diff options
Diffstat (limited to 'plugingui')
| m--------- | plugingui/lodepng | 0 | ||||
| -rw-r--r-- | plugingui/lodepng/lodepng.cpp | 6260 | ||||
| -rw-r--r-- | plugingui/lodepng/lodepng.h | 1716 |
3 files changed, 0 insertions, 7976 deletions
diff --git a/plugingui/lodepng b/plugingui/lodepng new file mode 160000 +Subproject a71964ed5fe4f82a32ac7f8201338900f66e855 diff --git a/plugingui/lodepng/lodepng.cpp b/plugingui/lodepng/lodepng.cpp deleted file mode 100644 index e4f35d7..0000000 --- a/plugingui/lodepng/lodepng.cpp +++ /dev/null @@ -1,6260 +0,0 @@ -/* -LodePNG version 20131222 - -Copyright (c) 2005-2013 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 <stdio.h> -#include <stdlib.h> - -#ifdef LODEPNG_COMPILE_CPP -#include <fstream> -#endif /*LODEPNG_COMPILE_CPP*/ - -#define VERSION_STRING "20131222" - -/* -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;\ -} - -/* -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_resize(uivector* p, size_t size) -{ - if(size * sizeof(unsigned) > p->allocsize) - { - size_t newsize = size * sizeof(unsigned) * 2; - void* data = lodepng_realloc(p->data, newsize); - if(data) - { - p->allocsize = newsize; - p->data = (unsigned*)data; - p->size = size; - } - else return 0; - } - else p->size = size; - return 1; -} - -/*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; -} - -/*copy q to p, returns 1 if success, 0 if failure ==> nothing done*/ -static unsigned uivector_copy(uivector* p, const uivector* q) -{ - size_t i; - if(!uivector_resize(p, q->size)) return 0; - for(i = 0; i < q->size; i++) p->data[i] = q->data[i]; - 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_resize(ucvector* p, size_t size) -{ - if(size * sizeof(unsigned char) > p->allocsize) - { - size_t newsize = size * sizeof(unsigned char) * 2; - void* data = lodepng_realloc(p->data, newsize); - if(data) - { - p->allocsize = newsize; - p->data = (unsigned char*)data; - p->size = size; - } - else return 0; /*error: not enough memory*/ - } - else p->size = size; - return 1; -} - -#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; -} - -#ifdef LODEPNG_COMPILE_DECODER -/*resize and give all new elements the value*/ -static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value) -{ - size_t oldsize = p->size, i; - if(!ucvector_resize(p, size)) return 0; - for(i = oldsize; i < size; i++) p->data[i] = value; - return 1; -} -#endif /*LODEPNG_COMPILE_DECODER*/ -#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 = 0; - 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 (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 - -unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename) -{ - FILE* file; - long size; - - /*provide some proper output values if error will happen*/ - *out = 0; - *outsize = 0; - - file = fopen(filename, "rb"); - if(!file) return 78; - - /*get filesize:*/ - fseek(file , 0 , SEEK_END); - size = ftell(file); - rewind(file); - - /*read contents of the file into the vector*/ - *outsize = 0; - *out = (unsigned char*)lodepng_malloc((size_t)size); - if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file); - - fclose(file); - if(!(*out) && size) return 83; /*the above malloc failed*/ - return 0; -} - -/*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 huffmann 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); - if(treepos > tree->numcodes - 2) return 55; /*oversubscribed, see comment in lodepng_error_text*/ - 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 bits, n, error = 0; - - 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 - -/* -A coin, this is the terminology used for the package-merge algorithm and the -coin collector's problem. This is used to generate the huffman tree. -A coin can be multiple coins (when they're merged) -*/ -typedef struct Coin -{ - uivector symbols; - float weight; /*the sum of all weights in this coin*/ -} Coin; - -static void coin_init(Coin* c) -{ - uivector_init(&c->symbols); -} - -/*argument c is void* so that this dtor can be given as function pointer to the vector resize function*/ -static void coin_cleanup(void* c) -{ - uivector_cleanup(&((Coin*)c)->symbols); -} - -static void coin_copy(Coin* c1, const Coin* c2) -{ - c1->weight = c2->weight; - uivector_copy(&c1->symbols, &c2->symbols); -} - -static void add_coins(Coin* c1, const Coin* c2) -{ - size_t i; - for(i = 0; i < c2->symbols.size; i++) uivector_push_back(&c1->symbols, c2->symbols.data[i]); - c1->weight += c2->weight; -} - -static void init_coins(Coin* coins, size_t num) -{ - size_t i; - for(i = 0; i < num; i++) coin_init(&coins[i]); -} - -static void cleanup_coins(Coin* coins, size_t num) -{ - size_t i; - for(i = 0; i < num; i++) coin_cleanup(&coins[i]); -} - -static int coin_compare(const void* a, const void* b) { - float wa = ((const Coin*)a)->weight; - float wb = ((const Coin*)b)->weight; - return wa > wb ? 1 : wa < wb ? -1 : 0; -} - -static unsigned append_symbol_coins(Coin* coins, const unsigned* frequencies, unsigned numcodes, size_t sum) -{ - unsigned i; - unsigned j = 0; /*index of present symbols*/ - for(i = 0; i < numcodes; i++) - { - if(frequencies[i] != 0) /*only include symbols that are present*/ - { - coins[j].weight = frequencies[i] / (float)sum; - uivector_push_back(&coins[j].symbols, i); - j++; - } - } - return 0; -} - -unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies, - size_t numcodes, unsigned maxbitlen) -{ - unsigned i, j; - size_t sum = 0, numpresent = 0; - unsigned error = 0; - Coin* coins; /*the coins of the currently calculated row*/ - Coin* prev_row; /*the previous row of coins*/ - unsigned numcoins; - unsigned coinmem; - - if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/ - - for(i = 0; i < numcodes; i++) - { - if(frequencies[i] > 0) - { - numpresent++; - sum += frequencies[i]; - } - } - - 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. To 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) - { - for(i = 0; i < numcodes; i++) - { - if(frequencies[i]) - { - lengths[i] = 1; - lengths[i == 0 ? 1 : 0] = 1; - break; - } - } - } - else - { - /*Package-Merge algorithm represented by coin collector's problem - For every symbol, maxbitlen coins will be created*/ - - coinmem = numpresent * 2; /*max amount of coins needed with the current algo*/ - coins = (Coin*)lodepng_malloc(sizeof(Coin) * coinmem); - prev_row = (Coin*)lodepng_malloc(sizeof(Coin) * coinmem); - if(!coins || !prev_row) - { - lodepng_free(coins); - lodepng_free(prev_row); - return 83; /*alloc fail*/ - } - init_coins(coins, coinmem); - init_coins(prev_row, coinmem); - - /*first row, lowest denominator*/ - error = append_symbol_coins(coins, frequencies, numcodes, sum); - numcoins = numpresent; - qsort(coins, numcoins, sizeof(Coin), coin_compare); - if(!error) - { - unsigned numprev = 0; - for(j = 1; j <= maxbitlen && !error; j++) /*each of the remaining rows*/ - { - unsigned tempnum; - Coin* tempcoins; - /*swap prev_row and coins, and their amounts*/ - tempcoins = prev_row; prev_row = coins; coins = tempcoins; - tempnum = numprev; numprev = numcoins; numcoins = tempnum; - - cleanup_coins(coins, numcoins); - init_coins(coins, numcoins); - - numcoins = 0; - - /*fill in the merged coins of the previous row*/ - for(i = 0; i + 1 < numprev; i += 2) - { - /*merge prev_row[i] and prev_row[i + 1] into new coin*/ - Coin* coin = &coins[numcoins++]; - coin_copy(coin, &prev_row[i]); - add_coins(coin, &prev_row[i + 1]); - } - /*fill in all the original symbols again*/ - if(j < maxbitlen) - { - error = append_symbol_coins(coins + numcoins, frequencies, numcodes, sum); - numcoins += numpresent; - } - qsort(coins, numcoins, sizeof(Coin), coin_compare); - } - } - - if(!error) - { - /*calculate the lenghts of each symbol, as the amount of times a coin of each symbol is used*/ - for(i = 0; i < numpresent - 1; i++) - { - Coin* coin = &coins[i]; - for(j = 0; j < coin->symbols.size; j++) lengths[coin->symbols.data[j]]++; - } - } - - cleanup_coins(coins, coinmem); - lodepng_free(coins); - cleanup_coins(prev_row, coinmem); - lodepng_free(prev_row); - } - - 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) >> 3 >= inlength - 2) 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; - - 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(*bp >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ - if (i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/ - - 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 >= 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 >= 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*/ - { - if((*pos) >= out->size) - { - /*reserve more room at once*/ - if(!ucvector_resize(out, ((*pos) + 1) * 2)) 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 >= 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 >= 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((*pos) + length >= out->size) - { - /*reserve more room at once*/ - if(!ucvector_resize(out, ((*pos) + length) * 2)) ERROR_BREAK(83 /*alloc fail*/); - } - - for(forward = 0; forward < length; forward++) - { - out->data[(*pos)] = out->data[backward]; - (*pos)++; - backward++; - if(backward >= start) backward = start - distance; - } - } - 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) -{ - /*go to first boundary of byte*/ - size_t p; - unsigned LEN, NLEN, n, error = 0; - while(((*bp) & 0x7) != 0) (*bp)++; - p = (*bp) / 8; /*byte position*/ - - /*read LEN (2 bytes) and NLEN (2 bytes)*/ - if(p >= inlength - 4) return 52; /*error, bit pointer will jump past memory*/ - LEN = in[p] + 256 * in[p + 1]; p += 2; - NLEN = in[p] + 256 * 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((*pos) + LEN >= out->size) - { - 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 = 1 * readBitFromStream(&bp, in); - BTYPE += 2 * 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; - } - - /*Only now we know the true size of out, resize it to that*/ - if(!ucvector_resize(out, pos)) error = 83; /*alloc fail*/ - - 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) -{ - /*linear search implementation*/ - /*for(size_t i = 1; i < array_size; i++) if(array[i] > value) return i - 1; - return array_size - 1;*/ - - /*binary search implementation (not that much faster) (precondition: array_size > 0)*/ - size_t left = 1; - size_t right = array_size - 1; - while(left <= right) - { - size_t mid = (left + right) / 2; - if(array[mid] <= value) left = mid + 1; /*the value to find is more to the right*/ - else if(array[mid - 1] > value) right = mid - 1; /*the value to find is more to the left*/ - else return mid - 1; - } - return array_size - 1; -} - -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); -} - -static const unsigned HASH_BIT_MASK = 65535; -static const unsigned HASH_NUM_VALUES = 65536; -static const unsigned HASH_NUM_CHARACTERS = 3; -static const unsigned HASH_SHIFT = 2; -/* -The HASH_NUM_CHARACTERS value is used to make encoding faster by using longer -sequences to generate a hash value from the stream bytes. Setting it to 3 -gives exactly the same compression as the brute force method, since deflate's -run length encoding starts with lengths of 3. Setting it to higher values, -like 6, can make the encoding faster (not always though!), but will cause the -encoding to miss any length between 3 and this value, so that the compression -may be worse (but this can vary too depending on the image, sometimes it is -even a bit better instead). -The HASH_NUM_VALUES is the amount of unique possible hash values that -combinations of bytes can give, the higher it is the more memory is needed, but -if it's too low the advantage of hashing is gone. -*/ - -typedef struct Hash -{ - int* head; /*hash value to head circular pos*/ - int* val; /*circular pos to hash value*/ - /*circular pos to prev circular pos*/ - unsigned short* chain; - unsigned short* zeros; -} 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); - - if(!hash->head || !hash->val || !hash->chain || !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*/ - - return 0; -} - -static void hash_cleanup(Hash* hash) -{ - lodepng_free(hash->head); - lodepng_free(hash->val); - lodepng_free(hash->chain); - lodepng_free(hash->zeros); -} - -static unsigned getHash(const unsigned char* data, size_t size, size_t pos) -{ - unsigned result = 0; - if (HASH_NUM_CHARACTERS == 3 && pos + 2 < size) { - result ^= (data[pos + 0] << (0 * HASH_SHIFT)); - result ^= (data[pos + 1] << (1 * HASH_SHIFT)); - result ^= (data[pos + 2] << (2 * HASH_SHIFT)); - } else { - size_t amount, i; - if(pos >= size) return 0; - amount = HASH_NUM_CHARACTERS; - if(pos + amount >= size) amount = size - pos; - for(i = 0; i < amount; i++) result ^= (data[pos + i] << (i * HASH_SHIFT)); - } - 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, int hashval) -{ - hash->val[wpos] = hashval; - if(hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval]; - hash->head[hashval] = 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) -{ - unsigned pos, 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; - const unsigned char *lastptr, *foreptr, *backptr; - unsigned hashpos, prevpos; - - 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); - updateHashChain(hash, wpos, hashval); - - if(usezeros && hashval == 0) - { - if (numzeros == 0) numzeros = countZeros(in, insize, pos); - else if (pos + numzeros >= insize || in[pos + numzeros - 1] != 0) numzeros--; - hash->zeros[wpos] = numzeros; - } - else - { - numzeros = 0; - } - - /*the length and offset found for the current position*/ - length = 0; - offset = 0; - - prevpos = hash->head[hashval]; - hashpos = hash->chain[prevpos]; - - lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH]; - - /*search for the longest string*/ - for(;;) - { - /*stop when went completely around the circular buffer*/ - if(prevpos < wpos && hashpos > prevpos && hashpos <= wpos) break; - if(prevpos > wpos && (hashpos <= wpos || hashpos > prevpos)) break; - if(chainlength++ >= maxchainlength) break; - - current_offset = hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize; - 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(usezeros && hashval == 0 && hash->val[hashpos] == 0 /*hashval[hashpos] may be out of date*/) - { - 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; - - prevpos = hashpos; - hashpos = hash->chain[hashpos]; - } - - 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*/ - 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); - updateHashChain(hash, wpos, hashval); - if(usezeros && hashval == 0) - { - if (numzeros == 0) numzeros = countZeros(in, insize, pos); - else if (pos + numzeros >= insize || in[pos + numzeros - 1] != 0) numzeros--; - hash->zeros[wpos] = numzeros; - } - else - { - numzeros = 0; - } - } - } - } /*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 % 256)); - ucvector_push_back(out, (unsigned char)(LEN / 256)); - ucvector_push_back(out, (unsigned char)(NLEN % 256)); - ucvector_push_back(out, (unsigned char)(NLEN / 256)); - - /*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, int 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] = 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, int 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)*/ - { - blocksize = insize / 8 + 8; - if(blocksize < 65535) blocksize = 65535; - } - - 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++) - { - int 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; - - unsigned ADLER32; - /*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 / 256)); - ucvector_push_back(&outv, (unsigned char)(CMFFLG % 256)); - - error = deflate(&deflatedata, &deflatesize, in, insize, settings); - - if(!error) - { - 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 / */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/* 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* buf, size_t len) -{ - unsigned c = 0xffffffffL; - size_t n; - - for(n = 0; n < len; n++) - { - c = lodepng_crc32_table[(c ^ buf[n]) & 0xff] ^ (c >> 8); - } - return c ^ 0xffffffffL; -} - -/* ////////////////////////////////////////////////////////////////////////// */ -/* / 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 = nbits - 1; i < nbits; i--) - { - result += (unsigned)readBitFromReversedStream(bitpointer, bitstream) << i; - } - 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] = 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] = type[0]; - chunk[5] = type[1]; - chunk[6] = type[2]; - chunk[7] = 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(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) -{ - return (w * h * lodepng_get_bpp(color) + 7) / 8; -} - -size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) -{ - return (w * h * lodepng_get_bpp_lct(colortype, bitdepth) + 7) / 8; -} - -#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 &= (1 << bits) - 1; /*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, int 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 = 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, 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 unsigned rgba16ToPixel(unsigned char* out, size_t i, - const LodePNGColorMode* mode, - unsigned short r, unsigned short g, unsigned short b, unsigned short a) -{ - if(mode->bitdepth != 16) return 85; /*must be 16 for this function*/ - 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; - } - - return 0; /*no error*/ -} - -/*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/ -static unsigned getPixelColorRGBA8(unsigned char* r, unsigned char* g, - unsigned char* b, unsigned char* a, - const unsigned char* in, size_t i, - const LodePNGColorMode* mode, - unsigned fix_png) -{ - 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 fix_png can ignore it*/ - if(!fix_png) return (mode->bitdepth == 8 ? 46 : 47); /*index out of palette*/ - *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]; - } - } - - return 0; /*no error*/ -} - -/*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 unsigned getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels, - unsigned has_alpha, const unsigned char* in, - const LodePNGColorMode* mode, - unsigned fix_png) -{ - 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 fix_png can ignore it*/ - if(!fix_png) return (mode->bitdepth == 8 ? 46 : 47); /*index out of palette*/ - 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]; - } - } - } - - return 0; /*no error*/ -} - -/*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 unsigned 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->bitdepth != 16) return 85; /*error: this function only supports 16-bit input*/ - - 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 = 256 * in[i * 6 + 0] + in[i * 6 + 1]; - *g = 256 * in[i * 6 + 2] + in[i * 6 + 3]; - *b = 256 * 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 = 256 * in[i * 4 + 0] + in[i * 4 + 1]; - *a = 256 * in[i * 4 + 2] + in[i * 4 + 3]; - } - else if(mode->colortype == LCT_RGBA) - { - *r = 256 * in[i * 8 + 0] + in[i * 8 + 1]; - *g = 256 * in[i * 8 + 2] + in[i * 8 + 3]; - *b = 256 * in[i * 8 + 4] + in[i * 8 + 5]; - *a = 256 * in[i * 8 + 6] + in[i * 8 + 7]; - } - else return 85; /*error: this function only supports 16-bit input, not palettes*/ - - return 0; /*no error*/ -} - -/* -converts from any color type to 24-bit or 32-bit (later maybe more supported). return value = LodePNG error code -the out buffer must have (w * h * bpp + 7) / 8 bytes, where bpp is the bits per pixel of the output color type -(lodepng_get_bpp) for < 8 bpp images, there may _not_ be padding bits at the end of scanlines. -*/ -unsigned lodepng_convert(unsigned char* out, const unsigned char* in, - LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in, - unsigned w, unsigned h, unsigned fix_png) -{ - unsigned error = 0; - 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 error; - } - - if(mode_out->colortype == LCT_PALETTE) - { - size_t palsize = 1 << mode_out->bitdepth; - if(mode_out->palettesize < palsize) palsize = mode_out->palettesize; - color_tree_init(&tree); - for(i = 0; i < palsize; i++) - { - unsigned char* p = &mode_out->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; - error = getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); - if(error) break; - error = rgba16ToPixel(out, i, mode_out, r, g, b, a); - if(error) break; - } - } - else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA) - { - error = getPixelColorsRGBA8(out, numpixels, 1, in, mode_in, fix_png); - } - else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) - { - error = getPixelColorsRGBA8(out, numpixels, 0, in, mode_in, fix_png); - } - else - { - unsigned char r = 0, g = 0, b = 0, a = 0; - for(i = 0; i < numpixels; i++) - { - error = getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in, fix_png); - if(error) break; - error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a); - if(error) break; - } - } - - if(mode_out->colortype == LCT_PALETTE) - { - color_tree_cleanup(&tree); - } - - return error; -} - -#ifdef LODEPNG_COMPILE_ENCODER - -typedef struct ColorProfile -{ - unsigned char sixteenbit; /*needs more than 8 bits per channel*/ - unsigned char sixteenbit_done; - - - unsigned char colored; /*not greyscale*/ - unsigned char colored_done; - - unsigned char key; /*a color key is required, or more*/ - unsigned short key_r; /*these values are always in 16-bit bitdepth in the profile*/ - unsigned short key_g; - unsigned short key_b; - unsigned char alpha; /*alpha channel, or alpha palette, required*/ - unsigned char alpha_done; - - unsigned numcolors; - ColorTree tree; /*for listing the counted colors, up to 256*/ - unsigned char* palette; /*size 1024. Remember up to the first 256 RGBA colors*/ - unsigned maxnumcolors; /*if more than that amount counted*/ - unsigned char numcolors_done; - - unsigned greybits; /*amount of bits required for greyscale (1, 2, 4, 8). Does not take 16 bit into account.*/ - unsigned char greybits_done; - -} ColorProfile; - -static void color_profile_init(ColorProfile* profile, const LodePNGColorMode* mode) -{ - profile->sixteenbit = 0; - profile->sixteenbit_done = mode->bitdepth == 16 ? 0 : 1; - - profile->colored = 0; - profile->colored_done = lodepng_is_greyscale_type(mode) ? 1 : 0; - - profile->key = 0; - profile->alpha = 0; - profile->alpha_done = lodepng_can_have_alpha(mode) ? 0 : 1; - - profile->numcolors = 0; - color_tree_init(&profile->tree); - profile->palette = (unsigned char*)lodepng_malloc(1024); - profile->maxnumcolors = 257; - if(lodepng_get_bpp(mode) <= 8) - { - int bpp = lodepng_get_bpp(mode); - profile->maxnumcolors = bpp == 1 ? 2 : (bpp == 2 ? 4 : (bpp == 4 ? 16 : 256)); - } - profile->numcolors_done = 0; - - profile->greybits = 1; - profile->greybits_done = lodepng_get_bpp(mode) == 1 ? 1 : 0; -} - -static void color_profile_cleanup(ColorProfile* profile) -{ - color_tree_cleanup(&profile->tree); - lodepng_free(profile->palette); -} - -/*function used for debug purposes with C++*/ -/*void printColorProfile(ColorProfile* p) -{ - std::cout << "sixteenbit: " << (int)p->sixteenbit << std::endl; - std::cout << "sixteenbit_done: " << (int)p->sixteenbit_done << std::endl; - std::cout << "colored: " << (int)p->colored << std::endl; - std::cout << "colored_done: " << (int)p->colored_done << std::endl; - std::cout << "key: " << (int)p->key << std::endl; - std::cout << "key_r: " << (int)p->key_r << std::endl; - std::cout << "key_g: " << (int)p->key_g << std::endl; - std::cout << "key_b: " << (int)p->key_b << std::endl; - std::cout << "alpha: " << (int)p->alpha << std::endl; - std::cout << "alpha_done: " << (int)p->alpha_done << std::endl; - std::cout << "numcolors: " << (int)p->numcolors << std::endl; - std::cout << "maxnumcolors: " << (int)p->maxnumcolors << std::endl; - std::cout << "numcolors_done: " << (int)p->numcolors_done << std::endl; - std::cout << "greybits: " << (int)p->greybits << std::endl; - std::cout << "greybits_done: " << (int)p->greybits_done << std::endl; -}*/ - -/*Returns how many bits needed to represent given value (max 8 bit)*/ -unsigned getValueRequiredBits(unsigned short 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.*/ -static unsigned get_color_profile(ColorProfile* profile, - const unsigned char* in, - size_t numpixels /*must be full image size, for certain filesize based choices*/, - const LodePNGColorMode* mode, - unsigned fix_png) -{ - unsigned error = 0; - size_t i; - - if(mode->bitdepth == 16) - { - for(i = 0; i < numpixels; i++) - { - unsigned short r, g, b, a; - error = getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode); - if(error) break; - - /*a color is considered good for 8-bit if the first byte and the second byte are equal, - (so if it's divisible through 257), NOT necessarily if the second byte is 0*/ - if(!profile->sixteenbit_done - && (((r & 255) != ((r >> 8) & 255)) - || ((g & 255) != ((g >> 8) & 255)) - || ((b & 255) != ((b >> 8) & 255)))) - { - profile->sixteenbit = 1; - profile->sixteenbit_done = 1; - profile->greybits_done = 1; /*greybits is not applicable anymore at 16-bit*/ - profile->numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/ - } - - if(!profile->colored_done && (r != g || r != b)) - { - profile->colored = 1; - profile->colored_done = 1; - profile->greybits_done = 1; /*greybits is not applicable anymore*/ - } - - if(!profile->alpha_done && a != 65535) - { - /*only use color key if numpixels large enough to justify tRNS chunk size*/ - if(a == 0 && numpixels > 16 && !(profile->key && (r != profile->key_r || g != profile->key_g || b != profile->key_b))) - { - if(!profile->alpha && !profile->key) - { - profile->key = 1; - profile->key_r = r; - profile->key_g = g; - profile->key_b = b; - } - } - else - { - profile->alpha = 1; - profile->alpha_done = 1; - profile->greybits_done = 1; /*greybits is not applicable anymore*/ - } - } - - /* Color key cannot be used if an opaque pixel also has that RGB color. */ - if(!profile->alpha_done && a == 65535 && profile->key - && r == profile->key_r && g == profile->key_g && b == profile->key_b) - { - profile->alpha = 1; - profile->alpha_done = 1; - profile->greybits_done = 1; /*greybits is not applicable anymore*/ - } - - if(!profile->greybits_done) - { - /*assuming 8-bit r, this test does not care about 16-bit*/ - unsigned bits = getValueRequiredBits(r); - if(bits > profile->greybits) profile->greybits = bits; - if(profile->greybits >= 8) profile->greybits_done = 1; - } - - if(!profile->numcolors_done) - { - /*assuming 8-bit rgba, this test does not care about 16-bit*/ - if(!color_tree_has(&profile->tree, (unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a)) - { - color_tree_add(&profile->tree, (unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a, - profile->numcolors); - if(profile->numcolors < 256) - { - unsigned char* p = profile->palette; - unsigned i = profile->numcolors; - p[i * 4 + 0] = (unsigned char)r; - p[i * 4 + 1] = (unsigned char)g; - p[i * 4 + 2] = (unsigned char)b; - p[i * 4 + 3] = (unsigned char)a; - } - profile->numcolors++; - if(profile->numcolors >= profile->maxnumcolors) profile->numcolors_done = 1; - } - } - - if(profile->alpha_done && profile->numcolors_done - && profile->colored_done && profile->sixteenbit_done && profile->greybits_done) - { - break; - } - }; - } - else /* < 16-bit */ - { - for(i = 0; i < numpixels; i++) - { - unsigned char r = 0, g = 0, b = 0, a = 0; - error = getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode, fix_png); - if(error) break; - - if(!profile->colored_done && (r != g || r != b)) - { - profile->colored = 1; - profile->colored_done = 1; - profile->greybits_done = 1; /*greybits is not applicable anymore*/ - } - - if(!profile->alpha_done && a != 255) - { - if(a == 0 && !(profile->key && (r != profile->key_r || g != profile->key_g || b != profile->key_b))) - { - if(!profile->key) - { - profile->key = 1; - profile->key_r = r; - profile->key_g = g; - profile->key_b = b; - } - } - else - { - profile->alpha = 1; - profile->alpha_done = 1; - profile->greybits_done = 1; /*greybits is not applicable anymore*/ - } - } - - /* Color key cannot be used if an opaque pixel also has that RGB color. */ - if(!profile->alpha_done && a == 255 && profile->key - && r == profile->key_r && g == profile->key_g && b == profile->key_b) - { - profile->alpha = 1; - profile->alpha_done = 1; - profile->greybits_done = 1; /*greybits is not applicable anymore*/ - } - - if(!profile->greybits_done) - { - unsigned bits = getValueRequiredBits(r); - if(bits > profile->greybits) profile->greybits = bits; - if(profile->greybits >= 8) profile->greybits_done = 1; - } - - if(!profile->numcolors_done) - { - if(!color_tree_has(&profile->tree, r, g, b, a)) - { - - color_tree_add(&profile->tree, r, g, b, a, profile->numcolors); - if(profile->numcolors < 256) - { - unsigned char* p = profile->palette; - unsigned i = profile->numcolors; - p[i * 4 + 0] = r; - p[i * 4 + 1] = g; - p[i * 4 + 2] = b; - p[i * 4 + 3] = a; - } - profile->numcolors++; - if(profile->numcolors >= profile->maxnumcolors) profile->numcolors_done = 1; - } - } - - if(profile->alpha_done && profile->numcolors_done && profile->colored_done && profile->greybits_done) - { - break; - } - }; - } - - /*make the profile's key always 16-bit for consistency*/ - if(mode->bitdepth < 16) - { - /*repeat each byte twice*/ - profile->key_r *= 257; - profile->key_g *= 257; - profile->key_b *= 257; - } - - return error; -} - -static void setColorKeyFrom16bit(LodePNGColorMode* mode_out, unsigned r, unsigned g, unsigned b, unsigned bitdepth) -{ - unsigned mask = (1 << bitdepth) - 1; - mode_out->key_defined = 1; - mode_out->key_r = r & mask; - mode_out->key_g = g & mask; - mode_out->key_b = b & mask; -} - -/*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, - LodePNGAutoConvert auto_convert) -{ - ColorProfile profile; - unsigned error = 0; - int no_nibbles = auto_convert == LAC_AUTO_NO_NIBBLES || auto_convert == LAC_AUTO_NO_NIBBLES_NO_PALETTE; - int no_palette = auto_convert == LAC_AUTO_NO_PALETTE || auto_convert == LAC_AUTO_NO_NIBBLES_NO_PALETTE; - - if(auto_convert == LAC_ALPHA) - { - if(mode_out->colortype != LCT_RGBA && mode_out->colortype != LCT_GREY_ALPHA) return 0; - } - - color_profile_init(&profile, mode_in); - if(auto_convert == LAC_ALPHA) - { - profile.colored_done = 1; - profile.greybits_done = 1; - profile.numcolors_done = 1; - profile.sixteenbit_done = 1; - } - error = get_color_profile(&profile, image, w * h, mode_in, 0 /*fix_png*/); - if(!error && auto_convert == LAC_ALPHA) - { - if(!profile.alpha) - { - mode_out->colortype = (mode_out->colortype == LCT_RGBA ? LCT_RGB : LCT_GREY); - if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth); - } - } - else if(!error && auto_convert != LAC_ALPHA) - { - mode_out->key_defined = 0; - - if(profile.sixteenbit) - { - mode_out->bitdepth = 16; - if(profile.alpha) - { - mode_out->colortype = profile.colored ? LCT_RGBA : LCT_GREY_ALPHA; - } - else - { - mode_out->colortype = profile.colored ? LCT_RGB : LCT_GREY; - if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth); - } - } - else /*less than 16 bits per channel*/ - { - /*don't add palette overhead if image hasn't got a lot of pixels*/ - unsigned n = profile.numcolors; - int palette_ok = !no_palette && n <= 256 && (n * 2 < w * h); - unsigned palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8)); - int grey_ok = !profile.colored && !profile.alpha; /*grey without alpha, with potentially low bits*/ - if(palette_ok || grey_ok) - { - if(!palette_ok || (grey_ok && profile.greybits <= palettebits)) - { - unsigned grey = profile.key_r; - mode_out->colortype = LCT_GREY; - mode_out->bitdepth = profile.greybits; - if(profile.key) setColorKeyFrom16bit(mode_out, grey, grey, grey, mode_out->bitdepth); - } - else - { - /*fill in the palette*/ - unsigned i; - unsigned char* p = profile.palette; - /*remove potential earlier palette*/ - lodepng_palette_clear(mode_out); - for(i = 0; i < profile.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; - } - } - else /*8-bit per channel*/ - { - mode_out->bitdepth = 8; - if(profile.alpha) - { - mode_out->colortype = profile.colored ? LCT_RGBA : LCT_GREY_ALPHA; - } - else - { - mode_out->colortype = profile.colored ? LCT_RGB : LCT_GREY /*LCT_GREY normally won't occur, already done earlier*/; - if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth); - } - } - } - } - - color_profile_cleanup(&profile); - - if(mode_out->colortype == LCT_PALETTE && mode_in->palettesize == mode_out->palettesize) - { - /*In this case keep the palette order of the input, so that the user can choose an optimal one*/ - size_t i; - for(i = 0; i < mode_in->palettesize * 4; i++) - { - mode_out->palette[i] = mode_in->palette[i]; - } - } - - if(no_nibbles && mode_out->bitdepth < 8) - { - /*palette can keep its small amount of colors, as long as no indices use it*/ - mode_out->bitdepth = 8; - } - - 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 < 29) - { - 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(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R') - { - 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(!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] / 2; - for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2); - } - else - { - for(i = 0; i < bytewidth; i++) recon[i] = scanline[i]; - for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth] / 2; - } - 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 immediatly 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 = 256 * 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 = 256 * data[0] + data[1]; - color->key_g = 256 * data[2] + data[3]; - color->key_b = 256 * 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 - = 256 * 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 = 256 * data[0] + data[1]; - info->background_g = 256 * data[2] + data[3]; - info->background_b = 256 * 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] = 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] = 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] = 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] = 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] = 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] = 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 = 256 * 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 = 16777216 * data[0] + 65536 * data[1] + 256 * data[2] + data[3]; - info->phys_y = 16777216 * data[4] + 65536 * data[5] + 256 * 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; - - /*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; - - 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); - if(!state->error) - { - /*maximum final image length is already reserved in the vector's length - this is not really necessary*/ - if(!ucvector_resize(&scanlines, lodepng_get_raw_size(*w, *h, &state->info_png.color) + *h)) - { - state->error = 83; /*alloc fail*/ - } - } - if(!state->error) - { - /*decompress with the Zlib decompressor*/ - state->error = zlib_decompress(&scanlines.data, &scanlines.size, idat.data, - idat.size, &state->decoder.zlibsettings); - } - ucvector_cleanup(&idat); - - if(!state->error) - { - ucvector outv; - ucvector_init(&outv); - if(!ucvector_resizev(&outv, - lodepng_get_raw_size(*w, *h, &state->info_png.color), 0)) state->error = 83; /*alloc fail*/ - if(!state->error) state->error = postProcessScanlines(outv.data, scanlines.data, *w, *h, &state->info_png); - *out = outv.data; - } - 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, state->decoder.fix_png); - 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; - 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; - settings->fix_png = 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 / 256)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256)); - } - } - else if(info->colortype == LCT_RGB) - { - if(info->key_defined) - { - ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_g / 256)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_g % 256)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_b / 256)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_b % 256)); - } - } - - 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 / 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); - } - else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) - { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_g / 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_g % 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_b / 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_b % 256)); - } - else if(info->color.colortype == LCT_PALETTE) - { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); /*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 / 256); - data[1] = (unsigned char)(time->year % 256); - data[2] = time->month; - data[3] = time->day; - data[4] = time->hour; - data[5] = time->minute; - data[6] = 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*/ - if(prevline) - { - for(i = 0; i < bytewidth; i++) out[i] = scanline[i]; - for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth]; - } - else - { - 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] / 2; - for(i = bytewidth; i < length; i++) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) / 2); - } - else - { - for(i = 0; i < bytewidth; i++) out[i] = scanline[i]; - for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth] / 2; - } - 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]; - ucvector attempt[5]; /*five filtering attempts, one for each filter type*/ - size_t smallest = 0; - unsigned type, bestType = 0; - - for(type = 0; type < 5; type++) - { - ucvector_init(&attempt[type]); - if(!ucvector_resize(&attempt[type], linebytes)) 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].data, &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].data[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.*/ - signed char s = (signed char)(attempt[type].data[x]); - sum[type] += s < 0 ? -s : 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].data[x]; - } - } - - for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]); - } - else if(strategy == LFS_ENTROPY) - { - float sum[5]; - ucvector 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++) - { - ucvector_init(&attempt[type]); - if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*alloc fail*/ - } - - for(y = 0; y < h; y++) - { - /*try the 5 filter types*/ - for(type = 0; type < 5; type++) - { - filterScanline(attempt[type].data, &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].data[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].data[x]; - } - - for(type = 0; type < 5; type++) ucvector_cleanup(&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 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]; - ucvector 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++) - { - ucvector_init(&attempt[type]); - ucvector_resize(&attempt[type], linebytes); /*todo: give error if resize failed*/ - } - for(y = 0; y < h; y++) /*try the 5 filter types*/ - { - for(type = 0; type < 5; type++) - { - unsigned testsize = attempt[type].size; - /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/ - - filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type); - size[type] = 0; - dummy = 0; - zlib_compress(&dummy, &size[type], attempt[type].data, 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].data[x]; - } - for(type = 0; type < 5; type++) ucvector_cleanup(&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 immediatly 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, 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 != LAC_NO) - { - state->error = lodepng_auto_choose_color(&info.color, image, w, h, &state->info_raw, - state->encoder.auto_convert); - } - 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 * 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, 0 /*fix_png*/); - } - 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", 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 = LAC_AUTO; - 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"; - /*Is the palette too small?*/ - case 46: return "a value in indexed image is larger than the palette size (bitdepth = 8)"; - /*Is the palette too small?*/ - case 47: return "a value in indexed image is larger than the palette size (bitdepth < 8)"; - /*the input data is empty, maybe a PNG file doesn't exist or is in the wrong path*/ - case 48: return "empty input or file doesn't exist"; - 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 85: return "internal color conversion bug"; - 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"; - } - return "unknown error code"; -} -#endif /*LODEPNG_COMPILE_ERROR_TEXT*/ - -/* ////////////////////////////////////////////////////////////////////////// */ -/* ////////////////////////////////////////////////////////////////////////// */ -/* // C++ Wrapper // */ -/* ////////////////////////////////////////////////////////////////////////// */ -/* ////////////////////////////////////////////////////////////////////////// */ - -#ifdef LODEPNG_COMPILE_CPP -namespace lodepng -{ - -#ifdef LODEPNG_COMPILE_DISK -void load_file(std::vector<unsigned char>& buffer, const std::string& filename) -{ - std::ifstream file(filename.c_str(), std::ios::in|std::ios::binary|std::ios::ate); - - /*get filesize*/ - std::streamsize size = 0; - if(file.seekg(0, std::ios::end).good()) size = file.tellg(); - if(file.seekg(0, std::ios::beg).good()) size -= file.tellg(); - - /*read contents of the file into the vector*/ - buffer.resize(size_t(size)); - if(size > 0) file.read((char*)(&buffer[0]), size); -} - -/*write given buffer to the file, overwriting the file, it doesn't append to it.*/ -void save_file(const std::vector<unsigned char>& buffer, const std::string& filename) -{ - std::ofstream file(filename.c_str(), std::ios::out|std::ios::binary); - file.write(buffer.empty() ? 0 : (char*)&buffer[0], std::streamsize(buffer.size())); -} -#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; - load_file(buffer, filename); - 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) 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*/ diff --git a/plugingui/lodepng/lodepng.h b/plugingui/lodepng/lodepng.h deleted file mode 100644 index c497a5c..0000000 --- a/plugingui/lodepng/lodepng.h +++ /dev/null @@ -1,1716 +0,0 @@ -/* -LodePNG version 20131222 - -Copyright (c) 2005-2013 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. -*/ - -#ifndef LODEPNG_H -#define LODEPNG_H - -#include <string.h> /*for size_t*/ - -#ifdef __cplusplus -#include <vector> -#include <string> -#endif /*__cplusplus*/ - -/* -The following #defines are used to create code sections. They can be disabled -to disable code sections, which can give faster compile time and smaller binary. -The "NO_COMPILE" defines are designed to be used to pass as defines to the -compiler command to disable them without modifying this header, e.g. --DLODEPNG_NO_COMPILE_ZLIB for gcc. -*/ -/*deflate & zlib. If disabled, you must specify alternative zlib functions in -the custom_zlib field of the compress and decompress settings*/ -#ifndef LODEPNG_NO_COMPILE_ZLIB -#define LODEPNG_COMPILE_ZLIB -#endif -/*png encoder and png decoder*/ -#ifndef LODEPNG_NO_COMPILE_PNG -#define LODEPNG_COMPILE_PNG -#endif -/*deflate&zlib decoder and png decoder*/ -#ifndef LODEPNG_NO_COMPILE_DECODER -#define LODEPNG_COMPILE_DECODER -#endif -/*deflate&zlib encoder and png encoder*/ -#ifndef LODEPNG_NO_COMPILE_ENCODER -#define LODEPNG_COMPILE_ENCODER -#endif -/*the optional built in harddisk file loading and saving functions*/ -#ifndef LODEPNG_NO_COMPILE_DISK -#define LODEPNG_COMPILE_DISK -#endif -/*support for chunks other than IHDR, IDAT, PLTE, tRNS, IEND: ancillary and unknown chunks*/ -#ifndef LODEPNG_NO_COMPILE_ANCILLARY_CHUNKS -#define LODEPNG_COMPILE_ANCILLARY_CHUNKS -#endif -/*ability to convert error numerical codes to English text string*/ -#ifndef LODEPNG_NO_COMPILE_ERROR_TEXT -#define LODEPNG_COMPILE_ERROR_TEXT -#endif -/*Compile the default allocators (C's free, malloc and realloc). If you disable this, -you can define the functions lodepng_free, lodepng_malloc and lodepng_realloc in your -source files with custom allocators.*/ -#ifndef LODEPNG_NO_COMPILE_ALLOCATORS -#define LODEPNG_COMPILE_ALLOCATORS -#endif -/*compile the C++ version (you can disable the C++ wrapper here even when compiling for C++)*/ -#ifdef __cplusplus -#ifndef LODEPNG_NO_COMPILE_CPP -#define LODEPNG_COMPILE_CPP -#endif -#endif - -#ifdef LODEPNG_COMPILE_PNG -/*The PNG color types (also used for raw).*/ -typedef enum LodePNGColorType -{ - LCT_GREY = 0, /*greyscale: 1,2,4,8,16 bit*/ - LCT_RGB = 2, /*RGB: 8,16 bit*/ - LCT_PALETTE = 3, /*palette: 1,2,4,8 bit*/ - LCT_GREY_ALPHA = 4, /*greyscale with alpha: 8,16 bit*/ - LCT_RGBA = 6 /*RGB with alpha: 8,16 bit*/ -} LodePNGColorType; - -#ifdef LODEPNG_COMPILE_DECODER -/* -Converts PNG data in memory to raw pixel data. -out: Output parameter. Pointer to buffer that will contain the raw pixel data. - After decoding, its size is w * h * (bytes per pixel) bytes larger than - initially. Bytes per pixel depends on colortype and bitdepth. - Must be freed after usage with free(*out). - Note: for 16-bit per channel colors, uses big endian format like PNG does. -w: Output parameter. Pointer to width of pixel data. -h: Output parameter. Pointer to height of pixel data. -in: Memory buffer with the PNG file. -insize: size of the in buffer. -colortype: the desired color type for the raw output image. See explanation on PNG color types. -bitdepth: the desired bit depth for the raw output image. See explanation on PNG color types. -Return value: LodePNG error code (0 means no error). -*/ -unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, - const unsigned char* in, size_t insize, - LodePNGColorType colortype, unsigned bitdepth); - -/*Same as lodepng_decode_memory, but always decodes to 32-bit RGBA raw image*/ -unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, - const unsigned char* in, size_t insize); - -/*Same as lodepng_decode_memory, but always decodes to 24-bit RGB raw image*/ -unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, - const unsigned char* in, size_t insize); - -#ifdef LODEPNG_COMPILE_DISK -/* -Load PNG from disk, from file with given name. -Same as the other decode functions, but instead takes a filename as input. -*/ -unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, - const char* filename, - LodePNGColorType colortype, unsigned bitdepth); - -/*Same as lodepng_decode_file, but always decodes to 32-bit RGBA raw image.*/ -unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, - const char* filename); - -/*Same as lodepng_decode_file, but always decodes to 24-bit RGB raw image.*/ -unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, - const char* filename); -#endif /*LODEPNG_COMPILE_DISK*/ -#endif /*LODEPNG_COMPILE_DECODER*/ - - -#ifdef LODEPNG_COMPILE_ENCODER -/* -Converts raw pixel data into a PNG image in memory. The colortype and bitdepth - of the output PNG image cannot be chosen, they are automatically determined - by the colortype, bitdepth and content of the input pixel data. - Note: for 16-bit per channel colors, needs big endian format like PNG does. -out: Output parameter. Pointer to buffer that will contain the PNG image data. - Must be freed after usage with free(*out). -outsize: Output parameter. Pointer to the size in bytes of the out buffer. -image: The raw pixel data to encode. The size of this buffer should be - w * h * (bytes per pixel), bytes per pixel depends on colortype and bitdepth. -w: width of the raw pixel data in pixels. -h: height of the raw pixel data in pixels. -colortype: the color type of the raw input image. See explanation on PNG color types. -bitdepth: the bit depth of the raw input image. See explanation on PNG color types. -Return value: LodePNG error code (0 means no error). -*/ -unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, - const unsigned char* image, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth); - -/*Same as lodepng_encode_memory, but always encodes from 32-bit RGBA raw image.*/ -unsigned lodepng_encode32(unsigned char** out, size_t* outsize, - const unsigned char* image, unsigned w, unsigned h); - -/*Same as lodepng_encode_memory, but always encodes from 24-bit RGB raw image.*/ -unsigned lodepng_encode24(unsigned char** out, size_t* outsize, - const unsigned char* image, unsigned w, unsigned h); - -#ifdef LODEPNG_COMPILE_DISK -/* -Converts raw pixel data into a PNG file on disk. -Same as the other encode functions, but instead takes a filename as output. -NOTE: This overwrites existing files without warning! -*/ -unsigned lodepng_encode_file(const char* filename, - const unsigned char* image, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth); - -/*Same as lodepng_encode_file, but always encodes from 32-bit RGBA raw image.*/ -unsigned lodepng_encode32_file(const char* filename, - const unsigned char* image, unsigned w, unsigned h); - -/*Same as lodepng_encode_file, but always encodes from 24-bit RGB raw image.*/ -unsigned lodepng_encode24_file(const char* filename, - const unsigned char* image, unsigned w, unsigned h); -#endif /*LODEPNG_COMPILE_DISK*/ -#endif /*LODEPNG_COMPILE_ENCODER*/ - - -#ifdef LODEPNG_COMPILE_CPP -namespace lodepng -{ -#ifdef LODEPNG_COMPILE_DECODER -/*Same as lodepng_decode_memory, but decodes to an std::vector.*/ -unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - const unsigned char* in, size_t insize, - LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); -unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - const std::vector<unsigned char>& in, - LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); -#ifdef LODEPNG_COMPILE_DISK -/* -Converts PNG file from disk to raw pixel data in memory. -Same as the other decode functions, but instead takes a filename as input. -*/ -unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - const std::string& filename, - LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); -#endif //LODEPNG_COMPILE_DISK -#endif //LODEPNG_COMPILE_DECODER - -#ifdef LODEPNG_COMPILE_ENCODER -/*Same as lodepng_encode_memory, but encodes to an std::vector.*/ -unsigned encode(std::vector<unsigned char>& out, - const unsigned char* in, unsigned w, unsigned h, - LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); -unsigned encode(std::vector<unsigned char>& out, - const std::vector<unsigned char>& in, unsigned w, unsigned h, - LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); -#ifdef LODEPNG_COMPILE_DISK -/* -Converts 32-bit RGBA raw pixel data into a PNG file on disk. -Same as the other encode functions, but instead takes a filename as output. -NOTE: This overwrites existing files without warning! -*/ -unsigned encode(const std::string& filename, - const unsigned char* in, unsigned w, unsigned h, - LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); -unsigned encode(const std::string& filename, - const std::vector<unsigned char>& in, unsigned w, unsigned h, - LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8); -#endif //LODEPNG_COMPILE_DISK -#endif //LODEPNG_COMPILE_ENCODER -} //namespace lodepng -#endif /*LODEPNG_COMPILE_CPP*/ -#endif /*LODEPNG_COMPILE_PNG*/ - -#ifdef LODEPNG_COMPILE_ERROR_TEXT -/*Returns an English description of the numerical error code.*/ -const char* lodepng_error_text(unsigned code); -#endif /*LODEPNG_COMPILE_ERROR_TEXT*/ - -#ifdef LODEPNG_COMPILE_DECODER -/*Settings for zlib decompression*/ -typedef struct LodePNGDecompressSettings LodePNGDecompressSettings; -struct LodePNGDecompressSettings -{ - unsigned ignore_adler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/ - - /*use custom zlib decoder instead of built in one (default: null)*/ - unsigned (*custom_zlib)(unsigned char**, size_t*, - const unsigned char*, size_t, - const LodePNGDecompressSettings*); - /*use custom deflate decoder instead of built in one (default: null) - if custom_zlib is used, custom_deflate is ignored since only the built in - zlib function will call custom_deflate*/ - unsigned (*custom_inflate)(unsigned char**, size_t*, - const unsigned char*, size_t, - const LodePNGDecompressSettings*); - - const void* custom_context; /*optional custom settings for custom functions*/ -}; - -extern const LodePNGDecompressSettings lodepng_default_decompress_settings; -void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings); -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER -/* -Settings for zlib compression. Tweaking these settings tweaks the balance -between speed and compression ratio. -*/ -typedef struct LodePNGCompressSettings LodePNGCompressSettings; -struct LodePNGCompressSettings /*deflate = compress*/ -{ - /*LZ77 related settings*/ - unsigned btype; /*the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression.*/ - unsigned use_lz77; /*whether or not to use LZ77. Should be 1 for proper compression.*/ - unsigned windowsize; /*must be a power of two <= 32768. higher compresses more but is slower. Typical value: 2048.*/ - unsigned minmatch; /*mininum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0*/ - unsigned nicematch; /*stop searching if >= this length found. Set to 258 for best compression. Default: 128*/ - unsigned lazymatching; /*use lazy matching: better compression but a bit slower. Default: true*/ - - /*use custom zlib encoder instead of built in one (default: null)*/ - unsigned (*custom_zlib)(unsigned char**, size_t*, - const unsigned char*, size_t, - const LodePNGCompressSettings*); - /*use custom deflate encoder instead of built in one (default: null) - if custom_zlib is used, custom_deflate is ignored since only the built in - zlib function will call custom_deflate*/ - unsigned (*custom_deflate)(unsigned char**, size_t*, - const unsigned char*, size_t, - const LodePNGCompressSettings*); - - const void* custom_context; /*optional custom settings for custom functions*/ -}; - -extern const LodePNGCompressSettings lodepng_default_compress_settings; -void lodepng_compress_settings_init(LodePNGCompressSettings* settings); -#endif /*LODEPNG_COMPILE_ENCODER*/ - -#ifdef LODEPNG_COMPILE_PNG -/* -Color mode of an image. Contains all information required to decode the pixel -bits to RGBA colors. This information is the same as used in the PNG file -format, and is used both for PNG and raw image data in LodePNG. -*/ -typedef struct LodePNGColorMode -{ - /*header (IHDR)*/ - LodePNGColorType colortype; /*color type, see PNG standard or documentation further in this header file*/ - unsigned bitdepth; /*bits per sample, see PNG standard or documentation further in this header file*/ - - /* - palette (PLTE and tRNS) - - Dynamically allocated with the colors of the palette, including alpha. - When encoding a PNG, to store your colors in the palette of the LodePNGColorMode, first use - lodepng_palette_clear, then for each color use lodepng_palette_add. - If you encode an image without alpha with palette, don't forget to put value 255 in each A byte of the palette. - - When decoding, by default you can ignore this palette, since LodePNG already - fills the palette colors in the pixels of the raw RGBA output. - - The palette is only supported for color type 3. - */ - unsigned char* palette; /*palette in RGBARGBA... order. When allocated, must be either 0, or have size 1024*/ - size_t palettesize; /*palette size in number of colors (amount of bytes is 4 * palettesize)*/ - - /* - transparent color key (tRNS) - - This color uses the same bit depth as the bitdepth value in this struct, which can be 1-bit to 16-bit. - For greyscale PNGs, r, g and b will all 3 be set to the same. - - When decoding, by default you can ignore this information, since LodePNG sets - pixels with this key to transparent already in the raw RGBA output. - - The color key is only supported for color types 0 and 2. - */ - unsigned key_defined; /*is a transparent color key given? 0 = false, 1 = true*/ - unsigned key_r; /*red/greyscale component of color key*/ - unsigned key_g; /*green component of color key*/ - unsigned key_b; /*blue component of color key*/ -} LodePNGColorMode; - -/*init, cleanup and copy functions to use with this struct*/ -void lodepng_color_mode_init(LodePNGColorMode* info); -void lodepng_color_mode_cleanup(LodePNGColorMode* info); -/*return value is error code (0 means no error)*/ -unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source); - -void lodepng_palette_clear(LodePNGColorMode* info); -/*add 1 color to the palette*/ -unsigned lodepng_palette_add(LodePNGColorMode* info, - unsigned char r, unsigned char g, unsigned char b, unsigned char a); - -/*get the total amount of bits per pixel, based on colortype and bitdepth in the struct*/ -unsigned lodepng_get_bpp(const LodePNGColorMode* info); -/*get the amount of color channels used, based on colortype in the struct. -If a palette is used, it counts as 1 channel.*/ -unsigned lodepng_get_channels(const LodePNGColorMode* info); -/*is it a greyscale type? (only colortype 0 or 4)*/ -unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info); -/*has it got an alpha channel? (only colortype 2 or 6)*/ -unsigned lodepng_is_alpha_type(const LodePNGColorMode* info); -/*has it got a palette? (only colortype 3)*/ -unsigned lodepng_is_palette_type(const LodePNGColorMode* info); -/*only returns true if there is a palette and there is a value in the palette with alpha < 255. -Loops through the palette to check this.*/ -unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info); -/* -Check if the given color info indicates the possibility of having non-opaque pixels in the PNG image. -Returns true if the image can have translucent or invisible pixels (it still be opaque if it doesn't use such pixels). -Returns false if the image can only have opaque pixels. -In detail, it returns true only if it's a color type with alpha, or has a palette with non-opaque values, -or if "key_defined" is true. -*/ -unsigned lodepng_can_have_alpha(const LodePNGColorMode* info); -/*Returns the byte size of a raw image buffer with given width, height and color mode*/ -size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color); - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -/*The information of a Time chunk in PNG.*/ -typedef struct LodePNGTime -{ - unsigned year; /*2 bytes used (0-65535)*/ - unsigned month; /*1-12*/ - unsigned day; /*1-31*/ - unsigned hour; /*0-23*/ - unsigned minute; /*0-59*/ - unsigned second; /*0-60 (to allow for leap seconds)*/ -} LodePNGTime; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -/*Information about the PNG image, except pixels, width and height.*/ -typedef struct LodePNGInfo -{ - /*header (IHDR), palette (PLTE) and transparency (tRNS) chunks*/ - unsigned compression_method;/*compression method of the original file. Always 0.*/ - unsigned filter_method; /*filter method of the original file*/ - unsigned interlace_method; /*interlace method of the original file*/ - LodePNGColorMode color; /*color type and bits, palette and transparency of the PNG file*/ - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /* - suggested background color chunk (bKGD) - This color uses the same color mode as the PNG (except alpha channel), which can be 1-bit to 16-bit. - - For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding - the encoder writes the red one. For palette PNGs: When decoding, the RGB value - will be stored, not a palette index. But when encoding, specify the index of - the palette in background_r, the other two are then ignored. - - The decoder does not use this background color to edit the color of pixels. - */ - unsigned background_defined; /*is a suggested background color given?*/ - unsigned background_r; /*red component of suggested background color*/ - unsigned background_g; /*green component of suggested background color*/ - unsigned background_b; /*blue component of suggested background color*/ - - /* - non-international text chunks (tEXt and zTXt) - - The char** arrays each contain num strings. The actual messages are in - text_strings, while text_keys are keywords that give a short description what - the actual text represents, e.g. Title, Author, Description, or anything else. - - A keyword is minimum 1 character and maximum 79 characters long. It's - discouraged to use a single line length longer than 79 characters for texts. - - Don't allocate these text buffers yourself. Use the init/cleanup functions - correctly and use lodepng_add_text and lodepng_clear_text. - */ - size_t text_num; /*the amount of texts in these char** buffers (there may be more texts in itext)*/ - char** text_keys; /*the keyword of a text chunk (e.g. "Comment")*/ - char** text_strings; /*the actual text*/ - - /* - international text chunks (iTXt) - Similar to the non-international text chunks, but with additional strings - "langtags" and "transkeys". - */ - size_t itext_num; /*the amount of international texts in this PNG*/ - char** itext_keys; /*the English keyword of the text chunk (e.g. "Comment")*/ - char** itext_langtags; /*language tag for this text's language, ISO/IEC 646 string, e.g. ISO 639 language tag*/ - char** itext_transkeys; /*keyword translated to the international language - UTF-8 string*/ - char** itext_strings; /*the actual international text - UTF-8 string*/ - - /*time chunk (tIME)*/ - unsigned time_defined; /*set to 1 to make the encoder generate a tIME chunk*/ - LodePNGTime time; - - /*phys chunk (pHYs)*/ - unsigned phys_defined; /*if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one*/ - unsigned phys_x; /*pixels per unit in x direction*/ - unsigned phys_y; /*pixels per unit in y direction*/ - unsigned phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/ - - /* - unknown chunks - There are 3 buffers, one for each position in the PNG where unknown chunks can appear - each buffer contains all unknown chunks for that position consecutively - The 3 buffers are the unknown chunks between certain critical chunks: - 0: IHDR-PLTE, 1: PLTE-IDAT, 2: IDAT-IEND - Do not allocate or traverse this data yourself. Use the chunk traversing functions declared - later, such as lodepng_chunk_next and lodepng_chunk_append, to read/write this struct. - */ - unsigned char* unknown_chunks_data[3]; - size_t unknown_chunks_size[3]; /*size in bytes of the unknown chunks, given for protection*/ -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -} LodePNGInfo; - -/*init, cleanup and copy functions to use with this struct*/ -void lodepng_info_init(LodePNGInfo* info); -void lodepng_info_cleanup(LodePNGInfo* info); -/*return value is error code (0 means no error)*/ -unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source); - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -void lodepng_clear_text(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/ -unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str); /*push back both texts at once*/ - -void lodepng_clear_itext(LodePNGInfo* info); /*use this to clear the itexts again after you filled them in*/ -unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag, - const char* transkey, const char* str); /*push back the 4 texts of 1 chunk at once*/ -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -/* -Converts raw buffer from one color type to another color type, based on -LodePNGColorMode structs to describe the input and output color type. -See the reference manual at the end of this header file to see which color conversions are supported. -return value = LodePNG error code (0 if all went ok, an error if the conversion isn't supported) -The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel -of the output color type (lodepng_get_bpp) -The fix_png value works as described in struct LodePNGDecoderSettings. -Note: for 16-bit per channel colors, uses big endian format like PNG does. -*/ -unsigned lodepng_convert(unsigned char* out, const unsigned char* in, - LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in, - unsigned w, unsigned h, unsigned fix_png); - -#ifdef LODEPNG_COMPILE_DECODER -/* -Settings for the decoder. This contains settings for the PNG and the Zlib -decoder, but not the Info settings from the Info structs. -*/ -typedef struct LodePNGDecoderSettings -{ - LodePNGDecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/ - - unsigned ignore_crc; /*ignore CRC checksums*/ - /* - The fix_png setting, if 1, makes the decoder tolerant towards some PNG images - that do not correctly follow the PNG specification. This only supports errors - that are fixable, were found in images that are actually used on the web, and - are silently tolerated by other decoders as well. Currently only one such fix - is implemented: if a palette index is out of bounds given the palette size, - interpret it as opaque black. - By default this value is 0, which makes it stop with an error on such images. - */ - unsigned fix_png; - unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/ - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - unsigned read_text_chunks; /*if false but remember_unknown_chunks is true, they're stored in the unknown chunks*/ - /*store all bytes from unknown chunks in the LodePNGInfo (off by default, useful for a png editor)*/ - unsigned remember_unknown_chunks; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -} LodePNGDecoderSettings; - -void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings); -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER -/*automatically use color type with less bits per pixel if losslessly possible. Default: AUTO*/ -typedef enum LodePNGFilterStrategy -{ - /*every filter at zero*/ - LFS_ZERO, - /*Use filter that gives minumum sum, as described in the official PNG filter heuristic.*/ - LFS_MINSUM, - /*Use the filter type that gives smallest Shannon entropy for this scanline. Depending - on the image, this is better or worse than minsum.*/ - LFS_ENTROPY, - /* - Brute-force-search PNG filters by compressing each filter for each scanline. - Experimental, very slow, and only rarely gives better compression than MINSUM. - */ - LFS_BRUTE_FORCE, - /*use predefined_filters buffer: you specify the filter type for each scanline*/ - LFS_PREDEFINED -} LodePNGFilterStrategy; - -/*automatically use color type with less bits per pixel if losslessly possible. Default: LAC_AUTO*/ -typedef enum LodePNGAutoConvert -{ - LAC_NO, /*use color type user requested*/ - LAC_ALPHA, /*use color type user requested, but if only opaque pixels and RGBA or grey+alpha, use RGB or grey*/ - LAC_AUTO, /*use PNG color type that can losslessly represent the uncompressed image the smallest possible*/ - /* - like AUTO, but do not choose 1, 2 or 4 bit per pixel types. - sometimes a PNG image compresses worse if less than 8 bits per pixels. - */ - LAC_AUTO_NO_NIBBLES, - /* - like AUTO, but never choose palette color type. For small images, encoding - the palette may take more bytes than what is gained. Note that AUTO also - already prevents encoding the palette for extremely small images, but that may - not be sufficient because due to the compression it cannot predict when to - switch. - */ - LAC_AUTO_NO_PALETTE, - LAC_AUTO_NO_NIBBLES_NO_PALETTE -} LodePNGAutoConvert; - - -/* -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, ... -The auto_convert parameter allows limiting it to not use palette, ... -*/ -unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out, - const unsigned char* image, unsigned w, unsigned h, - const LodePNGColorMode* mode_in, - LodePNGAutoConvert auto_convert); - -/*Settings for the encoder.*/ -typedef struct LodePNGEncoderSettings -{ - LodePNGCompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/ - - LodePNGAutoConvert auto_convert; /*how to automatically choose output PNG color type, if at all*/ - - /*If true, follows the official PNG heuristic: if the PNG uses a palette or lower than - 8 bit depth, set all filters to zero. Otherwise use the filter_strategy. Note that to - completely follow the official PNG heuristic, filter_palette_zero must be true and - filter_strategy must be LFS_MINSUM*/ - unsigned filter_palette_zero; - /*Which filter strategy to use when not using zeroes due to filter_palette_zero. - Set filter_palette_zero to 0 to ensure always using your chosen strategy. Default: LFS_MINSUM*/ - LodePNGFilterStrategy filter_strategy; - /*used if filter_strategy is LFS_PREDEFINED. In that case, this must point to a buffer with - the same length as the amount of scanlines in the image, and each value must <= 5. You - have to cleanup this buffer, LodePNG will never free it. Don't forget that filter_palette_zero - must be set to 0 to ensure this is also used on palette or low bitdepth images.*/ - const unsigned char* predefined_filters; - - /*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette). - If colortype is 3, PLTE is _always_ created.*/ - unsigned force_palette; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /*add LodePNG identifier and version as a text chunk, for debugging*/ - unsigned add_id; - /*encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks*/ - unsigned text_compression; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -} LodePNGEncoderSettings; - -void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings); -#endif /*LODEPNG_COMPILE_ENCODER*/ - - -#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) -/*The settings, state and information for extended encoding and decoding.*/ -typedef struct LodePNGState -{ -#ifdef LODEPNG_COMPILE_DECODER - LodePNGDecoderSettings decoder; /*the decoding settings*/ -#endif /*LODEPNG_COMPILE_DECODER*/ -#ifdef LODEPNG_COMPILE_ENCODER - LodePNGEncoderSettings encoder; /*the encoding settings*/ -#endif /*LODEPNG_COMPILE_ENCODER*/ - LodePNGColorMode info_raw; /*specifies the format in which you would like to get the raw pixel buffer*/ - LodePNGInfo info_png; /*info of the PNG image obtained after decoding*/ - unsigned error; -#ifdef LODEPNG_COMPILE_CPP - //For the lodepng::State subclass. - virtual ~LodePNGState(){} -#endif -} LodePNGState; - -/*init, cleanup and copy functions to use with this struct*/ -void lodepng_state_init(LodePNGState* state); -void lodepng_state_cleanup(LodePNGState* state); -void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source); -#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */ - -#ifdef LODEPNG_COMPILE_DECODER -/* -Same as lodepng_decode_memory, but uses a LodePNGState to allow custom settings and -getting much more information about the PNG image and color mode. -*/ -unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h, - LodePNGState* state, - const unsigned char* in, size_t insize); - -/* -Read the PNG header, but not the actual data. This returns only the information -that is in the header chunk of the PNG, such as width, height and color type. The -information is placed in the info_png field of the LodePNGState. -*/ -unsigned lodepng_inspect(unsigned* w, unsigned* h, - LodePNGState* state, - const unsigned char* in, size_t insize); -#endif /*LODEPNG_COMPILE_DECODER*/ - - -#ifdef LODEPNG_COMPILE_ENCODER -/*This function allocates the out buffer with standard malloc and stores the size in *outsize.*/ -unsigned lodepng_encode(unsigned char** out, size_t* outsize, - const unsigned char* image, unsigned w, unsigned h, - LodePNGState* state); -#endif /*LODEPNG_COMPILE_ENCODER*/ - -/* -The lodepng_chunk functions are normally not needed, except to traverse the -unknown chunks stored in the LodePNGInfo struct, or add new ones to it. -It also allows traversing the chunks of an encoded PNG file yourself. - -PNG standard chunk naming conventions: -First byte: uppercase = critical, lowercase = ancillary -Second byte: uppercase = public, lowercase = private -Third byte: must be uppercase -Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy -*/ - -/*get the length of the data of the chunk. Total chunk length has 12 bytes more.*/ -unsigned lodepng_chunk_length(const unsigned char* chunk); - -/*puts the 4-byte type in null terminated string*/ -void lodepng_chunk_type(char type[5], const unsigned char* chunk); - -/*check if the type is the given type*/ -unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type); - -/*0: it's one of the critical chunk types, 1: it's an ancillary chunk (see PNG standard)*/ -unsigned char lodepng_chunk_ancillary(const unsigned char* chunk); - -/*0: public, 1: private (see PNG standard)*/ -unsigned char lodepng_chunk_private(const unsigned char* chunk); - -/*0: the chunk is unsafe to copy, 1: the chunk is safe to copy (see PNG standard)*/ -unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk); - -/*get pointer to the data of the chunk, where the input points to the header of the chunk*/ -unsigned char* lodepng_chunk_data(unsigned char* chunk); -const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk); - -/*returns 0 if the crc is correct, 1 if it's incorrect (0 for OK as usual!)*/ -unsigned lodepng_chunk_check_crc(const unsigned char* chunk); - -/*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/ -void lodepng_chunk_generate_crc(unsigned char* chunk); - -/*iterate to next chunks. don't use on IEND chunk, as there is no next chunk then*/ -unsigned char* lodepng_chunk_next(unsigned char* chunk); -const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk); - -/* -Appends chunk to the data in out. The given chunk should already have its chunk header. -The out variable and outlength are updated to reflect the new reallocated buffer. -Returns error code (0 if it went ok) -*/ -unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk); - -/* -Appends new chunk to out. The chunk to append is given by giving its length, type -and data separately. The type is a 4-letter string. -The out variable and outlength are updated to reflect the new reallocated buffer. -Returne error code (0 if it went ok) -*/ -unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length, - const char* type, const unsigned char* data); - - -/*Calculate CRC32 of buffer*/ -unsigned lodepng_crc32(const unsigned char* buf, size_t len); -#endif /*LODEPNG_COMPILE_PNG*/ - - -#ifdef LODEPNG_COMPILE_ZLIB -/* -This zlib part can be used independently to zlib compress and decompress a -buffer. It cannot be used to create gzip files however, and it only supports the -part of zlib that is required for PNG, it does not support dictionaries. -*/ - -#ifdef LODEPNG_COMPILE_DECODER -/*Inflate a buffer. Inflate is the decompression step of deflate. Out buffer must be freed after use.*/ -unsigned lodepng_inflate(unsigned char** out, size_t* outsize, - const unsigned char* in, size_t insize, - const LodePNGDecompressSettings* settings); - -/* -Decompresses Zlib data. Reallocates the out buffer and appends the data. The -data must be according to the zlib specification. -Either, *out must be NULL and *outsize must be 0, or, *out must be a valid -buffer and *outsize its size in bytes. out must be freed by user after usage. -*/ -unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, - const unsigned char* in, size_t insize, - const LodePNGDecompressSettings* settings); -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER -/* -Compresses data with Zlib. Reallocates the out buffer and appends the data. -Zlib adds a small header and trailer around the deflate data. -The data is output in the format of the zlib specification. -Either, *out must be NULL and *outsize must be 0, or, *out must be a valid -buffer and *outsize its size in bytes. out must be freed by user after usage. -*/ -unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize, - const unsigned char* in, size_t insize, - const LodePNGCompressSettings* settings); - -/* -Find length-limited Huffman code for given frequencies. This function is in the -public interface only for tests, it's used internally by lodepng_deflate. -*/ -unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies, - size_t numcodes, unsigned maxbitlen); - -/*Compress a buffer with deflate. See RFC 1951. Out buffer must be freed after use.*/ -unsigned lodepng_deflate(unsigned char** out, size_t* outsize, - const unsigned char* in, size_t insize, - const LodePNGCompressSettings* settings); - -#endif /*LODEPNG_COMPILE_ENCODER*/ -#endif /*LODEPNG_COMPILE_ZLIB*/ - -#ifdef LODEPNG_COMPILE_DISK -/* -Load a file from disk into buffer. The function allocates the out buffer, and -after usage you should free it. -out: output parameter, contains pointer to loaded buffer. -outsize: output parameter, size of the allocated out buffer -filename: the path to the file to load -return value: error code (0 means ok) -*/ -unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename); - -/* -Save a file from buffer to disk. Warning, if it exists, this function overwrites -the file without warning! -buffer: the buffer to write -buffersize: size of the buffer to write -filename: the path to the file to save to -return value: error code (0 means ok) -*/ -unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename); -#endif /*LODEPNG_COMPILE_DISK*/ - -#ifdef LODEPNG_COMPILE_CPP -//The LodePNG C++ wrapper uses std::vectors instead of manually allocated memory buffers. -namespace lodepng -{ -#ifdef LODEPNG_COMPILE_PNG -class State : public LodePNGState -{ - public: - State(); - State(const State& other); - virtual ~State(); - State& operator=(const State& other); -}; - -#ifdef LODEPNG_COMPILE_DECODER -//Same as other lodepng::decode, but using a State for more settings and information. -unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - State& state, - const unsigned char* in, size_t insize); -unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - State& state, - const std::vector<unsigned char>& in); -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER -//Same as other lodepng::encode, but using a State for more settings and information. -unsigned encode(std::vector<unsigned char>& out, - const unsigned char* in, unsigned w, unsigned h, - State& state); -unsigned encode(std::vector<unsigned char>& out, - const std::vector<unsigned char>& in, unsigned w, unsigned h, - State& state); -#endif /*LODEPNG_COMPILE_ENCODER*/ - -#ifdef LODEPNG_COMPILE_DISK -/* -Load a file from disk into an std::vector. If the vector is empty, then either -the file doesn't exist or is an empty file. -*/ -void load_file(std::vector<unsigned char>& buffer, const std::string& filename); - -/* -Save the binary data in an std::vector to a file on disk. The file is overwritten -without warning. -*/ -void save_file(const std::vector<unsigned char>& buffer, const std::string& filename); -#endif //LODEPNG_COMPILE_DISK -#endif //LODEPNG_COMPILE_PNG - -#ifdef LODEPNG_COMPILE_ZLIB -#ifdef LODEPNG_COMPILE_DECODER -//Zlib-decompress an unsigned char buffer -unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize, - const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings); - -//Zlib-decompress an std::vector -unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, - const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings); -#endif //LODEPNG_COMPILE_DECODER - -#ifdef LODEPNG_COMPILE_ENCODER -//Zlib-compress an unsigned char buffer -unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize, - const LodePNGCompressSettings& settings = lodepng_default_compress_settings); - -//Zlib-compress an std::vector -unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, - const LodePNGCompressSettings& settings = lodepng_default_compress_settings); -#endif //LODEPNG_COMPILE_ENCODER -#endif //LODEPNG_COMPILE_ZLIB -} //namespace lodepng -#endif /*LODEPNG_COMPILE_CPP*/ - -/* -TODO: -[.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often -[.] check compatibility with vareous compilers - done but needs to be redone for every newer version -[X] converting color to 16-bit per channel types -[ ] read all public PNG chunk types (but never let the color profile and gamma ones touch RGB values) -[ ] make sure encoder generates no chunks with size > (2^31)-1 -[ ] partial decoding (stream processing) -[X] let the "isFullyOpaque" function check color keys and transparent palettes too -[X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl" -[ ] don't stop decoding on errors like 69, 57, 58 (make warnings) -[ ] make option to choose if the raw image with non multiple of 8 bits per scanline should have padding bits or not -[ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes -*/ - -#endif /*LODEPNG_H inclusion guard*/ - -/* -LodePNG Documentation ---------------------- - -0. table of contents --------------------- - - 1. about - 1.1. supported features - 1.2. features not supported - 2. C and C++ version - 3. security - 4. decoding - 5. encoding - 6. color conversions - 6.1. PNG color types - 6.2. color conversions - 6.3. padding bits - 6.4. A note about 16-bits per channel and endianness - 7. error values - 8. chunks and PNG editing - 9. compiler support - 10. examples - 10.1. decoder C++ example - 10.2. decoder C example - 11. changes - 12. contact information - - -1. about --------- - -PNG is a file format to store raster images losslessly with good compression, -supporting different color types and alpha channel. - -LodePNG is a PNG codec according to the Portable Network Graphics (PNG) -Specification (Second Edition) - W3C Recommendation 10 November 2003. - -The specifications used are: - -*) Portable Network Graphics (PNG) Specification (Second Edition): - http://www.w3.org/TR/2003/REC-PNG-20031110 -*) RFC 1950 ZLIB Compressed Data Format version 3.3: - http://www.gzip.org/zlib/rfc-zlib.html -*) RFC 1951 DEFLATE Compressed Data Format Specification ver 1.3: - http://www.gzip.org/zlib/rfc-deflate.html - -The most recent version of LodePNG can currently be found at -http://lodev.org/lodepng/ - -LodePNG works both in C (ISO C90) and C++, with a C++ wrapper that adds -extra functionality. - -LodePNG exists out of two files: --lodepng.h: the header file for both C and C++ --lodepng.c(pp): give it the name lodepng.c or lodepng.cpp (or .cc) depending on your usage - -If you want to start using LodePNG right away without reading this doc, get the -examples from the LodePNG website to see how to use it in code, or check the -smaller examples in chapter 13 here. - -LodePNG is simple but only supports the basic requirements. To achieve -simplicity, the following design choices were made: There are no dependencies -on any external library. There are functions to decode and encode a PNG with -a single function call, and extended versions of these functions taking a -LodePNGState struct allowing to specify or get more information. By default -the colors of the raw image are always RGB or RGBA, no matter what color type -the PNG file uses. To read and write files, there are simple functions to -convert the files to/from buffers in memory. - -This all makes LodePNG suitable for loading textures in games, demos and small -programs, ... It's less suitable for full fledged image editors, loading PNGs -over network (it requires all the image data to be available before decoding can -begin), life-critical systems, ... - -1.1. supported features ------------------------ - -The following features are supported by the decoder: - -*) decoding of PNGs with any color type, bit depth and interlace mode, to a 24- or 32-bit color raw image, - or the same color type as the PNG -*) encoding of PNGs, from any raw image to 24- or 32-bit color, or the same color type as the raw image -*) Adam7 interlace and deinterlace for any color type -*) loading the image from harddisk or decoding it from a buffer from other sources than harddisk -*) support for alpha channels, including RGBA color model, translucent palettes and color keying -*) zlib decompression (inflate) -*) zlib compression (deflate) -*) CRC32 and ADLER32 checksums -*) handling of unknown chunks, allowing making a PNG editor that stores custom and unknown chunks. -*) the following chunks are supported (generated/interpreted) by both encoder and decoder: - IHDR: header information - PLTE: color palette - IDAT: pixel data - IEND: the final chunk - tRNS: transparency for palettized images - tEXt: textual information - zTXt: compressed textual information - iTXt: international textual information - bKGD: suggested background color - pHYs: physical dimensions - tIME: modification time - -1.2. features not supported ---------------------------- - -The following features are _not_ supported: - -*) some features needed to make a conformant PNG-Editor might be still missing. -*) partial loading/stream processing. All data must be available and is processed in one call. -*) The following public chunks are not supported but treated as unknown chunks by LodePNG - cHRM, gAMA, iCCP, sRGB, sBIT, hIST, sPLT - Some of these are not supported on purpose: LodePNG wants to provide the RGB values - stored in the pixels, not values modified by system dependent gamma or color models. - - -2. C and C++ version --------------------- - -The C version uses buffers allocated with alloc that you need to free() -yourself. You need to use init and cleanup functions for each struct whenever -using a struct from the C version to avoid exploits and memory leaks. - -The C++ version has extra functions with std::vectors in the interface and the -lodepng::State class which is a LodePNGState with constructor and destructor. - -These files work without modification for both C and C++ compilers because all -the additional C++ code is in "#ifdef __cplusplus" blocks that make C-compilers -ignore it, and the C code is made to compile both with strict ISO C90 and C++. - -To use the C++ version, you need to rename the source file to lodepng.cpp -(instead of lodepng.c), and compile it with a C++ compiler. - -To use the C version, you need to rename the source file to lodepng.c (instead -of lodepng.cpp), and compile it with a C compiler. - - -3. Security ------------ - -Even if carefully designed, it's always possible that LodePNG contains possible -exploits. If you discover one, please let me know, and it will be fixed. - -When using LodePNG, care has to be taken with the C version of LodePNG, as well -as the C-style structs when working with C++. The following conventions are used -for all C-style structs: - --if a struct has a corresponding init function, always call the init function when making a new one --if a struct has a corresponding cleanup function, call it before the struct disappears to avoid memory leaks --if a struct has a corresponding copy function, use the copy function instead of "=". - The destination must also be inited already. - - -4. Decoding ------------ - -Decoding converts a PNG compressed image to a raw pixel buffer. - -Most documentation on using the decoder is at its declarations in the header -above. For C, simple decoding can be done with functions such as -lodepng_decode32, and more advanced decoding can be done with the struct -LodePNGState and lodepng_decode. For C++, all decoding can be done with the -various lodepng::decode functions, and lodepng::State can be used for advanced -features. - -When using the LodePNGState, it uses the following fields for decoding: -*) LodePNGInfo info_png: it stores extra information about the PNG (the input) in here -*) LodePNGColorMode info_raw: here you can say what color mode of the raw image (the output) you want to get -*) LodePNGDecoderSettings decoder: you can specify a few extra settings for the decoder to use - -LodePNGInfo info_png --------------------- - -After decoding, this contains extra information of the PNG image, except the actual -pixels, width and height because these are already gotten directly from the decoder -functions. - -It contains for example the original color type of the PNG image, text comments, -suggested background color, etc... More details about the LodePNGInfo struct are -at its declaration documentation. - -LodePNGColorMode info_raw -------------------------- - -When decoding, here you can specify which color type you want -the resulting raw image to be. If this is different from the colortype of the -PNG, then the decoder will automatically convert the result. This conversion -always works, except if you want it to convert a color PNG to greyscale or to -a palette with missing colors. - -By default, 32-bit color is used for the result. - -LodePNGDecoderSettings decoder ------------------------------- - -The settings can be used to ignore the errors created by invalid CRC and Adler32 -chunks, and to disable the decoding of tEXt chunks. - -There's also a setting color_convert, true by default. If false, no conversion -is done, the resulting data will be as it was in the PNG (after decompression) -and you'll have to puzzle the colors of the pixels together yourself using the -color type information in the LodePNGInfo. - - -5. Encoding ------------ - -Encoding converts a raw pixel buffer to a PNG compressed image. - -Most documentation on using the encoder is at its declarations in the header -above. For C, simple encoding can be done with functions such as -lodepng_encode32, and more advanced decoding can be done with the struct -LodePNGState and lodepng_encode. For C++, all encoding can be done with the -various lodepng::encode functions, and lodepng::State can be used for advanced -features. - -Like the decoder, the encoder can also give errors. However it gives less errors -since the encoder input is trusted, the decoder input (a PNG image that could -be forged by anyone) is not trusted. - -When using the LodePNGState, it uses the following fields for encoding: -*) LodePNGInfo info_png: here you specify how you want the PNG (the output) to be. -*) LodePNGColorMode info_raw: here you say what color type of the raw image (the input) has -*) LodePNGEncoderSettings encoder: you can specify a few settings for the encoder to use - -LodePNGInfo info_png --------------------- - -When encoding, you use this the opposite way as when decoding: for encoding, -you fill in the values you want the PNG to have before encoding. By default it's -not needed to specify a color type for the PNG since it's automatically chosen, -but it's possible to choose it yourself given the right settings. - -The encoder will not always exactly match the LodePNGInfo struct you give, -it tries as close as possible. Some things are ignored by the encoder. The -encoder uses, for example, the following settings from it when applicable: -colortype and bitdepth, text chunks, time chunk, the color key, the palette, the -background color, the interlace method, unknown chunks, ... - -When encoding to a PNG with colortype 3, the encoder will generate a PLTE chunk. -If the palette contains any colors for which the alpha channel is not 255 (so -there are translucent colors in the palette), it'll add a tRNS chunk. - -LodePNGColorMode info_raw -------------------------- - -You specify the color type of the raw image that you give to the input here, -including a possible transparent color key and palette you happen to be using in -your raw image data. - -By default, 32-bit color is assumed, meaning your input has to be in RGBA -format with 4 bytes (unsigned chars) per pixel. - -LodePNGEncoderSettings encoder ------------------------------- - -The following settings are supported (some are in sub-structs): -*) auto_convert: when this option is enabled, the encoder will -automatically choose the smallest possible color mode (including color key) that -can encode the colors of all pixels without information loss. -*) btype: the block type for LZ77. 0 = uncompressed, 1 = fixed huffman tree, - 2 = dynamic huffman tree (best compression). Should be 2 for proper - compression. -*) use_lz77: whether or not to use LZ77 for compressed block types. Should be - true for proper compression. -*) windowsize: the window size used by the LZ77 encoder (1 - 32768). Has value - 2048 by default, but can be set to 32768 for better, but slow, compression. -*) force_palette: if colortype is 2 or 6, you can make the encoder write a PLTE - chunk if force_palette is true. This can used as suggested palette to convert - to by viewers that don't support more than 256 colors (if those still exist) -*) add_id: add text chunk "Encoder: LodePNG <version>" to the image. -*) text_compression: default 1. If 1, it'll store texts as zTXt instead of tEXt chunks. - zTXt chunks use zlib compression on the text. This gives a smaller result on - large texts but a larger result on small texts (such as a single program name). - It's all tEXt or all zTXt though, there's no separate setting per text yet. - - -6. color conversions --------------------- - -An important thing to note about LodePNG, is that the color type of the PNG, and -the color type of the raw image, are completely independent. By default, when -you decode a PNG, you get the result as a raw image in the color type you want, -no matter whether the PNG was encoded with a palette, greyscale or RGBA color. -And if you encode an image, by default LodePNG will automatically choose the PNG -color type that gives good compression based on the values of colors and amount -of colors in the image. It can be configured to let you control it instead as -well, though. - -To be able to do this, LodePNG does conversions from one color mode to another. -It can convert from almost any color type to any other color type, except the -following conversions: RGB to greyscale is not supported, and converting to a -palette when the palette doesn't have a required color is not supported. This is -not supported on purpose: this is information loss which requires a color -reduction algorithm that is beyong the scope of a PNG encoder (yes, RGB to grey -is easy, but there are multiple ways if you want to give some channels more -weight). - -By default, when decoding, you get the raw image in 32-bit RGBA or 24-bit RGB -color, no matter what color type the PNG has. And by default when encoding, -LodePNG automatically picks the best color model for the output PNG, and expects -the input image to be 32-bit RGBA or 24-bit RGB. So, unless you want to control -the color format of the images yourself, you can skip this chapter. - -6.1. PNG color types --------------------- - -A PNG image can have many color types, ranging from 1-bit color to 64-bit color, -as well as palettized color modes. After the zlib decompression and unfiltering -in the PNG image is done, the raw pixel data will have that color type and thus -a certain amount of bits per pixel. If you want the output raw image after -decoding to have another color type, a conversion is done by LodePNG. - -The PNG specification gives the following color types: - -0: greyscale, bit depths 1, 2, 4, 8, 16 -2: RGB, bit depths 8 and 16 -3: palette, bit depths 1, 2, 4 and 8 -4: greyscale with alpha, bit depths 8 and 16 -6: RGBA, bit depths 8 and 16 - -Bit depth is the amount of bits per pixel per color channel. So the total amount -of bits per pixel is: amount of channels * bitdepth. - -6.2. color conversions ----------------------- - -As explained in the sections about the encoder and decoder, you can specify -color types and bit depths in info_png and info_raw to change the default -behaviour. - -If, when decoding, you want the raw image to be something else than the default, -you need to set the color type and bit depth you want in the LodePNGColorMode, -or the parameters of the simple function of LodePNG you're using. - -If, when encoding, you use another color type than the default in the input -image, you need to specify its color type and bit depth in the LodePNGColorMode -of the raw image, or use the parameters of the simplefunction of LodePNG you're -using. - -If, when encoding, you don't want LodePNG to choose the output PNG color type -but control it yourself, you need to set auto_convert in the encoder settings -to LAC_NONE, and specify the color type you want in the LodePNGInfo of the -encoder. - -If you do any of the above, LodePNG may need to do a color conversion, which -follows the rules below, and may sometimes not be allowed. - -To avoid some confusion: --the decoder converts from PNG to raw image --the encoder converts from raw image to PNG --the colortype and bitdepth in LodePNGColorMode info_raw, are those of the raw image --the colortype and bitdepth in the color field of LodePNGInfo info_png, are those of the PNG --when encoding, the color type in LodePNGInfo is ignored if auto_convert - is enabled, it is automatically generated instead --when decoding, the color type in LodePNGInfo is set by the decoder to that of the original - PNG image, but it can be ignored since the raw image has the color type you requested instead --if the color type of the LodePNGColorMode and PNG image aren't the same, a conversion - between the color types is done if the color types are supported. If it is not - supported, an error is returned. If the types are the same, no conversion is done. --even though some conversions aren't supported, LodePNG supports loading PNGs from any - colortype and saving PNGs to any colortype, sometimes it just requires preparing - the raw image correctly before encoding. --both encoder and decoder use the same color converter. - -Non supported color conversions: --color to greyscale: no error is thrown, but the result will look ugly because -only the red channel is taken --anything, to palette when that palette does not have that color in it: in this -case an error is thrown - -Supported color conversions: --anything to 8-bit RGB, 8-bit RGBA, 16-bit RGB, 16-bit RGBA --any grey or grey+alpha, to grey or grey+alpha --anything to a palette, as long as the palette has the requested colors in it --removing alpha channel --higher to smaller bitdepth, and vice versa - -If you want no color conversion to be done: --In the encoder, you can make it save a PNG with any color type by giving the -raw color mode and LodePNGInfo the same color mode, and setting auto_convert to -LAC_NO. --In the decoder, you can make it store the pixel data in the same color type -as the PNG has, by setting the color_convert setting to false. Settings in -info_raw are then ignored. - -The function lodepng_convert does the color conversion. It is available in the -interface but normally isn't needed since the encoder and decoder already call -it. - -6.3. padding bits ------------------ - -In the PNG file format, if a less than 8-bit per pixel color type is used and the scanlines -have a bit amount that isn't a multiple of 8, then padding bits are used so that each -scanline starts at a fresh byte. But that is NOT true for the LodePNG raw input and output. -The raw input image you give to the encoder, and the raw output image you get from the decoder -will NOT have these padding bits, e.g. in the case of a 1-bit image with a width -of 7 pixels, the first pixel of the second scanline will the the 8th bit of the first byte, -not the first bit of a new byte. - -6.4. A note about 16-bits per channel and endianness ----------------------------------------------------- - -LodePNG uses unsigned char arrays for 16-bit per channel colors too, just like -for any other color format. The 16-bit values are stored in big endian (most -significant byte first) in these arrays. This is the opposite order of the -little endian used by x86 CPU's. - -LodePNG always uses big endian because the PNG file format does so internally. -Conversions to other formats than PNG uses internally are not supported by -LodePNG on purpose, there are myriads of formats, including endianness of 16-bit -colors, the order in which you store R, G, B and A, and so on. Supporting and -converting to/from all that is outside the scope of LodePNG. - -This may mean that, depending on your use case, you may want to convert the big -endian output of LodePNG to little endian with a for loop. This is certainly not -always needed, many applications and libraries support big endian 16-bit colors -anyway, but it means you cannot simply cast the unsigned char* buffer to an -unsigned short* buffer on x86 CPUs. - - -7. error values ---------------- - -All functions in LodePNG that return an error code, return 0 if everything went -OK, or a non-zero code if there was an error. - -The meaning of the LodePNG error values can be retrieved with the function -lodepng_error_text: given the numerical error code, it returns a description -of the error in English as a string. - -Check the implementation of lodepng_error_text to see the meaning of each code. - - -8. chunks and PNG editing -------------------------- - -If you want to add extra chunks to a PNG you encode, or use LodePNG for a PNG -editor that should follow the rules about handling of unknown chunks, or if your -program is able to read other types of chunks than the ones handled by LodePNG, -then that's possible with the chunk functions of LodePNG. - -A PNG chunk has the following layout: - -4 bytes length -4 bytes type name -length bytes data -4 bytes CRC - -8.1. iterating through chunks ------------------------------ - -If you have a buffer containing the PNG image data, then the first chunk (the -IHDR chunk) starts at byte number 8 of that buffer. The first 8 bytes are the -signature of the PNG and are not part of a chunk. But if you start at byte 8 -then you have a chunk, and can check the following things of it. - -NOTE: none of these functions check for memory buffer boundaries. To avoid -exploits, always make sure the buffer contains all the data of the chunks. -When using lodepng_chunk_next, make sure the returned value is within the -allocated memory. - -unsigned lodepng_chunk_length(const unsigned char* chunk): - -Get the length of the chunk's data. The total chunk length is this length + 12. - -void lodepng_chunk_type(char type[5], const unsigned char* chunk): -unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type): - -Get the type of the chunk or compare if it's a certain type - -unsigned char lodepng_chunk_critical(const unsigned char* chunk): -unsigned char lodepng_chunk_private(const unsigned char* chunk): -unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk): - -Check if the chunk is critical in the PNG standard (only IHDR, PLTE, IDAT and IEND are). -Check if the chunk is private (public chunks are part of the standard, private ones not). -Check if the chunk is safe to copy. If it's not, then, when modifying data in a critical -chunk, unsafe to copy chunks of the old image may NOT be saved in the new one if your -program doesn't handle that type of unknown chunk. - -unsigned char* lodepng_chunk_data(unsigned char* chunk): -const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk): - -Get a pointer to the start of the data of the chunk. - -unsigned lodepng_chunk_check_crc(const unsigned char* chunk): -void lodepng_chunk_generate_crc(unsigned char* chunk): - -Check if the crc is correct or generate a correct one. - -unsigned char* lodepng_chunk_next(unsigned char* chunk): -const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk): - -Iterate to the next chunk. This works if you have a buffer with consecutive chunks. Note that these -functions do no boundary checking of the allocated data whatsoever, so make sure there is enough -data available in the buffer to be able to go to the next chunk. - -unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk): -unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length, - const char* type, const unsigned char* data): - -These functions are used to create new chunks that are appended to the data in *out that has -length *outlength. The append function appends an existing chunk to the new data. The create -function creates a new chunk with the given parameters and appends it. Type is the 4-letter -name of the chunk. - -8.2. chunks in info_png ------------------------ - -The LodePNGInfo struct contains fields with the unknown chunk in it. It has 3 -buffers (each with size) to contain 3 types of unknown chunks: -the ones that come before the PLTE chunk, the ones that come between the PLTE -and the IDAT chunks, and the ones that come after the IDAT chunks. -It's necessary to make the distionction between these 3 cases because the PNG -standard forces to keep the ordering of unknown chunks compared to the critical -chunks, but does not force any other ordering rules. - -info_png.unknown_chunks_data[0] is the chunks before PLTE -info_png.unknown_chunks_data[1] is the chunks after PLTE, before IDAT -info_png.unknown_chunks_data[2] is the chunks after IDAT - -The chunks in these 3 buffers can be iterated through and read by using the same -way described in the previous subchapter. - -When using the decoder to decode a PNG, you can make it store all unknown chunks -if you set the option settings.remember_unknown_chunks to 1. By default, this -option is off (0). - -The encoder will always encode unknown chunks that are stored in the info_png. -If you need it to add a particular chunk that isn't known by LodePNG, you can -use lodepng_chunk_append or lodepng_chunk_create to the chunk data in -info_png.unknown_chunks_data[x]. - -Chunks that are known by LodePNG should not be added in that way. E.g. to make -LodePNG add a bKGD chunk, set background_defined to true and add the correct -parameters there instead. - - -9. compiler support -------------------- - -No libraries other than the current standard C library are needed to compile -LodePNG. For the C++ version, only the standard C++ library is needed on top. -Add the files lodepng.c(pp) and lodepng.h to your project, include -lodepng.h where needed, and your program can read/write PNG files. - -If performance is important, use optimization when compiling! For both the -encoder and decoder, this makes a large difference. - -Make sure that LodePNG is compiled with the same compiler of the same version -and with the same settings as the rest of the program, or the interfaces with -std::vectors and std::strings in C++ can be incompatible. - -CHAR_BITS must be 8 or higher, because LodePNG uses unsigned chars for octets. - -*) gcc and g++ - -LodePNG is developed in gcc so this compiler is natively supported. It gives no -warnings with compiler options "-Wall -Wextra -pedantic -ansi", with gcc and g++ -version 4.7.1 on Linux, 32-bit and 64-bit. - -*) Mingw - -The Mingw compiler (a port of gcc) for Windows is fully supported by LodePNG. - -*) Visual Studio 2005 and up, Visual C++ Express Edition 2005 and up - -Visual Studio may give warnings about 'fopen' being deprecated. A multiplatform library -can't support the proposed Visual Studio alternative however, so LodePNG keeps using -fopen. If you don't want to see the deprecated warnings, put this on top of lodepng.h -before the inclusions: -#define _CRT_SECURE_NO_DEPRECATE - -Other than the above warnings, LodePNG should be warning-free with warning -level 3 (W3). Warning level 4 (W4) will give warnings about integer conversions. -I'm not planning to resolve these warnings. To get rid of them, let Visual -Studio use warning level W3 for lodepng.cpp only: right click lodepng.cpp, -Properties, C/C++, General, Warning Level: Level 3 (/W3). - -Visual Studio may want "stdafx.h" files to be included in each source file and -give an error "unexpected end of file while looking for precompiled header". -That is not standard C++ and will not be added to the stock LodePNG. You can -disable it for lodepng.cpp only by right clicking it, Properties, C/C++, -Precompiled Headers, and set it to Not Using Precompiled Headers there. - -*) Visual Studio 6.0 - -LodePNG support for Visual Studio 6.0 is not guaranteed because VS6 doesn't -follow the C++ standard correctly. - -*) Comeau C/C++ - -Vesion 20070107 compiles without problems on the Comeau C/C++ Online Test Drive -at http://www.comeaucomputing.com/tryitout in both C90 and C++ mode. - -*) Compilers on Macintosh - -LodePNG has been reported to work both with the gcc and LLVM for Macintosh, both -for C and C++. - -*) Other Compilers - -If you encounter problems on other compilers, feel free to let me know and I may -try to fix it if the compiler is modern standards complient. - - -10. examples ------------- - -This decoder example shows the most basic usage of LodePNG. More complex -examples can be found on the LodePNG website. - -10.1. decoder C++ example -------------------------- - -#include "lodepng.h" -#include <iostream> - -int main(int argc, char *argv[]) -{ - const char* filename = argc > 1 ? argv[1] : "test.png"; - - //load and decode - std::vector<unsigned char> image; - unsigned width, height; - unsigned error = lodepng::decode(image, width, height, filename); - - //if there's an error, display it - if(error) std::cout << "decoder error " << error << ": " << lodepng_error_text(error) << std::endl; - - //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ... -} - -10.2. decoder C example ------------------------ - -#include "lodepng.h" - -int main(int argc, char *argv[]) -{ - unsigned error; - unsigned char* image; - size_t width, height; - const char* filename = argc > 1 ? argv[1] : "test.png"; - - error = lodepng_decode32_file(&image, &width, &height, filename); - - if(error) printf("decoder error %u: %s\n", error, lodepng_error_text(error)); - - / * use image here * / - - free(image); - return 0; -} - - -11. changes ------------ - -The version number of LodePNG is the date of the change given in the format -yyyymmdd. - -Some changes aren't backwards compatible. Those are indicated with a (!) -symbol. - -*) 22 dec 2013: Power of two windowsize required for optimization. -*) 15 apr 2013: Fixed bug with LAC_ALPHA and color key. -*) 25 mar 2013: Added an optional feature to ignore some PNG errors (fix_png). -*) 11 mar 2013 (!): Bugfix with custom free. Changed from "my" to "lodepng_" - prefix for the custom allocators and made it possible with a new #define to - use custom ones in your project without needing to change lodepng's code. -*) 28 jan 2013: Bugfix with color key. -*) 27 okt 2012: Tweaks in text chunk keyword length error handling. -*) 8 okt 2012 (!): Added new filter strategy (entropy) and new auto color mode. - (no palette). Better deflate tree encoding. New compression tweak settings. - Faster color conversions while decoding. Some internal cleanups. -*) 23 sep 2012: Reduced warnings in Visual Studio a little bit. -*) 1 sep 2012 (!): Removed #define's for giving custom (de)compression functions - and made it work with function pointers instead. -*) 23 jun 2012: Added more filter strategies. Made it easier to use custom alloc - and free functions and toggle #defines from compiler flags. Small fixes. -*) 6 may 2012 (!): Made plugging in custom zlib/deflate functions more flexible. -*) 22 apr 2012 (!): Made interface more consistent, renaming a lot. Removed - redundant C++ codec classes. Reduced amount of structs. Everything changed, - but it is cleaner now imho and functionality remains the same. Also fixed - several bugs and shrinked the implementation code. Made new samples. -*) 6 nov 2011 (!): By default, the encoder now automatically chooses the best - PNG color model and bit depth, based on the amount and type of colors of the - raw image. For this, autoLeaveOutAlphaChannel replaced by auto_choose_color. -*) 9 okt 2011: simpler hash chain implementation for the encoder. -*) 8 sep 2011: lz77 encoder lazy matching instead of greedy matching. -*) 23 aug 2011: tweaked the zlib compression parameters after benchmarking. - A bug with the PNG filtertype heuristic was fixed, so that it chooses much - better ones (it's quite significant). A setting to do an experimental, slow, - brute force search for PNG filter types is added. -*) 17 aug 2011 (!): changed some C zlib related function names. -*) 16 aug 2011: made the code less wide (max 120 characters per line). -*) 17 apr 2011: code cleanup. Bugfixes. Convert low to 16-bit per sample colors. -*) 21 feb 2011: fixed compiling for C90. Fixed compiling with sections disabled. -*) 11 dec 2010: encoding is made faster, based on suggestion by Peter Eastman - to optimize long sequences of zeros. -*) 13 nov 2010: added LodePNG_InfoColor_hasPaletteAlpha and - LodePNG_InfoColor_canHaveAlpha functions for convenience. -*) 7 nov 2010: added LodePNG_error_text function to get error code description. -*) 30 okt 2010: made decoding slightly faster -*) 26 okt 2010: (!) changed some C function and struct names (more consistent). - Reorganized the documentation and the declaration order in the header. -*) 08 aug 2010: only changed some comments and external samples. -*) 05 jul 2010: fixed bug thanks to warnings in the new gcc version. -*) 14 mar 2010: fixed bug where too much memory was allocated for char buffers. -*) 02 sep 2008: fixed bug where it could create empty tree that linux apps could - read by ignoring the problem but windows apps couldn't. -*) 06 jun 2008: added more error checks for out of memory cases. -*) 26 apr 2008: added a few more checks here and there to ensure more safety. -*) 06 mar 2008: crash with encoding of strings fixed -*) 02 feb 2008: support for international text chunks added (iTXt) -*) 23 jan 2008: small cleanups, and #defines to divide code in sections -*) 20 jan 2008: support for unknown chunks allowing using LodePNG for an editor. -*) 18 jan 2008: support for tIME and pHYs chunks added to encoder and decoder. -*) 17 jan 2008: ability to encode and decode compressed zTXt chunks added - Also vareous fixes, such as in the deflate and the padding bits code. -*) 13 jan 2008: Added ability to encode Adam7-interlaced images. Improved - filtering code of encoder. -*) 07 jan 2008: (!) changed LodePNG to use ISO C90 instead of C++. A - C++ wrapper around this provides an interface almost identical to before. - Having LodePNG be pure ISO C90 makes it more portable. The C and C++ code - are together in these files but it works both for C and C++ compilers. -*) 29 dec 2007: (!) changed most integer types to unsigned int + other tweaks -*) 30 aug 2007: bug fixed which makes this Borland C++ compatible -*) 09 aug 2007: some VS2005 warnings removed again -*) 21 jul 2007: deflate code placed in new namespace separate from zlib code -*) 08 jun 2007: fixed bug with 2- and 4-bit color, and small interlaced images -*) 04 jun 2007: improved support for Visual Studio 2005: crash with accessing - invalid std::vector element [0] fixed, and level 3 and 4 warnings removed -*) 02 jun 2007: made the encoder add a tag with version by default -*) 27 may 2007: zlib and png code separated (but still in the same file), - simple encoder/decoder functions added for more simple usage cases -*) 19 may 2007: minor fixes, some code cleaning, new error added (error 69), - moved some examples from here to lodepng_examples.cpp -*) 12 may 2007: palette decoding bug fixed -*) 24 apr 2007: changed the license from BSD to the zlib license -*) 11 mar 2007: very simple addition: ability to encode bKGD chunks. -*) 04 mar 2007: (!) tEXt chunk related fixes, and support for encoding - palettized PNG images. Plus little interface change with palette and texts. -*) 03 mar 2007: Made it encode dynamic Huffman shorter with repeat codes. - Fixed a bug where the end code of a block had length 0 in the Huffman tree. -*) 26 feb 2007: Huffman compression with dynamic trees (BTYPE 2) now implemented - and supported by the encoder, resulting in smaller PNGs at the output. -*) 27 jan 2007: Made the Adler-32 test faster so that a timewaste is gone. -*) 24 jan 2007: gave encoder an error interface. Added color conversion from any - greyscale type to 8-bit greyscale with or without alpha. -*) 21 jan 2007: (!) Totally changed the interface. It allows more color types - to convert to and is more uniform. See the manual for how it works now. -*) 07 jan 2007: Some cleanup & fixes, and a few changes over the last days: - encode/decode custom tEXt chunks, separate classes for zlib & deflate, and - at last made the decoder give errors for incorrect Adler32 or Crc. -*) 01 jan 2007: Fixed bug with encoding PNGs with less than 8 bits per channel. -*) 29 dec 2006: Added support for encoding images without alpha channel, and - cleaned out code as well as making certain parts faster. -*) 28 dec 2006: Added "Settings" to the encoder. -*) 26 dec 2006: The encoder now does LZ77 encoding and produces much smaller files now. - Removed some code duplication in the decoder. Fixed little bug in an example. -*) 09 dec 2006: (!) Placed output parameters of public functions as first parameter. - Fixed a bug of the decoder with 16-bit per color. -*) 15 okt 2006: Changed documentation structure -*) 09 okt 2006: Encoder class added. It encodes a valid PNG image from the - given image buffer, however for now it's not compressed. -*) 08 sep 2006: (!) Changed to interface with a Decoder class -*) 30 jul 2006: (!) LodePNG_InfoPng , width and height are now retrieved in different - way. Renamed decodePNG to decodePNGGeneric. -*) 29 jul 2006: (!) Changed the interface: image info is now returned as a - struct of type LodePNG::LodePNG_Info, instead of a vector, which was a bit clumsy. -*) 28 jul 2006: Cleaned the code and added new error checks. - Corrected terminology "deflate" into "inflate". -*) 23 jun 2006: Added SDL example in the documentation in the header, this - example allows easy debugging by displaying the PNG and its transparency. -*) 22 jun 2006: (!) Changed way to obtain error value. Added - loadFile function for convenience. Made decodePNG32 faster. -*) 21 jun 2006: (!) Changed type of info vector to unsigned. - Changed position of palette in info vector. Fixed an important bug that - happened on PNGs with an uncompressed block. -*) 16 jun 2006: Internally changed unsigned into unsigned where - needed, and performed some optimizations. -*) 07 jun 2006: (!) Renamed functions to decodePNG and placed them - in LodePNG namespace. Changed the order of the parameters. Rewrote the - documentation in the header. Renamed files to lodepng.cpp and lodepng.h -*) 22 apr 2006: Optimized and improved some code -*) 07 sep 2005: (!) Changed to std::vector interface -*) 12 aug 2005: Initial release (C++, decoder only) - - -12. contact information ------------------------ - -Feel free to contact me with suggestions, problems, comments, ... concerning -LodePNG. If you encounter a PNG image that doesn't work properly with this -decoder, feel free to send it and I'll use it to find and fix the problem. - -My email address is (puzzle the account and domain together with an @ symbol): -Domain: gmail dot com. -Account: lode dot vandevenne. - - -Copyright (c) 2005-2013 Lode Vandevenne -*/ |