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diff --git a/src/lodepng.cpp b/src/lodepng.cpp new file mode 100644 index 0000000..9d21668 --- /dev/null +++ b/src/lodepng.cpp @@ -0,0 +1,5797 @@ +/* +LodePNG version 20110908 + +Copyright (c) 2005-2011 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 __cplusplus +#include <fstream> +#endif /*__cplusplus*/ + +#define VERSION_STRING "20110908" + +/* +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 +*/ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* // 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(9924); +*/ +#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) + +/* +About vector, 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 +#ifdef LODEPNG_COMPILE_ENCODER + +typedef struct vector /*dynamic vector of void* pointers. This one is used only by the deflate compressor*/ +{ + void* data; + size_t size; /*in groups of bytes depending on type*/ + size_t allocsize; /*in bytes*/ + unsigned typesize; /*sizeof the type you store in data*/ +} vector; + +static unsigned vector_resize(vector* p, size_t size) /*returns 1 if success, 0 if failure ==> nothing done*/ +{ + if(size * p->typesize > p->allocsize) + { + size_t newsize = size * p->typesize * 2; + void* data = realloc(p->data, newsize); + if(data) + { + p->allocsize = newsize; + p->data = data; + p->size = size; + } + else return 0; + } + else p->size = size; + return 1; +} + +/*resize and use destructor on elements if it gets smaller*/ +static unsigned vector_resized(vector* p, size_t size, void dtor(void*)) +{ + size_t i; + if(size < p->size) + { + for(i = size; i < p->size; i++) + { + dtor(&((char*)(p->data))[i * p->typesize]); + } + } + return vector_resize(p, size); +} + +static void vector_cleanup(void* p) +{ + ((vector*)p)->size = ((vector*)p)->allocsize = 0; + free(((vector*)p)->data); + ((vector*)p)->data = NULL; +} + +static void vector_cleanupd(vector* p, void dtor(void*)) /*clear and use destructor on elements*/ +{ + vector_resized(p, 0, dtor); + vector_cleanup(p); +} + +static void vector_init(vector* p, unsigned typesize) +{ + p->data = NULL; + p->size = p->allocsize = 0; + p->typesize = typesize; +} + +static void vector_swap(vector* p, vector* q) /*they're supposed to have the same typesize*/ +{ + size_t tmp; + void* tmpp; + tmp = p->size; p->size = q->size; q->size = tmp; + tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp; + tmpp = p->data; p->data = q->data; q->data = tmpp; +} + +static void* vector_get(vector* p, size_t index) +{ + return &((char*)p->data)[index * p->typesize]; +} + +#endif /*LODEPNG_COMPILE_ENCODER*/ +#endif /*LODEPNG_COMPILE_ZLIB*/ + +/* /////////////////////////////////////////////////////////////////////////// */ + +#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; + 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 = 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; +} + +static void uivector_swap(uivector* p, uivector* q) +{ + size_t tmp; + unsigned* tmpp; + tmp = p->size; p->size = q->size; q->size = tmp; + tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp; + tmpp = p->data; p->data = q->data; q->data = tmpp; +} +#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; + +static void ucvector_cleanup(void* p) +{ + ((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0; + free(((ucvector*)p)->data); + ((ucvector*)p)->data = NULL; +} + +/*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 = 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_DECODER +#ifdef LODEPNG_COMPILE_PNG +/*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_PNG*/ +#endif /*LODEPNG_COMPILE_DECODER*/ + +static void ucvector_init(ucvector* p) +{ + p->data = NULL; + p->size = p->allocsize = 0; +} + +#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*/ + +#ifdef 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 /*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*)realloc(*out, size + 1); + if(data) + { + data[size] = 0; /*null termination char*/ + *out = data; + } + return data != 0; +} + +/*init a {char*, size_t} pair for use as string*/ +static void string_init(char** out) +{ + *out = NULL; + string_resize(out, 0); +} + +/*free the above pair again*/ +static void string_cleanup(char** out) +{ + free(*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]; +} + +/*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); +} + +#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_loadFile(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*)malloc((size_t)size); + if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file); + + fclose(file); + if(!(*out) && size) return 9900; /*the above malloc failed*/ + return 0; +} + +/*write given buffer to the file, overwriting the file, it doesn't append to it.*/ +unsigned LodePNG_saveFile(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 + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Reading and writing single bits and bytes from/to stream for Deflate / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_ENCODER +/*TODO: this ignores potential out of memory errors*/ +static void addBitToStream(size_t* bitpointer, ucvector* bitstream, unsigned char bit) +{ + /*add a new byte at the end*/ + if((*bitpointer) % 8 == 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 +{ + uivector tree2d; + uivector tree1d; + uivector 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++*/ +/*#include <iostream> +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) +{ + uivector_init(&tree->tree2d); + uivector_init(&tree->tree1d); + uivector_init(&tree->lengths); +} + +static void HuffmanTree_cleanup(HuffmanTree* tree) +{ + uivector_cleanup(&tree->tree2d); + uivector_cleanup(&tree->tree1d); + uivector_cleanup(&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; + + if(!uivector_resize(&tree->tree2d, tree->numcodes * 2)) return 9901; /*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.data[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.data[n]; i++) /*the bits for this code*/ + { + unsigned char bit = (unsigned char)((tree->tree1d.data[n] >> (tree->lengths.data[n] - i - 1)) & 1); + if(treepos > tree->numcodes - 2) return 55; /*error 55: oversubscribed; see description in header*/ + if(tree->tree2d.data[2 * treepos + bit] == 32767) /*not yet filled in*/ + { + if(i + 1 == tree->lengths.data[n]) /*last bit*/ + { + tree->tree2d.data[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.data[2 * treepos + bit] = nodefilled + tree->numcodes; + treepos = nodefilled; + } + } + else treepos = tree->tree2d.data[2 * treepos + bit] - tree->numcodes; + } + } + + for(n = 0; n < tree->numcodes * 2; n++) + { + if(tree->tree2d.data[n] == 32767) tree->tree2d.data[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); + if(!uivector_resize(&tree->tree1d, tree->numcodes) + || !uivector_resizev(&blcount, tree->maxbitlen + 1, 0) + || !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0)) + error = 9902; /*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.data[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.data[n] != 0) tree->tree1d.data[n] = nextcode.data[tree->lengths.data[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; + if(!uivector_resize(&tree->lengths, numcodes)) return 9903; /*alloc fail*/ + for(i = 0; i < numcodes; i++) tree->lengths.data[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 addCoins(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; +} + +/* +Coin_sort: This uses a simple combsort to sort the data. This function is not critical for +overall encoding speed and the data amount isn't that large. +*/ +static void Coin_sort(Coin* data, size_t amount) +{ + size_t gap = amount; + unsigned char swapped = 0; + while((gap > 1) || swapped) + { + size_t i; + gap = (gap * 10) / 13; /*shrink factor 1.3*/ + if(gap == 9 || gap == 10) gap = 11; /*combsort11*/ + if(gap < 1) gap = 1; + swapped = 0; + for(i = 0; i < amount - gap; i++) + { + size_t j = i + gap; + if(data[j].weight < data[i].weight) + { + float temp = data[j].weight; data[j].weight = data[i].weight; data[i].weight = temp; + uivector_swap(&data[i].symbols, &data[j].symbols); + swapped = 1; + } + } + } +} + +static unsigned HuffmanTree_fillInCoins(vector* coins, const unsigned* frequencies, unsigned numcodes, size_t sum) +{ + unsigned i; + for(i = 0; i < numcodes; i++) + { + Coin* coin; + if(frequencies[i] == 0) continue; /*it's important to exclude symbols that aren't present*/ + if(!vector_resize(coins, coins->size + 1)) + { + vector_cleanup(coins); + return 9904; /*alloc fail*/ + } + coin = (Coin*)(vector_get(coins, coins->size - 1)); + Coin_init(coin); + coin->weight = frequencies[i] / (float)sum; + uivector_push_back(&coin->symbols, i); + } + if(coins->size) Coin_sort((Coin*)coins->data, coins->size); + return 0; +} + +/*Create the Huffman tree given the symbol frequencies*/ +static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies, + size_t numcodes, unsigned maxbitlen) +{ + unsigned i, j; + size_t sum = 0, numpresent = 0; + unsigned error = 0; + + vector prev_row; /*type Coin, the previous row of coins*/ + vector coins; /*type Coin, the coins of the currently calculated row*/ + + tree->maxbitlen = maxbitlen; + + for(i = 0; i < numcodes; i++) + { + if(frequencies[i] > 0) + { + numpresent++; + sum += frequencies[i]; + } + } + + if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/ + tree->numcodes = (unsigned)numcodes; /*number of symbols*/ + uivector_resize(&tree->lengths, 0); + if(!uivector_resizev(&tree->lengths, tree->numcodes, 0)) return 9905; /*alloc fail*/ + + /*there are no symbols at all, in that case add one symbol of value 0 to the tree (see RFC 1951 section 3.2.7) */ + if(numpresent == 0) + { + tree->lengths.data[0] = 1; + return HuffmanTree_makeFromLengths2(tree); + } + /*the package merge algorithm gives wrong results if there's only one symbol + (theoretically 0 bits would then suffice, but we need a proper symbol for zlib)*/ + else if(numpresent == 1) + { + for(i = 0; i < numcodes; i++) if(frequencies[i]) tree->lengths.data[i] = 1; + return HuffmanTree_makeFromLengths2(tree); + } + + vector_init(&coins, sizeof(Coin)); + vector_init(&prev_row, sizeof(Coin)); + + /*Package-Merge algorithm represented by coin collector's problem + For every symbol, maxbitlen coins will be created*/ + + /*first row, lowest denominator*/ + error = HuffmanTree_fillInCoins(&coins, frequencies, tree->numcodes, sum); + if(!error) + { + for(j = 1; j <= maxbitlen && !error; j++) /*each of the remaining rows*/ + { + vector_swap(&coins, &prev_row); /*swap instead of copying*/ + if(!vector_resized(&coins, 0, Coin_cleanup)) ERROR_BREAK(9906 /*alloc fail*/); + for(i = 0; i + 1 < prev_row.size; i += 2) + { + if(!vector_resize(&coins, coins.size + 1)) ERROR_BREAK(9907 /*alloc fail*/); + Coin_init((Coin*)vector_get(&coins, coins.size - 1)); + Coin_copy((Coin*)vector_get(&coins, coins.size - 1), (Coin*)vector_get(&prev_row, i)); + /*merge the coins into packages*/ + addCoins((Coin*)vector_get(&coins, coins.size - 1), (Coin*)vector_get(&prev_row, i + 1)); + } + if(j < maxbitlen) + { + error = HuffmanTree_fillInCoins(&coins, frequencies, tree->numcodes, sum); + } + } + } + + if(!error) + { + /*keep the coins with lowest weight, so that they add up to the amount of symbols - 1*/ + vector_resized(&coins, numpresent - 1, Coin_cleanup); + + /*calculate the lenghts of each symbol, as the amount of times a coin of each symbol is used*/ + for(i = 0; i < coins.size; i++) + { + Coin* coin = (Coin*)vector_get(&coins, i); + for(j = 0; j < coin->symbols.size; j++) tree->lengths.data[coin->symbols.data[j]]++; + } + + error = HuffmanTree_makeFromLengths2(tree); + } + + vector_cleanupd(&coins, Coin_cleanup); + vector_cleanupd(&prev_row, Coin_cleanup); + + return error; +} + +static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index) +{ + return tree->tree1d.data[index]; +} + +static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index) +{ + return tree->lengths.data[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; + uivector bitlen; + uivector_init(&bitlen); + if(!uivector_resize(&bitlen, NUM_DEFLATE_CODE_SYMBOLS)) error = 9909; /*alloc fail*/ + + if(!error) + { + /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/ + for(i = 0; i <= 143; i++) bitlen.data[i] = 8; + for(i = 144; i <= 255; i++) bitlen.data[i] = 9; + for(i = 256; i <= 279; i++) bitlen.data[i] = 7; + for(i = 280; i <= 287; i++) bitlen.data[i] = 8; + + error = HuffmanTree_makeFromLengths(tree, bitlen.data, NUM_DEFLATE_CODE_SYMBOLS, 15); + } + + uivector_cleanup(&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; + uivector bitlen; + uivector_init(&bitlen); + if(!uivector_resize(&bitlen, NUM_DISTANCE_SYMBOLS)) error = 9910; /*alloc fail*/ + + /*there are 32 distance codes, but 30-31 are unused*/ + if(!error) + { + for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen.data[i] = 5; + error = HuffmanTree_makeFromLengths(tree, bitlen.data, NUM_DISTANCE_SYMBOLS, 15); + } + uivector_cleanup(&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.data[(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) +{ + /*error checking not done, this is fixed stuff, it works, it doesn't depend on the image*/ + /*TODO: out of memory errors could still happen...*/ + 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*/ + uivector bitlen_ll; /*lit,len code lengths*/ + uivector bitlen_d; /*dist code lengths*/ + /*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/ + uivector bitlen_cl; + HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/ + + if((*bp) >> 3 >= inlength - 2) return 49; /*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); + uivector_init(&bitlen_ll); + uivector_init(&bitlen_d); + uivector_init(&bitlen_cl); + + while(!error) + { + /*read the code length codes out of 3 * (amount of code length codes) bits*/ + + if(!uivector_resize(&bitlen_cl, NUM_CODE_LENGTH_CODES)) ERROR_BREAK(9911); + + for(i = 0; i < NUM_CODE_LENGTH_CODES; i++) + { + if(i < HCLEN) bitlen_cl.data[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3); + else bitlen_cl.data[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/ + } + + error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl.data, bitlen_cl.size, 7); + if(error) break; + + /*now we can use this tree to read the lengths for the tree that this function will return*/ + uivector_resizev(&bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 0); + uivector_resizev(&bitlen_d, NUM_DISTANCE_SYMBOLS, 0); + i = 0; + if(!bitlen_ll.data || !bitlen_d.data) ERROR_BREAK(9912); /*alloc fail*/ + + /*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/ + while(i < HLIT + HDIST) + { + unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength); + if(code <= 15) /*a length code*/ + { + if(i < HLIT) bitlen_ll.data[i] = code; + else bitlen_d.data[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) >> 3 >= inlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ + + replength += readBitsFromStream(bp, in, 2); + + if((i - 1) < HLIT) value = bitlen_ll.data[i - 1]; + else value = bitlen_d.data[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.data[i] = value; + else bitlen_d.data[i - HLIT] = value; + i++; + } + } + else if(code == 17) /*repeat "0" 3-10 times*/ + { + unsigned replength = 3; /*read in the bits that indicate repeat length*/ + if((*bp) >> 3 >= inlength) 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.data[i] = 0; + else bitlen_d.data[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) >> 3 >= inlength) 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.data[i] = 0; + else bitlen_d.data[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) > inlength * 8 ? 10 : 11; + } + else error = 16; /*unexisting code, this can never happen*/ + break; + } + } + if(error) break; + + if(bitlen_ll.data[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.data[0], bitlen_ll.size, 15); + if(error) break; + error = HuffmanTree_makeFromLengths(tree_d, &bitlen_d.data[0], bitlen_d.size, 15); + + break; /*end of error-while*/ + } + + uivector_cleanup(&bitlen_cl); + uivector_cleanup(&bitlen_ll); + uivector_cleanup(&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); + } + + for(;;) /*decode all symbols until end reached*/ + { + /*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(9913 /*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) >> 3) >= inlength) 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) >> 3) >= inlength) 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); + backward = start - distance; + if((*pos) + length >= out->size) + { + /*reserve more room at once*/ + if(!ucvector_resize(out, ((*pos) + length) * 2)) ERROR_BREAK(9914 /*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 9915; /*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; +} + +/*inflate the deflated data (cfr. deflate spec); return value is the error*/ +static unsigned LodePNG_inflate(ucvector* out, const unsigned char* in, size_t insize, size_t inpos) +{ + /*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; + + while(!BFINAL) + { + unsigned BTYPE; + if(bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/ + BFINAL = readBitFromStream(&bp, &in[inpos]); + BTYPE = 1 * readBitFromStream(&bp, &in[inpos]); + BTYPE += 2 * readBitFromStream(&bp, &in[inpos]); + + if(BTYPE == 3) return 20; /*error: invalid BTYPE*/ + else if(BTYPE == 0) error = inflateNoCompression(out, &in[inpos], &bp, &pos, insize); /*no compression*/ + else error = inflateHuffmanBlock(out, &in[inpos], &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 = 9916; /*alloc fail*/ + + return error; +} + +#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); +} + +#if 0 +/*the "brute force" version of the encodeLZ7 algorithm, not used anymore, kept here for reference*/ +static unsigned encodeLZ77_brute(uivector* out, const unsigned char* in, size_t insize, unsigned windowSize) +{ + size_t pos; + for(pos = 0; pos < insize; pos++) + { + size_t length = 0, offset = 0; /*the length and offset found for the current position*/ + size_t max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/ + size_t current_offset; + + /**search for the longest string, backwards through all possible distances (=offsets)**/ + for(current_offset = 1; current_offset < max_offset; current_offset++) + { + size_t backpos = pos - current_offset; + if(in[backpos] == in[pos]) + { + /*test the next characters*/ + size_t current_length = 1; + size_t backtest = backpos + 1; + size_t foretest = pos + 1; + /*maximum supporte length by deflate is max length*/ + while(foretest < insize && in[backtest] == in[foretest] && current_length < MAX_SUPPORTED_DEFLATE_LENGTH) + { + if(backpos >= pos) + { + /*continue as if we work on the decoded bytes after pos by jumping back before pos*/ + backpos -= current_offset; + } + current_length++; + backtest++; + foretest++; + } + if(current_length > length) + { + length = current_length; /*the longest length*/ + offset = current_offset; /*the offset that is related to this longest length*/ + /*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/ + if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break; + } + } + } + + /**encode it as length/distance pair or literal value**/ + if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/ + { + uivector_push_back(out, in[pos]); + } + else + { + addLengthDistance(out, length, offset); + pos += (length - 1); + } + } /*end of the loop through each character of input*/ + return 0; +} +#endif + +static const unsigned HASH_NUM_VALUES = 2048; +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. +*/ + +static unsigned getHash(const unsigned char* data, size_t size, size_t pos, size_t num) +{ + unsigned result = 0; + size_t amount, i; + if(pos >= size) return 0; + amount = num; + if(pos + amount >= size) amount = size - pos; + for(i = 0; i < amount; i++) result ^= (data[pos + i] << (i * HASH_SHIFT)); + return result % HASH_NUM_VALUES; +} + +static unsigned countInitialZeros(const unsigned char* data, size_t size, size_t pos) +{ + size_t max_count = MAX_SUPPORTED_DEFLATE_LENGTH; + size_t i; + if(max_count > size - pos) max_count = size - pos; + for(i = 0; i < max_count; i++) + { + if(data[pos + i] != 0) + return i; + } + return max_count; +} + +/*push a value to the vector in a circular way. This is to do as if we're extending +the vector's size forever, but instead the size is limited to maxsize and it wraps +around, to avoid too large memory size. The pos pointer gets updated to the current +end (unless updatepos is false, in that case pos is only used to know the current +value). returns 1 on success, 0 if fail*/ +static unsigned push_circular(uivector* v, unsigned* pos, unsigned value, size_t maxsize, unsigned updatepos) +{ + if(v->size < maxsize) + { + if(!uivector_push_back(v, value)) return 0; + if(updatepos) (*pos)++; + } + else + { + if(updatepos) + { + (*pos)++; + if((*pos) > maxsize) (*pos) = 1; + } + v->data[(*pos) - 1] = value; + } + return 1; +} + +/*Enable to use lazy instead of greedy matghing. It looks one byte further +to see if that one gives a longer distance. This gives slightly better compression, at the cost +of a speed loss.*/ +#define LAZY_MATCHING + +/* +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, const unsigned char* in, size_t insize, unsigned windowSize) +{ + /**generate hash table**/ + /* + The hash table is 2-dimensional. For every possible hash value, it contains a list of positions + in the data where this hash occured. + tablepos1 and tablepos2 remember the last used start and end index in the hash table for each hash value. + */ + vector table; /*HASH_NUM_VALUES uivectors; this is what would be an std::vector<std::vector<unsigned> > in C++*/ + uivector tablepos1, tablepos2; + /*hash 0 indicates a possible common case of a long sequence of zeros, store and use the amount here for a speedup*/ + uivector initialZerosTable; + unsigned pos, i, error = 0; + unsigned hash_num_characters = HASH_NUM_CHARACTERS; + + vector_init(&table, sizeof(uivector)); + if(!vector_resize(&table, HASH_NUM_VALUES)) return 9917; /*alloc fail*/ + for(i = 0; i < HASH_NUM_VALUES; i++) + { + uivector* v = (uivector*)vector_get(&table, i); + uivector_init(v); + } + + /*remember start and end positions in the tables to search in*/ + uivector_init(&tablepos1); + uivector_init(&tablepos2); + uivector_init(&initialZerosTable); + + if(!uivector_resizev(&tablepos1, HASH_NUM_VALUES, 0)) error = 9918; /*alloc fail*/ + if(!uivector_resizev(&tablepos2, HASH_NUM_VALUES, 0)) error = 9919; /*alloc fail*/ + + if(!error) + { + unsigned offset, max_offset; /*the offset represents the distance in LZ77 terminology*/ + unsigned length, tablepos; +#ifdef LAZY_MATCHING + unsigned lazy = 0; + unsigned lazylength = 0, lazyoffset = 0; +#endif /*LAZY_MATCHING*/ + unsigned hash, initialZeros = 0; + unsigned backpos, current_offset, t1, t2, t11, current_length; + const unsigned char *lastptr, *foreptr, *backptr; + uivector* v; /*vector from the hash table we're currently working on*/ + unsigned hashWindow = windowSize; + unsigned numones = 0; + + for(pos = 0; pos < insize; pos++) + { + length = 0, offset = 0; /*the length and offset found for the current position*/ + max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/ + + /*search for the longest string. First find out where in the table to start + (the first value that is in the range from "pos - max_offset" to "pos")*/ + hash = getHash(in, insize, pos, hash_num_characters); + v = (uivector*)vector_get(&table, hash); + if(!push_circular(v, &tablepos2.data[hash], pos, hashWindow, 1)) ERROR_BREAK(9920 /*alloc fail*/); + + if(hash == 0) + { + initialZeros = countInitialZeros(in, insize, pos); + if(!push_circular(&initialZerosTable, &tablepos2.data[hash], initialZeros, hashWindow, 0)) + ERROR_BREAK(9920 /*alloc fail*/); + } + + while(v->data[tablepos1.data[hash]] < pos - max_offset) + { + /*it now points to the first value in the table for which the index is + larger than or equal to pos - max_offset*/ + tablepos1.data[hash]++; + if(tablepos1.data[hash] >= hashWindow) tablepos1.data[hash] = 0; + } + + t1 = tablepos1.data[hash]; + t2 = tablepos2.data[hash] - 1; + if(tablepos2.data[hash] == 0) t2 = hashWindow - 1; + + lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH]; + + t11 = t1 == 0 ? hashWindow - 1 : t1 - 1; + for(tablepos = t2 == 0 ? hashWindow - 1 : t2 - 1; + tablepos != t2 && tablepos != t11 && tablepos < v->size; + tablepos = tablepos == 0 ? hashWindow - 1 : tablepos - 1) + { + backpos = v->data[tablepos]; + current_offset = pos - backpos; + /*test the next characters*/ + foreptr = &in[pos]; + backptr = &in[backpos]; + + if(hash == 0) + { + unsigned skip = initialZerosTable.data[tablepos]; + if(skip > initialZeros) skip = initialZeros; + if(skip > insize - pos) skip = insize - pos; + 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*/ + /*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/ + if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break; + } + } + +#ifdef LAZY_MATCHING + if(!lazy && length >= 3 && length < MAX_SUPPORTED_DEFLATE_LENGTH) + { + lazylength = length; + lazyoffset = offset; + lazy = 1; + continue; + } + if(lazy) + { + if(pos == 0) ERROR_BREAK(81); + lazy = 0; + if(length > lazylength + 1) + { + /*push the previous character as literal*/ + if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(9921 /*alloc fail*/); + } + else + { + length = lazylength; + offset = lazyoffset; + pos--; + } + } +#endif /*LAZY_MATCHING*/ + + /**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(9921 /*alloc fail*/); + } + else + { + unsigned j, local_hash; + addLengthDistance(out, length, offset); + for(j = 0; j < length - 1; j++) + { + unsigned* t2p; /*pointer to current tablepos2 element*/ + pos++; + local_hash = getHash(in, insize, pos, hash_num_characters); + t2p = &tablepos2.data[local_hash]; + v = (uivector*)vector_get(&table, local_hash); + if(!push_circular(v, t2p, pos, hashWindow, 1)) ERROR_BREAK(9920 /*alloc fail*/); + + if(local_hash == 0) + { + initialZeros = countInitialZeros(in, insize, pos); + if(!push_circular(&initialZerosTable, t2p, initialZeros, hashWindow, 0)) + ERROR_BREAK(9922 /*alloc fail*/); + } + if(local_hash == 1 && hash_num_characters == 3) + { + /* + If many hash values are getting grouped together in hash value 1, 4, 16, 20, ..., + it indicates there are many near-zero values. This is not zero enough to benefit from a speed + increase from the initialZerosTable, and makes it very slow. For that case only, switch to + hash_num_characters = 6. Value 6 is experimentally found to be fastest. For this particular type + of file, the compression isn't even worse, despite the fact that lengths < 6 are now no longer + found, and that by changing hash_num_characters not all previously found hash values are still valid. + Almost all images compress fast enough and smaller with hash_num_characters = 3, except sine plasma + images. Those benefit a lot from this heuristic. + */ + if(numones > 8192 && numones > pos / 16) hash_num_characters = 6; + else numones++; + } + } + } + } /*end of the loop through each character of input*/ + } /*end of "if(!error)"*/ + + /*cleanup*/ + for(i = 0; i < table.size; i++) + { + uivector* v = (uivector*)vector_get(&table, i); + uivector_cleanup(v); + } + vector_cleanup(&table); + uivector_cleanup(&tablepos1); + uivector_cleanup(&tablepos2); + uivector_cleanup(&initialZerosTable); + 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 / 65536 + 1; + 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, const unsigned char* data, size_t datasize, + const LodePNG_CompressSettings* settings) +{ + 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; + + /* + 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 = 1; /*make only one block... the first and final one*/ + size_t numcodes_ll, numcodes_d, i; + size_t bp = 0; /*the bit pointer*/ + 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 is 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->useLZ77) + { + error = encodeLZ77(&lz77_encoded, data, datasize, settings->windowSize); /*LZ77 encoded*/ + if(error) break; + } + else + { + if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(9923 /*alloc fail*/); + for(i = 0; i < datasize; i++) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/ + } + + if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(9924 /*alloc fail*/); + if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(9925 /*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, frequencies_ll.size, 15); + if(error) break; + error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, 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(9926 /*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, 7); + if(error) break; + + if(!uivector_resize(&bitlen_cl, NUM_CODE_LENGTH_CODES)) ERROR_BREAK(9927 /*alloc fail*/); + for(i = 0; i < NUM_CODE_LENGTH_CODES; 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(9928 /*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; + 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, const unsigned char* data, + size_t datasize, const LodePNG_CompressSettings* settings) +{ + HuffmanTree tree_ll; /*tree for literal values and length codes*/ + HuffmanTree tree_d; /*tree for distance codes*/ + + unsigned BFINAL = 1; /*make only one block... the first and final one*/ + unsigned error = 0; + size_t i, bp = 0; /*the bit pointer*/ + + 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->useLZ77) /*LZ77 encoded*/ + { + uivector lz77_encoded; + uivector_init(&lz77_encoded); + error = encodeLZ77(&lz77_encoded, data, datasize, settings->windowSize); + 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 = 0; i < datasize; 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_deflate(ucvector* out, const unsigned char* data, size_t datasize, + const LodePNG_CompressSettings* settings) +{ + unsigned error = 0; + if(settings->btype == 0) error = deflateNoCompression(out, data, datasize); + else if(settings->btype == 1) error = deflateFixed(out, data, datasize, settings); + else if(settings->btype == 2) error = deflateDynamic(out, data, datasize, settings); + else error = 61; + return error; +} + +#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 = (s1 + *data++); + s2 = (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 LodePNG_DecompressSettings* settings) +{ + unsigned error = 0; + unsigned CM, CINFO, FDICT; + ucvector outv; + + 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; + } + + /*ucvector-controlled version of the output buffer, for dynamic array*/ + ucvector_init_buffer(&outv, *out, *outsize); + error = LodePNG_inflate(&outv, in, insize, 2); + *out = outv.data; + *outsize = outv.size; + if(error) return error; + + if(!settings->ignoreAdler32) + { + unsigned ADLER32 = LodePNG_read32bitInt(&in[insize - 4]); + unsigned checksum = adler32(outv.data, (unsigned)outv.size); + if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/ + } + + return 0; /*no error*/ +} + +#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 LodePNG_CompressSettings* 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 deflatedata, outv; + size_t i; + unsigned error; + + 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)); + + ucvector_init(&deflatedata); + error = LodePNG_deflate(&deflatedata, in, insize, settings); + + if(!error) + { + ADLER32 = adler32(in, (unsigned)insize); + for(i = 0; i < deflatedata.size; i++) ucvector_push_back(&outv, deflatedata.data[i]); + ucvector_cleanup(&deflatedata); + LodePNG_add32bitInt(&outv, ADLER32); + } + + *out = outv.data; + *outsize = outv.size; + + return error; +} + +#endif /*LODEPNG_COMPILE_ENCODER*/ + +#else /*no LODEPNG_COMPILE_ZLIB*/ + +/* +Dummy functions used if LODEPNG_COMPILE_ZLIB isn't defined. You need to implement +these yourself when disabling the LodePNG Zlib part, e.g. by calling another +library from here. + +*out must be NULL and *outsize must be 0 initially, and after the function is done, +*out must point to the decompressed data, *outsize must be the size of it, and must +be the size of the useful data in bytes, not the alloc size. +*/ + +#ifdef LODEPNG_COMPILE_DECODER +static unsigned LodePNG_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNG_DecompressSettings* settings) +{ + return 0; //Placeholder to be implemented if LODEPNG_COMPILE_ZLIB is disabled. +} +#endif /*LODEPNG_COMPILE_DECODER*/ +#ifdef LODEPNG_COMPILE_ENCODER +static unsigned LodePNG_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNG_CompressSettings* settings) +{ + return 0; //Placeholder to be implemented if LODEPNG_COMPILE_ZLIB is disabled. +} +#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_CompressSettings_init(LodePNG_CompressSettings* settings) +{ + /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/ + settings->btype = 2; + settings->useLZ77 = 1; + settings->windowSize = DEFAULT_WINDOWSIZE; +} + +const LodePNG_CompressSettings LodePNG_defaultCompressSettings = {2, 1, DEFAULT_WINDOWSIZE}; + +#endif /*LODEPNG_COMPILE_ENCODER*/ + +#ifdef LODEPNG_COMPILE_DECODER + +void LodePNG_DecompressSettings_init(LodePNG_DecompressSettings* settings) +{ + settings->ignoreAdler32 = 0; +} + +const LodePNG_DecompressSettings LodePNG_defaultDecompressSettings = {0}; + +#endif /*LODEPNG_COMPILE_DECODER*/ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* // End of Zlib related code. Begin of PNG related code. // */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_PNG + +/* ////////////////////////////////////////////////////////////////////////// */ +/* / CRC32 / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +static unsigned Crc32_crc_table_computed = 0; +static unsigned Crc32_crc_table[256]; + +/*Make the table for a fast CRC.*/ +static void Crc32_make_crc_table(void) +{ + unsigned c, k, n; + for(n = 0; n < 256; n++) + { + c = n; + for(k = 0; k < 8; k++) + { + if(c & 1) c = 0xedb88320L ^ (c >> 1); + else c = c >> 1; + } + Crc32_crc_table[n] = c; + } + Crc32_crc_table_computed = 1; +} + +/*Update a running CRC with the bytes buf[0..len-1]--the CRC should be +initialized to all 1's, and the transmitted value is the 1's complement of the +final running CRC (see the crc() routine below).*/ +static unsigned Crc32_update_crc(const unsigned char* buf, unsigned crc, size_t len) +{ + unsigned c = crc; + size_t n; + + if(!Crc32_crc_table_computed) Crc32_make_crc_table(); + for(n = 0; n < len; n++) + { + c = Crc32_crc_table[(c ^ buf[n]) & 0xff] ^ (c >> 8); + } + return c; +} + +/*Return the CRC of the bytes buf[0..len-1].*/ +static unsigned Crc32_crc(const unsigned char* buf, size_t len) +{ + return Crc32_update_crc(buf, 0xffffffffL, len) ^ 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_critical(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 = Crc32_crc(&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 = Crc32_crc(&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_append_chunk(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*)realloc(*out, new_length); + if(!new_buffer) return 9929; /*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_create_chunk(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*)realloc(*out, new_length); + if(!new_buffer) return 9930; /*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(unsigned 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(unsigned 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 getBpp(unsigned colorType, unsigned bitDepth) +{ + /*bits per pixel is amount of channels * bits per channel*/ + return getNumColorChannels(colorType) * bitDepth; +} + +/* ////////////////////////////////////////////////////////////////////////// */ + +void LodePNG_InfoColor_init(LodePNG_InfoColor* info) +{ + info->key_defined = 0; + info->key_r = info->key_g = info->key_b = 0; + info->colorType = 6; + info->bitDepth = 8; + info->palette = 0; + info->palettesize = 0; +} + +void LodePNG_InfoColor_cleanup(LodePNG_InfoColor* info) +{ + LodePNG_InfoColor_clearPalette(info); +} + +void LodePNG_InfoColor_clearPalette(LodePNG_InfoColor* info) +{ + if(info->palette) free(info->palette); + info->palettesize = 0; +} + +unsigned LodePNG_InfoColor_addPalette(LodePNG_InfoColor* 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->palettesize & (info->palettesize - 1))) /*if palettesize is 0 or a power of two*/ + { + /*allocated data must be at least 4* palettesize (for 4 color bytes)*/ + size_t alloc_size = info->palettesize == 0 ? 4 : info->palettesize * 4 * 2; + data = (unsigned char*)realloc(info->palette, alloc_size); + if(!data) return 9931; /*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_InfoColor_getBpp(const LodePNG_InfoColor* info) +{ + /*calculate bits per pixel out of colorType and bitDepth*/ + return getBpp(info->colorType, info->bitDepth); +} + +unsigned LodePNG_InfoColor_getChannels(const LodePNG_InfoColor* info) +{ + return getNumColorChannels(info->colorType); +} + +unsigned LodePNG_InfoColor_isGreyscaleType(const LodePNG_InfoColor* info) +{ + return info->colorType == 0 || info->colorType == 4; +} + +unsigned LodePNG_InfoColor_isAlphaType(const LodePNG_InfoColor* info) +{ + return (info->colorType & 4) != 0; +} + +unsigned LodePNG_InfoColor_isPaletteType(const LodePNG_InfoColor* info) +{ + return info->colorType == 3; +} + +unsigned LodePNG_InfoColor_hasPaletteAlpha(const LodePNG_InfoColor* info) +{ + size_t i; + for(i = 0; i < info->palettesize; i++) + { + if(info->palette[i * 4 + 3] < 255) return 1; + } + return 0; +} + +unsigned LodePNG_InfoColor_canHaveAlpha(const LodePNG_InfoColor* info) +{ + return info->key_defined + || LodePNG_InfoColor_isAlphaType(info) + || LodePNG_InfoColor_hasPaletteAlpha(info); +} + +unsigned LodePNG_InfoColor_equal(const LodePNG_InfoColor* info1, const LodePNG_InfoColor* info2) +{ + return info1->colorType == info2->colorType + && info1->bitDepth == info2->bitDepth; /*palette and color key not compared*/ +} + +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS +void LodePNG_UnknownChunks_init(LodePNG_UnknownChunks* chunks) +{ + unsigned i; + for(i = 0; i < 3; i++) chunks->data[i] = 0; + for(i = 0; i < 3; i++) chunks->datasize[i] = 0; +} + +void LodePNG_UnknownChunks_cleanup(LodePNG_UnknownChunks* chunks) +{ + unsigned i; + for(i = 0; i < 3; i++) free(chunks->data[i]); +} + +unsigned LodePNG_UnknownChunks_copy(LodePNG_UnknownChunks* dest, const LodePNG_UnknownChunks* src) +{ + unsigned i; + + LodePNG_UnknownChunks_cleanup(dest); + + for(i = 0; i < 3; i++) + { + size_t j; + dest->datasize[i] = src->datasize[i]; + dest->data[i] = (unsigned char*)malloc(src->datasize[i]); + if(!dest->data[i] && dest->datasize[i]) return 9932; /*alloc fail*/ + for(j = 0; j < src->datasize[i]; j++) dest->data[i][j] = src->data[i][j]; + } + + return 0; +} +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS +void LodePNG_Text_init(LodePNG_Text* text) +{ + text->num = 0; + text->keys = NULL; + text->strings = NULL; +} + +void LodePNG_Text_cleanup(LodePNG_Text* text) +{ + LodePNG_Text_clear(text); +} + +unsigned LodePNG_Text_copy(LodePNG_Text* dest, const LodePNG_Text* source) +{ + size_t i = 0; + dest->keys = 0; + dest->strings = 0; + dest->num = 0; + for(i = 0; i < source->num; i++) + { + unsigned error = LodePNG_Text_add(dest, source->keys[i], source->strings[i]); + if(error) return error; + } + return 0; +} + +void LodePNG_Text_clear(LodePNG_Text* text) +{ + size_t i; + for(i = 0; i < text->num; i++) + { + string_cleanup(&text->keys[i]); + string_cleanup(&text->strings[i]); + } + free(text->keys); + free(text->strings); +} + +unsigned LodePNG_Text_add(LodePNG_Text* text, const char* key, const char* str) +{ + char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1))); + char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1))); + if(!new_keys || !new_strings) + { + free(new_keys); + free(new_strings); + return 9933; /*alloc fail*/ + } + + text->num++; + text->keys = new_keys; + text->strings = new_strings; + + string_init(&text->keys[text->num - 1]); + string_set(&text->keys[text->num - 1], key); + + string_init(&text->strings[text->num - 1]); + string_set(&text->strings[text->num - 1], str); + + return 0; +} + +/******************************************************************************/ + +void LodePNG_IText_init(LodePNG_IText* text) +{ + text->num = 0; + text->keys = NULL; + text->langtags = NULL; + text->transkeys = NULL; + text->strings = NULL; +} + +void LodePNG_IText_cleanup(LodePNG_IText* text) +{ + LodePNG_IText_clear(text); +} + +unsigned LodePNG_IText_copy(LodePNG_IText* dest, const LodePNG_IText* source) +{ + size_t i = 0; + dest->keys = 0; + dest->langtags = 0; + dest->transkeys = 0; + dest->strings = 0; + dest->num = 0; + for(i = 0; i < source->num; i++) + { + unsigned error = LodePNG_IText_add(dest, source->keys[i], source->langtags[i], + source->transkeys[i], source->strings[i]); + if(error) return error; + } + return 0; +} + +void LodePNG_IText_clear(LodePNG_IText* text) +{ + size_t i; + for(i = 0; i < text->num; i++) + { + string_cleanup(&text->keys[i]); + string_cleanup(&text->langtags[i]); + string_cleanup(&text->transkeys[i]); + string_cleanup(&text->strings[i]); + } + free(text->keys); + free(text->langtags); + free(text->transkeys); + free(text->strings); +} + +unsigned LodePNG_IText_add(LodePNG_IText* text, const char* key, const char* langtag, + const char* transkey, const char* str) +{ + char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1))); + char** new_langtags = (char**)(realloc(text->langtags, sizeof(char*) * (text->num + 1))); + char** new_transkeys = (char**)(realloc(text->transkeys, sizeof(char*) * (text->num + 1))); + char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1))); + if(!new_keys || !new_langtags || !new_transkeys || !new_strings) + { + free(new_keys); + free(new_langtags); + free(new_transkeys); + free(new_strings); + return 9934; /*alloc fail*/ + } + + text->num++; + text->keys = new_keys; + text->langtags = new_langtags; + text->transkeys = new_transkeys; + text->strings = new_strings; + + string_init(&text->keys[text->num - 1]); + string_set(&text->keys[text->num - 1], key); + + string_init(&text->langtags[text->num - 1]); + string_set(&text->langtags[text->num - 1], langtag); + + string_init(&text->transkeys[text->num - 1]); + string_set(&text->transkeys[text->num - 1], transkey); + + string_init(&text->strings[text->num - 1]); + string_set(&text->strings[text->num - 1], str); + + return 0; +} +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +void LodePNG_InfoPng_init(LodePNG_InfoPng* info) +{ + info->width = info->height = 0; + LodePNG_InfoColor_init(&info->color); + info->interlaceMethod = 0; + info->compressionMethod = 0; + info->filterMethod = 0; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + info->background_defined = 0; + info->background_r = info->background_g = info->background_b = 0; + + LodePNG_Text_init(&info->text); + LodePNG_IText_init(&info->itext); + + info->time_defined = 0; + info->phys_defined = 0; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS + LodePNG_UnknownChunks_init(&info->unknown_chunks); +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ +} + +void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info) +{ + LodePNG_InfoColor_cleanup(&info->color); +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + LodePNG_Text_cleanup(&info->text); + LodePNG_IText_cleanup(&info->itext); +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS + LodePNG_UnknownChunks_cleanup(&info->unknown_chunks); +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ +} + +unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source) +{ + unsigned error = 0; + LodePNG_InfoPng_cleanup(dest); + *dest = *source; + LodePNG_InfoColor_init(&dest->color); + error = LodePNG_InfoColor_copy(&dest->color, &source->color); if(error) return error; + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + error = LodePNG_Text_copy(&dest->text, &source->text); if(error) return error; + error = LodePNG_IText_copy(&dest->itext, &source->itext); if(error) return error; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS + LodePNG_UnknownChunks_init(&dest->unknown_chunks); + error = LodePNG_UnknownChunks_copy(&dest->unknown_chunks, &source->unknown_chunks); if(error) return error; +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ + return error; +} + +void LodePNG_InfoPng_swap(LodePNG_InfoPng* a, LodePNG_InfoPng* b) +{ + LodePNG_InfoPng temp = *a; + *a = *b; + *b = temp; +} + +unsigned LodePNG_InfoColor_copy(LodePNG_InfoColor* dest, const LodePNG_InfoColor* source) +{ + size_t i; + LodePNG_InfoColor_cleanup(dest); + *dest = *source; + dest->palette = (unsigned char*)malloc(source->palettesize * 4); + if(!dest->palette && source->palettesize) return 9935; /*alloc fail*/ + for(i = 0; i < source->palettesize * 4; i++) dest->palette[i] = source->palette[i]; + return 0; +} + +void LodePNG_InfoRaw_init(LodePNG_InfoRaw* info) +{ + LodePNG_InfoColor_init(&info->color); +} + +void LodePNG_InfoRaw_cleanup(LodePNG_InfoRaw* info) +{ + LodePNG_InfoColor_cleanup(&info->color); +} + +unsigned LodePNG_InfoRaw_copy(LodePNG_InfoRaw* dest, const LodePNG_InfoRaw* source) +{ + unsigned error = 0; + LodePNG_InfoRaw_cleanup(dest); + *dest = *source; + LodePNG_InfoColor_init(&dest->color); + error = LodePNG_InfoColor_copy(&dest->color, &source->color); + return error; /*this variable could be removed, but it's more clear what is returned this way*/ +} + +/* ////////////////////////////////////////////////////////////////////////// */ + +/*convert from any color type to RGB or RGBA with 8 bits per sample*/ +static unsigned LodePNG_convert_rgb_a_8(unsigned char* out, const unsigned char* in, + LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha) +{ + size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/ + + if(infoIn->bitDepth == 8) + { + switch(infoIn->colorType) + { + case 0: /*greyscale color*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[i]; + if(alpha) out[bytes * i + 3] = infoIn->key_defined && in[i] == infoIn->key_r ? 0 : 255; + } + break; + case 2: /*RGB color*/ + for(i = 0; i < numpixels; i++) + { + for(c = 0; c < 3; c++) out[bytes * i + c] = in[3 * i + c]; + if(alpha) + { + if(infoIn->key_defined == 1 && in[3 * i + 0] == infoIn->key_r + && in[3 * i + 1] == infoIn->key_g && in[3 * i + 2] == infoIn->key_b) + out[bytes * i + 3] = 0; + else out[bytes * i + 3] = 255; + } + } + break; + case 3: /*indexed color (palette)*/ + for(i = 0; i < numpixels; i++) + { + if(in[i] >= infoIn->palettesize) return 46; /*invalid palette index*/ + for(c = 0; c < bytes; c++) out[bytes * i + c] = infoIn->palette[4 * in[i] + c]; + } + break; + case 4: /*greyscale with alpha*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[2 * i + 0]; + if(alpha) out[bytes * i + 3] = in[2 * i + 1]; + } + break; + case 6: /*RGB with alpha*/ + for(i = 0; i < numpixels; i++) + { + for(c = 0; c < bytes; c++) out[bytes * i + c] = in[4 * i + c]; + } + break; + default: break; + } + } + else if(infoIn->bitDepth == 16) + { + switch(infoIn->colorType) + { + case 0: /*greyscale color*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[2 * i]; + if(alpha) out[bytes * i + 3] = infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r ? 0 : 255; + } + break; + case 2: /*RGB color*/ + for(i = 0; i < numpixels; i++) + { + if(alpha) out[bytes * i + 3] = 255; + for(c = 0; c < 3; c++) out[bytes * i + c] = in[6 * i + 2 * c]; + if(alpha) + { + if(infoIn->key_defined && 256U * in[6 * i + 0] + in[6 * i + 1] == infoIn->key_r + && 256U * in[6 * i + 2] + in[6 * i + 3] == infoIn->key_g + && 256U * in[6 * i + 4] + in[6 * i + 5] == infoIn->key_b) + out[bytes * i + 3] = 0; + else out[bytes * i + 3] = 255; + } + } + break; + case 4: /*greyscale with alpha*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] = in[4 * i]; + if(alpha) out[bytes * i + 3] = in[4 * i + 2]; + } + break; + case 6: /*RGB with alpha*/ + for(i = 0; i < numpixels; i++) + { + for(c = 0; c < bytes; c++) out[bytes * i + c] = in[8 * i + 2 * c]; + } + break; + default: break; + } + } + else /*infoIn->bitDepth is less than 8 bit per channel*/ + { + switch(infoIn->colorType) + { + case 0: /*greyscale color*/ + for(i = 0; i < numpixels; i++) + { + unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth); + unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/ + /*scale value from 0 to 255*/ + out[bytes * i + 0] = out[bytes * i + 1] = out[bytes * i + 2] + = (unsigned char)((value * 255) / highest); + if(alpha) out[bytes * i + 3] = infoIn->key_defined && value == infoIn->key_r ? 0 : 255; + } + break; + case 3: /*indexed color (palette)*/ + for(i = 0; i < numpixels; i++) + { + unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth); + if(value >= infoIn->palettesize) return 47; + for(c = 0; c < bytes; c++) out[bytes * i + c] = infoIn->palette[4 * value + c]; + } + break; + default: break; + } + } + return 0; +} + +/*convert from any greyscale color type to 8-bit greyscale with or without alpha channel*/ +static unsigned LodePNG_convert_grey_8(unsigned char* out, const unsigned char* in, + LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha) +{ + size_t i, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/ + + if(infoIn->bitDepth == 8) + { + switch(infoIn->colorType) + { + case 0: /*greyscale color*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i] = in[i]; + if(alpha) out[bytes * i + 1] = infoIn->key_defined && in[i] == infoIn->key_r ? 0 : 255; + } + break; + case 4: /*greyscale with alpha*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = in[2 * i + 0]; + if(alpha) out[bytes * i + 1] = in[2 * i + 1]; + } + break; + default: return 31; + } + } + else if(infoIn->bitDepth == 16) + { + switch(infoIn->colorType) + { + case 0: /*greyscale color*/ + for(i = 0; i < numpixels; i++) + { + if(alpha) out[bytes * i + 1] = 255; + out[bytes * i] = in[2 * i]; + if(alpha && infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r) + { + out[bytes * i + 1] = 0; + } + } + break; + case 4: /*greyscale with alpha*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i] = in[4 * i]; /*most significant byte*/ + if(alpha) out[bytes * i + 1] = in[4 * i + 2]; /*most significant byte*/ + } + break; + default: return 31; + } + } + else /*infoIn->bitDepth is less than 8 bit per channel*/ + { + if(infoIn->colorType != 0) return 31; /*colorType 0 is the only greyscale type with < 8 bits per channel*/ + for(i = 0; i < numpixels; i++) + { + unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth); + unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/ + out[bytes * i] = (unsigned char)((value * 255) / highest); /*scale value from 0 to 255*/ + if(alpha) + { + if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 1] = 0; + else out[bytes * i + 1] = 255; + } + } + } + return 0; +} + +/*convert from any color type to RGB or RGBA with 8 bits per sample*/ +static unsigned LodePNG_convert_rgb_a_16(unsigned char* out, const unsigned char* in, + LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha) +{ + size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/ + + if(infoIn->bitDepth == 8) + { + switch(infoIn->colorType) + { + case 0: /*greyscale color*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[i]; + out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[i]; + if(alpha) + { + if(alpha && infoIn->key_defined && in[i] == infoIn->key_r) out[bytes * i + 6] = out[bytes * i + 7] = 0; + else out[bytes * i + 6] = out[bytes * i + 7] = 255; + } + } + break; + case 2: /*RGB color*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = out[bytes * i + 1] = in[3 * i + 0]; + out[bytes * i + 2] = out[bytes * i + 3] = in[3 * i + 1]; + out[bytes * i + 4] = out[bytes * i + 5] = in[3 * i + 2]; + if(alpha) + { + if(infoIn->key_defined == 1 && in[3 * i + 0] == infoIn->key_r + && in[3 * i + 1] == infoIn->key_g && in[3 * i + 2] == infoIn->key_b) + out[bytes * i + 6] = out[bytes * i + 7] = 0; + else out[bytes * i + 6] = out[bytes * i + 7] = 255; + } + } + break; + case 3: /*indexed color (palette)*/ + for(i = 0; i < numpixels; i++) + { + if(in[i] >= infoIn->palettesize) return 46; /*invalid palette index*/ + for(c = 0; c < bytes; c++) + { + out[bytes * i + 2 * c] = out[bytes * i + 2 * c + 1] = infoIn->palette[4 * in[i] + c]; + } + } + break; + case 4: /*greyscale with alpha*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[i]; + out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[i]; + if(alpha) + { + out[bytes * i + 6] = out[bytes * i + 7] = in[2 * i + 1]; + } + } + break; + case 6: /*RGB with alpha*/ + for(i = 0; i < numpixels; i++) + { + for(c = 0; c < 3; c++) + { + out[bytes * i + 2 * c] = out[bytes * i + 2 * c + 1] = in[4 * i + c]; + } + if(alpha) + { + out[bytes * i + 6] = out[bytes * i + 7] = in[4 * i + c]; + } + } + break; + default: break; + } + } + else if(infoIn->bitDepth == 16) + { + switch(infoIn->colorType) + { + case 0: /*greyscale color*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[2 * i]; + out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[2 * i + 1]; + if(alpha) + { + if(infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r) + out[bytes * i + 6] = out[bytes * i + 7] = 0; + else out[bytes * i + 6] = out[bytes * i + 7] = 255; + } + } + break; + case 2: /*RGB color*/ + for(i = 0; i < numpixels; i++) + { + for(c = 0; c < 6; c++) out[bytes * i + c] = in[6 * i + c]; + if(alpha) + { + if(infoIn->key_defined && 256U * in[6 * i + 0] + in[6 * i + 1] == infoIn->key_r + && 256U * in[6 * i + 2] + in[6 * i + 3] == infoIn->key_g + && 256U * in[6 * i + 4] + in[6 * i + 5] == infoIn->key_b) + out[bytes * i + 6] = out[bytes * i + 7] = 0; + else out[bytes * i + 6] = out[bytes * i + 7] = 255; + } + } + break; + case 4: /*greyscale with alpha*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] = in[4 * i + 0]; + out[bytes * i + 1] = out[bytes * i + 3] = out[bytes * i + 5] = in[4 * i + 1]; + if(alpha) + { + out[bytes * i + 6] = in[4 * i + 2]; + out[bytes * i + 7] = in[4 * i + 3]; + } + } + break; + case 6: /*RGB with alpha*/ + for(i = 0; i < numpixels; i++) + { + for(c = 0; c < bytes; c++) out[bytes * i + c] = in[8 * i + 2 * c]; + } + break; + default: break; + } + } + else /*infoIn->bitDepth is less than 8 bit per channel*/ + { + switch(infoIn->colorType) + { + case 0: /*greyscale color*/ + for(i = 0; i < numpixels; i++) + { + unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth); + unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/ + /*scale value from 0 to 255*/ + out[bytes * i + 0] = out[bytes * i + 2] = out[bytes * i + 4] + = out[bytes * i + 1] = out[bytes * i + 3] + = out[bytes * i + 5] = (unsigned char)((value * 255) / highest); + if(alpha) + { + if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 6] = out[bytes * i + 7] = 0; + else out[bytes * i + 6] = out[bytes * i + 7] = 255; + } + } + break; + case 3: /*indexed color (palette)*/ + for(i = 0; i < numpixels; i++) + { + unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth); + if(value >= infoIn->palettesize) return 47; + for(c = 0; c < bytes / 2; c++) + { + out[bytes * i + c * 2 + 0] = out[bytes * i + c * 2 + 1] = infoIn->palette[4 * value + c]; + } + } + break; + default: break; + } + } + return 0; +} + +/*convert from any greyscale color type to 16-bit greyscale with or without alpha channel*/ +static unsigned LodePNG_convert_grey_16(unsigned char* out, const unsigned char* in, + LodePNG_InfoColor* infoIn, size_t numpixels, unsigned bytes, unsigned alpha) +{ + size_t i, c, bp = 0; /*bp = bitpointer, used by less-than-8-bit color types*/ + + if(infoIn->bitDepth == 8) + { + switch(infoIn->colorType) + { + case 0: /*greyscale color*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i] = out[bytes * i + 1] = in[i]; + if(alpha) + { + if(infoIn->key_defined && in[i] == infoIn->key_r) out[bytes * i + 2] = out[bytes * i + 3] = 0; + else out[bytes * i + 2] = out[bytes * i + 3] = 255; + } + } + break; + case 4: /*greyscale with alpha*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = out[bytes * i + 1] = in[2 * i + 0]; + if(alpha) out[bytes * i + 2] = out[bytes * i + 3] = in[2 * i + 1]; + } + break; + default: return 31; + } + } + else if(infoIn->bitDepth == 16) + { + switch(infoIn->colorType) + { + case 0: /*greyscale color*/ + for(i = 0; i < numpixels; i++) + { + out[bytes * i + 0] = in[2 * i + 0]; + out[bytes * i + 1] = in[2 * i + 1]; + if(alpha) + { + if(infoIn->key_defined && 256U * in[i] + in[i + 1] == infoIn->key_r) + out[bytes * i + 2] = out[bytes * i + 3] = 0; + else out[bytes * i + 2] = out[bytes * i + 3] = 255; + } + } + break; + case 4: /*greyscale with alpha*/ + for(i = 0; i < numpixels; i++) + { + for(c = 0; c < bytes; c++) out[bytes * i + c] = in[4 * i + c]; + } + break; + default: return 31; + } + } + else /*infoIn->bitDepth is less than 8 bit per channel*/ + { + if(infoIn->colorType != 0) return 31; /*colorType 0 is the only greyscale type with < 8 bits per channel*/ + for(i = 0; i < numpixels; i++) + { + unsigned value = readBitsFromReversedStream(&bp, in, infoIn->bitDepth); + unsigned highest = ((1U << infoIn->bitDepth) - 1U); /*highest possible value for this bit depth*/ + out[bytes * i] = out[bytes * i + 1] = (unsigned char)((value * 255) / highest); /*scale value from 0 to 255*/ + if(alpha) + { + if(infoIn->key_defined && value == infoIn->key_r) out[bytes * i + 2] = out[bytes * i + 3] = 0; + else out[bytes * i + 2] = out[bytes * i + 3] = 255; + } + } + } + return 0; +} + +/* +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_InfoColor_getBpp) 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, LodePNG_InfoColor* infoOut, + LodePNG_InfoColor* infoIn, unsigned w, unsigned h) +{ + size_t numpixels = w * h; /*amount of pixels*/ + unsigned bytes = LodePNG_InfoColor_getBpp(infoOut) / 8; /*bytes per pixel in the output image*/ + unsigned alpha = LodePNG_InfoColor_isAlphaType(infoOut); /*use 8-bit alpha channel*/ + + /*cases where in and out already have the same format*/ + if(LodePNG_InfoColor_equal(infoIn, infoOut)) + { + size_t i; + size_t size = (numpixels * LodePNG_InfoColor_getBpp(infoIn) + 7) / 8; + for(i = 0; i < size; i++) out[i] = in[i]; + return 0; + } + else if((infoOut->colorType == 2 || infoOut->colorType == 6) && infoOut->bitDepth == 8) + { + LodePNG_convert_rgb_a_8(out, in, infoIn, numpixels, bytes, alpha); + } + else if(LodePNG_InfoColor_isGreyscaleType(infoOut) && infoOut->bitDepth == 8) + { + /*conversion from greyscale to greyscale*/ + if(!LodePNG_InfoColor_isGreyscaleType(infoIn)) return 62; /*converting from color to grey is not supported*/ + LodePNG_convert_grey_8(out, in, infoIn, numpixels, bytes, alpha); + } + else if((infoOut->colorType == 2 || infoOut->colorType == 6) && infoOut->bitDepth == 16) + { + LodePNG_convert_rgb_a_16(out, in, infoIn, numpixels, bytes, alpha); + } + else if(LodePNG_InfoColor_isGreyscaleType(infoOut) && infoOut->bitDepth == 16) + { + /*conversion from greyscale to greyscale*/ + if(!LodePNG_InfoColor_isGreyscaleType(infoIn)) return 62; /*converting from color to grey is not supported*/ + LodePNG_convert_grey_16(out, in, infoIn, numpixels, bytes, alpha); + } + else return 59; /*invalid color mode*/ + return 0; +} + +/* +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); + + /*short pc = a + b - c; + short pa = abs(pc - a); + short pb = abs(pc - b); + pc = abs(pc - c);*/ + + if(pa <= pb && pa <= pc) return (unsigned char)a; + else if(pb <= pc) return (unsigned char)b; + else return (unsigned char)c; +} + +/*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*/ + +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 LodePNG_Info. return value is error*/ +void LodePNG_Decoder_inspect(LodePNG_Decoder* decoder, const unsigned char* in, size_t inlength) +{ + if(inlength == 0 || in == 0) + { + decoder->error = 48; /*the given data is empty*/ + return; + } + if(inlength < 29) + { + decoder->error = 27; /*error: the data length is smaller than the length of a PNG header*/ + return; + } + + /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/ + LodePNG_InfoPng_cleanup(&decoder->infoPng); + LodePNG_InfoPng_init(&decoder->infoPng); + decoder->error = 0; + + 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) + { + decoder->error = 28; /*error: the first 8 bytes are not the correct PNG signature*/ + return; + } + if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R') + { + decoder->error = 29; /*error: it doesn't start with a IHDR chunk!*/ + return; + } + + /*read the values given in the header*/ + decoder->infoPng.width = LodePNG_read32bitInt(&in[16]); + decoder->infoPng.height = LodePNG_read32bitInt(&in[20]); + decoder->infoPng.color.bitDepth = in[24]; + decoder->infoPng.color.colorType = in[25]; + decoder->infoPng.compressionMethod = in[26]; + decoder->infoPng.filterMethod = in[27]; + decoder->infoPng.interlaceMethod = in[28]; + + if(!decoder->settings.ignoreCrc) + { + unsigned CRC = LodePNG_read32bitInt(&in[29]); + unsigned checksum = Crc32_crc(&in[12], 17); + if(CRC != checksum) + { + decoder->error = 57; /*invalid CRC*/ + return; + } + } + + /*error: only compression method 0 is allowed in the specification*/ + if(decoder->infoPng.compressionMethod != 0) { decoder->error = 32; return; } + /*error: only filter method 0 is allowed in the specification*/ + if(decoder->infoPng.filterMethod != 0) { decoder->error = 33; return; } + /*error: only interlace methods 0 and 1 exist in the specification*/ + if(decoder->infoPng.interlaceMethod > 1) { decoder->error = 34; return; } + + decoder->error = checkColorValidity(decoder->infoPng.color.colorType, decoder->infoPng.color.bitDepth); +} + +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]; + + unsigned error = unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes); + if(error) return error; + + prevline = &out[outindex]; + } + + return 0; +} + +static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) +{ + /*Note: this function works on image buffers WITHOUT padding bits at end of scanlines + with non-multiple-of-8 bit amounts, only between reduced images is padding + 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)*/ + 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, const LodePNG_InfoPng* infoPng) +{ + /* + 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_InfoColor_getBpp(&infoPng->color); + unsigned w = infoPng->width; + unsigned h = infoPng->height; + unsigned error = 0; + if(bpp == 0) return 31; /*error: invalid colortype*/ + + if(infoPng->interlaceMethod == 0) + { + if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) + { + error = unfilter(in, in, w, h, bpp); + if(error) return error; + removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h); + } + else error = unfilter(out, in, w, h, bpp); /*we can immediatly filter into the out buffer, no other steps needed*/ + } + else /*interlaceMethod 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++) + { + error = unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp); + if(error) return error; + /*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 error; +} + +/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/ +static void decodeGeneric(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize, + 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*/ + + /*for unknown chunk order*/ + unsigned unknown = 0; +#ifdef LODEPNG_COMPILE_UNKNOWN_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; + *outsize = 0; + + LodePNG_Decoder_inspect(decoder, in, insize); /*reads header and resets other parameters in decoder->infoPng*/ + if(decoder->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) + { + 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(decoder->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(decoder->error, 63); + + if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in) + { + CERROR_BREAK(decoder->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(decoder->error, 9936 /*alloc fail*/); + for(i = 0; i < chunkLength; i++) idat.data[oldsize + i] = data[i]; +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS + critical_pos = 3; +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ + } + /*IEND chunk*/ + else if(LodePNG_chunk_type_equals(chunk, "IEND")) + { + IEND = 1; + } + /*palette chunk (PLTE)*/ + else if(LodePNG_chunk_type_equals(chunk, "PLTE")) + { + unsigned pos = 0; + if(decoder->infoPng.color.palette) free(decoder->infoPng.color.palette); + decoder->infoPng.color.palettesize = chunkLength / 3; + decoder->infoPng.color.palette = (unsigned char*)malloc(4 * decoder->infoPng.color.palettesize); + if(!decoder->infoPng.color.palette && decoder->infoPng.color.palettesize) + { + decoder->infoPng.color.palettesize = 0; + CERROR_BREAK(decoder->error, 9937); /*alloc fail*/ + } + if(decoder->infoPng.color.palettesize > 256) CERROR_BREAK(decoder->error, 38); /*error: palette too big*/ + + for(i = 0; i < decoder->infoPng.color.palettesize; i++) + { + decoder->infoPng.color.palette[4 * i + 0] = data[pos++]; /*R*/ + decoder->infoPng.color.palette[4 * i + 1] = data[pos++]; /*G*/ + decoder->infoPng.color.palette[4 * i + 2] = data[pos++]; /*B*/ + decoder->infoPng.color.palette[4 * i + 3] = 255; /*alpha*/ + } +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS + critical_pos = 2; +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ + } + /*palette transparency chunk (tRNS)*/ + else if(LodePNG_chunk_type_equals(chunk, "tRNS")) + { + if(decoder->infoPng.color.colorType == 3) + { + /*error: more alpha values given than there are palette entries*/ + if(chunkLength > decoder->infoPng.color.palettesize) CERROR_BREAK(decoder->error, 38); + + for(i = 0; i < chunkLength; i++) decoder->infoPng.color.palette[4 * i + 3] = data[i]; + } + else if(decoder->infoPng.color.colorType == 0) + { + /*error: this chunk must be 2 bytes for greyscale image*/ + if(chunkLength != 2) CERROR_BREAK(decoder->error, 30); + + decoder->infoPng.color.key_defined = 1; + decoder->infoPng.color.key_r = decoder->infoPng.color.key_g + = decoder->infoPng.color.key_b = 256 * data[0] + data[1]; + } + else if(decoder->infoPng.color.colorType == 2) + { + /*error: this chunk must be 6 bytes for RGB image*/ + if(chunkLength != 6) CERROR_BREAK(decoder->error, 41); + + decoder->infoPng.color.key_defined = 1; + decoder->infoPng.color.key_r = 256 * data[0] + data[1]; + decoder->infoPng.color.key_g = 256 * data[2] + data[3]; + decoder->infoPng.color.key_b = 256 * data[4] + data[5]; + } + else CERROR_BREAK(decoder->error, 42); /*error: tRNS chunk not allowed for other color models*/ + } +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + /*background color chunk (bKGD)*/ + else if(LodePNG_chunk_type_equals(chunk, "bKGD")) + { + if(decoder->infoPng.color.colorType == 3) + { + /*error: this chunk must be 1 byte for indexed color image*/ + if(chunkLength != 1) CERROR_BREAK(decoder->error, 43); + + decoder->infoPng.background_defined = 1; + decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_b = data[0]; + } + else if(decoder->infoPng.color.colorType == 0 || decoder->infoPng.color.colorType == 4) + { + /*error: this chunk must be 2 bytes for greyscale image*/ + if(chunkLength != 2) CERROR_BREAK(decoder->error, 44); + + decoder->infoPng.background_defined = 1; + decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_b + = 256 * data[0] + data[1]; + } + else if(decoder->infoPng.color.colorType == 2 || decoder->infoPng.color.colorType == 6) + { + /*error: this chunk must be 6 bytes for greyscale image*/ + if(chunkLength != 6) CERROR_BREAK(decoder->error, 45); + + decoder->infoPng.background_defined = 1; + decoder->infoPng.background_r = 256 * data[0] + data[1]; + decoder->infoPng.background_g = 256 * data[2] + data[3]; + decoder->infoPng.background_b = 256 * data[4] + data[5]; + } + } + /*text chunk (tEXt)*/ + else if(LodePNG_chunk_type_equals(chunk, "tEXt")) + { + if(decoder->settings.readTextChunks) + { + char *key = 0, *str = 0; + + while(!decoder->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++; + /*error, end reached, no null terminator?*/ + if(length + 1 >= chunkLength) CERROR_BREAK(decoder->error, 75); + + key = (char*)malloc(length + 1); + if(!key) CERROR_BREAK(decoder->error, 9938); /*alloc fail*/ + + key[length] = 0; + for(i = 0; i < length; i++) key[i] = data[i]; + + string2_begin = length + 1; + /*error, end reached, no null terminator?*/ + if(string2_begin > chunkLength) CERROR_BREAK(decoder->error, 75); + + length = chunkLength - string2_begin; + str = (char*)malloc(length + 1); + if(!str) CERROR_BREAK(decoder->error, 9939); /*alloc fail*/ + + str[length] = 0; + for(i = 0; i < length; i++) str[i] = data[string2_begin + i]; + + decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, str); + + break; + } + + free(key); + free(str); + } + } + /*compressed text chunk (zTXt)*/ + else if(LodePNG_chunk_type_equals(chunk, "zTXt")) + { + if(decoder->settings.readTextChunks) + { + unsigned length, string2_begin; + char *key = 0; + ucvector decoded; + + ucvector_init(&decoded); + + while(!decoder->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(decoder->error, 75); /*no null termination, corrupt?*/ + + key = (char*)malloc(length + 1); + if(!key) CERROR_BREAK(decoder->error, 9940); /*alloc fail*/ + + key[length] = 0; + for(i = 0; i < length; i++) key[i] = data[i]; + + if(data[length + 1] != 0) CERROR_BREAK(decoder->error, 72); /*the 0 byte indicating compression must be 0*/ + + string2_begin = length + 2; + if(string2_begin > chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/ + + length = chunkLength - string2_begin; + decoder->error = LodePNG_zlib_decompress(&decoded.data, &decoded.size, + (unsigned char*)(&data[string2_begin]), + length, &decoder->settings.zlibsettings); + if(decoder->error) break; + ucvector_push_back(&decoded, 0); + + decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, (char*)decoded.data); + + break; + } + + free(key); + ucvector_cleanup(&decoded); + if(decoder->error) break; + } + } + /*international text chunk (iTXt)*/ + else if(LodePNG_chunk_type_equals(chunk, "iTXt")) + { + if(decoder->settings.readTextChunks) + { + unsigned length, begin, compressed; + char *key = 0, *langtag = 0, *transkey = 0; + ucvector decoded; + ucvector_init(&decoded); + + while(!decoder->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(decoder->error, 30); /*iTXt chunk too short*/ + + /*read the key*/ + for(length = 0; length < chunkLength && data[length] != 0; length++) ; + if(length + 2 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination char found*/ + + key = (char*)malloc(length + 1); + if(!key) CERROR_BREAK(decoder->error, 9941); /*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(decoder->error, 72); /*the 0 byte indicating compression must be 0*/ + + /*read the langtag*/ + begin = length + 3; + length = 0; + for(i = begin; i < chunkLength && data[i] != 0; i++) length++; + if(begin + length + 1 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination char found*/ + + langtag = (char*)malloc(length + 1); + if(!langtag) CERROR_BREAK(decoder->error, 9942); /*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++; + if(begin + length + 1 >= chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/ + + transkey = (char*)malloc(length + 1); + if(!transkey) CERROR_BREAK(decoder->error, 9943); /*alloc fail*/ + + transkey[length] = 0; + for(i = 0; i < length; i++) transkey[i] = data[begin + i]; + + /*read the actual text*/ + begin += length + 1; + if(begin > chunkLength) CERROR_BREAK(decoder->error, 75); /*no null termination, corrupt?*/ + + length = chunkLength - begin; + + if(compressed) + { + decoder->error = LodePNG_zlib_decompress(&decoded.data, &decoded.size, + (unsigned char*)(&data[begin]), + length, &decoder->settings.zlibsettings); + if(decoder->error) break; + ucvector_push_back(&decoded, 0); + } + else + { + if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(decoder->error, 9944 /*alloc fail*/); + + decoded.data[length] = 0; + for(i = 0; i < length; i++) decoded.data[i] = data[begin + i]; + } + + decoder->error = LodePNG_IText_add(&decoder->infoPng.itext, key, langtag, transkey, (char*)decoded.data); + + break; + } + + free(key); + free(langtag); + free(transkey); + ucvector_cleanup(&decoded); + if(decoder->error) break; + } + } + else if(LodePNG_chunk_type_equals(chunk, "tIME")) + { + if(chunkLength != 7) CERROR_BREAK(decoder->error, 73); /*invalid tIME chunk size*/ + + decoder->infoPng.time_defined = 1; + decoder->infoPng.time.year = 256 * data[0] + data[+ 1]; + decoder->infoPng.time.month = data[2]; + decoder->infoPng.time.day = data[3]; + decoder->infoPng.time.hour = data[4]; + decoder->infoPng.time.minute = data[5]; + decoder->infoPng.time.second = data[6]; + } + else if(LodePNG_chunk_type_equals(chunk, "pHYs")) + { + if(chunkLength != 9) CERROR_BREAK(decoder->error, 74); /*invalid pHYs chunk size*/ + + decoder->infoPng.phys_defined = 1; + decoder->infoPng.phys_x = 16777216 * data[0] + 65536 * data[1] + 256 * data[2] + data[3]; + decoder->infoPng.phys_y = 16777216 * data[4] + 65536 * data[5] + 256 * data[6] + data[7]; + decoder->infoPng.phys_unit = data[8]; + } +#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_critical(chunk)) CERROR_BREAK(decoder->error, 69); + + unknown = 1; +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS + if(decoder->settings.rememberUnknownChunks) + { + LodePNG_UnknownChunks* unknown = &decoder->infoPng.unknown_chunks; + decoder->error = LodePNG_append_chunk(&unknown->data[critical_pos - 1], + &unknown->datasize[critical_pos - 1], chunk); + if(decoder->error) break; + } +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ + } + + if(!decoder->settings.ignoreCrc && !unknown) /*check CRC if wanted, only on known chunk types*/ + { + if(LodePNG_chunk_check_crc(chunk)) CERROR_BREAK(decoder->error, 57); /*invalid CRC*/ + } + + if(!IEND) chunk = LodePNG_chunk_next_const(chunk); + } + + if(!decoder->error) + { + ucvector scanlines; + ucvector_init(&scanlines); + + /*maximum final image length is already reserved in the vector's length - this is not really necessary*/ + if(!ucvector_resize(&scanlines, ((decoder->infoPng.width * (decoder->infoPng.height + * LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7)) / 8) + decoder->infoPng.height)) + { + decoder->error = 9945; /*alloc fail*/ + } + if(!decoder->error) + { + /*decompress with the Zlib decompressor*/ + decoder->error = LodePNG_zlib_decompress(&scanlines.data, &scanlines.size, idat.data, + idat.size, &decoder->settings.zlibsettings); + } + + if(!decoder->error) + { + ucvector outv; + ucvector_init(&outv); + if(!ucvector_resizev(&outv, (decoder->infoPng.height * decoder->infoPng.width + * LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7) / 8, 0)) decoder->error = 9946; /*alloc fail*/ + if(!decoder->error) decoder->error = postProcessScanlines(outv.data, scanlines.data, &decoder->infoPng); + *out = outv.data; + *outsize = outv.size; + } + ucvector_cleanup(&scanlines); + } + + ucvector_cleanup(&idat); +} + +void LodePNG_Decoder_decode(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize, + const unsigned char* in, size_t insize) +{ + *out = 0; + *outsize = 0; + decodeGeneric(decoder, out, outsize, in, insize); + if(decoder->error) return; + if(!decoder->settings.color_convert || LodePNG_InfoColor_equal(&decoder->infoRaw.color, &decoder->infoPng.color)) + { + /*same color type, no copying or converting of data needed*/ + /*store the infoPng color settings on the infoRaw so that the infoRaw still reflects what colorType + the raw image has to the end user*/ + if(!decoder->settings.color_convert) + { + decoder->error = LodePNG_InfoColor_copy(&decoder->infoRaw.color, &decoder->infoPng.color); + if(decoder->error) return; + } + } + else + { + /*color conversion needed; sort of copy of the data*/ + unsigned char* data = *out; + + /*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(!(decoder->infoRaw.color.colorType == 2 || decoder->infoRaw.color.colorType == 6) + && !(decoder->infoRaw.color.bitDepth == 8)) + { + decoder->error = 56; /*unsupported color mode conversion*/ + return; + } + + *outsize = (decoder->infoPng.width * decoder->infoPng.height + * LodePNG_InfoColor_getBpp(&decoder->infoRaw.color) + 7) / 8; + *out = (unsigned char*)malloc(*outsize); + if(!(*out)) + { + decoder->error = 9947; /*alloc fail*/ + *outsize = 0; + } + else decoder->error = LodePNG_convert(*out, data, &decoder->infoRaw.color, &decoder->infoPng.color, + decoder->infoPng.width, decoder->infoPng.height); + free(data); + } +} + +unsigned LodePNG_decode(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, + size_t insize, unsigned colorType, unsigned bitDepth) +{ + unsigned error; + size_t dummy_size; + LodePNG_Decoder decoder; + LodePNG_Decoder_init(&decoder); + decoder.infoRaw.color.colorType = colorType; + decoder.infoRaw.color.bitDepth = bitDepth; + LodePNG_Decoder_decode(&decoder, out, &dummy_size, in, insize); + error = decoder.error; + *w = decoder.infoPng.width; + *h = decoder.infoPng.height; + LodePNG_Decoder_cleanup(&decoder); + return error; +} + +unsigned LodePNG_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) +{ + return LodePNG_decode(out, w, h, in, insize, 6, 8); +} + +unsigned LodePNG_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) +{ + return LodePNG_decode(out, w, h, in, insize, 2, 8); +} + +#ifdef LODEPNG_COMPILE_DISK +unsigned LodePNG_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename, + unsigned colorType, unsigned bitDepth) +{ + unsigned char* buffer; + size_t buffersize; + unsigned error; + error = LodePNG_loadFile(&buffer, &buffersize, filename); + if(!error) error = LodePNG_decode(out, w, h, buffer, buffersize, colorType, bitDepth); + 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, 6, 8); +} + +unsigned LodePNG_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) +{ + return LodePNG_decode_file(out, w, h, filename, 2, 8); +} +#endif /*LODEPNG_COMPILE_DISK*/ + +void LodePNG_DecodeSettings_init(LodePNG_DecodeSettings* settings) +{ + settings->color_convert = 1; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + settings->readTextChunks = 1; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + settings->ignoreCrc = 0; +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS + settings->rememberUnknownChunks = 0; +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ + LodePNG_DecompressSettings_init(&settings->zlibsettings); +} + +void LodePNG_Decoder_init(LodePNG_Decoder* decoder) +{ + LodePNG_DecodeSettings_init(&decoder->settings); + LodePNG_InfoRaw_init(&decoder->infoRaw); + LodePNG_InfoPng_init(&decoder->infoPng); + decoder->error = 1; +} + +void LodePNG_Decoder_cleanup(LodePNG_Decoder* decoder) +{ + LodePNG_InfoRaw_cleanup(&decoder->infoRaw); + LodePNG_InfoPng_cleanup(&decoder->infoPng); +} + +void LodePNG_Decoder_copy(LodePNG_Decoder* dest, const LodePNG_Decoder* source) +{ + LodePNG_Decoder_cleanup(dest); + *dest = *source; + LodePNG_InfoRaw_init(&dest->infoRaw); + LodePNG_InfoPng_init(&dest->infoPng); + dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw); if(dest->error) return; + dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng); if(dest->error) return; +} + +#endif /*LODEPNG_COMPILE_DECODER*/ + +#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) +{ + unsigned error = LodePNG_create_chunk(&out->data, &out->size, (unsigned)length, chunkName, data); + if(error) return error; + 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, unsigned bitDepth, + unsigned colorType, unsigned interlaceMethod) +{ + 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, interlaceMethod); /*interlace method*/ + + error = addChunk(out, "IHDR", header.data, header.size); + ucvector_cleanup(&header); + + return error; +} + +static unsigned addChunk_PLTE(ucvector* out, const LodePNG_InfoColor* 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 LodePNG_InfoColor* info) +{ + unsigned error = 0; + size_t i; + ucvector tRNS; + ucvector_init(&tRNS); + if(info->colorType == 3) + { + /*add only alpha channel*/ + for(i = 0; i < info->palettesize; i++) ucvector_push_back(&tRNS, info->palette[4 * i + 3]); + } + else if(info->colorType == 0) + { + 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 == 2) + { + 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, + LodePNG_CompressSettings* zlibsettings) +{ + ucvector zlibdata; + unsigned error = 0; + + /*compress with the Zlib compressor*/ + ucvector_init(&zlibdata); + error = LodePNG_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]); + ucvector_push_back(&text, 0); + 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, + LodePNG_CompressSettings* 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]); + ucvector_push_back(&data, 0); /* 0 termination char*/ + ucvector_push_back(&data, 0); /*compression method: 0*/ + + error = LodePNG_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, LodePNG_CompressSettings* zlibsettings) +{ + unsigned error = 0; + ucvector data, compressed_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]); + 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_init(&compressed_data); + error = LodePNG_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]); + for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]); + } + } + 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 LodePNG_InfoPng* info) +{ + unsigned error = 0; + ucvector bKGD; + ucvector_init(&bKGD); + if(info->color.colorType == 0 || info->color.colorType == 4) + { + 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 == 2 || info->color.colorType == 6) + { + 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 == 3) + { + 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 LodePNG_Time* time) +{ + unsigned error = 0; + unsigned char* data = (unsigned char*)malloc(7); + if(!data) return 9948; /*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); + free(data); + return error; +} + +static unsigned addChunk_pHYs(ucvector* out, const LodePNG_InfoPng* 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*/ + } +} + +static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, + const LodePNG_InfoColor* info, const LodePNG_EncodeSettings* 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_InfoColor_getBpp(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; + + if(bpp == 0) return 31; /*error: invalid color type*/ + + if(!settings->bruteForceFilters) + { + /* + 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. + */ + if(info->colorType == 3 || info->bitDepth < 8) /*None filtertype for everything*/ + { + for(y = 0; y < h; y++) + { + size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ + size_t inindex = linebytes * y; + const unsigned TYPE = 0; + out[outindex] = TYPE; /*filter type byte*/ + filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, TYPE); + prevline = &in[inindex]; + } + } + else /*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]); + for(type = 0; type < 5; type++) + { + if(!ucvector_resize(&attempt[type], linebytes)) ERROR_BREAK(9949 /*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; + /*note that not all pixels are checked to speed this up while still having probably the best choice*/ + for(x = 0; x < attempt[type].size; x+=3) + { + /*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.*/ + if(type == 0) sum[type] += (unsigned char)(attempt[type].data[x]); + else + { + 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 + { + /*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; + LodePNG_CompressSettings 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; + 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; + /*unsigned testsize = attempt[type].size / 8;*/ /*it already works good enough by testing a part of the row*/ + /*if(testsize == 0) testsize = attempt[type].size;*/ + + filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type); + size[type] = 0; + dummy = 0; + LodePNG_zlib_compress(&dummy, &size[type], attempt[type].data, testsize, &zlibsettings); + 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]); + } + + 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); + } +} + +static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) +{ + /*Note: this function works on image buffers WITHOUT padding bits at end of scanlines with non-multiple-of-8 + bit amounts, only between reduced images is padding*/ + 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, + const LodePNG_InfoPng* infoPng, const LodePNG_EncodeSettings* 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_InfoColor_getBpp(&infoPng->color); + unsigned w = infoPng->width; + unsigned h = infoPng->height; + unsigned error = 0; + + if(infoPng->interlaceMethod == 0) + { + *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/ + *out = (unsigned char*)malloc(*outsize); + if(!(*out) && (*outsize)) error = 9950; /*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) + { + ucvector padded; + ucvector_init(&padded); + if(!ucvector_resize(&padded, h * ((w * bpp + 7) / 8))) error = 9951; /*alloc fail*/ + if(!error) + { + addPaddingBits(padded.data, in, ((w * bpp + 7) / 8) * 8, w * bpp, h); + error = filter(*out, padded.data, w, h, &infoPng->color, settings); + } + ucvector_cleanup(&padded); + } + else + { + /*we can immediatly filter into the out buffer, no other steps needed*/ + error = filter(*out, in, w, h, &infoPng->color, settings); + } + } + } + else /*interlaceMethod is 1 (Adam7)*/ + { + unsigned char* adam7 = (unsigned char*)malloc((h * w * bpp + 7) / 8); + if(!adam7 && ((h * w * bpp + 7) / 8)) error = 9952; /*alloc fail*/ + + while(!error) /*not a real while loop, used to break out to cleanup to avoid a goto*/ + { + 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); + + *outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/ + *out = (unsigned char*)malloc(*outsize); + if(!(*out) && (*outsize)) ERROR_BREAK(9953 /*alloc fail*/); + + Adam7_interlace(adam7, in, w, h, bpp); + + for(i = 0; i < 7; i++) + { + if(bpp < 8) + { + ucvector padded; + ucvector_init(&padded); + if(!ucvector_resize(&padded, h * ((w * bpp + 7) / 8))) error = 9954; /*alloc fail*/ + if(!error) + { + addPaddingBits(&padded.data[padded_passstart[i]], &adam7[passstart[i]], + ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]); + error = filter(&(*out)[filter_passstart[i]], &padded.data[padded_passstart[i]], + passw[i], passh[i], &infoPng->color, settings); + } + + ucvector_cleanup(&padded); + } + else + { + error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]], + passw[i], passh[i], &infoPng->color, settings); + } + } + + break; + } + + free(adam7); + } + + return error; +} + +/*palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA...*/ +static unsigned isPaletteFullyOpaque(const unsigned char* palette, size_t palettesize) +{ + size_t i; + for(i = 0; i < palettesize; i++) + { + if(palette[4 * i + 3] != 255) return 0; + } + return 1; +} + +/*this function checks if the input image given by the user has no transparent pixels*/ +static unsigned isFullyOpaque(const unsigned char* image, unsigned w, unsigned h, const LodePNG_InfoColor* info) +{ + /*TODO: When the user specified a color key for the input image, then this function must + also check for pixels that are the same as the color key and treat those as transparent.*/ + + unsigned i, numpixels = w * h; + if(info->colorType == 6) + { + if(info->bitDepth == 8) + { + for(i = 0; i < numpixels; i++) + { + if(image[i * 4 + 3] != 255) return 0; + } + } + else + { + for(i = 0; i < numpixels; i++) + { + if(image[i * 8 + 6] != 255 || image[i * 8 + 7] != 255) return 0; + } + } + return 1; /*no single pixel with alpha channel other than 255 found*/ + } + else if(info->colorType == 4) + { + if(info->bitDepth == 8) + { + for(i = 0; i < numpixels; i++) + { + if(image[i * 2 + 1] != 255) return 0; + } + } + else + { + for(i = 0; i < numpixels; i++) + { + if(image[i * 4 + 2] != 255 || image[i * 4 + 3] != 255) return 0; + } + } + return 1; /*no single pixel with alpha channel other than 255 found*/ + } + else if(info->colorType == 3) + { + /*when there's a palette, we could check every pixel for translucency, + but much quicker is to just check the palette*/ + return(isPaletteFullyOpaque(info->palette, info->palettesize)); + } + + return 0; /*color type that isn't supported by this function yet, so assume there is transparency to be safe*/ +} + +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS +static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize) +{ + unsigned char* inchunk = data; + while((size_t)(inchunk - data) < datasize) + { + unsigned error = LodePNG_append_chunk(&out->data, &out->size, inchunk); + if(error) return error; /*error: not enough memory*/ + out->allocsize = out->size; /*fix the allocsize again*/ + inchunk = LodePNG_chunk_next(inchunk); + } + return 0; +} +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ + +void LodePNG_Encoder_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsize, + const unsigned char* image, unsigned w, unsigned h) +{ + LodePNG_InfoPng 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; + encoder->error = 0; + + /*UNSAFE copy to avoid having to cleanup! but we will only change primitive parameters, + and not invoke the cleanup function nor touch the palette's buffer so we use it safely*/ + info = encoder->infoPng; + info.width = w; + info.height = h; + + if(encoder->settings.autoLeaveOutAlphaChannel && isFullyOpaque(image, w, h, &encoder->infoRaw.color)) + { + /*go to a color type without alpha channel*/ + if(info.color.colorType == 6) info.color.colorType = 2; + else if(info.color.colorType == 4) info.color.colorType = 0; + } + + if(encoder->settings.zlibsettings.windowSize > 32768) + { + encoder->error = 60; /*error: windowsize larger than allowed*/ + return; + } + if(encoder->settings.zlibsettings.btype > 2) + { + encoder->error = 61; /*error: unexisting btype*/ + return; + } + if(encoder->infoPng.interlaceMethod > 1) + { + encoder->error = 71; /*error: unexisting interlace mode*/ + return; + } + /*error: unexisting color type given*/ + if((encoder->error = checkColorValidity(info.color.colorType, info.color.bitDepth))) return; + /*error: unexisting color type given*/ + if((encoder->error = checkColorValidity(encoder->infoRaw.color.colorType, encoder->infoRaw.color.bitDepth))) return; + + if(!LodePNG_InfoColor_equal(&encoder->infoRaw.color, &info.color)) + { + unsigned char* converted; + size_t size = (w * h * LodePNG_InfoColor_getBpp(&info.color) + 7) / 8; + + if((info.color.colorType != 6 && info.color.colorType != 2) || (info.color.bitDepth != 8)) + { + encoder->error = 59; /*for the output image, only these types are supported*/ + return; + } + converted = (unsigned char*)malloc(size); + if(!converted && size) encoder->error = 9955; /*alloc fail*/ + if(!encoder->error) + { + encoder->error = LodePNG_convert(converted, image, &info.color, &encoder->infoRaw.color, w, h); + } + if(!encoder->error) preProcessScanlines(&data, &datasize, converted, &info, &encoder->settings); + free(converted); + } + else preProcessScanlines(&data, &datasize, image, &info, &encoder->settings); + + ucvector_init(&outv); + while(!encoder->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.bitDepth, info.color.colorType, info.interlaceMethod); +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS + /*unknown chunks between IHDR and PLTE*/ + if(info.unknown_chunks.data[0]) + { + encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[0], info.unknown_chunks.datasize[0]); + if(encoder->error) break; + } +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ + /*PLTE*/ + if(info.color.colorType == 3) + { + if(info.color.palettesize == 0 || info.color.palettesize > 256) + { + encoder->error = 68; /*invalid palette size*/ + break; + } + addChunk_PLTE(&outv, &info.color); + } + if(encoder->settings.force_palette && (info.color.colorType == 2 || info.color.colorType == 6)) + { + if(info.color.palettesize == 0 || info.color.palettesize > 256) + { + encoder->error = 68; /*invalid palette size*/ + break; + } + addChunk_PLTE(&outv, &info.color); + } + /*tRNS*/ + if(info.color.colorType == 3 && !isPaletteFullyOpaque(info.color.palette, info.color.palettesize)) + { + addChunk_tRNS(&outv, &info.color); + } + if((info.color.colorType == 0 || info.color.colorType == 2) && 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); +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS + /*unknown chunks between PLTE and IDAT*/ + if(info.unknown_chunks.data[1]) + { + encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[1], info.unknown_chunks.datasize[1]); + if(encoder->error) break; + } +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ + /*IDAT (multiple IDAT chunks must be consecutive)*/ + encoder->error = addChunk_IDAT(&outv, data, datasize, &encoder->settings.zlibsettings); + if(encoder->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) + { + encoder->error = 66; /*text chunk too large*/ + break; + } + if(strlen(info.text.keys[i]) < 1) + { + encoder->error = 67; /*text chunk too small*/ + break; + } + if(encoder->settings.text_compression) + addChunk_zTXt(&outv, info.text.keys[i], info.text.strings[i], &encoder->settings.zlibsettings); + else + addChunk_tEXt(&outv, info.text.keys[i], info.text.strings[i]); + } + /*LodePNG version id in text chunk*/ + if(encoder->settings.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) + { + encoder->error = 66; /*text chunk too large*/ + break; + } + if(strlen(info.itext.keys[i]) < 1) + { + encoder->error = 67; /*text chunk too small*/ + break; + } + addChunk_iTXt(&outv, encoder->settings.text_compression, + info.itext.keys[i], info.itext.langtags[i], info.itext.transkeys[i], info.itext.strings[i], + &encoder->settings.zlibsettings); + } +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS + /*unknown chunks between IDAT and IEND*/ + if(info.unknown_chunks.data[2]) + { + encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[2], info.unknown_chunks.datasize[2]); + if(encoder->error) break; + } +#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ + /*IEND*/ + addChunk_IEND(&outv); + + break; /*this isn't really a while loop; no error happened so break out now!*/ + } + + free(data); + /*instead of cleaning the vector up, give it to the output*/ + *out = outv.data; + *outsize = outv.size; +} + +unsigned LodePNG_encode(unsigned char** out, size_t* outsize, const unsigned char* image, + unsigned w, unsigned h, unsigned colorType, unsigned bitDepth) +{ + unsigned error; + LodePNG_Encoder encoder; + LodePNG_Encoder_init(&encoder); + encoder.infoRaw.color.colorType = colorType; + encoder.infoRaw.color.bitDepth = bitDepth; + encoder.infoPng.color.colorType = colorType; + encoder.infoPng.color.bitDepth = bitDepth; + LodePNG_Encoder_encode(&encoder, out, outsize, image, w, h); + error = encoder.error; + LodePNG_Encoder_cleanup(&encoder); + return error; +} + +unsigned LodePNG_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) +{ + return LodePNG_encode(out, outsize, image, w, h, 6, 8); +} + +unsigned LodePNG_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) +{ + return LodePNG_encode(out, outsize, image, w, h, 2, 8); +} + +#ifdef LODEPNG_COMPILE_DISK +unsigned LodePNG_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h, + unsigned colorType, unsigned bitDepth) +{ + unsigned char* buffer; + size_t buffersize; + unsigned error = LodePNG_encode(&buffer, &buffersize, image, w, h, colorType, bitDepth); + if(!error) error = LodePNG_saveFile(buffer, buffersize, filename); + 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, 6, 8); +} + +unsigned LodePNG_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) +{ + return LodePNG_encode_file(filename, image, w, h, 2, 8); +} +#endif /*LODEPNG_COMPILE_DISK*/ + +void LodePNG_EncodeSettings_init(LodePNG_EncodeSettings* settings) +{ + LodePNG_CompressSettings_init(&settings->zlibsettings); + settings->bruteForceFilters = 0; + settings->autoLeaveOutAlphaChannel = 1; + settings->force_palette = 0; +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + settings->add_id = 1; + settings->text_compression = 0; +#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +} + +void LodePNG_Encoder_init(LodePNG_Encoder* encoder) +{ + LodePNG_EncodeSettings_init(&encoder->settings); + LodePNG_InfoPng_init(&encoder->infoPng); + LodePNG_InfoRaw_init(&encoder->infoRaw); + encoder->error = 1; +} + +void LodePNG_Encoder_cleanup(LodePNG_Encoder* encoder) +{ + LodePNG_InfoPng_cleanup(&encoder->infoPng); + LodePNG_InfoRaw_cleanup(&encoder->infoRaw); +} + +void LodePNG_Encoder_copy(LodePNG_Encoder* dest, const LodePNG_Encoder* source) +{ + LodePNG_Encoder_cleanup(dest); + *dest = *source; + LodePNG_InfoPng_init(&dest->infoPng); + LodePNG_InfoRaw_init(&dest->infoRaw); + dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng); + if(dest->error) return; + dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw); + if(dest->error) return; +} + +#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"; + + /*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 "conversion to unexisting color mode or color mode 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 RGB 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"; + default: ; /*nothing to do here, checks for other error values are below*/ + } + + if(code >= 9900 && code <= 9999) return "memory allocation failed"; + + return "unknown error code"; +} + +#endif /*LODEPNG_COMPILE_ERROR_TEXT*/ + +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* // End of PNG related code. Begin of C++ wrapper. // */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef __cplusplus +namespace LodePNG +{ +#ifdef LODEPNG_COMPILE_DISK + void loadFile(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 saveFile(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 LodePNG_DecompressSettings& settings) + { + unsigned char* buffer = 0; + size_t buffersize = 0; + unsigned error = LodePNG_zlib_decompress(&buffer, &buffersize, in, insize, &settings); + if(buffer) + { + out.insert(out.end(), &buffer[0], &buffer[buffersize]); + free(buffer); + } + return error; + } + + unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, + const LodePNG_DecompressSettings& 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 LodePNG_CompressSettings& settings) + { + unsigned char* buffer = 0; + size_t buffersize = 0; + unsigned error = LodePNG_zlib_compress(&buffer, &buffersize, in, insize, &settings); + if(buffer) + { + out.insert(out.end(), &buffer[0], &buffer[buffersize]); + free(buffer); + } + return error; + } + + unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, + const LodePNG_CompressSettings& settings) + { + return compress(out, in.empty() ? 0 : &in[0], in.size(), settings); + } +#endif //LODEPNG_COMPILE_ENCODER +#endif //LODEPNG_COMPILE_ZLIB + +#ifdef LODEPNG_COMPILE_PNG +#ifdef LODEPNG_COMPILE_DECODER + Decoder::Decoder() + { + LodePNG_Decoder_init(this); + } + + Decoder::~Decoder() + { + LodePNG_Decoder_cleanup(this); + } + + void Decoder::operator=(const LodePNG_Decoder& other) + { + LodePNG_Decoder_copy(this, &other); + } + + bool Decoder::hasError() const + { + return error != 0; + } + unsigned Decoder::getError() const + { + return error; + } + + unsigned Decoder::getWidth() const + { + return infoPng.width; + } + + unsigned Decoder::getHeight() const + { + return infoPng.height; + } + + unsigned Decoder::getBpp() + { + return LodePNG_InfoColor_getBpp(&infoPng.color); + } + + unsigned Decoder::getChannels() + { + return LodePNG_InfoColor_getChannels(&infoPng.color); + } + + unsigned Decoder::isGreyscaleType() + { + return LodePNG_InfoColor_isGreyscaleType(&infoPng.color); + } + + unsigned Decoder::isAlphaType() + { + return LodePNG_InfoColor_isAlphaType(&infoPng.color); + } + + void Decoder::decode(std::vector<unsigned char>& out, const unsigned char* in, size_t insize) + { + unsigned char* buffer; + size_t buffersize; + LodePNG_Decoder_decode(this, &buffer, &buffersize, in, insize); + if(buffer) + { + out.insert(out.end(), &buffer[0], &buffer[buffersize]); + free(buffer); + } + } + + void Decoder::decode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in) + { + decode(out, in.empty() ? 0 : &in[0], in.size()); + } + + void Decoder::inspect(const unsigned char* in, size_t insize) + { + LodePNG_Decoder_inspect(this, in, insize); + } + + void Decoder::inspect(const std::vector<unsigned char>& in) + { + inspect(in.empty() ? 0 : &in[0], in.size()); + } + + const LodePNG_DecodeSettings& Decoder::getSettings() const + { + return settings; + } + + LodePNG_DecodeSettings& Decoder::getSettings() + { + return settings; + } + + void Decoder::setSettings(const LodePNG_DecodeSettings& settings) + { + this->settings = settings; + } + + const LodePNG_InfoPng& Decoder::getInfoPng() const + { + return infoPng; + } + + LodePNG_InfoPng& Decoder::getInfoPng() + { + return infoPng; + } + + void Decoder::setInfoPng(const LodePNG_InfoPng& info) + { + error = LodePNG_InfoPng_copy(&this->infoPng, &info); + } + + void Decoder::swapInfoPng(LodePNG_InfoPng& info) + { + LodePNG_InfoPng_swap(&this->infoPng, &info); + } + + const LodePNG_InfoRaw& Decoder::getInfoRaw() const + { + return infoRaw; + } + + LodePNG_InfoRaw& Decoder::getInfoRaw() + { + return infoRaw; + } + + void Decoder::setInfoRaw(const LodePNG_InfoRaw& info) + { + error = LodePNG_InfoRaw_copy(&this->infoRaw, &info); + } + +#endif //LODEPNG_COMPILE_DECODER + + /* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_ENCODER + + Encoder::Encoder() + { + LodePNG_Encoder_init(this); + } + + Encoder::~Encoder() + { + LodePNG_Encoder_cleanup(this); + } + + void Encoder::operator=(const LodePNG_Encoder& other) + { + LodePNG_Encoder_copy(this, &other); + } + + bool Encoder::hasError() const + { + return error != 0; + } + + unsigned Encoder::getError() const + { + return error; + } + + void Encoder::encode(std::vector<unsigned char>& out, const unsigned char* image, unsigned w, unsigned h) + { + unsigned char* buffer; + size_t buffersize; + LodePNG_Encoder_encode(this, &buffer, &buffersize, image, w, h); + if(buffer) + { + out.insert(out.end(), &buffer[0], &buffer[buffersize]); + free(buffer); + } + } + + void Encoder::encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& image, + unsigned w, unsigned h) + { + encode(out, image.empty() ? 0 : &image[0], w, h); + } + + void Encoder::clearPalette() + { + LodePNG_InfoColor_clearPalette(&infoPng.color); + } + + void Encoder::addPalette(unsigned char r, unsigned char g, unsigned char b, unsigned char a) + { + error = LodePNG_InfoColor_addPalette(&infoPng.color, r, g, b, a); + } + +#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS + void Encoder::clearText() + { + LodePNG_Text_clear(&infoPng.text); + } + + void Encoder::addText(const std::string& key, const std::string& str) + { + error = LodePNG_Text_add(&infoPng.text, key.c_str(), str.c_str()); + } + + void Encoder::clearIText() + { + LodePNG_IText_clear(&infoPng.itext); + } + + void Encoder::addIText(const std::string& key, const std::string& langtag, + const std::string& transkey, const std::string& str) + { + error = LodePNG_IText_add(&infoPng.itext, key.c_str(), langtag.c_str(), transkey.c_str(), str.c_str()); + } +#endif //LODEPNG_COMPILE_ANCILLARY_CHUNKS + + const LodePNG_EncodeSettings& Encoder::getSettings() const + { + return settings; + } + + LodePNG_EncodeSettings& Encoder::getSettings() + { + return settings; + } + + void Encoder::setSettings(const LodePNG_EncodeSettings& settings) + { + this->settings = settings; + } + + const LodePNG_InfoPng& Encoder::getInfoPng() const + { + return infoPng; + } + + LodePNG_InfoPng& Encoder::getInfoPng() + { + return infoPng; + } + + void Encoder::setInfoPng(const LodePNG_InfoPng& info) + { + error = LodePNG_InfoPng_copy(&this->infoPng, &info); + } + + void Encoder::swapInfoPng(LodePNG_InfoPng& info) + { + LodePNG_InfoPng_swap(&this->infoPng, &info); + } + + const LodePNG_InfoRaw& Encoder::getInfoRaw() const + { + return infoRaw; + } + + LodePNG_InfoRaw& Encoder::getInfoRaw() + { + return infoRaw; + } + + void Encoder::setInfoRaw(const LodePNG_InfoRaw& info) + { + error = LodePNG_InfoRaw_copy(&this->infoRaw, &info); + } +#endif //LODEPNG_COMPILE_ENCODER + + /* ////////////////////////////////////////////////////////////////////////// */ + +#ifdef LODEPNG_COMPILE_DECODER + + unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in, + size_t insize, unsigned colorType, unsigned bitDepth) + { + Decoder decoder; + decoder.getInfoRaw().color.colorType = colorType; + decoder.getInfoRaw().color.bitDepth = bitDepth; + decoder.decode(out, in, insize); + w = decoder.getWidth(); + h = decoder.getHeight(); + return decoder.getError(); + } + + unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, + const std::vector<unsigned char>& in, unsigned colorType, unsigned bitDepth) + { + return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colorType, bitDepth); + } + +#ifdef LODEPNG_COMPILE_DISK + unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename, + unsigned colorType, unsigned bitDepth) + { + std::vector<unsigned char> buffer; + loadFile(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, + unsigned colorType, unsigned bitDepth) + { + Encoder encoder; + encoder.getInfoRaw().color.colorType = colorType; + encoder.getInfoRaw().color.bitDepth = bitDepth; + encoder.getInfoPng().color.colorType = colorType; + encoder.getInfoPng().color.bitDepth = bitDepth; + encoder.encode(out, in, w, h); + return encoder.getError(); + } + + unsigned encode(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, unsigned w, unsigned h, + unsigned colorType, unsigned bitDepth) + { + return encode(out, in.empty() ? 0 : &in[0], w, h, colorType, bitDepth); + } + +#ifdef LODEPNG_COMPILE_DISK + unsigned encode(const std::string& filename, const unsigned char* in, unsigned w, unsigned h, + unsigned colorType, unsigned bitDepth) + { + std::vector<unsigned char> buffer; + Encoder encoder; + encoder.getInfoRaw().color.colorType = colorType; + encoder.getInfoRaw().color.bitDepth = bitDepth; + encoder.encode(buffer, in, w, h); + if(!encoder.hasError()) saveFile(buffer, filename); + return encoder.getError(); + } + + unsigned encode(const std::string& filename, const std::vector<unsigned char>& in, unsigned w, unsigned h, + unsigned colorType, unsigned bitDepth) + { + 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 /*__cplusplus C++ RAII wrapper*/ |