0; | |
} | |
static void HuffmanTree_cleanup(HuffmanTree* tree) | |
{ | |
lodepng_free(tree->tree2d); | |
lodepng_free(tree->tree1d); | |
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; | |
} | |
} | |
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*/ | |
} | |
return 0; | |
} | |
/* | |
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; | |
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*/ | |
if(!uivector_resizev(&blcount, tree->maxbitlen + 1, 0) | |
|| !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0)) | |
error = 83; /*alloc fail*/ | |
if(!error) | |
{ | |
/*step 1: count number of instances of each code length*/ | |
for(bits = 0; bits != tree->numcodes; ++bits) ++blcount.data[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; | |
} | |
/*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]]++; | |
} | |
} | |
uivector_cleanup(&blcount); | |
uivector_cleanup(&nextcode); | |
if(!error) return HuffmanTree_make2DTree(tree); | |
else return error; | |
} | |
/* | |
given the code lengths (as stored in the PNG file), generate the tree as defined | |
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) | |
{ | |
unsigned i; | |
tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned)); | |
if(!tree->lengths) return 83; /*alloc fail*/ | |
for(i = 0; i != numcodes; ++i) tree->lengths[i] = bitlen[i]; | |
tree->numcodes = (unsigned)numcodes; /*number of symbols*/ | |
tree->maxbitlen = maxbitlen; | |
return HuffmanTree_makeFromLengths2(tree); | |
} | |
#ifdef LODEPNG_COMPILE_ENCODER | |
/*BPM: Boundary Package Merge, see "A Fast and Space-Economical Algorithm for Length-Limited Coding", | |
Jyrki Katajainen, Alistair Moffat, Andrew Turpin, 1995.*/ | |
/*chain node for boundary package merge*/ | |
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)*/ | |
int in_use; | |
} BPMNode; | |
/*lists of chains*/ | |
typedef struct BPMLists | |
{ | |
/*memory pool*/ | |
unsigned memsize; | |
BPMNode* memory; | |
unsigned numfree; | |
unsigned nextfree; | |
BPMNode** freelist; | |
/*two heads of lookahead chains per list*/ | |
unsigned listsize; | |
BPMNode** chains0; | |
BPMNode** chains1; | |
} 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) | |
{ | |
unsigned i; | |
BPMNode* result; | |
/*memory full, so garbage collect*/ | |
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) | |
{ | |
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) | |
{ | |
if(!lists->memory[i].in_use) lists->freelist[lists->numfree++] = &lists->memory[i]; | |
} | |
lists->nextfree = 0; | |
} | |
result = lists->freelist[lists->nextfree++]; | |
result->weight = weight; | |
result->index = index; | |
result->tail = tail; | |
return result; | |
} | |
/*sort the leaves with stable mergesort*/ | |
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) | |
{ | |
BPMNode* a = (counter & 1) ? mem : leaves; | |
BPMNode* b = (counter & 1) ? leaves : mem; | |
size_t p; | |
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++) | |
{ | |
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); | |
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) | |
{ | |
unsigned lastindex = lists->chains1[c]->index; | |
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 | |
{ | |
/*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) | |
{ | |
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)) | |
{ | |
boundaryPM(lists, leaves, numpresent, c - 1, num); | |
boundaryPM(lists, leaves, numpresent, c - 1, num); | |
} | |
} | |
} | |
unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies, | |
size_t numcodes, unsigned maxbitlen) | |
{ | |
unsigned error = 0; | |
unsigned i; | |
size_t numpresent = 0; /*number of symbols with non-zero frequency*/ | |
BPMNode* leaves; /*the symbols, only those with > 0 frequency*/ | |
if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/ | |
if((1u << maxbitlen) < numcodes) return 80; /*error: represent all symbols*/ | |
leaves = (BPMNode*)lodepng_malloc(numcodes * sizeof(*leaves)); | |
if(!leaves) return 83; /*alloc fail*/ | |
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; | |
/*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) | |
{ | |
lengths[0] = lengths[1] = 1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/ | |
} | |
else if(numpresent == 1) | |
{ | |
lengths[leaves[0].index] = 1; | |
lengths[leaves[0].index == 0 ? 1 : 0] = 1; | |
} | |
else | |
{ | |
BPMLists lists; | |
BPMNode* node; | |
bpmnode_sort(leaves, numpresent); | |
lists.listsize = maxbitlen; | |
lists.memsize = 2 * maxbitlen * (maxbitlen + 1); | |
lists.nextfree = 0; | |
lists.numfree = lists.memsize; | |
lists.memory = (BPMNode*)lodepng_malloc(lists.memsize * sizeof(*lists.memory)); | |
lists.freelist = (BPMNode**)lodepng_malloc(lists.memsize * sizeof(BPMNode*)); | |
lists.chains0 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*)); | |
lists.chains1 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*)); | |
if(!lists.memory || !lists.freelist || !lists.chains0 || !lists.chains1) error = 83; /*alloc fail*/ | |
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) | |
{ | |
lists.chains0[i] = &lists.memory[0]; | |
lists.chains1[i] = &lists.memory[1]; | |
} | |
/*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(i = 0; i != node->index; ++i) ++lengths[leaves[i].index]; | |
} | |
} | |
lodepng_free(lists.memory); | |
lodepng_free(lists.freelist); | |
lodepng_free(lists.chains0); | |
lodepng_free(lists.chains1); | |
} | |
lodepng_free(leaves); | |
return error; | |
} | |
/*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) | |
{ | |
unsigned error = 0; | |
while(!frequencies[numcodes - 1] && numcodes > mincodes) --numcodes; /*trim zeroes*/ | |
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) | |
{ | |
unsigned i, error = 0; | |
unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned)); | |
if(!bitlen) return 83; /*alloc fail*/ | |
/*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/ | |
for(i = 0; i <= 143; ++i) bitlen[i] = 8; | |
for(i = 144; i <= 255; ++i) bitlen[i] = 9; | |
for(i = 256; i <= 279; ++i) bitlen[i] = 7; | |
for(i = 280; i <= 287; ++i) bitlen[i] = 8; | |
error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DEFLATE_CODE_SYMBOLS, 15); | |
lodepng_free(bitlen); | |
return error; | |
} | |
/*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/ | |
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*/ | |
/*there are 32 distance codes, but 30-31 are unused*/ | |
for(i = 0; i != NUM_DISTANCE_SYMBOLS; ++i) bitlen[i] = 5; | |
error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DISTANCE_SYMBOLS, 15); | |
lodepng_free(bitlen); | |
return error; | |
} | |
#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) | |
*/ | |
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*/ | |
} | |
} | |
#endif /*LODEPNG_COMPILE_DECODER*/ | |
#ifdef LODEPNG_COMPILE_DECODER | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* / 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 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) | |
{ | |
/*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*/ | |
unsigned* bitlen_d = 0; /*dist code lengths*/ | |
/*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_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*/ | |
/*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/ | |
HLIT = readBitsFromStream(bp, in, 5) + 257; | |
/*number of distance codes. Unlike the spec, the value 1 is added to it here already*/ | |
HDIST = readBitsFromStream(bp, in, 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; | |
if((*bp) + HCLEN * 3 > (inlength << 3)) return 50; /*error: the bit pointer is or will go past the memory*/ | |
HuffmanTree_init(&tree_cl); | |
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*/ | |
} | |
error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7); | |
if(error) break; | |
/*now we can use this tree to read the lengths for the tree that this function will return*/ | |
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; | |
/*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*/ | |
{ | |
if(i < HLIT) bitlen_ll[i] = code; | |
else bitlen_d[i - HLIT] = code; | |
++i; | |
} | |
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); | |
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) | |
{ | |
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*/ | |
{ | |
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); | |
/*repeat this value in the next lengths*/ | |
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*/ | |
{ | |
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); | |
/*repeat this value in the next lengths*/ | |
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 == (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; | |
} | |
} | |
if(error) break; | |
if(bitlen_ll[256] == 0) ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/ | |
/*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/ | |
error = HuffmanTree_makeFromLengths(tree_ll, bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 15); | |
if(error) break; | |
error = HuffmanTree_makeFromLengths(tree_d, bitlen_d, NUM_DISTANCE_SYMBOLS, 15); | |
break; /*end of error-while*/ | |
} | |
lodepng_free(bitlen_cl); | |
lodepng_free(bitlen_ll); | |
lodepng_free(bitlen_d); | |
HuffmanTree_cleanup(&tree_cl); | |
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) | |
{ | |
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); | |
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_d, distance; | |
unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/ | |
size_t start, forward, 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); | |
/*part 3: get distance code*/ | |
code_d = huffmanDecodeSymbol(in, bp, &tree_d, inbitlength); | |
if(code_d > 29) | |
{ | |
if(code_ll == (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; | |
} | |
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); | |
/*part 5: fill in all the out[n] values based on the length and dist*/ | |
start = (*pos); | |
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++]; | |
} | |
} else { | |
memcpy(out->data + *pos, out->data + backward, length); | |
*pos += length; | |
} | |
} | |
else if(code_ll == 256) | |
{ | |
break; /*end code, break the loop*/ | |
} | |
else /*if(code == (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; | |
break; | |
} | |
} | |
HuffmanTree_cleanup(&tree_ll); | |
HuffmanTree_cleanup(&tree_d); | |
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; | |
/*go to first boundary of byte*/ | |
while(((*bp) & 0x7) != 0) ++(*bp); | |
p = (*bp) / 8; /*byte position*/ | |
/*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; | |
/*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(!ucvector_resize(out, (*pos) + 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++]; | |
(*bp) = p * 8; | |
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; | |
unsigned BFINAL = 0; | |
size_t pos = 0; /*byte position in the out buffer*/ | |
unsigned error = 0; | |
(void)settings; | |
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(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*/ | |
if(error) return error; | |
} | |
return error; | |
} | |
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); | |
*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); | |
} | |
} | |
#endif /*LODEPNG_COMPILE_DECODER*/ | |
#ifdef LODEPNG_COMPILE_ENCODER | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* / Deflator (Compressor) / */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
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) | |
{ | |
/*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; | |
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) | |
{ | |
/*values in encoded vector are those used by deflate: | |
0-255: literal bytes | |
256: end | |
257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits) | |
286-287: invalid*/ | |
unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length); | |
unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]); | |
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); | |
} | |
/*3 bytes of data get encoded into two bytes. The hash cannot use more than 3 | |
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 | |
{ | |
int* head; /*hash value to head circular pos - can be outdated if went around window*/ | |
/*circular pos to prev circular pos*/ | |
unsigned short* chain; | |
int* val; /*circular pos to hash value*/ | |
/*TODO: do this not only for zeros but for any repeated byte. However for PNG | |
it's always going to be the zeros that dominate, so not important for PNG*/ | |
int* headz; /*similar to head, but for chainz*/ | |
unsigned short* chainz; /*those with same amount of zeros*/ | |
unsigned short* zeros; /*length of zeros streak, used as a second hash chain*/ | |
} Hash; | |
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); | |
hash->chain = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize); | |
hash->zeros = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * 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) | |
{ | |
return 83; /*alloc fail*/ | |
} | |
/*initialize hash table*/ | |
for(i = 0; i != HASH_NUM_VALUES; ++i) hash->head[i] = -1; | |
for(i = 0; i != windowsize; ++i) hash->val[i] = -1; | |
for(i = 0; i != windowsize; ++i) hash->chain[i] = i; /*same value as index indicates uninitialized*/ | |
for(i = 0; i <= MAX_SUPPORTED_DEFLATE_LENGTH; ++i) hash->headz[i] = -1; | |
for(i = 0; i != windowsize; ++i) hash->chainz[i] = i; /*same value as index indicates uninitialized*/ | |
return 0; | |
} | |
static void hash_cleanup(Hash* hash) | |
{ | |
lodepng_free(hash->head); | |
lodepng_free(hash->val); | |
lodepng_free(hash->chain); | |
lodepng_free(hash->zeros); | |
lodepng_free(hash->headz); | |
lodepng_free(hash->chainz); | |
} | |
static unsigned getHash(const unsigned char* data, size_t size, size_t pos) | |
{ | |
unsigned result = 0; | |
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); | |
} 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)); | |
} | |
return result & HASH_BIT_MASK; | |
} | |
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; | |
data = start; | |
while(data != end && *data == 0) ++data; | |
/*subtracting two addresses returned as 32-bit number (max value is MAX_SUPPORTED_DEFLATE_LENGTH)*/ | |
return (unsigned)(data - start); | |
} | |
/*wpos = pos & (windowsize - 1)*/ | |
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] = wpos; | |
hash->zeros[wpos] = numzeros; | |
if(hash->headz[numzeros] != -1) hash->chainz[wpos] = hash->headz[numzeros]; | |
hash->headz[numzeros] = wpos; | |
} | |
/* | |
LZ77-encode the data. Return value is error code. The input are raw bytes, the output | |
is in the form of unsigned integers with codes representing for example literal bytes, or | |
length/distance pairs. | |
It uses a hash table technique to let it encode faster. When doing LZ77 encoding, a | |
sliding window (of windowsize) is used, and all past bytes in that window can be used as | |
the "dictionary". A brute force search through all possible distances would be slow, and | |
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) | |
{ | |
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 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*/ | |
unsigned numzeros = 0; | |
unsigned offset; /*the offset represents the distance in LZ77 terminology*/ | |
unsigned length; | |
unsigned lazy = 0; | |
unsigned lazylength = 0, lazyoffset = 0; | |
unsigned hashval; | |
unsigned current_offset, current_length; | |
unsigned prev_offset; | |
const unsigned char *lastptr, *foreptr, *backptr; | |
unsigned hashpos; | |
if(windowsize == 0 || windowsize > 32768) return 60; /*error: windowsize smaller/larger than allowed*/ | |
if((windowsize & (windowsize - 1)) != 0) return 90; /*error: must be power of two*/ | |
if(nicematch > MAX_SUPPORTED_DEFLATE_LENGTH) nicematch = MAX_SUPPORTED_DEFLATE_LENGTH; | |
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(numzeros == 0) numzeros = countZeros(in, insize, pos); | |
else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros; | |
} | |
else | |
{ | |
numzeros = 0; | |
} | |
updateHashChain(hash, wpos, hashval, numzeros); | |
/*the length and offset found for the current position*/ | |
length = 0; | |
offset = 0; | |
hashpos = hash->chain[wpos]; | |
lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH]; | |
/*search for the longest string*/ | |
prev_offset = 0; | |
for(;;) | |
{ | |
if(chainlength++ >= maxchainlength) break; | |
current_offset = 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) | |
{ | |
/*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) | |
{ | |
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*/ | |
{ | |
++backptr; | |
++foreptr; | |
} | |
current_length = (unsigned)(foreptr - &in[pos]); | |
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 | |
out if length is MAX_SUPPORTED_DEFLATE_LENGTH*/ | |
if(current_length >= nicematch) break; | |
} | |
} | |
if(hashpos == hash->chain[hashpos]) break; | |
if(numzeros >= 3 && length > numzeros) | |
{ | |
hashpos = hash->chainz[hashpos]; | |
if(hash->zeros[hashpos] != numzeros) break; | |
} | |
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) | |
{ | |
lazy = 1; | |
lazylength = length; | |
lazyoffset = offset; | |
continue; /*try the next byte*/ | |
} | |
if(lazy) | |
{ | |
lazy = 0; | |
if(pos == 0) ERROR_BREAK(81); | |
if(length > lazylength + 1) | |
{ | |
/*push the previous character as literal*/ | |
if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(83 /*alloc fail*/); | |
} | |
else | |
{ | |
length = lazylength; | |
offset = lazyoffset; | |
hash->head[hashval] = -1; /*the same hashchain update will be done, this ensures no wrong alteration*/ | |
hash->headz[numzeros] = -1; /*idem*/ | |
--pos; | |
} | |
} | |
} | |
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(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/); | |
} | |
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 | |
{ | |
addLengthDistance(out, length, offset); | |
for(i = 1; i < length; ++i) | |
{ | |
++pos; | |
wpos = pos & (windowsize - 1); | |
hashval = getHash(in, insize, pos); | |
if(usezeros && hashval == 0) | |
{ | |
if(numzeros == 0) numzeros = countZeros(in, insize, pos); | |
else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros; | |
} | |
else | |
{ | |
numzeros = 0; | |
} | |
updateHashChain(hash, wpos, hashval, numzeros); | |
} | |
} | |
} /*end of the loop through each character of input*/ | |
return error; | |
} | |
/* /////////////////////////////////////////////////////////////////////////// */ | |
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; | |
unsigned datapos = 0; | |
for(i = 0; i != numdeflateblocks; ++i) | |
{ | |
unsigned BFINAL, BTYPE, LEN, NLEN; | |
unsigned char firstbyte; | |
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; | |
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)); | |
/*Decompressed data*/ | |
for(j = 0; j < 65535 && datapos < datasize; ++j) | |
{ | |
ucvector_push_back(out, data[datapos++]); | |
} | |
} | |
return 0; | |
} | |
/* | |
write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees. | |
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) | |
{ | |
size_t i = 0; | |
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*/ | |
{ | |
unsigned length_index = val - FIRST_LENGTH_CODE_INDEX; | |
unsigned n_length_extra_bits = LENGTHEXTRA[length_index]; | |
unsigned length_extra_bits = lz77_encoded->data[++i]; | |
unsigned distance_code = lz77_encoded->data[++i]; | |
unsigned distance_index = distance_code; | |
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); | |
} | |
} | |
} | |
/*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, | |
const unsigned char* data, size_t datapos, size_t dataend, | |
const LodePNGCompressSettings* settings, unsigned final) | |
{ | |
unsigned error = 0; | |
/* | |
A block is compressed as follows: The PNG data is lz77 encoded, resulting in | |
literal bytes and length/distance pairs. This is then huffman compressed with | |
two huffman trees. One huffman tree is used for the lit and len values ("ll"), | |
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 | |
the code length code lengths ("clcl"). | |
*/ | |
/*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/ | |
uivector lz77_encoded; | |
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; | |
size_t datasize = dataend - datapos; | |
/* | |
Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies: | |
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; | |
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); | |
/*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) | |
{ | |
error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize, | |
settings->minmatch, settings->nicematch, settings->lazymatching); | |
if(error) break; | |
} | |
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) | |
{ | |
unsigned symbol = lz77_encoded.data[i]; | |
++frequencies_ll.data[symbol]; | |
if(symbol > 256) | |
{ | |
unsigned dist = lz77_encoded.data[i + 2]; | |
++frequencies_d.data[dist]; | |
i += 3; | |
} | |
} | |
frequencies_ll.data[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); | |
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); | |
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; | |
/*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)); | |
/*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; | |
if(bitlen_lld.data[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 > 138) j = 138; | |
uivector_push_back(&bitlen_lld_e, 18); | |
uivector_push_back(&bitlen_lld_e, j - 11); | |
} | |
i += (j - 1); | |
} | |
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); | |
} | |
if(rest >= 3) | |
{ | |
uivector_push_back(&bitlen_lld_e, 16); | |
uivector_push_back(&bitlen_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]); | |
} | |
} | |
/*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]]; | |
/*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; | |
} | |
error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data, | |
frequencies_cl.size, frequencies_cl.size, 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*/); | |
} | |
if(error) break; | |
/* | |
Write everything into the output | |
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 | |
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) | |
- compressed data | |
- 256 (end code) | |
*/ | |
/*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"*/ | |
/*write the HLIT, HDIST and HCLEN values*/ | |
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])); | |
/*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); | |
} | |
/*write the compressed data symbols*/ | |
writeLZ77data(bp, out, &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); | |
/*write the end code*/ | |
addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256)); | |
break; /*end of error-while*/ | |
} | |
/*cleanup*/ | |
uivector_cleanup(&lz77_encoded); | |
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); | |
return error; | |
} | |
static unsigned deflateFixed(ucvector* out, size_t* bp, Hash* hash, | |
const unsigned char* data, | |
size_t datapos, size_t dataend, | |
const LodePNGCompressSettings* settings, unsigned final) | |
{ | |
HuffmanTree tree_ll; /*tree for literal values and length codes*/ | |
HuffmanTree tree_d; /*tree for distance codes*/ | |
unsigned BFINAL = final; | |
unsigned error = 0; | |
size_t i; | |
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])); | |
} | |
} | |
/*add END code*/ | |
if(!error) addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256)); | |
/*cleanup*/ | |
HuffmanTree_cleanup(&tree_ll); | |
HuffmanTree_cleanup(&tree_d); | |
return error; | |
} | |
static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t insize, | |
const LodePNGCompressSettings* settings) | |
{ | |
unsigned error = 0; | |
size_t i, blocksize, numdeflateblocks; | |
size_t bp = 0; /*the bit pointer*/ | |
Hash hash; | |
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)*/ | |
{ | |
/*on PNGs, deflate blocks of 65-262k seem to give most dense encoding*/ | |
blocksize = insize / 8 + 8; | |
if(blocksize < 65536) blocksize = 65536; | |
if(blocksize > 262144) blocksize = 262144; | |
} | |
numdeflateblocks = (insize + blocksize - 1) / blocksize; | |
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(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); | |
} | |
hash_cleanup(&hash); | |
return error; | |
} | |
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); | |
*out = v.data; | |
*outsize = v.size; | |
return error; | |
} | |
static unsigned deflate(unsigned char** out, size_t* outsize, | |
const unsigned char* in, size_t insize, | |
const LodePNGCompressSettings* settings) | |
{ | |
if(settings->custom_deflate) | |
{ | |
return settings->custom_deflate(out, outsize, in, insize, settings); | |
} | |
else | |
{ | |
return lodepng_deflate(out, outsize, in, insize, settings); | |
} | |
} | |
#endif /*LODEPNG_COMPILE_DECODER*/ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* / Adler32 */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len) | |
{ | |
unsigned s1 = adler & 0xffff; | |
unsigned s2 = (adler >> 16) & 0xffff; | |
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; | |
len -= amount; | |
while(amount > 0) | |
{ | |
s1 += (*data++); | |
s2 += s1; | |
--amount; | |
} | |
s1 %= 65521; | |
s2 %= 65521; | |
} | |
return (s2 << 16) | 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); | |
} | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* / Zlib / */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
#ifdef LODEPNG_COMPILE_DECODER | |
unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, 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) | |
{ | |
/*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/ | |
return 24; | |
} | |
CM = in[0] & 15; | |
CINFO = (in[0] >> 4) & 15; | |
/*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/ | |
FDICT = (in[1] >> 5) & 1; | |
/*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/ | |
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) | |
{ | |
/*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); | |
if(error) return error; | |
if(!settings->ignore_adler32) | |
{ | |
unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]); | |
unsigned checksum = adler32(*out, (unsigned)(*outsize)); | |
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) | |
{ | |
return settings->custom_zlib(out, outsize, in, insize, settings); | |
} | |
else | |
{ | |
return lodepng_zlib_decompress(out, outsize, in, insize, settings); | |
} | |
} | |
#endif /*LODEPNG_COMPILE_DECODER*/ | |
#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 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 = outv.data; | |
*outsize = outv.size; | |
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) | |
{ | |
return settings->custom_zlib(out, outsize, in, insize, settings); | |
} | |
else | |
{ | |
return lodepng_zlib_compress(out, outsize, in, insize, settings); | |
} | |
} | |
#endif /*LODEPNG_COMPILE_ENCODER*/ | |
#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) | |
{ | |
if(!settings->custom_zlib) return 87; /*no custom zlib function provided */ | |
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) | |
{ | |
if(!settings->custom_zlib) return 87; /*no custom zlib function provided */ | |
return settings->custom_zlib(out, outsize, in, insize, settings); | |
} | |
#endif /*LODEPNG_COMPILE_ENCODER*/ | |
#endif /*LODEPNG_COMPILE_ZLIB*/ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
#ifdef LODEPNG_COMPILE_ENCODER | |
/*this is a good tradeoff between speed and compression ratio*/ | |
#define DEFAULT_WINDOWSIZE 2048 | |
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; | |
settings->windowsize = DEFAULT_WINDOWSIZE; | |
settings->minmatch = 3; | |
settings->nicematch = 128; | |
settings->lazymatching = 1; | |
settings->custom_zlib = 0; | |
settings->custom_deflate = 0; | |
settings->custom_context = 0; | |
} | |
const LodePNGCompressSettings lodepng_default_compress_settings = {2, 1, DEFAULT_WINDOWSIZE, 3, 128, 1, 0, 0, 0}; | |
#endif /*LODEPNG_COMPILE_ENCODER*/ | |
#ifdef LODEPNG_COMPILE_DECODER | |
void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings) | |
{ | |
settings->ignore_adler32 = 0; | |
settings->custom_zlib = 0; | |
settings->custom_inflate = 0; | |
settings->custom_context = 0; | |
} | |
const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0}; | |
#endif /*LODEPNG_COMPILE_DECODER*/ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* // End of Zlib related code. Begin of PNG related code. // */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
#ifdef LODEPNG_COMPILE_PNG | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* / CRC32 / */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
#ifndef LODEPNG_NO_COMPILE_CRC | |
/* CRC polynomial: 0xedb88320 */ | |
static unsigned lodepng_crc32_table[256] = { | |
0u, 1996959894u, 3993919788u, 2567524794u, 124634137u, 1886057615u, 3915621685u, 2657392035u, | |
249268274u, 2044508324u, 3772115230u, 2547177864u, 162941995u, 2125561021u, 3887607047u, 2428444049u, | |
498536548u, 1789927666u, 4089016648u, 2227061214u, 450548861u, 1843258603u, 4107580753u, 2211677639u, | |
325883990u, 1684777152u, 4251122042u, 2321926636u, 335633487u, 1661365465u, 4195302755u, 2366115317u, | |
997073096u, 1281953886u, 3579855332u, 2724688242u, 1006888145u, 1258607687u, 3524101629u, 2768942443u, | |
901097722u, 1119000684u, 3686517206u, 2898065728u, 853044451u, 1172266101u, 3705015759u, 2882616665u, | |
651767980u, 1373503546u, 3369554304u, 3218104598u, 565507253u, 1454621731u, 3485111705u, 3099436303u, | |
671266974u, 1594198024u, 3322730930u, 2970347812u, 795835527u, 1483230225u, 3244367275u, 3060149565u, | |
1994146192u, 31158534u, 2563907772u, 4023717930u, 1907459465u, 112637215u, 2680153253u, 3904427059u, | |
2013776290u, 251722036u, 2517215374u, 3775830040u, 2137656763u, 141376813u, 2439277719u, 3865271297u, | |
1802195444u, 476864866u, 2238001368u, 4066508878u, 1812370925u, 453092731u, 2181625025u, 4111451223u, | |
1706088902u, 314042704u, 2344532202u, 4240017532u, 1658658271u, 366619977u, 2362670323u, 4224994405u, | |
1303535960u, 984961486u, 2747007092u, 3569037538u, 1256170817u, 1037604311u, 2765210733u, 3554079995u, | |
1131014506u, 879679996u, 2909243462u, 3663771856u, 1141124467u, 855842277u, 2852801631u, 3708648649u, | |
1342533948u, 654459306u, 3188396048u, 3373015174u, 1466479909u, 544179635u, 3110523913u, 3462522015u, | |
1591671054u, 702138776u, 2966460450u, 3352799412u, 1504918807u, 783551873u, 3082640443u, 3233442989u, | |
3988292384u, 2596254646u, 62317068u, 1957810842u, 3939845945u, 2647816111u, 81470997u, 1943803523u, | |
3814918930u, 2489596804u, 225274430u, 2053790376u, 3826175755u, 2466906013u, 167816743u, 2097651377u, | |
4027552580u, 2265490386u, 503444072u, 1762050814u, 4150417245u, 2154129355u, 426522225u, 1852507879u, | |
4275313526u, 2312317920u, 282753626u, 1742555852u, 4189708143u, 2394877945u, 397917763u, 1622183637u, | |
3604390888u, 2714866558u, 953729732u, 1340076626u, 3518719985u, 2797360999u, 1068828381u, 1219638859u, | |
3624741850u, 2936675148u, 906185462u, 1090812512u, 3747672003u, 2825379669u, 829329135u, 1181335161u, | |
3412177804u, 3160834842u, 628085408u, 1382605366u, 3423369109u, 3138078467u, 570562233u, 1426400815u, | |
3317316542u, 2998733608u, 733239954u, 1555261956u, 3268935591u, 3050360625u, 752459403u, 1541320221u, | |
2607071920u, 3965973030u, 1969922972u, 40735498u, 2617837225u, 3943577151u, 1913087877u, 83908371u, | |
2512341634u, 3803740692u, 2075208622u, 213261112u, 2463272603u, 3855990285u, 2094854071u, 198958881u, | |
2262029012u, 4057260610u, 1759359992u, 534414190u, 2176718541u, 4139329115u, 1873836001u, 414664567u, | |
2282248934u, 4279200368u, 1711684554u, 285281116u, 2405801727u, 4167216745u, 1634467795u, 376229701u, | |
2685067896u, 3608007406u, 1308918612u, 956543938u, 2808555105u, 3495958263u, 1231636301u, 1047427035u, | |
2932959818u, 3654703836u, 1088359270u, 936918000u, 2847714899u, 3736837829u, 1202900863u, 817233897u, | |
3183342108u, 3401237130u, 1404277552u, 615818150u, 3134207493u, 3453421203u, 1423857449u, 601450431u, | |
3009837614u, 3294710456u, 1567103746u, 711928724u, 3020668471u, 3272380065u, 1510334235u, 755167117u | |
}; | |
/*Return the CRC of the bytes buf[0..len-1].*/ | |
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); | |
} | |
return r ^ 0xffffffffu; | |
} | |
#else /* !LODEPNG_NO_COMPILE_CRC */ | |
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 / */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
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) | |
{ | |
unsigned result = 0; | |
size_t i; | |
for(i = 0 ; i < nbits; ++i) | |
{ | |
result <<= 1; | |
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) | |
{ | |
/*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))); | |
++(*bitpointer); | |
} | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* / PNG chunks / */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
unsigned lodepng_chunk_length(const unsigned char* chunk) | |
{ | |
return lodepng_read32bitInt(&chunk[0]); | |
} | |
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; | |
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) | |
{ | |
return((chunk[4] & 32) != 0); | |
} | |
unsigned char lodepng_chunk_private(const unsigned char* chunk) | |
{ | |
return((chunk[6] & 32) != 0); | |
} | |
unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk) | |
{ | |
return((chunk[7] & 32) != 0); | |
} | |
unsigned char* lodepng_chunk_data(unsigned char* chunk) | |
{ | |
return &chunk[8]; | |
} | |
const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk) | |
{ | |
return &chunk[8]; | |
} | |
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*/ | |
unsigned checksum = lodepng_crc32(&chunk[4], length + 4); | |
if(CRC != checksum) return 1; | |
else return 0; | |
} | |
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]; | |
} | |
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]; | |
} | |
unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk) | |
{ | |
unsigned i; | |
unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; | |
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*/ | |
new_buffer = (unsigned char*)lodepng_realloc(*out, new_length); | |
if(!new_buffer) return 83; /*alloc fail*/ | |
(*out) = new_buffer; | |
(*outlength) = new_length; | |
chunk_start = &(*out)[new_length - total_chunk_length]; | |
for(i = 0; i != total_chunk_length; ++i) chunk_start[i] = chunk[i]; | |
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]; | |
/*1: length*/ | |
lodepng_set32bitInt(chunk, (unsigned)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]; | |
/*3: the data*/ | |
for(i = 0; i != length; ++i) chunk[8 + i] = data[i]; | |
/*4: CRC (of the chunkname characters and the data)*/ | |
lodepng_chunk_generate_crc(chunk); | |
return 0; | |
} | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* / Color types and such / */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/*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; | |
} | |
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*/ | |
} | |
return 0; /*unexisting color type*/ | |
} | |
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) | |
{ | |
info->key_defined = 0; | |
info->key_r = info->key_g = info->key_b = 0; | |
info->colortype = LCT_RGBA; | |
info->bitdepth = 8; | |
info->palette = 0; | |
info->palettesize = 0; | |
} | |
void lodepng_color_mode_cleanup(LodePNGColorMode* info) | |
{ | |
lodepng_palette_clear(info); | |
} | |
unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source) | |
{ | |
size_t i; | |
lodepng_color_mode_cleanup(dest); | |
*dest = *source; | |
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]; | |
} | |
return 0; | |
} | |
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_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 one of the palette sizes is 0, then we consider it to be the same as the | |
other: it means that e.g. the palette was not given by the user and should be | |
considered the same as the palette inside the PNG.*/ | |
if(1/*a->palettesize != 0 && b->palettesize != 0*/) { | |
if(a->palettesize != b->palettesize) return 0; | |
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) | |
{ | |
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; | |
} | |
info->palette[4 * info->palettesize + 0] = r; | |
info->palette[4 * info->palettesize + 1] = g; | |
info->palette[4 * info->palettesize + 2] = b; | |
info->palette[4 * info->palettesize + 3] = a; | |
++info->palettesize; | |
return 0; | |
} | |
unsigned lodepng_get_bpp(const LodePNGColorMode* info) | |
{ | |
/*calculate bits per pixel out of colortype and bitdepth*/ | |
return lodepng_get_bpp_lct(info->colortype, info->bitdepth); | |
} | |
unsigned lodepng_get_channels(const LodePNGColorMode* info) | |
{ | |
return getNumColorChannels(info->colortype); | |
} | |
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) | |
{ | |
return (info->colortype & 4) != 0; /*4 or 6*/ | |
} | |
unsigned lodepng_is_palette_type(const LodePNGColorMode* info) | |
{ | |
return info->colortype == LCT_PALETTE; | |
} | |
unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info) | |
{ | |
size_t 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) | |
{ | |
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; | |
} | |
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; | |
} | |
#ifdef LODEPNG_COMPILE_PNG | |
#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; | |
} | |
#endif /*LODEPNG_COMPILE_DECODER*/ | |
#endif /*LODEPNG_COMPILE_PNG*/ | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
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) | |
{ | |
unsigned i; | |
for(i = 0; i != 3; ++i) lodepng_free(info->unknown_chunks_data[i]); | |
} | |
static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src) | |
{ | |
unsigned i; | |
LodePNGUnknownChunks_cleanup(dest); | |
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) | |
{ | |
dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j]; | |
} | |
} | |
return 0; | |
} | |
/******************************************************************************/ | |
static void LodePNGText_init(LodePNGInfo* info) | |
{ | |
info->text_num = 0; | |
info->text_keys = NULL; | |
info->text_strings = NULL; | |
} | |
static void LodePNGText_cleanup(LodePNGInfo* info) | |
{ | |
size_t i; | |
for(i = 0; i != info->text_num; ++i) | |
{ | |
string_cleanup(&info->text_keys[i]); | |
string_cleanup(&info->text_strings[i]); | |
} | |
lodepng_free(info->text_keys); | |
lodepng_free(info->text_strings); | |
} | |
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) | |
{ | |
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) | |
{ | |
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; | |
string_init(&info->text_keys[info->text_num - 1]); | |
string_set(&info->text_keys[info->text_num - 1], key); | |
string_init(&info->text_strings[info->text_num - 1]); | |
string_set(&info->text_strings[info->text_num - 1], str); | |
return 0; | |
} | |
/******************************************************************************/ | |
static void LodePNGIText_init(LodePNGInfo* info) | |
{ | |
info->itext_num = 0; | |
info->itext_keys = NULL; | |
info->itext_langtags = NULL; | |
info->itext_transkeys = NULL; | |
info->itext_strings = NULL; | |
} | |
static void LodePNGIText_cleanup(LodePNGInfo* info) | |
{ | |
size_t 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]); | |
string_cleanup(&info->itext_strings[i]); | |
} | |
lodepng_free(info->itext_keys); | |
lodepng_free(info->itext_langtags); | |
lodepng_free(info->itext_transkeys); | |
lodepng_free(info->itext_strings); | |
} | |
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) | |
{ | |
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) | |
{ | |
LodePNGIText_cleanup(info); | |
} | |
unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag, | |
const char* transkey, const char* str) | |
{ | |
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*/ | |
} | |
++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); | |
string_init(&info->itext_langtags[info->itext_num - 1]); | |
string_set(&info->itext_langtags[info->itext_num - 1], langtag); | |
string_init(&info->itext_transkeys[info->itext_num - 1]); | |
string_set(&info->itext_transkeys[info->itext_num - 1], transkey); | |
string_init(&info->itext_strings[info->itext_num - 1]); | |
string_set(&info->itext_strings[info->itext_num - 1], str); | |
return 0; | |
} | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
void lodepng_info_init(LodePNGInfo* info) | |
{ | |
lodepng_color_mode_init(&info->color); | |
info->interlace_method = 0; | |
info->compression_method = 0; | |
info->filter_method = 0; | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
info->background_defined = 0; | |
info->background_r = info->background_g = info->background_b = 0; | |
LodePNGText_init(info); | |
LodePNGIText_init(info); | |
info->time_defined = 0; | |
info->phys_defined = 0; | |
LodePNGUnknownChunks_init(info); | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
} | |
void lodepng_info_cleanup(LodePNGInfo* info) | |
{ | |
lodepng_color_mode_cleanup(&info->color); | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
LodePNGText_cleanup(info); | |
LodePNGIText_cleanup(info); | |
LodePNGUnknownChunks_cleanup(info); | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
} | |
unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) | |
{ | |
lodepng_info_cleanup(dest); | |
*dest = *source; | |
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)); | |
LodePNGUnknownChunks_init(dest); | |
CERROR_TRY_RETURN(LodePNGUnknownChunks_copy(dest, source)); | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
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) | |
{ | |
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; | |
} | |
typedef struct ColorTree ColorTree; | |
/* | |
One node of a color tree | |
This is the data structure used to count the number of unique colors and to get a palette | |
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 | |
{ | |
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; | |
tree->index = -1; | |
} | |
static void color_tree_cleanup(ColorTree* tree) | |
{ | |
int i; | |
for(i = 0; i != 16; ++i) | |
{ | |
if(tree->children[i]) | |
{ | |
color_tree_cleanup(tree->children[i]); | |
lodepng_free(tree->children[i]); | |
} | |
} | |
} | |
/*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) | |
{ | |
int bit = 0; | |
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]; | |
} | |
return tree ? tree->index : -1; | |
} | |
#ifdef LODEPNG_COMPILE_ENCODER | |
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) | |
{ | |
int 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]) | |
{ | |
tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree)); | |
color_tree_init(tree->children[i]); | |
} | |
tree = tree->children[i]; | |
} | |
tree->index = (int)index; | |
} | |
/*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) | |
{ | |
out[i * 3 + 0] = r; | |
out[i * 3 + 1] = g; | |
out[i * 3 + 2] = b; | |
} | |
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) | |
{ | |
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; | |
out[i * 2 + 1] = a; | |
} | |
else if(mode->bitdepth == 16) | |
{ | |
out[i * 4 + 0] = out[i * 4 + 1] = grey; | |
out[i * 4 + 2] = out[i * 4 + 3] = a; | |
} | |
} | |
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 | |
{ | |
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; | |
out[i * 8 + 6] = out[i * 8 + 7] = a; | |
} | |
} | |
return 0; /*no error*/ | |
} | |
/*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) | |
{ | |
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; | |
out[i * 4 + 2] = (a >> 8) & 255; | |
out[i * 4 + 3] = a & 255; | |
} | |
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; | |
out[i * 8 + 3] = g & 255; | |
out[i * 8 + 4] = (b >> 8) & 255; | |
out[i * 8 + 5] = b & 255; | |
out[i * 8 + 6] = (a >> 8) & 255; | |
out[i * 8 + 7] = a & 255; | |
} | |
} | |
/*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/ | |
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) | |
{ | |
*r = *g = *b = in[i]; | |
if(mode->key_defined && *r == mode->key_r) *a = 0; | |
else *a = 255; | |
} | |
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 | |
{ | |
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); | |
*r = *g = *b = (value * 255) / highest; | |
if(mode->key_defined && value == mode->key_r) *a = 0; | |
else *a = 255; | |
} | |
} | |
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 | |
{ | |
*r = in[i * 6 + 0]; | |
*g = in[i * 6 + 2]; | |
*b = in[i * 6 + 4]; | |
if(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) *a = 0; | |
else *a = 255; | |
} | |
} | |
else if(mode->colortype == LCT_PALETTE) | |
{ | |
unsigned index; | |
if(mode->bitdepth == 8) index = in[i]; | |
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) | |
{ | |
*r = *g = *b = in[i * 2 + 0]; | |
*a = in[i * 2 + 1]; | |
} | |
else | |
{ | |
*r = *g = *b = in[i * 4 + 0]; | |
*a = in[i * 4 + 2]; | |
} | |
} | |
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 | |
{ | |
*r = in[i * 8 + 0]; | |
*g = in[i * 8 + 2]; | |
*b = in[i * 8 + 4]; | |
*a = in[i * 8 + 6]; | |
} | |
} | |
} | |
/*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; | |
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]; | |
if(has_alpha) buffer[3] = mode->key_defined && in[i] == mode->key_r ? 0 : 255; | |
} | |
} | |
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; | |
} | |
} | |
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; | |
if(has_alpha) 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 | |
{ | |
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 | |
&& 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 | |
{ | |
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 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]; | |
} | |
} | |
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]; | |
} | |
} | |
} | |
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]; | |
} | |
} | |
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]; | |
} | |
} | |
} | |
} | |
/*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) | |
{ | |
*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) | |
{ | |
*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]; | |
if(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) *a = 0; | |
else *a = 65535; | |
} | |
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) | |
{ | |
*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]; | |
*a = 256u * in[i * 8 + 6] + in[i * 8 + 7]; | |
} | |
} | |
unsigned lodepng_convert(unsigned char* out, const unsigned char* in, | |
const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in, | |
unsigned w, unsigned h) | |
{ | |
size_t i; | |
ColorTree tree; | |
size_t numpixels = w * h; | |
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]; | |
return 0; | |
} | |
if(mode_out->colortype == LCT_PALETTE) | |
{ | |
size_t palettesize = mode_out->palettesize; | |
const unsigned char* palette = mode_out->palette; | |
size_t palsize = 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) | |
{ | |
palettesize = mode_in->palettesize; | |
palette = mode_in->palette; | |
} | |
if(palettesize < palsize) palsize = palettesize; | |
color_tree_init(&tree); | |
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], i); | |
} | |
} | |
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); | |
CERROR_TRY_RETURN(rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a)); | |
} | |
} | |
if(mode_out->colortype == LCT_PALETTE) | |
{ | |
color_tree_cleanup(&tree); | |
} | |
return 0; /*no error*/ | |
} | |
#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; | |
} | |
/*function used for debug purposes with C++*/ | |
/*void printColorProfile(LodePNGColorProfile* p) | |
{ | |
std::cout << "colored: " << (int)p->colored << ", "; | |
std::cout << "key: " << (int)p->key << ", "; | |
std::cout << "key_r: " << (int)p->key_r << ", "; | |
std::cout << "key_g: " << (int)p->key_g << ", "; | |
std::cout << "key_b: " << (int)p->key_b << ", "; | |
std::cout << "alpha: " << (int)p->alpha << ", "; | |
std::cout << "numcolors: " << (int)p->numcolors << ", "; | |
std::cout << "bits: " << (int)p->bits << std::endl; | |
}*/ | |
/*Returns how many bits needed to represent given value (max 8 bit)*/ | |
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; | |
size_t i; | |
ColorTree tree; | |
size_t numpixels = w * h; | |
unsigned colored_done = lodepng_is_greyscale_type(mode) ? 1 : 0; | |
unsigned alpha_done = lodepng_can_have_alpha(mode) ? 0 : 1; | |
unsigned numcolors_done = 0; | |
unsigned bpp = lodepng_get_bpp(mode); | |
unsigned bits_done = bpp == 1 ? 1 : 0; | |
unsigned maxnumcolors = 257; | |
unsigned sixteen = 0; | |
if(bpp <= 8) maxnumcolors = bpp == 1 ? 2 : (bpp == 2 ? 4 : (bpp == 4 ? 16 : 256)); | |
color_tree_init(&tree); | |
/*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((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*/ | |
{ | |
sixteen = 1; | |
break; | |
} | |
} | |
} | |
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); | |
if(!colored_done && (r != g || r != b)) | |
{ | |
profile->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; | |
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) | |
{ | |
/* Color key cannot be used if an opaque pixel also has that RGB color. */ | |
profile->alpha = 1; | |
profile->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) | |
{ | |
/* Color key cannot be used if an opaque pixel also has that RGB color. */ | |
profile->alpha = 1; | |
profile->key = 0; | |
alpha_done = 1; | |
} | |
} | |
} | |
} | |
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); | |
if(!bits_done && profile->bits < 8) | |
{ | |
/*only r is checked, < 8 bits is only relevant for greyscale*/ | |
unsigned bits = getValueRequiredBits(r); | |
if(bits > profile->bits) profile->bits = bits; | |
} | |
bits_done = (profile->bits >= bpp); | |
if(!colored_done && (r != g || r != b)) | |
{ | |
profile->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(!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; | |
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) | |
{ | |
/* Color key cannot be used if an opaque pixel also has that RGB color. */ | |
profile->alpha = 1; | |
profile->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(!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; | |
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; | |
} | |
} | |
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) | |
{ | |
/* Color key cannot be used if an opaque pixel also has that RGB color. */ | |
profile->alpha = 1; | |
profile->key = 0; | |
alpha_done = 1; | |
if(profile->bits < 8) profile->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); | |
} | |
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; | |
unsigned error = 0; | |
unsigned i, n, palettebits, palette_ok; | |
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*/ | |
} | |
n = prof.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*/ | |
if(palette_ok) | |
{ | |
unsigned char* p = prof.palette; | |
lodepng_palette_clear(mode_out); /*remove potential earlier palette*/ | |
for(i = 0; i != prof.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; | |
} | |
mode_out->colortype = LCT_PALETTE; | |
mode_out->bitdepth = palettebits; | |
if(mode_in->colortype == LCT_PALETTE && mode_in->palettesize >= mode_out->palettesize | |
&& 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; | |
mode_out->key_defined = 1; | |
} | |
} | |
return error; | |
} | |
#endif /* #ifdef LODEPNG_COMPILE_ENCODER */ | |
/* | |
Paeth predicter, 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; | |
} | |
/*shared values used by multiple Adam7 related functions*/ | |
static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/ | |
static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/ | |
static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/ | |
static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/ | |
/* | |
Outputs various dimensions and positions in the image related to the Adam7 reduced images. | |
passw: output containing the width of the 7 passes | |
passh: output containing the height of the 7 passes | |
filter_passstart: output containing the index of the start and end of each | |
reduced image with filter bytes | |
padded_passstart output containing the index of the start and end of each | |
reduced image when without filter bytes but with padded scanlines | |
passstart: output containing the index of the start and end of each reduced | |
image without padding between scanlines, but still padding between the images | |
w, h: width and height of non-interlaced image | |
bpp: bits per pixel | |
"padded" is only relevant if bpp is less than 8 and a scanline or image does not | |
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) | |
{ | |
/*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) | |
{ | |
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; | |
if(passh[i] == 0) passw[i] = 0; | |
} | |
filter_passstart[0] = padded_passstart[0] = passstart[0] = 0; | |
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); | |
/*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); | |
/*only padded at end of reduced image*/ | |
passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8; | |
} | |
} | |
#ifdef LODEPNG_COMPILE_DECODER | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* / PNG Decoder / */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/*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) | |
{ | |
LodePNGInfo* info = &state->info_png; | |
if(insize == 0 || in == 0) | |
{ | |
CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/ | |
} | |
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*/ | |
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) | |
{ | |
CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/ | |
} | |
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")) | |
{ | |
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]); | |
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*/ | |
} | |
} | |
/*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*/ | |
if(info->filter_method != 0) CERROR_RETURN_ERROR(state->error, 33); | |
/*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); | |
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) | |
{ | |
/* | |
For PNG filter method 0 | |
unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte, | |
the filter works byte per byte (bytewidth = 1) | |
precon is the previous unfiltered scanline, recon the result, scanline the current one | |
the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead | |
recon and scanline MAY be the same memory address! precon must be disjoint. | |
*/ | |
size_t i; | |
switch(filterType) | |
{ | |
case 0: | |
for(i = 0; i != length; ++i) recon[i] = scanline[i]; | |
break; | |
case 1: | |
for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i]; | |
for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + recon[i - bytewidth]; | |
break; | |
case 2: | |
if(precon) | |
{ | |
for(i = 0; i != length; ++i) recon[i] = scanline[i] + precon[i]; | |
} | |
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 | |
{ | |
for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i]; | |
for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + (recon[i - bytewidth] >> 1); | |
} | |
break; | |
case 4: | |
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) | |
{ | |
recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth])); | |
} | |
} | |
else | |
{ | |
for(i = 0; i != bytewidth; ++i) | |
{ | |
recon[i] = scanline[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*/ | |
} | |
return 0; | |
} | |
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) | |
out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline | |
w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel | |
in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes) | |
*/ | |
unsigned y; | |
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; | |
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]; | |
CERROR_TRY_RETURN(unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes)); | |
prevline = &out[outindex]; | |
} | |
return 0; | |
} | |
/* | |
in: Adam7 interlaced image, with no padding bits between scanlines, but between | |
reduced images so that each reduced image starts at a byte. | |
out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h | |
bpp: bits per pixel | |
out has the following size in bits: w * h * bpp. | |
in is possibly bigger due to padding bits between reduced images. | |
out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation | |
(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) | |
{ | |
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) | |
{ | |
unsigned x, y, b; | |
size_t bytewidth = bpp / 8; | |
for(y = 0; y < passh[i]; ++y) | |
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) | |
{ | |
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) | |
{ | |
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) | |
{ | |
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) | |
{ | |
unsigned char bit = readBitFromReversedStream(&ibp, in); | |
/*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/ | |
setBitOfReversedStream0(&obp, out, bit); | |
} | |
} | |
} | |
} | |
} | |
static void removePaddingBits(unsigned char* out, const unsigned char* in, | |
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 | |
for the Adam7 code, the color convert code and the output to the user. | |
in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must | |
have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits | |
also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7 | |
only useful if (ilinebits - olinebits) is a value in the range 1..7 | |
*/ | |
unsigned y; | |
size_t diff = ilinebits - olinebits; | |
size_t ibp = 0, obp = 0; /*input and output bit pointers*/ | |
for(y = 0; y < h; ++y) | |
{ | |
size_t x; | |
for(x = 0; x < olinebits; ++x) | |
{ | |
unsigned char bit = readBitFromReversedStream(&ibp, in); | |
setBitOfReversedStream(&obp, out, bit); | |
} | |
ibp += diff; | |
} | |
} | |
/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from | |
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) | |
{ | |
/* | |
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 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) | |
{ | |
CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp)); | |
removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, 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)*/ | |
{ | |
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) | |
{ | |
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) | |
{ | |
/*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]); | |
} | |
} | |
Adam7_deinterlace(out, in, w, h, bpp); | |
} | |
return 0; | |
} | |
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 = 0; | |
return 83; /*alloc fail*/ | |
} | |
if(color->palettesize > 256) return 38; /*error: palette too big*/ | |
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*/ | |
color->palette[4 * i + 3] = 255; /*alpha*/ | |
} | |
return 0; /* OK */ | |
} | |
static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) | |
{ | |
unsigned i; | |
if(color->colortype == LCT_PALETTE) | |
{ | |
/*error: more alpha values given than there are palette entries*/ | |
if(chunkLength > color->palettesize) return 38; | |
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*/ | |
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) | |
{ | |
/*error: this chunk must be 6 bytes for RGB image*/ | |
if(chunkLength != 6) return 41; | |
color->key_defined = 1; | |
color->key_r = 256u * data[0] + data[1]; | |
color->key_g = 256u * data[2] + data[3]; | |
color->key_b = 256u * data[4] + data[5]; | |
} | |
else return 42; /*error: tRNS chunk not allowed for other color models*/ | |
return 0; /* OK */ | |
} | |
#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) | |
{ | |
/*error: this chunk must be 1 byte for indexed color image*/ | |
if(chunkLength != 1) return 43; | |
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*/ | |
if(chunkLength != 2) return 44; | |
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*/ | |
if(chunkLength != 6) return 45; | |
info->background_defined = 1; | |
info->background_r = 256u * data[0] + data[1]; | |
info->background_g = 256u * data[2] + data[3]; | |
info->background_b = 256u * data[4] + data[5]; | |
} | |
return 0; /* OK */ | |
} | |
/*text chunk (tEXt)*/ | |
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*/ | |
{ | |
unsigned length, string2_begin; | |
length = 0; | |
while(length < chunkLength && data[length] != 0) ++length; | |
/*even though it's not allowed by the standard, no error is thrown if | |
there's no null termination char, if the text is empty*/ | |
if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ | |
key = (char*)lodepng_malloc(length + 1); | |
if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ | |
key[length] = 0; | |
for(i = 0; i != length; ++i) key[i] = (char)data[i]; | |
string2_begin = length + 1; /*skip keyword null terminator*/ | |
length = chunkLength < string2_begin ? 0 : chunkLength - string2_begin; | |
str = (char*)lodepng_malloc(length + 1); | |
if(!str) CERROR_BREAK(error, 83); /*alloc fail*/ | |
str[length] = 0; | |
for(i = 0; i != length; ++i) str[i] = (char)data[string2_begin + i]; | |
error = lodepng_add_text(info, key, str); | |
break; | |
} | |
lodepng_free(key); | |
lodepng_free(str); | |
return error; | |
} | |
/*compressed text chunk (zTXt)*/ | |
static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, | |
const unsigned char* data, size_t chunkLength) | |
{ | |
unsigned error = 0; | |
unsigned i; | |
unsigned length, string2_begin; | |
char *key = 0; | |
ucvector decoded; | |
ucvector_init(&decoded); | |
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*/ | |
key = (char*)lodepng_malloc(length + 1); | |
if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ | |
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*/ | |
string2_begin = length + 2; | |
if(string2_begin > chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/ | |
length = 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]), | |
length, zlibsettings); | |
if(error) break; | |
ucvector_push_back(&decoded, 0); | |
error = lodepng_add_text(info, key, (char*)decoded.data); | |
break; | |
} | |
lodepng_free(key); | |
ucvector_cleanup(&decoded); | |
return error; | |
} | |
/*international text chunk (iTXt)*/ | |
static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, | |
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*/ | |
{ | |
/*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*/ | |
/*read the key*/ | |
for(length = 0; length < chunkLength && data[length] != 0; ++length) ; | |
if(length + 3 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination char, corrupt?*/ | |
if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ | |
key = (char*)lodepng_malloc(length + 1); | |
if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ | |
key[length] = 0; | |
for(i = 0; i != length; ++i) key[i] = (char)data[i]; | |
/*read the compression method*/ | |
compressed = data[length + 1]; | |
if(data[length + 2] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/ | |
/*even though it's not allowed by the standard, no error is thrown if | |
there's no null termination char, if the text is empty for the next 3 texts*/ | |
/*read the langtag*/ | |
begin = length + 3; | |
length = 0; | |
for(i = begin; i < chunkLength && data[i] != 0; ++i) ++length; | |
langtag = (char*)lodepng_malloc(length + 1); | |
if(!langtag) CERROR_BREAK(error, 83); /*alloc fail*/ | |
langtag[length] = 0; | |
for(i = 0; i != length; ++i) langtag[i] = (char)data[begin + i]; | |
/*read the transkey*/ | |
begin += length + 1; | |
length = 0; | |
for(i = begin; i < chunkLength && data[i] != 0; ++i) ++length; | |
transkey = (char*)lodepng_malloc(length + 1); | |
if(!transkey) CERROR_BREAK(error, 83); /*alloc fail*/ | |
transkey[length] = 0; | |
for(i = 0; i != length; ++i) transkey[i] = (char)data[begin + i]; | |
/*read the actual text*/ | |
begin += length + 1; | |
length = chunkLength < begin ? 0 : chunkLength - begin; | |
if(compressed) | |
{ | |
/*will fail if zlib error, e.g. if length is too small*/ | |
error = zlib_decompress(&decoded.data, &decoded.size, | |
(unsigned char*)(&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]; | |
} | |
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) | |
{ | |
if(chunkLength != 7) return 73; /*invalid tIME chunk size*/ | |
info->time_defined = 1; | |
info->time.year = 256u * data[0] + data[1]; | |
info->time.month = data[2]; | |
info->time.day = data[3]; | |
info->time.hour = data[4]; | |
info->time.minute = data[5]; | |
info->time.second = data[6]; | |
return 0; /* OK */ | |
} | |
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; | |
info->phys_x = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3]; | |
info->phys_y = 16777216u * data[4] + 65536u * data[5] + 256u * data[6] + data[7]; | |
info->phys_unit = data[8]; | |
return 0; /* OK */ | |
} | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
/*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) | |
{ | |
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; | |
size_t outsize = 0; | |
/*for unknown chunk order*/ | |
unsigned unknown = 0; | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
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*/ | |
*out = 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; | |
/*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); | |
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) | |
{ | |
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) CERROR_BREAK(state->error, 30); | |
/*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) CERROR_BREAK(state->error, 63); | |
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); | |
/*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]; | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
critical_pos = 3; | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
} | |
/*IEND chunk*/ | |
else if(lodepng_chunk_type_equals(chunk, "IEND")) | |
{ | |
IEND = 1; | |
} | |
/*palette chunk (PLTE)*/ | |
else if(lodepng_chunk_type_equals(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")) | |
{ | |
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")) | |
{ | |
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) | |
{ | |
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) | |
{ | |
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) | |
{ | |
state->error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); | |
if(state->error) break; | |
} | |
} | |
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")) | |
{ | |
state->error = readChunk_pHYs(&state->info_png, 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*/ | |
{ | |
/*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/ | |
if(!lodepng_chunk_ancillary(chunk)) CERROR_BREAK(state->error, 69); | |
unknown = 1; | |
#ifdef LODEPNG_COMPILE_ANCILLARY_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; | |
} | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
} | |
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) | |
{ | |
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); | |
} | |
ucvector_cleanup(&scanlines); | |
} | |
unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h, | |
LodePNGState* state, | |
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)) | |
{ | |
/*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) | |
{ | |
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*/ | |
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"*/ | |
if(!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA) | |
&& !(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)) | |
{ | |
state->error = 83; /*alloc fail*/ | |
} | |
else state->error = lodepng_convert(*out, data, &state->info_raw, | |
&state->info_png.color, *w, *h); | |
lodepng_free(data); | |
} | |
return state->error; | |
} | |
unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, | |
size_t insize, LodePNGColorType colortype, unsigned bitdepth) | |
{ | |
unsigned error; | |
LodePNGState state; | |
lodepng_state_init(&state); | |
state.info_raw.colortype = colortype; | |
state.info_raw.bitdepth = bitdepth; | |
error = lodepng_decode(out, w, h, &state, in, insize); | |
lodepng_state_cleanup(&state); | |
return error; | |
} | |
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) | |
{ | |
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) | |
{ | |
unsigned char* buffer = 0; | |
size_t buffersize; | |
unsigned error; | |
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) | |
{ | |
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) | |
{ | |
return lodepng_decode_file(out, w, h, filename, LCT_RGB, 8); | |
} | |
#endif /*LODEPNG_COMPILE_DISK*/ | |
void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) | |
{ | |
settings->color_convert = 1; | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
settings->read_text_chunks = 1; | |
settings->remember_unknown_chunks = 0; | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
settings->ignore_crc = 0; | |
lodepng_decompress_settings_init(&settings->zlibsettings); | |
} | |
#endif /*LODEPNG_COMPILE_DECODER*/ | |
#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) | |
void lodepng_state_init(LodePNGState* state) | |
{ | |
#ifdef LODEPNG_COMPILE_DECODER | |
lodepng_decoder_settings_init(&state->decoder); | |
#endif /*LODEPNG_COMPILE_DECODER*/ | |
#ifdef LODEPNG_COMPILE_ENCODER | |
lodepng_encoder_settings_init(&state->encoder); | |
#endif /*LODEPNG_COMPILE_ENCODER*/ | |
lodepng_color_mode_init(&state->info_raw); | |
lodepng_info_init(&state->info_png); | |
state->error = 1; | |
} | |
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) | |
{ | |
lodepng_state_cleanup(dest); | |
*dest = *source; | |
lodepng_color_mode_init(&dest->info_raw); | |
lodepng_info_init(&dest->info_png); | |
dest->error = lodepng_color_mode_copy(&dest->info_raw, &source->info_raw); if(dest->error) return; | |
dest->error = lodepng_info_copy(&dest->info_png, &source->info_png); if(dest->error) return; | |
} | |
#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */ | |
#ifdef LODEPNG_COMPILE_ENCODER | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* / 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) | |
{ | |
/*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); | |
} | |
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); | |
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*/ | |
error = addChunk(out, "IHDR", header.data, header.size); | |
ucvector_cleanup(&header); | |
return error; | |
} | |
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) | |
{ | |
/*add all channels except alpha channel*/ | |
if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]); | |
} | |
error = addChunk(out, "PLTE", PLTE.data, PLTE.size); | |
ucvector_cleanup(&PLTE); | |
return error; | |
} | |
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; | |
/*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; | |
} | |
/*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)); | |
} | |
} | |
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)); | |
} | |
} | |
error = addChunk(out, "tRNS", tRNS.data, tRNS.size); | |
ucvector_cleanup(&tRNS); | |
return error; | |
} | |
static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize, | |
LodePNGCompressSettings* zlibsettings) | |
{ | |
ucvector zlibdata; | |
unsigned error = 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); | |
return error; | |
} | |
static unsigned addChunk_IEND(ucvector* out) | |
{ | |
unsigned error = 0; | |
error = addChunk(out, "IEND", 0, 0); | |
return error; | |
} | |
#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_zTXt(ucvector* out, const char* keyword, const char* textstring, | |
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); | |
return error; | |
} | |
static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, 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); | |
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); | |
return error; | |
} | |
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 error = 0; | |
ucvector data; | |
ucvector_init(&data); | |
lodepng_add32bitInt(&data, info->phys_x); | |
lodepng_add32bitInt(&data, info->phys_y); | |
ucvector_push_back(&data, info->phys_unit); | |
error = addChunk(out, "pHYs", data.data, data.size); | |
ucvector_cleanup(&data); | |
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 i; | |
switch(filterType) | |
{ | |
case 0: /*None*/ | |
for(i = 0; i != length; ++i) out[i] = scanline[i]; | |
break; | |
case 1: /*Sub*/ | |
for(i = 0; i != bytewidth; ++i) out[i] = scanline[i]; | |
for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - scanline[i - bytewidth]; | |
break; | |
case 2: /*Up*/ | |
if(prevline) | |
{ | |
for(i = 0; i != length; ++i) out[i] = scanline[i] - prevline[i]; | |
} | |
else | |
{ | |
for(i = 0; i != length; ++i) out[i] = scanline[i]; | |
} | |
break; | |
case 3: /*Average*/ | |
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 | |
{ | |
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) | |
{ | |
/*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) | |
{ | |
out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth])); | |
} | |
} | |
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*/ | |
} | |
} | |
/* 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); | |
} | |
static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, | |
const LodePNGColorMode* info, 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 | |
the scanlines with 1 extra byte per scanline | |
*/ | |
unsigned bpp = lodepng_get_bpp(info); | |
/*the width of a scanline in bytes, not including the filter type*/ | |
size_t linebytes = (w * bpp + 7) / 8; | |
/*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ | |
size_t bytewidth = (bpp + 7) / 8; | |
const unsigned char* prevline = 0; | |
unsigned x, y; | |
unsigned error = 0; | |
LodePNGFilterStrategy strategy = settings->filter_strategy; | |
/* | |
There is a heuristic called the minimum sum of absolute differences heuristic, suggested by the PNG standard: | |
* If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e. | |
use fixed filtering, with the filter None). | |
* (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is | |
not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply | |
all five filters and select the filter that produces the smallest sum of absolute values per row. | |
This heuristic is used if filter strategy is LFS_MINSUM and filter_palette_zero is true. | |
If filter_palette_zero is true and filter_strategy is not LFS_MINSUM, the above heuristic is followed, | |
but for "the other case", whatever strategy filter_strategy is set to instead of the minimum sum | |
heuristic is used. | |
*/ | |
if(settings->filter_palette_zero && | |
(info->colortype == LCT_PALETTE || info->bitdepth < 8)) strategy = LFS_ZERO; | |
if(bpp == 0) return 31; /*error: invalid color type*/ | |
if(strategy == LFS_ZERO) | |
{ | |
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); | |
prevline = &in[inindex]; | |
} | |
} | |
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) | |
{ | |
attempt[type] = (unsigned char*)lodepng_malloc(linebytes); | |
if(!attempt[type]) return 83; /*alloc fail*/ | |
} | |
if(!error) | |
{ | |
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); | |
/*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) | |
{ | |
/*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); | |
} | |
} | |
/*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]; | |
} | |
} | |
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]; | |
} | |
} | |
for(type = 0; type != 5; ++type) lodepng_free(attempt[type]); | |
} | |
else if(strategy == LFS_ENTROPY) | |
{ | |
float sum[5]; | |
unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/ | |
float smallest = 0; | |
unsigned type, bestType = 0; | |
unsigned count[256]; | |
for(type = 0; type != 5; ++type) | |
{ | |
attempt[type] = (unsigned char*)lodepng_malloc(linebytes); | |
if(!attempt[type]) return 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]; | |
} | |
} | |
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]; | |
} | |
for(type = 0; type != 5; ++type) lodepng_free(attempt[type]); | |
} | |
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]; | |
out[outindex] = type; /*filter type byte*/ | |
filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type); | |
prevline = &in[inindex]; | |
} | |
} | |
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*/ | |
size_t size[5]; | |
unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/ | |
size_t smallest = 0; | |
unsigned type = 0, bestType = 0; | |
unsigned char* dummy; | |
LodePNGCompressSettings zlibsettings = settings->zlibsettings; | |
/*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 | |
cases better compression. It does make this a bit less slow, so it's worth doing this.*/ | |
zlibsettings.btype = 1; | |
/*a custom encoder likely doesn't read the btype setting and is optimized for complete PNG | |
images only, so disable it*/ | |
zlibsettings.custom_zlib = 0; | |
zlibsettings.custom_deflate = 0; | |
for(type = 0; type != 5; ++type) | |
{ | |
attempt[type] = (unsigned char*)lodepng_malloc(linebytes); | |
if(!attempt[type]) return 83; /*alloc fail*/ | |
} | |
for(y = 0; y != h; ++y) /*try the 5 filter types*/ | |
{ | |
for(type = 0; type != 5; ++type) | |
{ | |
unsigned testsize = 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]; | |
} | |
for(type = 0; type != 5; ++type) lodepng_free(attempt[type]); | |
} | |
else return 88; /* unknown filter strategy */ | |
return error; | |
} | |
static void addPaddingBits(unsigned char* out, const unsigned char* in, | |
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) | |
{ | |
size_t x; | |
for(x = 0; x < ilinebits; ++x) | |
{ | |
unsigned char bit = readBitFromReversedStream(&ibp, in); | |
setBitOfReversedStream(&obp, out, bit); | |
} | |
/*obp += diff; --> no, fill in some value in the padding bits too, to avoid | |
"Use of uninitialised value of size ###" warning from valgrind*/ | |
for(x = 0; x != diff; ++x) setBitOfReversedStream(&obp, out, 0); | |
} | |
} | |
/* | |
in: non-interlaced image with size w*h | |
out: the same pixels, but re-ordered according to PNG's Adam7 interlacing, with | |
no padding bits between scanlines, but between reduced images so that each | |
reduced image starts at a byte. | |
bpp: bits per pixel | |
there are no padding bits, not between scanlines, not between reduced images | |
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) | |
{ | |
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) | |
{ | |
unsigned x, y, b; | |
size_t bytewidth = bpp / 8; | |
for(y = 0; y < passh[i]; ++y) | |
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) | |
{ | |
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) | |
{ | |
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) | |
{ | |
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) | |
{ | |
unsigned char bit = readBitFromReversedStream(&ibp, in); | |
setBitOfReversedStream(&obp, out, bit); | |
} | |
} | |
} | |
} | |
} | |
/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image. | |
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) | |
{ | |
/* | |
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 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*/ | |
*out = (unsigned char*)lodepng_malloc(*outsize); | |
if(!(*out) && (*outsize)) error = 83; /*alloc fail*/ | |
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(!padded) error = 83; /*alloc fail*/ | |
if(!error) | |
{ | |
addPaddingBits(padded, in, ((w * bpp + 7) / 8) * 8, w * bpp, h); | |
error = filter(*out, padded, w, h, &info_png->color, settings); | |
} | |
lodepng_free(padded); | |
} | |
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)*/ | |
{ | |
unsigned passw[7], passh[7]; | |
size_t filter_passstart[8], padded_passstart[8], passstart[8]; | |
unsigned char* adam7; | |
Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); | |
*outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/ | |
*out = (unsigned char*)lodepng_malloc(*outsize); | |
if(!(*out)) error = 83; /*alloc fail*/ | |
adam7 = (unsigned char*)lodepng_malloc(passstart[7]); | |
if(!adam7 && passstart[7]) error = 83; /*alloc fail*/ | |
if(!error) | |
{ | |
unsigned i; | |
Adam7_interlace(adam7, in, w, h, bpp); | |
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]); | |
error = filter(&(*out)[filter_passstart[i]], padded, | |
passw[i], passh[i], &info_png->color, settings); | |
lodepng_free(padded); | |
} | |
else | |
{ | |
error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]], | |
passw[i], passh[i], &info_png->color, settings); | |
} | |
if(error) break; | |
} | |
} | |
lodepng_free(adam7); | |
} | |
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) | |
{ | |
unsigned char* inchunk = data; | |
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); | |
} | |
return 0; | |
} | |
#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; | |
unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/ | |
size_t datasize = 0; | |
/*provide some proper output values if error will happen*/ | |
*out = 0; | |
*outsize = 0; | |
state->error = 0; | |
lodepng_info_init(&info); | |
lodepng_info_copy(&info, &state->info_png); | |
if((info.color.colortype == LCT_PALETTE || state->encoder.force_palette) | |
&& (info.color.palettesize == 0 || info.color.palettesize > 256)) | |
{ | |
state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/ | |
return state->error; | |
} | |
if(state->encoder.auto_convert) | |
{ | |
state->error = lodepng_auto_choose_color(&info.color, image, w, h, &state->info_raw); | |
} | |
if(state->error) return state->error; | |
if(state->encoder.zlibsettings.btype > 2) | |
{ | |
CERROR_RETURN_ERROR(state->error, 61); /*error: unexisting btype*/ | |
} | |
if(state->info_png.interlace_method > 1) | |
{ | |
CERROR_RETURN_ERROR(state->error, 71); /*error: unexisting interlace mode*/ | |
} | |
state->error = checkColorValidity(info.color.colortype, info.color.bitdepth); | |
if(state->error) return state->error; /*error: unexisting 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(!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->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder); | |
lodepng_free(converted); | |
} | |
else preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder); | |
ucvector_init(&outv); | |
while(!state->error) /*while only executed once, to break on error*/ | |
{ | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
size_t i; | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
/*write signature and chunks*/ | |
writeSignature(&outv); | |
/*IHDR*/ | |
addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method); | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
/*unknown chunks between IHDR and PLTE*/ | |
if(info.unknown_chunks_data[0]) | |
{ | |
state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0], info.unknown_chunks_size[0]); | |
if(state->error) break; | |
} | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
/*PLTE*/ | |
if(info.color.colortype == LCT_PALETTE) | |
{ | |
addChunk_PLTE(&outv, &info.color); | |
} | |
if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA)) | |
{ | |
addChunk_PLTE(&outv, &info.color); | |
} | |
/*tRNS*/ | |
if(info.color.colortype == LCT_PALETTE && getPaletteTranslucency(info.color.palette, info.color.palettesize) != 0) | |
{ | |
addChunk_tRNS(&outv, &info.color); | |
} | |
if((info.color.colortype == LCT_GREY || info.color.colortype == LCT_RGB) && info.color.key_defined) | |
{ | |
addChunk_tRNS(&outv, &info.color); | |
} | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
/*bKGD (must come between PLTE and the IDAt chunks*/ | |
if(info.background_defined) addChunk_bKGD(&outv, &info); | |
/*pHYs (must come before the IDAT chunks)*/ | |
if(info.phys_defined) addChunk_pHYs(&outv, &info); | |
/*unknown chunks between PLTE and IDAT*/ | |
if(info.unknown_chunks_data[1]) | |
{ | |
state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1], info.unknown_chunks_size[1]); | |
if(state->error) break; | |
} | |
#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; | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
/*tIME*/ | |
if(info.time_defined) addChunk_tIME(&outv, &info.time); | |
/*tEXt and/or zTXt*/ | |
for(i = 0; i != info.text_num; ++i) | |
{ | |
if(strlen(info.text_keys[i]) > 79) | |
{ | |
state->error = 66; /*text chunk too large*/ | |
break; | |
} | |
if(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); | |
} | |
else | |
{ | |
addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]); | |
} | |
} | |
/*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; | |
break; | |
} | |
} | |
if(alread_added_id_text == 0) | |
{ | |
addChunk_tEXt(&outv, "LodePNG", LODEPNG_VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/ | |
} | |
} | |
/*iTXt*/ | |
for(i = 0; i != info.itext_num; ++i) | |
{ | |
if(strlen(info.itext_keys[i]) > 79) | |
{ | |
state->error = 66; /*text chunk too large*/ | |
break; | |
} | |
if(strlen(info.itext_keys[i]) < 1) | |
{ | |
state->error = 67; /*text chunk too small*/ | |
break; | |
} | |
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); | |
} | |
/*unknown chunks between IDAT and IEND*/ | |
if(info.unknown_chunks_data[2]) | |
{ | |
state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2], info.unknown_chunks_size[2]); | |
if(state->error) break; | |
} | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
addChunk_IEND(&outv); | |
break; /*this isn't really a while loop; no error happened so break out now!*/ | |
} | |
lodepng_info_cleanup(&info); | |
lodepng_free(data); | |
/*instead of cleaning the vector up, give it to the output*/ | |
*out = outv.data; | |
*outsize = outv.size; | |
return state->error; | |
} | |
unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsigned char* image, | |
unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) | |
{ | |
unsigned error; | |
LodePNGState state; | |
lodepng_state_init(&state); | |
state.info_raw.colortype = colortype; | |
state.info_raw.bitdepth = bitdepth; | |
state.info_png.color.colortype = colortype; | |
state.info_png.color.bitdepth = bitdepth; | |
lodepng_encode(out, outsize, image, w, h, &state); | |
error = state.error; | |
lodepng_state_cleanup(&state); | |
return error; | |
} | |
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) | |
{ | |
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) | |
{ | |
unsigned char* buffer; | |
size_t buffersize; | |
unsigned error = lodepng_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth); | |
if(!error) error = lodepng_save_file(buffer, buffersize, filename); | |
lodepng_free(buffer); | |
return error; | |
} | |
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) | |
{ | |
return lodepng_encode_file(filename, image, w, h, LCT_RGB, 8); | |
} | |
#endif /*LODEPNG_COMPILE_DISK*/ | |
void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings) | |
{ | |
lodepng_compress_settings_init(&settings->zlibsettings); | |
settings->filter_palette_zero = 1; | |
settings->filter_strategy = LFS_MINSUM; | |
settings->auto_convert = 1; | |
settings->force_palette = 0; | |
settings->predefined_filters = 0; | |
#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS | |
settings->add_id = 0; | |
settings->text_compression = 1; | |
#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ | |
} | |
#endif /*LODEPNG_COMPILE_ENCODER*/ | |
#endif /*LODEPNG_COMPILE_PNG*/ | |
#ifdef LODEPNG_COMPILE_ERROR_TEXT | |
/* | |
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) | |
{ | |
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*/ | |
case 11: return "error in code tree made it jump outside of huffman tree"; /*while huffman decoding*/ | |
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"; | |
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.*/ | |
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"; | |
case 25: return "invalid compression method in zlib header"; | |
case 26: return "FDICT encountered in zlib header while it's not used for PNG"; | |
case 27: return "PNG file is smaller than a PNG header"; | |
/*Checks the magic file header, the first 8 bytes of the PNG file*/ | |
case 28: return "incorrect PNG signature, it's no PNG or corrupted"; | |
case 29: return "first chunk is not the header chunk"; | |
case 30: return "chunk length too large, chunk broken off at end of file"; | |
case 31: return "illegal PNG color type or bpp"; | |
case 32: return "illegal PNG compression method"; | |
case 33: return "illegal PNG filter method"; | |
case 34: return "illegal PNG interlace method"; | |
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 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 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"; | |
case 50: return "jumped past memory while generating dynamic huffman tree"; | |
case 51: return "jumped past memory while inflating huffman block"; | |
case 52: return "jumped past memory while inflating"; | |
case 53: return "size of zlib data too small"; | |
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.*/ | |
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)"; | |
case 58: return "invalid ADLER32 encountered (checking ADLER32 can be disabled)"; | |
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)*/ | |
/*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 73: return "invalid tIME chunk size"; | |
case 74: return "invalid pHYs chunk size"; | |
/*length could be wrong, or data chopped off*/ | |
case 75: return "no null termination char found while decoding text chunk"; | |
case 76: return "iTXt chunk too short to contain required bytes"; | |
case 77: return "integer overflow in buffer size"; | |
case 78: return "failed to open file for reading"; /*file doesn't exist or couldn't be opened for reading*/ | |
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 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)"; | |
case 87: return "must provide custom zlib function pointer if LODEPNG_COMPILE_ZLIB is not defined"; | |
case 88: return "invalid filter strategy given for LodePNGEncoderSettings.filter_strategy"; | |
case 89: return "text chunk keyword too short or long: must have size 1-79"; | |
/*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 93: return "zero width or height is invalid"; | |
case 94: return "header chunk must have a size of 13 bytes"; | |
} | |
return "unknown error code"; | |
} | |
#endif /*LODEPNG_COMPILE_ERROR_TEXT*/ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* // C++ Wrapper // */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
/* ////////////////////////////////////////////////////////////////////////// */ | |
#ifdef LODEPNG_COMPILE_CPP | |
namespace lodepng | |
{ | |
#ifdef LODEPNG_COMPILE_DISK | |
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); | |
return size == 0 ? 0 : lodepng_buffer_file(&buffer[0], (size_t)size, filename.c_str()); | |
} | |
/*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) | |
{ | |
return lodepng_save_file(buffer.empty() ? 0 : &buffer[0], buffer.size(), filename.c_str()); | |
} | |
#endif /* LODEPNG_COMPILE_DISK */ | |
#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) | |
{ | |
unsigned char* buffer = 0; | |
size_t buffersize = 0; | |
unsigned error = zlib_decompress(&buffer, &buffersize, in, insize, &settings); | |
if(buffer) | |
{ | |
out.insert(out.end(), &buffer[0], &buffer[buffersize]); | |
lodepng_free(buffer); | |
} | |
return error; | |
} | |
unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, | |
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) | |
{ | |
unsigned char* buffer = 0; | |
size_t buffersize = 0; | |
unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings); | |
if(buffer) | |
{ | |
out.insert(out.end(), &buffer[0], &buffer[buffersize]); | |
lodepng_free(buffer); | |
} | |
return error; | |
} | |
unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, | |
const LodePNGCompressSettings& settings) | |
{ | |
return compress(out, in.empty() ? 0 : &in[0], in.size(), settings); | |
} | |
#endif /* LODEPNG_COMPILE_ENCODER */ | |
#endif /* LODEPNG_COMPILE_ZLIB */ | |
#ifdef LODEPNG_COMPILE_PNG | |
State::State() | |
{ | |
lodepng_state_init(this); | |
} | |
State::State(const State& other) | |
{ | |
lodepng_state_init(this); | |
lodepng_state_copy(this, &other); | |
} | |
State::~State() | |
{ | |
lodepng_state_cleanup(this); | |
} | |
State& State::operator=(const State& other) | |
{ | |
lodepng_state_copy(this, &other); | |
return *this; | |
} | |
#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; | |
unsigned error = lodepng_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth); | |
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); | |
} | |
return error; | |
} | |
unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, | |
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) | |
{ | |
unsigned char* buffer = NULL; | |
unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize); | |
if(buffer && !error) | |
{ | |
size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw); | |
out.insert(out.end(), &buffer[0], &buffer[buffersize]); | |
} | |
lodepng_free(buffer); | |
return error; | |
} | |
unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, | |
State& state, | |
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) | |
{ | |
std::vector<unsigned char> buffer; | |
unsigned error = load_file(buffer, filename); | |
if(error) return error; | |
return decode(out, w, h, buffer, colortype, bitdepth); | |
} | |
#endif /* LODEPNG_COMPILE_DECODER */ | |
#endif /* LODEPNG_COMPILE_DISK */ | |
#ifdef LODEPNG_COMPILE_ENCODER | |
unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h, | |
LodePNGColorType colortype, unsigned bitdepth) | |
{ | |
unsigned char* buffer; | |
size_t buffersize; | |
unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth); | |
if(buffer) | |
{ | |
out.insert(out.end(), &buffer[0], &buffer[buffersize]); | |
lodepng_free(buffer); | |
} | |
return error; | |
} | |
unsigned encode(std::vector<unsigned char>& out, | |
const std::vector<unsigned char>& in, unsigned w, unsigned h, | |
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) | |
{ | |
unsigned char* buffer; | |
size_t buffersize; | |
unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state); | |
if(buffer) | |
{ | |
out.insert(out.end(), &buffer[0], &buffer[buffersize]); | |
lodepng_free(buffer); | |
} | |
return error; | |
} | |
unsigned encode(std::vector<unsigned char>& out, | |
const std::vector<unsigned char>& in, unsigned w, unsigned h, | |
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); | |
} | |
#ifdef LODEPNG_COMPILE_DISK | |
unsigned encode(const std::string& filename, | |
const unsigned char* in, unsigned w, unsigned h, | |
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); | |
return error; | |
} | |
unsigned encode(const std::string& filename, | |
const std::vector<unsigned char>& in, unsigned w, unsigned h, | |
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); | |
} | |
#endif /* LODEPNG_COMPILE_DISK */ | |
#endif /* LODEPNG_COMPILE_ENCODER */ | |
#endif /* LODEPNG_COMPILE_PNG */ | |
} /* namespace lodepng */ | |
#endif /*LODEPNG_COMPILE_CPP*/ |