| /* |
| LodePNG version 20130415 |
| |
| Copyright (c) 2005-2013 Lode Vandevenne |
| |
| This software is provided 'as-is', without any express or implied |
| warranty. In no event will the authors be held liable for any damages |
| arising from the use of this software. |
| |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it |
| freely, subject to the following restrictions: |
| |
| 1. The origin of this software must not be misrepresented; you must not |
| claim that you wrote the original software. If you use this software |
| in a product, an acknowledgment in the product documentation would be |
| appreciated but is not required. |
| |
| 2. Altered source versions must be plainly marked as such, and must not be |
| misrepresented as being the original software. |
| |
| 3. This notice may not be removed or altered from any source |
| distribution. |
| */ |
| |
| /* |
| The manual and changelog are in the header file "lodepng.h" |
| Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for C. |
| */ |
| |
| #include "lodepng.h" |
| |
| #include <stdio.h> |
| #include <stdlib.h> |
| |
| #ifdef LODEPNG_COMPILE_CPP |
| #include <fstream> |
| #endif /*LODEPNG_COMPILE_CPP*/ |
| |
| #define VERSION_STRING "20130415" |
| |
| /* |
| This source file is built up in the following large parts. The code sections |
| with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way. |
| -Tools for C and common code for PNG and Zlib |
| -C Code for Zlib (huffman, deflate, ...) |
| -C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...) |
| -The C++ wrapper around all of the above |
| */ |
| |
| /*The malloc, realloc and free functions defined here with "lodepng_" in front |
| of the name, so that you can easily change them to others related to your |
| platform if needed. Everything else in the code calls these. Pass |
| -DLODEPNG_NO_COMPILE_ALLOCATORS to the compiler, or comment out |
| #define LODEPNG_COMPILE_ALLOCATORS in the header, to disable the ones here and |
| define them in your own project's source files without needing to change |
| lodepng source code. Don't forget to remove "static" if you copypaste them |
| from here.*/ |
| |
| #ifdef LODEPNG_COMPILE_ALLOCATORS |
| static void* lodepng_malloc(size_t size) |
| { |
| return malloc(size); |
| } |
| |
| static void* lodepng_realloc(void* ptr, size_t new_size) |
| { |
| return realloc(ptr, new_size); |
| } |
| |
| static void lodepng_free(void* ptr) |
| { |
| free(ptr); |
| } |
| #else /*LODEPNG_COMPILE_ALLOCATORS*/ |
| void* lodepng_malloc(size_t size); |
| void* lodepng_realloc(void* ptr, size_t new_size); |
| void lodepng_free(void* ptr); |
| #endif /*LODEPNG_COMPILE_ALLOCATORS*/ |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* // Tools for C, and common code for PNG and Zlib. // */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| /* |
| Often in case of an error a value is assigned to a variable and then it breaks |
| out of a loop (to go to the cleanup phase of a function). This macro does that. |
| It makes the error handling code shorter and more readable. |
| |
| Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83); |
| */ |
| #define CERROR_BREAK(errorvar, code)\ |
| {\ |
| errorvar = code;\ |
| break;\ |
| } |
| |
| /*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/ |
| #define ERROR_BREAK(code) CERROR_BREAK(error, code) |
| |
| /*Set error var to the error code, and return it.*/ |
| #define CERROR_RETURN_ERROR(errorvar, code)\ |
| {\ |
| errorvar = code;\ |
| return code;\ |
| } |
| |
| /*Try the code, if it returns error, also return the error.*/ |
| #define CERROR_TRY_RETURN(call)\ |
| {\ |
| unsigned error = call;\ |
| if(error) return error;\ |
| } |
| |
| /* |
| About uivector, ucvector and string: |
| -All of them wrap dynamic arrays or text strings in a similar way. |
| -LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version. |
| -The string tools are made to avoid problems with compilers that declare things like strncat as deprecated. |
| -They're not used in the interface, only internally in this file as static functions. |
| -As with many other structs in this file, the init and cleanup functions serve as ctor and dtor. |
| */ |
| |
| #ifdef LODEPNG_COMPILE_ZLIB |
| /*dynamic vector of unsigned ints*/ |
| typedef struct uivector |
| { |
| unsigned* data; |
| size_t size; /*size in number of unsigned longs*/ |
| size_t allocsize; /*allocated size in bytes*/ |
| } uivector; |
| |
| static void uivector_cleanup(void* p) |
| { |
| ((uivector*)p)->size = ((uivector*)p)->allocsize = 0; |
| lodepng_free(((uivector*)p)->data); |
| ((uivector*)p)->data = NULL; |
| } |
| |
| /*returns 1 if success, 0 if failure ==> nothing done*/ |
| static unsigned uivector_resize(uivector* p, size_t size) |
| { |
| if(size * sizeof(unsigned) > p->allocsize) |
| { |
| size_t newsize = size * sizeof(unsigned) * 2; |
| void* data = lodepng_realloc(p->data, newsize); |
| if(data) |
| { |
| p->allocsize = newsize; |
| p->data = (unsigned*)data; |
| p->size = size; |
| } |
| else return 0; |
| } |
| else p->size = size; |
| return 1; |
| } |
| |
| /*resize and give all new elements the value*/ |
| static unsigned uivector_resizev(uivector* p, size_t size, unsigned value) |
| { |
| size_t oldsize = p->size, i; |
| if(!uivector_resize(p, size)) return 0; |
| for(i = oldsize; i < size; i++) p->data[i] = value; |
| return 1; |
| } |
| |
| static void uivector_init(uivector* p) |
| { |
| p->data = NULL; |
| p->size = p->allocsize = 0; |
| } |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| /*returns 1 if success, 0 if failure ==> nothing done*/ |
| static unsigned uivector_push_back(uivector* p, unsigned c) |
| { |
| if(!uivector_resize(p, p->size + 1)) return 0; |
| p->data[p->size - 1] = c; |
| return 1; |
| } |
| |
| /*copy q to p, returns 1 if success, 0 if failure ==> nothing done*/ |
| static unsigned uivector_copy(uivector* p, const uivector* q) |
| { |
| size_t i; |
| if(!uivector_resize(p, q->size)) return 0; |
| for(i = 0; i < q->size; i++) p->data[i] = q->data[i]; |
| return 1; |
| } |
| |
| 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; |
| |
| /*returns 1 if success, 0 if failure ==> nothing done*/ |
| static unsigned ucvector_resize(ucvector* p, size_t size) |
| { |
| if(size * sizeof(unsigned char) > p->allocsize) |
| { |
| size_t newsize = size * sizeof(unsigned char) * 2; |
| void* data = lodepng_realloc(p->data, newsize); |
| if(data) |
| { |
| p->allocsize = newsize; |
| p->data = (unsigned char*)data; |
| p->size = size; |
| } |
| else return 0; /*error: not enough memory*/ |
| } |
| else p->size = size; |
| return 1; |
| } |
| |
| #ifdef LODEPNG_COMPILE_PNG |
| |
| static void ucvector_cleanup(void* p) |
| { |
| ((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0; |
| lodepng_free(((ucvector*)p)->data); |
| ((ucvector*)p)->data = NULL; |
| } |
| |
| static void ucvector_init(ucvector* p) |
| { |
| p->data = NULL; |
| p->size = p->allocsize = 0; |
| } |
| |
| #ifdef LODEPNG_COMPILE_DECODER |
| /*resize and give all new elements the value*/ |
| static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value) |
| { |
| size_t oldsize = p->size, i; |
| if(!ucvector_resize(p, size)) return 0; |
| for(i = oldsize; i < size; i++) p->data[i] = value; |
| return 1; |
| } |
| #endif /*LODEPNG_COMPILE_DECODER*/ |
| #endif /*LODEPNG_COMPILE_PNG*/ |
| |
| #ifdef LODEPNG_COMPILE_ZLIB |
| /*you can both convert from vector to buffer&size and vica versa. If you use |
| init_buffer to take over a buffer and size, it is not needed to use cleanup*/ |
| static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size) |
| { |
| p->data = buffer; |
| p->allocsize = p->size = size; |
| } |
| #endif /*LODEPNG_COMPILE_ZLIB*/ |
| |
| #if (defined(LODEPNG_COMPILE_PNG) && defined(LODEPNG_COMPILE_ANCILLARY_CHUNKS)) || defined(LODEPNG_COMPILE_ENCODER) |
| /*returns 1 if success, 0 if failure ==> nothing done*/ |
| static unsigned ucvector_push_back(ucvector* p, unsigned char c) |
| { |
| if(!ucvector_resize(p, p->size + 1)) return 0; |
| p->data[p->size - 1] = c; |
| return 1; |
| } |
| #endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/ |
| |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| #ifdef LODEPNG_COMPILE_PNG |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| /*returns 1 if success, 0 if failure ==> nothing done*/ |
| static unsigned string_resize(char** out, size_t size) |
| { |
| char* data = (char*)lodepng_realloc(*out, size + 1); |
| if(data) |
| { |
| data[size] = 0; /*null termination char*/ |
| *out = data; |
| } |
| return data != 0; |
| } |
| |
| /*init a {char*, size_t} pair for use as string*/ |
| static void string_init(char** out) |
| { |
| *out = NULL; |
| string_resize(out, 0); |
| } |
| |
| /*free the above pair again*/ |
| static void string_cleanup(char** out) |
| { |
| lodepng_free(*out); |
| *out = NULL; |
| } |
| |
| static void string_set(char** out, const char* in) |
| { |
| size_t insize = strlen(in), i = 0; |
| if(string_resize(out, insize)) |
| { |
| for(i = 0; i < insize; i++) |
| { |
| (*out)[i] = in[i]; |
| } |
| } |
| } |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| #endif /*LODEPNG_COMPILE_PNG*/ |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| unsigned lodepng_read32bitInt(const unsigned char* buffer) |
| { |
| return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3]; |
| } |
| |
| #if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER) |
| /*buffer must have at least 4 allocated bytes available*/ |
| static void lodepng_set32bitInt(unsigned char* buffer, unsigned value) |
| { |
| buffer[0] = (unsigned char)((value >> 24) & 0xff); |
| buffer[1] = (unsigned char)((value >> 16) & 0xff); |
| buffer[2] = (unsigned char)((value >> 8) & 0xff); |
| buffer[3] = (unsigned char)((value ) & 0xff); |
| } |
| #endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/ |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| static void lodepng_add32bitInt(ucvector* buffer, unsigned value) |
| { |
| ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/ |
| lodepng_set32bitInt(&buffer->data[buffer->size - 4], value); |
| } |
| #endif /*LODEPNG_COMPILE_ENCODER*/ |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* / File IO / */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| #ifdef LODEPNG_COMPILE_DISK |
| |
| unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename) |
| { |
| FILE* file; |
| long size; |
| |
| /*provide some proper output values if error will happen*/ |
| *out = 0; |
| *outsize = 0; |
| |
| file = fopen(filename, "rb"); |
| if(!file) return 78; |
| |
| /*get filesize:*/ |
| fseek(file , 0 , SEEK_END); |
| size = ftell(file); |
| rewind(file); |
| |
| /*read contents of the file into the vector*/ |
| *outsize = 0; |
| *out = (unsigned char*)lodepng_malloc((size_t)size); |
| if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file); |
| |
| fclose(file); |
| if(!(*out) && size) return 83; /*the above malloc failed*/ |
| return 0; |
| } |
| |
| /*write given buffer to the file, overwriting the file, it doesn't append to it.*/ |
| unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename) |
| { |
| FILE* file; |
| file = fopen(filename, "wb" ); |
| if(!file) return 79; |
| fwrite((char*)buffer , 1 , buffersize, file); |
| fclose(file); |
| return 0; |
| } |
| |
| #endif /*LODEPNG_COMPILE_DISK*/ |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* // End of common code and tools. Begin of Zlib related code. // */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| #ifdef LODEPNG_COMPILE_ZLIB |
| #ifdef LODEPNG_COMPILE_ENCODER |
| /*TODO: this ignores potential out of memory errors*/ |
| 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 |
| { |
| unsigned* tree2d; |
| unsigned* tree1d; |
| unsigned* lengths; /*the lengths of the codes of the 1d-tree*/ |
| unsigned maxbitlen; /*maximum number of bits a single code can get*/ |
| unsigned numcodes; /*number of symbols in the alphabet = number of codes*/ |
| } HuffmanTree; |
| |
| /*function used for debug purposes to draw the tree in ascii art with C++*/ |
| /* |
| static void HuffmanTree_draw(HuffmanTree* tree) |
| { |
| std::cout << "tree. length: " << tree->numcodes << " maxbitlen: " << tree->maxbitlen << std::endl; |
| for(size_t i = 0; i < tree->tree1d.size; i++) |
| { |
| if(tree->lengths.data[i]) |
| std::cout << i << " " << tree->tree1d.data[i] << " " << tree->lengths.data[i] << std::endl; |
| } |
| std::cout << std::endl; |
| }*/ |
| |
| static void HuffmanTree_init(HuffmanTree* tree) |
| { |
| tree->tree2d = 0; |
| tree->tree1d = 0; |
| tree->lengths = 0; |
| } |
| |
| static void HuffmanTree_cleanup(HuffmanTree* tree) |
| { |
| lodepng_free(tree->tree2d); |
| lodepng_free(tree->tree1d); |
| lodepng_free(tree->lengths); |
| } |
| |
| /*the tree representation used by the decoder. return value is error*/ |
| static unsigned HuffmanTree_make2DTree(HuffmanTree* tree) |
| { |
| unsigned nodefilled = 0; /*up to which node it is filled*/ |
| unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/ |
| unsigned n, i; |
| |
| tree->tree2d = (unsigned*)lodepng_malloc(tree->numcodes * 2 * sizeof(unsigned)); |
| if(!tree->tree2d) return 83; /*alloc fail*/ |
| |
| /* |
| convert tree1d[] to tree2d[][]. In the 2D array, a value of 32767 means |
| uninited, a value >= numcodes is an address to another bit, a value < numcodes |
| is a code. The 2 rows are the 2 possible bit values (0 or 1), there are as |
| many columns as codes - 1. |
| A good huffmann tree has N * 2 - 1 nodes, of which N - 1 are internal nodes. |
| Here, the internal nodes are stored (what their 0 and 1 option point to). |
| There is only memory for such good tree currently, if there are more nodes |
| (due to too long length codes), error 55 will happen |
| */ |
| for(n = 0; n < tree->numcodes * 2; n++) |
| { |
| tree->tree2d[n] = 32767; /*32767 here means the tree2d isn't filled there yet*/ |
| } |
| |
| for(n = 0; n < tree->numcodes; n++) /*the codes*/ |
| { |
| for(i = 0; i < tree->lengths[n]; i++) /*the bits for this code*/ |
| { |
| unsigned char bit = (unsigned char)((tree->tree1d[n] >> (tree->lengths[n] - i - 1)) & 1); |
| if(treepos > tree->numcodes - 2) return 55; /*oversubscribed, see comment in lodepng_error_text*/ |
| if(tree->tree2d[2 * treepos + bit] == 32767) /*not yet filled in*/ |
| { |
| if(i + 1 == tree->lengths[n]) /*last bit*/ |
| { |
| tree->tree2d[2 * treepos + bit] = n; /*put the current code in it*/ |
| treepos = 0; |
| } |
| else |
| { |
| /*put address of the next step in here, first that address has to be found of course |
| (it's just nodefilled + 1)...*/ |
| nodefilled++; |
| /*addresses encoded with numcodes added to it*/ |
| tree->tree2d[2 * treepos + bit] = nodefilled + tree->numcodes; |
| treepos = nodefilled; |
| } |
| } |
| else treepos = tree->tree2d[2 * treepos + bit] - tree->numcodes; |
| } |
| } |
| |
| for(n = 0; n < tree->numcodes * 2; n++) |
| { |
| if(tree->tree2d[n] == 32767) tree->tree2d[n] = 0; /*remove possible remaining 32767's*/ |
| } |
| |
| return 0; |
| } |
| |
| /* |
| Second step for the ...makeFromLengths and ...makeFromFrequencies functions. |
| numcodes, lengths and maxbitlen must already be filled in correctly. return |
| value is error. |
| */ |
| static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree) |
| { |
| uivector blcount; |
| uivector nextcode; |
| unsigned bits, n, error = 0; |
| |
| uivector_init(&blcount); |
| uivector_init(&nextcode); |
| |
| tree->tree1d = (unsigned*)lodepng_malloc(tree->numcodes * sizeof(unsigned)); |
| if(!tree->tree1d) error = 83; /*alloc fail*/ |
| |
| if(!uivector_resizev(&blcount, tree->maxbitlen + 1, 0) |
| || !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0)) |
| error = 83; /*alloc fail*/ |
| |
| if(!error) |
| { |
| /*step 1: count number of instances of each code length*/ |
| for(bits = 0; bits < tree->numcodes; bits++) blcount.data[tree->lengths[bits]]++; |
| /*step 2: generate the nextcode values*/ |
| for(bits = 1; bits <= tree->maxbitlen; bits++) |
| { |
| nextcode.data[bits] = (nextcode.data[bits - 1] + blcount.data[bits - 1]) << 1; |
| } |
| /*step 3: generate all the codes*/ |
| for(n = 0; n < tree->numcodes; n++) |
| { |
| if(tree->lengths[n] != 0) tree->tree1d[n] = nextcode.data[tree->lengths[n]]++; |
| } |
| } |
| |
| uivector_cleanup(&blcount); |
| uivector_cleanup(&nextcode); |
| |
| if(!error) return HuffmanTree_make2DTree(tree); |
| else return error; |
| } |
| |
| /* |
| given the code lengths (as stored in the PNG file), generate the tree as defined |
| by Deflate. maxbitlen is the maximum bits that a code in the tree can have. |
| return value is error. |
| */ |
| static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen, |
| size_t numcodes, unsigned maxbitlen) |
| { |
| unsigned i; |
| tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned)); |
| if(!tree->lengths) return 83; /*alloc fail*/ |
| for(i = 0; i < numcodes; i++) tree->lengths[i] = bitlen[i]; |
| tree->numcodes = (unsigned)numcodes; /*number of symbols*/ |
| tree->maxbitlen = maxbitlen; |
| return HuffmanTree_makeFromLengths2(tree); |
| } |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| |
| /* |
| A coin, this is the terminology used for the package-merge algorithm and the |
| coin collector's problem. This is used to generate the huffman tree. |
| A coin can be multiple coins (when they're merged) |
| */ |
| typedef struct Coin |
| { |
| uivector symbols; |
| float weight; /*the sum of all weights in this coin*/ |
| } Coin; |
| |
| static void coin_init(Coin* c) |
| { |
| uivector_init(&c->symbols); |
| } |
| |
| /*argument c is void* so that this dtor can be given as function pointer to the vector resize function*/ |
| static void coin_cleanup(void* c) |
| { |
| uivector_cleanup(&((Coin*)c)->symbols); |
| } |
| |
| static void coin_copy(Coin* c1, const Coin* c2) |
| { |
| c1->weight = c2->weight; |
| uivector_copy(&c1->symbols, &c2->symbols); |
| } |
| |
| static void add_coins(Coin* c1, const Coin* c2) |
| { |
| size_t i; |
| for(i = 0; i < c2->symbols.size; i++) uivector_push_back(&c1->symbols, c2->symbols.data[i]); |
| c1->weight += c2->weight; |
| } |
| |
| static void init_coins(Coin* coins, size_t num) |
| { |
| size_t i; |
| for(i = 0; i < num; i++) coin_init(&coins[i]); |
| } |
| |
| static void cleanup_coins(Coin* coins, size_t num) |
| { |
| size_t i; |
| for(i = 0; i < num; i++) coin_cleanup(&coins[i]); |
| } |
| |
| /* |
| 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 sort_coins(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 append_symbol_coins(Coin* coins, const unsigned* frequencies, unsigned numcodes, size_t sum) |
| { |
| unsigned i; |
| unsigned j = 0; /*index of present symbols*/ |
| for(i = 0; i < numcodes; i++) |
| { |
| if(frequencies[i] != 0) /*only include symbols that are present*/ |
| { |
| coins[j].weight = frequencies[i] / (float)sum; |
| uivector_push_back(&coins[j].symbols, i); |
| j++; |
| } |
| } |
| return 0; |
| } |
| |
| unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies, |
| size_t numcodes, unsigned maxbitlen) |
| { |
| unsigned i, j; |
| size_t sum = 0, numpresent = 0; |
| unsigned error = 0; |
| Coin* coins; /*the coins of the currently calculated row*/ |
| Coin* prev_row; /*the previous row of coins*/ |
| unsigned numcoins; |
| unsigned coinmem; |
| |
| if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/ |
| |
| for(i = 0; i < numcodes; i++) |
| { |
| if(frequencies[i] > 0) |
| { |
| numpresent++; |
| sum += frequencies[i]; |
| } |
| } |
| |
| for(i = 0; i < numcodes; i++) lengths[i] = 0; |
| |
| /*ensure at least two present symbols. There should be at least one symbol |
| according to RFC 1951 section 3.2.7. To decoders incorrectly require two. To |
| make these work as well ensure there are at least two symbols. The |
| Package-Merge code below also doesn't work correctly if there's only one |
| symbol, it'd give it the theoritical 0 bits but in practice zlib wants 1 bit*/ |
| if(numpresent == 0) |
| { |
| lengths[0] = lengths[1] = 1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/ |
| } |
| else if(numpresent == 1) |
| { |
| for(i = 0; i < numcodes; i++) |
| { |
| if(frequencies[i]) |
| { |
| lengths[i] = 1; |
| lengths[i == 0 ? 1 : 0] = 1; |
| break; |
| } |
| } |
| } |
| else |
| { |
| /*Package-Merge algorithm represented by coin collector's problem |
| For every symbol, maxbitlen coins will be created*/ |
| |
| coinmem = numpresent * 2; /*max amount of coins needed with the current algo*/ |
| coins = (Coin*)lodepng_malloc(sizeof(Coin) * coinmem); |
| prev_row = (Coin*)lodepng_malloc(sizeof(Coin) * coinmem); |
| if(!coins || !prev_row) return 83; /*alloc fail*/ |
| init_coins(coins, coinmem); |
| init_coins(prev_row, coinmem); |
| |
| /*first row, lowest denominator*/ |
| error = append_symbol_coins(coins, frequencies, numcodes, sum); |
| numcoins = numpresent; |
| sort_coins(coins, numcoins); |
| if(!error) |
| { |
| unsigned numprev = 0; |
| for(j = 1; j <= maxbitlen && !error; j++) /*each of the remaining rows*/ |
| { |
| unsigned tempnum; |
| Coin* tempcoins; |
| /*swap prev_row and coins, and their amounts*/ |
| tempcoins = prev_row; prev_row = coins; coins = tempcoins; |
| tempnum = numprev; numprev = numcoins; numcoins = tempnum; |
| |
| cleanup_coins(coins, numcoins); |
| init_coins(coins, numcoins); |
| |
| numcoins = 0; |
| |
| /*fill in the merged coins of the previous row*/ |
| for(i = 0; i + 1 < numprev; i += 2) |
| { |
| /*merge prev_row[i] and prev_row[i + 1] into new coin*/ |
| Coin* coin = &coins[numcoins++]; |
| coin_copy(coin, &prev_row[i]); |
| add_coins(coin, &prev_row[i + 1]); |
| } |
| /*fill in all the original symbols again*/ |
| if(j < maxbitlen) |
| { |
| error = append_symbol_coins(coins + numcoins, frequencies, numcodes, sum); |
| numcoins += numpresent; |
| } |
| sort_coins(coins, numcoins); |
| } |
| } |
| |
| if(!error) |
| { |
| /*calculate the lenghts of each symbol, as the amount of times a coin of each symbol is used*/ |
| for(i = 0; i < numpresent - 1; i++) |
| { |
| Coin* coin = &coins[i]; |
| for(j = 0; j < coin->symbols.size; j++) lengths[coin->symbols.data[j]]++; |
| } |
| } |
| |
| cleanup_coins(coins, coinmem); |
| lodepng_free(coins); |
| cleanup_coins(prev_row, coinmem); |
| lodepng_free(prev_row); |
| } |
| |
| return error; |
| } |
| |
| /*Create the Huffman tree given the symbol frequencies*/ |
| static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies, |
| size_t mincodes, size_t numcodes, unsigned maxbitlen) |
| { |
| unsigned error = 0; |
| while(!frequencies[numcodes - 1] && numcodes > mincodes) numcodes--; /*trim zeroes*/ |
| tree->maxbitlen = maxbitlen; |
| tree->numcodes = (unsigned)numcodes; /*number of symbols*/ |
| tree->lengths = (unsigned*)lodepng_realloc(tree->lengths, numcodes * sizeof(unsigned)); |
| if(!tree->lengths) return 83; /*alloc fail*/ |
| /*initialize all lengths to 0*/ |
| memset(tree->lengths, 0, numcodes * sizeof(unsigned)); |
| |
| error = lodepng_huffman_code_lengths(tree->lengths, frequencies, numcodes, maxbitlen); |
| if(!error) error = HuffmanTree_makeFromLengths2(tree); |
| return error; |
| } |
| |
| static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index) |
| { |
| return tree->tree1d[index]; |
| } |
| |
| static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index) |
| { |
| return tree->lengths[index]; |
| } |
| #endif /*LODEPNG_COMPILE_ENCODER*/ |
| |
| /*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/ |
| static unsigned generateFixedLitLenTree(HuffmanTree* tree) |
| { |
| unsigned i, error = 0; |
| unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned)); |
| if(!bitlen) return 83; /*alloc fail*/ |
| |
| /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/ |
| for(i = 0; i <= 143; i++) bitlen[i] = 8; |
| for(i = 144; i <= 255; i++) bitlen[i] = 9; |
| for(i = 256; i <= 279; i++) bitlen[i] = 7; |
| for(i = 280; i <= 287; i++) bitlen[i] = 8; |
| |
| error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DEFLATE_CODE_SYMBOLS, 15); |
| |
| lodepng_free(bitlen); |
| return error; |
| } |
| |
| /*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/ |
| static unsigned generateFixedDistanceTree(HuffmanTree* tree) |
| { |
| unsigned i, error = 0; |
| unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned)); |
| if(!bitlen) return 83; /*alloc fail*/ |
| |
| /*there are 32 distance codes, but 30-31 are unused*/ |
| for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen[i] = 5; |
| error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DISTANCE_SYMBOLS, 15); |
| |
| lodepng_free(bitlen); |
| return error; |
| } |
| |
| #ifdef LODEPNG_COMPILE_DECODER |
| |
| /* |
| returns the code, or (unsigned)(-1) if error happened |
| inbitlength is the length of the complete buffer, in bits (so its byte length times 8) |
| */ |
| static unsigned huffmanDecodeSymbol(const unsigned char* in, size_t* bp, |
| const HuffmanTree* codetree, size_t inbitlength) |
| { |
| unsigned treepos = 0, ct; |
| for(;;) |
| { |
| if(*bp >= inbitlength) return (unsigned)(-1); /*error: end of input memory reached without endcode*/ |
| /* |
| decode the symbol from the tree. The "readBitFromStream" code is inlined in |
| the expression below because this is the biggest bottleneck while decoding |
| */ |
| ct = codetree->tree2d[(treepos << 1) + READBIT(*bp, in)]; |
| (*bp)++; |
| if(ct < codetree->numcodes) return ct; /*the symbol is decoded, return it*/ |
| else treepos = ct - codetree->numcodes; /*symbol not yet decoded, instead move tree position*/ |
| |
| if(treepos >= codetree->numcodes) return (unsigned)(-1); /*error: it appeared outside the codetree*/ |
| } |
| } |
| #endif /*LODEPNG_COMPILE_DECODER*/ |
| |
| #ifdef LODEPNG_COMPILE_DECODER |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* / Inflator (Decompressor) / */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| /*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/ |
| static void getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d) |
| { |
| /*TODO: check for out of memory errors*/ |
| generateFixedLitLenTree(tree_ll); |
| generateFixedDistanceTree(tree_d); |
| } |
| |
| /*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/ |
| static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d, |
| const unsigned char* in, size_t* bp, size_t inlength) |
| { |
| /*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/ |
| unsigned error = 0; |
| unsigned n, HLIT, HDIST, HCLEN, i; |
| size_t inbitlength = inlength * 8; |
| |
| /*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/ |
| unsigned* bitlen_ll = 0; /*lit,len code lengths*/ |
| unsigned* bitlen_d = 0; /*dist code lengths*/ |
| /*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/ |
| unsigned* bitlen_cl = 0; |
| HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/ |
| |
| if((*bp) >> 3 >= inlength - 2) return 49; /*error: the bit pointer is or will go past the memory*/ |
| |
| /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/ |
| HLIT = readBitsFromStream(bp, in, 5) + 257; |
| /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/ |
| HDIST = readBitsFromStream(bp, in, 5) + 1; |
| /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/ |
| HCLEN = readBitsFromStream(bp, in, 4) + 4; |
| |
| HuffmanTree_init(&tree_cl); |
| |
| while(!error) |
| { |
| /*read the code length codes out of 3 * (amount of code length codes) bits*/ |
| |
| bitlen_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned)); |
| if(!bitlen_cl) ERROR_BREAK(83 /*alloc fail*/); |
| |
| for(i = 0; i < NUM_CODE_LENGTH_CODES; i++) |
| { |
| if(i < HCLEN) bitlen_cl[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3); |
| else bitlen_cl[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/ |
| } |
| |
| error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7); |
| if(error) break; |
| |
| /*now we can use this tree to read the lengths for the tree that this function will return*/ |
| bitlen_ll = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned)); |
| bitlen_d = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned)); |
| if(!bitlen_ll || !bitlen_d) ERROR_BREAK(83 /*alloc fail*/); |
| for(i = 0; i < NUM_DEFLATE_CODE_SYMBOLS; i++) bitlen_ll[i] = 0; |
| for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen_d[i] = 0; |
| |
| /*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/ |
| i = 0; |
| while(i < HLIT + HDIST) |
| { |
| unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength); |
| if(code <= 15) /*a length code*/ |
| { |
| if(i < HLIT) bitlen_ll[i] = code; |
| else bitlen_d[i - HLIT] = code; |
| i++; |
| } |
| else if(code == 16) /*repeat previous*/ |
| { |
| unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/ |
| unsigned value; /*set value to the previous code*/ |
| |
| if(*bp >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ |
| if (i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/ |
| |
| replength += readBitsFromStream(bp, in, 2); |
| |
| if(i < HLIT + 1) value = bitlen_ll[i - 1]; |
| else value = bitlen_d[i - HLIT - 1]; |
| /*repeat this value in the next lengths*/ |
| for(n = 0; n < replength; n++) |
| { |
| if(i >= HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/ |
| if(i < HLIT) bitlen_ll[i] = value; |
| else bitlen_d[i - HLIT] = value; |
| i++; |
| } |
| } |
| else if(code == 17) /*repeat "0" 3-10 times*/ |
| { |
| unsigned replength = 3; /*read in the bits that indicate repeat length*/ |
| if(*bp >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ |
| |
| replength += readBitsFromStream(bp, in, 3); |
| |
| /*repeat this value in the next lengths*/ |
| for(n = 0; n < replength; n++) |
| { |
| if(i >= HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/ |
| |
| if(i < HLIT) bitlen_ll[i] = 0; |
| else bitlen_d[i - HLIT] = 0; |
| i++; |
| } |
| } |
| else if(code == 18) /*repeat "0" 11-138 times*/ |
| { |
| unsigned replength = 11; /*read in the bits that indicate repeat length*/ |
| if(*bp >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/ |
| |
| replength += readBitsFromStream(bp, in, 7); |
| |
| /*repeat this value in the next lengths*/ |
| for(n = 0; n < replength; n++) |
| { |
| if(i >= HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/ |
| |
| if(i < HLIT) bitlen_ll[i] = 0; |
| else bitlen_d[i - HLIT] = 0; |
| i++; |
| } |
| } |
| else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/ |
| { |
| if(code == (unsigned)(-1)) |
| { |
| /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol |
| (10=no endcode, 11=wrong jump outside of tree)*/ |
| error = (*bp) > inbitlength ? 10 : 11; |
| } |
| else error = 16; /*unexisting code, this can never happen*/ |
| break; |
| } |
| } |
| if(error) break; |
| |
| if(bitlen_ll[256] == 0) ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/ |
| |
| /*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/ |
| error = HuffmanTree_makeFromLengths(tree_ll, bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 15); |
| if(error) break; |
| error = HuffmanTree_makeFromLengths(tree_d, bitlen_d, NUM_DISTANCE_SYMBOLS, 15); |
| |
| break; /*end of error-while*/ |
| } |
| |
| lodepng_free(bitlen_cl); |
| lodepng_free(bitlen_ll); |
| lodepng_free(bitlen_d); |
| HuffmanTree_cleanup(&tree_cl); |
| |
| return error; |
| } |
| |
| /*inflate a block with dynamic of fixed Huffman tree*/ |
| static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size_t* bp, |
| size_t* pos, size_t inlength, unsigned btype) |
| { |
| unsigned error = 0; |
| HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/ |
| HuffmanTree tree_d; /*the huffman tree for distance codes*/ |
| size_t inbitlength = inlength * 8; |
| |
| HuffmanTree_init(&tree_ll); |
| HuffmanTree_init(&tree_d); |
| |
| if(btype == 1) getTreeInflateFixed(&tree_ll, &tree_d); |
| else if(btype == 2) error = getTreeInflateDynamic(&tree_ll, &tree_d, in, bp, inlength); |
| |
| while(!error) /*decode all symbols until end reached, breaks at end code*/ |
| { |
| /*code_ll is literal, length or end code*/ |
| unsigned code_ll = huffmanDecodeSymbol(in, bp, &tree_ll, inbitlength); |
| if(code_ll <= 255) /*literal symbol*/ |
| { |
| if((*pos) >= out->size) |
| { |
| /*reserve more room at once*/ |
| if(!ucvector_resize(out, ((*pos) + 1) * 2)) ERROR_BREAK(83 /*alloc fail*/); |
| } |
| out->data[(*pos)] = (unsigned char)(code_ll); |
| (*pos)++; |
| } |
| else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/ |
| { |
| unsigned code_d, distance; |
| unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/ |
| size_t start, forward, backward, length; |
| |
| /*part 1: get length base*/ |
| length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX]; |
| |
| /*part 2: get extra bits and add the value of that to length*/ |
| numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX]; |
| if(*bp >= inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/ |
| length += readBitsFromStream(bp, in, numextrabits_l); |
| |
| /*part 3: get distance code*/ |
| code_d = huffmanDecodeSymbol(in, bp, &tree_d, inbitlength); |
| if(code_d > 29) |
| { |
| if(code_ll == (unsigned)(-1)) /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/ |
| { |
| /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol |
| (10=no endcode, 11=wrong jump outside of tree)*/ |
| error = (*bp) > inlength * 8 ? 10 : 11; |
| } |
| else error = 18; /*error: invalid distance code (30-31 are never used)*/ |
| break; |
| } |
| distance = DISTANCEBASE[code_d]; |
| |
| /*part 4: get extra bits from distance*/ |
| numextrabits_d = DISTANCEEXTRA[code_d]; |
| if(*bp >= inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/ |
| |
| distance += readBitsFromStream(bp, in, numextrabits_d); |
| |
| /*part 5: fill in all the out[n] values based on the length and dist*/ |
| start = (*pos); |
| if(distance > start) ERROR_BREAK(52); /*too long backward distance*/ |
| backward = start - distance; |
| if((*pos) + length >= out->size) |
| { |
| /*reserve more room at once*/ |
| if(!ucvector_resize(out, ((*pos) + length) * 2)) ERROR_BREAK(83 /*alloc fail*/); |
| } |
| |
| for(forward = 0; forward < length; forward++) |
| { |
| out->data[(*pos)] = out->data[backward]; |
| (*pos)++; |
| backward++; |
| if(backward >= start) backward = start - distance; |
| } |
| } |
| else if(code_ll == 256) |
| { |
| break; /*end code, break the loop*/ |
| } |
| else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/ |
| { |
| /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol |
| (10=no endcode, 11=wrong jump outside of tree)*/ |
| error = (*bp) > inlength * 8 ? 10 : 11; |
| break; |
| } |
| } |
| |
| HuffmanTree_cleanup(&tree_ll); |
| HuffmanTree_cleanup(&tree_d); |
| |
| return error; |
| } |
| |
| static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength) |
| { |
| /*go to first boundary of byte*/ |
| size_t p; |
| unsigned LEN, NLEN, n, error = 0; |
| while(((*bp) & 0x7) != 0) (*bp)++; |
| p = (*bp) / 8; /*byte position*/ |
| |
| /*read LEN (2 bytes) and NLEN (2 bytes)*/ |
| if(p >= inlength - 4) return 52; /*error, bit pointer will jump past memory*/ |
| LEN = in[p] + 256 * in[p + 1]; p += 2; |
| NLEN = in[p] + 256 * in[p + 1]; p += 2; |
| |
| /*check if 16-bit NLEN is really the one's complement of LEN*/ |
| if(LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/ |
| |
| if((*pos) + LEN >= out->size) |
| { |
| if(!ucvector_resize(out, (*pos) + LEN)) return 83; /*alloc fail*/ |
| } |
| |
| /*read the literal data: LEN bytes are now stored in the out buffer*/ |
| if(p + LEN > inlength) return 23; /*error: reading outside of in buffer*/ |
| for(n = 0; n < LEN; n++) out->data[(*pos)++] = in[p++]; |
| |
| (*bp) = p * 8; |
| |
| return error; |
| } |
| |
| static unsigned lodepng_inflatev(ucvector* out, |
| const unsigned char* in, size_t insize, |
| const LodePNGDecompressSettings* settings) |
| { |
| /*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/ |
| size_t bp = 0; |
| unsigned BFINAL = 0; |
| size_t pos = 0; /*byte position in the out buffer*/ |
| |
| unsigned error = 0; |
| |
| (void)settings; |
| |
| while(!BFINAL) |
| { |
| unsigned BTYPE; |
| if(bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/ |
| BFINAL = readBitFromStream(&bp, in); |
| BTYPE = 1 * readBitFromStream(&bp, in); |
| BTYPE += 2 * readBitFromStream(&bp, in); |
| |
| if(BTYPE == 3) return 20; /*error: invalid BTYPE*/ |
| else if(BTYPE == 0) error = inflateNoCompression(out, in, &bp, &pos, insize); /*no compression*/ |
| else error = inflateHuffmanBlock(out, in, &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/ |
| |
| if(error) return error; |
| } |
| |
| /*Only now we know the true size of out, resize it to that*/ |
| if(!ucvector_resize(out, pos)) error = 83; /*alloc fail*/ |
| |
| return error; |
| } |
| |
| unsigned lodepng_inflate(unsigned char** out, size_t* outsize, |
| const unsigned char* in, size_t insize, |
| const LodePNGDecompressSettings* settings) |
| { |
| unsigned error; |
| ucvector v; |
| ucvector_init_buffer(&v, *out, *outsize); |
| error = lodepng_inflatev(&v, in, insize, settings); |
| *out = v.data; |
| *outsize = v.size; |
| return error; |
| } |
| |
| static unsigned inflate(unsigned char** out, size_t* outsize, |
| const unsigned char* in, size_t insize, |
| const LodePNGDecompressSettings* settings) |
| { |
| if(settings->custom_inflate) |
| { |
| return settings->custom_inflate(out, outsize, in, insize, settings); |
| } |
| else |
| { |
| return lodepng_inflate(out, outsize, in, insize, settings); |
| } |
| } |
| |
| #endif /*LODEPNG_COMPILE_DECODER*/ |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* / Deflator (Compressor) / */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258; |
| |
| /*bitlen is the size in bits of the code*/ |
| static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen) |
| { |
| addBitsToStreamReversed(bp, compressed, code, bitlen); |
| } |
| |
| /*search the index in the array, that has the largest value smaller than or equal to the given value, |
| given array must be sorted (if no value is smaller, it returns the size of the given array)*/ |
| static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value) |
| { |
| /*linear search implementation*/ |
| /*for(size_t i = 1; i < array_size; i++) if(array[i] > value) return i - 1; |
| return array_size - 1;*/ |
| |
| /*binary search implementation (not that much faster) (precondition: array_size > 0)*/ |
| size_t left = 1; |
| size_t right = array_size - 1; |
| while(left <= right) |
| { |
| size_t mid = (left + right) / 2; |
| if(array[mid] <= value) left = mid + 1; /*the value to find is more to the right*/ |
| else if(array[mid - 1] > value) right = mid - 1; /*the value to find is more to the left*/ |
| else return mid - 1; |
| } |
| return array_size - 1; |
| } |
| |
| static void addLengthDistance(uivector* values, size_t length, size_t distance) |
| { |
| /*values in encoded vector are those used by deflate: |
| 0-255: literal bytes |
| 256: end |
| 257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits) |
| 286-287: invalid*/ |
| |
| unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length); |
| unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]); |
| unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance); |
| unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]); |
| |
| uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX); |
| uivector_push_back(values, extra_length); |
| uivector_push_back(values, dist_code); |
| uivector_push_back(values, extra_distance); |
| } |
| |
| static const unsigned HASH_NUM_VALUES = 65536; |
| static const unsigned HASH_NUM_CHARACTERS = 3; |
| static const unsigned HASH_SHIFT = 2; |
| /* |
| The HASH_NUM_CHARACTERS value is used to make encoding faster by using longer |
| sequences to generate a hash value from the stream bytes. Setting it to 3 |
| gives exactly the same compression as the brute force method, since deflate's |
| run length encoding starts with lengths of 3. Setting it to higher values, |
| like 6, can make the encoding faster (not always though!), but will cause the |
| encoding to miss any length between 3 and this value, so that the compression |
| may be worse (but this can vary too depending on the image, sometimes it is |
| even a bit better instead). |
| The HASH_NUM_VALUES is the amount of unique possible hash values that |
| combinations of bytes can give, the higher it is the more memory is needed, but |
| if it's too low the advantage of hashing is gone. |
| */ |
| |
| typedef struct Hash |
| { |
| int* head; /*hash value to head circular pos*/ |
| int* val; /*circular pos to hash value*/ |
| /*circular pos to prev circular pos*/ |
| unsigned short* chain; |
| unsigned short* zeros; |
| } Hash; |
| |
| static unsigned hash_init(Hash* hash, unsigned windowsize) |
| { |
| unsigned i; |
| hash->head = (int*)lodepng_malloc(sizeof(int) * HASH_NUM_VALUES); |
| hash->val = (int*)lodepng_malloc(sizeof(int) * windowsize); |
| hash->chain = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize); |
| hash->zeros = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize); |
| |
| if(!hash->head || !hash->val || !hash->chain || !hash->zeros) return 83; /*alloc fail*/ |
| |
| /*initialize hash table*/ |
| for(i = 0; i < HASH_NUM_VALUES; i++) hash->head[i] = -1; |
| for(i = 0; i < windowsize; i++) hash->val[i] = -1; |
| for(i = 0; i < windowsize; i++) hash->chain[i] = i; /*same value as index indicates uninitialized*/ |
| |
| return 0; |
| } |
| |
| static void hash_cleanup(Hash* hash) |
| { |
| lodepng_free(hash->head); |
| lodepng_free(hash->val); |
| lodepng_free(hash->chain); |
| lodepng_free(hash->zeros); |
| } |
| |
| static unsigned getHash(const unsigned char* data, size_t size, size_t pos) |
| { |
| unsigned result = 0; |
| size_t amount, i; |
| if(pos >= size) return 0; |
| amount = HASH_NUM_CHARACTERS; |
| if(pos + amount >= size) amount = size - pos; |
| for(i = 0; i < amount; i++) result ^= (data[pos + i] << (i * HASH_SHIFT)); |
| return result % HASH_NUM_VALUES; |
| } |
| |
| static unsigned countZeros(const unsigned char* data, size_t size, size_t pos) |
| { |
| const unsigned char* start = data + pos; |
| const unsigned char* end = start + MAX_SUPPORTED_DEFLATE_LENGTH; |
| if(end > data + size) end = data + size; |
| data = start; |
| while (data != end && *data == 0) data++; |
| /*subtracting two addresses returned as 32-bit number (max value is MAX_SUPPORTED_DEFLATE_LENGTH)*/ |
| return (unsigned)(data - start); |
| } |
| |
| static void updateHashChain(Hash* hash, size_t pos, int hashval, unsigned windowsize) |
| { |
| unsigned wpos = pos % windowsize; |
| hash->val[wpos] = hashval; |
| if(hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval]; |
| hash->head[hashval] = wpos; |
| } |
| |
| /* |
| LZ77-encode the data. Return value is error code. The input are raw bytes, the output |
| is in the form of unsigned integers with codes representing for example literal bytes, or |
| length/distance pairs. |
| It uses a hash table technique to let it encode faster. When doing LZ77 encoding, a |
| sliding window (of windowsize) is used, and all past bytes in that window can be used as |
| the "dictionary". A brute force search through all possible distances would be slow, and |
| this hash technique is one out of several ways to speed this up. |
| */ |
| static unsigned encodeLZ77(uivector* out, Hash* hash, |
| const unsigned char* in, size_t inpos, size_t insize, unsigned windowsize, |
| unsigned minmatch, unsigned nicematch, unsigned lazymatching) |
| { |
| unsigned short numzeros = 0; |
| int usezeros = windowsize >= 8192; /*for small window size, the 'max chain length' optimization does a better job*/ |
| unsigned pos, i, error = 0; |
| /*for large window lengths, assume the user wants no compression loss. Otherwise, max hash chain length speedup.*/ |
| unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8; |
| unsigned maxlazymatch = windowsize >= 8192 ? MAX_SUPPORTED_DEFLATE_LENGTH : 64; |
| |
| if(!error) |
| { |
| unsigned offset; /*the offset represents the distance in LZ77 terminology*/ |
| unsigned length; |
| unsigned lazy = 0; |
| unsigned lazylength = 0, lazyoffset = 0; |
| unsigned hashval; |
| unsigned current_offset, current_length; |
| const unsigned char *lastptr, *foreptr, *backptr; |
| unsigned short hashpos, prevpos; |
| |
| for(pos = inpos; pos < insize; pos++) |
| { |
| size_t wpos = pos % windowsize; /*position for in 'circular' hash buffers*/ |
| |
| hashval = getHash(in, insize, pos); |
| updateHashChain(hash, pos, hashval, windowsize); |
| |
| if(usezeros && hashval == 0) |
| { |
| numzeros = countZeros(in, insize, pos); |
| hash->zeros[wpos] = numzeros; |
| } |
| |
| /*the length and offset found for the current position*/ |
| length = 0; |
| offset = 0; |
| |
| prevpos = hash->head[hashval]; |
| hashpos = hash->chain[prevpos]; |
| |
| lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH]; |
| |
| /*search for the longest string*/ |
| if(hash->val[wpos] == (int)hashval) |
| { |
| unsigned chainlength = 0; |
| for(;;) |
| { |
| /*stop when went completely around the circular buffer*/ |
| if(prevpos < wpos && hashpos > prevpos && hashpos <= wpos) break; |
| if(prevpos > wpos && (hashpos <= wpos || hashpos > prevpos)) break; |
| if(chainlength++ >= maxchainlength) break; |
| |
| current_offset = hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize; |
| if(current_offset > 0) |
| { |
| /*test the next characters*/ |
| foreptr = &in[pos]; |
| backptr = &in[pos - current_offset]; |
| |
| /*common case in PNGs is lots of zeros. Quickly skip over them as a speedup*/ |
| if(usezeros && hashval == 0 && hash->val[hashpos] == 0 /*hashval[hashpos] may be out of date*/) |
| { |
| unsigned short skip = hash->zeros[hashpos]; |
| if(skip > numzeros) skip = numzeros; |
| backptr += skip; |
| foreptr += skip; |
| } |
| |
| /* multiple checks at once per array bounds check */ |
| while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/ |
| { |
| ++backptr; |
| ++foreptr; |
| } |
| current_length = (unsigned)(foreptr - &in[pos]); |
| |
| if(current_length > length) |
| { |
| length = current_length; /*the longest length*/ |
| offset = current_offset; /*the offset that is related to this longest length*/ |
| /*jump out once a length of max length is found (speed gain)*/ |
| if(current_length >= nicematch || current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break; |
| } |
| } |
| |
| if(hashpos == hash->chain[hashpos]) break; |
| |
| prevpos = hashpos; |
| hashpos = hash->chain[hashpos]; |
| } |
| } |
| |
| if(lazymatching) |
| { |
| if(!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH) |
| { |
| lazy = 1; |
| lazylength = length; |
| lazyoffset = offset; |
| continue; /*try the next byte*/ |
| } |
| if(lazy) |
| { |
| lazy = 0; |
| if(pos == 0) ERROR_BREAK(81); |
| if(length > lazylength + 1) |
| { |
| /*push the previous character as literal*/ |
| if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(83 /*alloc fail*/); |
| } |
| else |
| { |
| length = lazylength; |
| offset = lazyoffset; |
| hash->head[hashval] = -1; /*the same hashchain update will be done, this ensures no wrong alteration*/ |
| pos--; |
| } |
| } |
| } |
| if(length >= 3 && offset > windowsize) ERROR_BREAK(86 /*too big (or overflown negative) offset*/); |
| |
| /**encode it as length/distance pair or literal value**/ |
| if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/ |
| { |
| if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/); |
| } |
| else if(length < minmatch || (length == 3 && offset > 4096)) |
| { |
| /*compensate for the fact that longer offsets have more extra bits, a |
| length of only 3 may be not worth it then*/ |
| if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/); |
| } |
| else |
| { |
| addLengthDistance(out, length, offset); |
| for(i = 1; i < length; i++) |
| { |
| pos++; |
| hashval = getHash(in, insize, pos); |
| updateHashChain(hash, pos, hashval, windowsize); |
| if(usezeros && hashval == 0) |
| { |
| hash->zeros[pos % windowsize] = countZeros(in, insize, pos); |
| } |
| } |
| } |
| |
| } /*end of the loop through each character of input*/ |
| } /*end of "if(!error)"*/ |
| |
| return error; |
| } |
| |
| /* /////////////////////////////////////////////////////////////////////////// */ |
| |
| static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize) |
| { |
| /*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte, |
| 2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/ |
| |
| size_t i, j, numdeflateblocks = (datasize + 65534) / 65535; |
| unsigned datapos = 0; |
| for(i = 0; i < numdeflateblocks; i++) |
| { |
| unsigned BFINAL, BTYPE, LEN, NLEN; |
| unsigned char firstbyte; |
| |
| BFINAL = (i == numdeflateblocks - 1); |
| BTYPE = 0; |
| |
| firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1)); |
| ucvector_push_back(out, firstbyte); |
| |
| LEN = 65535; |
| if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos; |
| NLEN = 65535 - LEN; |
| |
| ucvector_push_back(out, (unsigned char)(LEN % 256)); |
| ucvector_push_back(out, (unsigned char)(LEN / 256)); |
| ucvector_push_back(out, (unsigned char)(NLEN % 256)); |
| ucvector_push_back(out, (unsigned char)(NLEN / 256)); |
| |
| /*Decompressed data*/ |
| for(j = 0; j < 65535 && datapos < datasize; j++) |
| { |
| ucvector_push_back(out, data[datapos++]); |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* |
| write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees. |
| tree_ll: the tree for lit and len codes. |
| tree_d: the tree for distance codes. |
| */ |
| static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded, |
| const HuffmanTree* tree_ll, const HuffmanTree* tree_d) |
| { |
| size_t i = 0; |
| for(i = 0; i < lz77_encoded->size; i++) |
| { |
| unsigned val = lz77_encoded->data[i]; |
| addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_ll, val), HuffmanTree_getLength(tree_ll, val)); |
| if(val > 256) /*for a length code, 3 more things have to be added*/ |
| { |
| unsigned length_index = val - FIRST_LENGTH_CODE_INDEX; |
| unsigned n_length_extra_bits = LENGTHEXTRA[length_index]; |
| unsigned length_extra_bits = lz77_encoded->data[++i]; |
| |
| unsigned distance_code = lz77_encoded->data[++i]; |
| |
| unsigned distance_index = distance_code; |
| unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index]; |
| unsigned distance_extra_bits = lz77_encoded->data[++i]; |
| |
| addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits); |
| addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_d, distance_code), |
| HuffmanTree_getLength(tree_d, distance_code)); |
| addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits); |
| } |
| } |
| } |
| |
| /*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/ |
| static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash, |
| const unsigned char* data, size_t datapos, size_t dataend, |
| const LodePNGCompressSettings* settings, int final) |
| { |
| unsigned error = 0; |
| |
| /* |
| A block is compressed as follows: The PNG data is lz77 encoded, resulting in |
| literal bytes and length/distance pairs. This is then huffman compressed with |
| two huffman trees. One huffman tree is used for the lit and len values ("ll"), |
| another huffman tree is used for the dist values ("d"). These two trees are |
| stored using their code lengths, and to compress even more these code lengths |
| are also run-length encoded and huffman compressed. This gives a huffman tree |
| of code lengths "cl". The code lenghts used to describe this third tree are |
| the code length code lengths ("clcl"). |
| */ |
| |
| /*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/ |
| uivector lz77_encoded; |
| HuffmanTree tree_ll; /*tree for lit,len values*/ |
| HuffmanTree tree_d; /*tree for distance codes*/ |
| HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/ |
| uivector frequencies_ll; /*frequency of lit,len codes*/ |
| uivector frequencies_d; /*frequency of dist codes*/ |
| uivector frequencies_cl; /*frequency of code length codes*/ |
| uivector bitlen_lld; /*lit,len,dist code lenghts (int bits), literally (without repeat codes).*/ |
| uivector bitlen_lld_e; /*bitlen_lld encoded with repeat codes (this is a rudemtary run length compression)*/ |
| /*bitlen_cl is the code length code lengths ("clcl"). The bit lengths of codes to represent tree_cl |
| (these are written as is in the file, it would be crazy to compress these using yet another huffman |
| tree that needs to be represented by yet another set of code lengths)*/ |
| uivector bitlen_cl; |
| size_t datasize = dataend - datapos; |
| |
| /* |
| Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies: |
| bitlen_lld is to tree_cl what data is to tree_ll and tree_d. |
| bitlen_lld_e is to bitlen_lld what lz77_encoded is to data. |
| bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded. |
| */ |
| |
| unsigned BFINAL = final; |
| size_t numcodes_ll, numcodes_d, i; |
| unsigned HLIT, HDIST, HCLEN; |
| |
| uivector_init(&lz77_encoded); |
| HuffmanTree_init(&tree_ll); |
| HuffmanTree_init(&tree_d); |
| HuffmanTree_init(&tree_cl); |
| uivector_init(&frequencies_ll); |
| uivector_init(&frequencies_d); |
| uivector_init(&frequencies_cl); |
| uivector_init(&bitlen_lld); |
| uivector_init(&bitlen_lld_e); |
| uivector_init(&bitlen_cl); |
| |
| /*This while loop never loops due to a break at the end, it is here to |
| allow breaking out of it to the cleanup phase on error conditions.*/ |
| while(!error) |
| { |
| if(settings->use_lz77) |
| { |
| error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize, |
| settings->minmatch, settings->nicematch, settings->lazymatching); |
| if(error) break; |
| } |
| else |
| { |
| if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83 /*alloc fail*/); |
| for(i = datapos; i < dataend; i++) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/ |
| } |
| |
| if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83 /*alloc fail*/); |
| if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(83 /*alloc fail*/); |
| |
| /*Count the frequencies of lit, len and dist codes*/ |
| for(i = 0; i < lz77_encoded.size; i++) |
| { |
| unsigned symbol = lz77_encoded.data[i]; |
| frequencies_ll.data[symbol]++; |
| if(symbol > 256) |
| { |
| unsigned dist = lz77_encoded.data[i + 2]; |
| frequencies_d.data[dist]++; |
| i += 3; |
| } |
| } |
| frequencies_ll.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/ |
| |
| /*Make both huffman trees, one for the lit and len codes, one for the dist codes*/ |
| error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll.data, 257, frequencies_ll.size, 15); |
| if(error) break; |
| /*2, not 1, is chosen for mincodes: some buggy PNG decoders require at least 2 symbols in the dist tree*/ |
| error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, 2, frequencies_d.size, 15); |
| if(error) break; |
| |
| numcodes_ll = tree_ll.numcodes; if(numcodes_ll > 286) numcodes_ll = 286; |
| numcodes_d = tree_d.numcodes; if(numcodes_d > 30) numcodes_d = 30; |
| /*store the code lengths of both generated trees in bitlen_lld*/ |
| for(i = 0; i < numcodes_ll; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_ll, (unsigned)i)); |
| for(i = 0; i < numcodes_d; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_d, (unsigned)i)); |
| |
| /*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times), |
| 17 (3-10 zeroes), 18 (11-138 zeroes)*/ |
| for(i = 0; i < (unsigned)bitlen_lld.size; i++) |
| { |
| unsigned j = 0; /*amount of repititions*/ |
| while(i + j + 1 < (unsigned)bitlen_lld.size && bitlen_lld.data[i + j + 1] == bitlen_lld.data[i]) j++; |
| |
| if(bitlen_lld.data[i] == 0 && j >= 2) /*repeat code for zeroes*/ |
| { |
| j++; /*include the first zero*/ |
| if(j <= 10) /*repeat code 17 supports max 10 zeroes*/ |
| { |
| uivector_push_back(&bitlen_lld_e, 17); |
| uivector_push_back(&bitlen_lld_e, j - 3); |
| } |
| else /*repeat code 18 supports max 138 zeroes*/ |
| { |
| if(j > 138) j = 138; |
| uivector_push_back(&bitlen_lld_e, 18); |
| uivector_push_back(&bitlen_lld_e, j - 11); |
| } |
| i += (j - 1); |
| } |
| else if(j >= 3) /*repeat code for value other than zero*/ |
| { |
| size_t k; |
| unsigned num = j / 6, rest = j % 6; |
| uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]); |
| for(k = 0; k < num; k++) |
| { |
| uivector_push_back(&bitlen_lld_e, 16); |
| uivector_push_back(&bitlen_lld_e, 6 - 3); |
| } |
| if(rest >= 3) |
| { |
| uivector_push_back(&bitlen_lld_e, 16); |
| uivector_push_back(&bitlen_lld_e, rest - 3); |
| } |
| else j -= rest; |
| i += j; |
| } |
| else /*too short to benefit from repeat code*/ |
| { |
| uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]); |
| } |
| } |
| |
| /*generate tree_cl, the huffmantree of huffmantrees*/ |
| |
| if(!uivector_resizev(&frequencies_cl, NUM_CODE_LENGTH_CODES, 0)) ERROR_BREAK(83 /*alloc fail*/); |
| for(i = 0; i < bitlen_lld_e.size; i++) |
| { |
| frequencies_cl.data[bitlen_lld_e.data[i]]++; |
| /*after a repeat code come the bits that specify the number of repetitions, |
| those don't need to be in the frequencies_cl calculation*/ |
| if(bitlen_lld_e.data[i] >= 16) i++; |
| } |
| |
| error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data, |
| frequencies_cl.size, frequencies_cl.size, 7); |
| if(error) break; |
| |
| if(!uivector_resize(&bitlen_cl, tree_cl.numcodes)) ERROR_BREAK(83 /*alloc fail*/); |
| for(i = 0; i < tree_cl.numcodes; i++) |
| { |
| /*lenghts of code length tree is in the order as specified by deflate*/ |
| bitlen_cl.data[i] = HuffmanTree_getLength(&tree_cl, CLCL_ORDER[i]); |
| } |
| while(bitlen_cl.data[bitlen_cl.size - 1] == 0 && bitlen_cl.size > 4) |
| { |
| /*remove zeros at the end, but minimum size must be 4*/ |
| if(!uivector_resize(&bitlen_cl, bitlen_cl.size - 1)) ERROR_BREAK(83 /*alloc fail*/); |
| } |
| if(error) break; |
| |
| /* |
| Write everything into the output |
| |
| After the BFINAL and BTYPE, the dynamic block consists out of the following: |
| - 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN |
| - (HCLEN+4)*3 bits code lengths of code length alphabet |
| - HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length |
| alphabet, + possible repetition codes 16, 17, 18) |
| - HDIST + 1 code lengths of distance alphabet (encoded using the code length |
| alphabet, + possible repetition codes 16, 17, 18) |
| - compressed data |
| - 256 (end code) |
| */ |
| |
| /*Write block type*/ |
| addBitToStream(bp, out, BFINAL); |
| addBitToStream(bp, out, 0); /*first bit of BTYPE "dynamic"*/ |
| addBitToStream(bp, out, 1); /*second bit of BTYPE "dynamic"*/ |
| |
| /*write the HLIT, HDIST and HCLEN values*/ |
| HLIT = (unsigned)(numcodes_ll - 257); |
| HDIST = (unsigned)(numcodes_d - 1); |
| HCLEN = (unsigned)bitlen_cl.size - 4; |
| /*trim zeroes for HCLEN. HLIT and HDIST were already trimmed at tree creation*/ |
| while(!bitlen_cl.data[HCLEN + 4 - 1] && HCLEN > 0) HCLEN--; |
| addBitsToStream(bp, out, HLIT, 5); |
| addBitsToStream(bp, out, HDIST, 5); |
| addBitsToStream(bp, out, HCLEN, 4); |
| |
| /*write the code lenghts of the code length alphabet*/ |
| for(i = 0; i < HCLEN + 4; i++) addBitsToStream(bp, out, bitlen_cl.data[i], 3); |
| |
| /*write the lenghts of the lit/len AND the dist alphabet*/ |
| for(i = 0; i < bitlen_lld_e.size; i++) |
| { |
| addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_cl, bitlen_lld_e.data[i]), |
| HuffmanTree_getLength(&tree_cl, bitlen_lld_e.data[i])); |
| /*extra bits of repeat codes*/ |
| if(bitlen_lld_e.data[i] == 16) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 2); |
| else if(bitlen_lld_e.data[i] == 17) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 3); |
| else if(bitlen_lld_e.data[i] == 18) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 7); |
| } |
| |
| /*write the compressed data symbols*/ |
| writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d); |
| /*error: the length of the end code 256 must be larger than 0*/ |
| if(HuffmanTree_getLength(&tree_ll, 256) == 0) ERROR_BREAK(64); |
| |
| /*write the end code*/ |
| addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256)); |
| |
| break; /*end of error-while*/ |
| } |
| |
| /*cleanup*/ |
| uivector_cleanup(&lz77_encoded); |
| HuffmanTree_cleanup(&tree_ll); |
| HuffmanTree_cleanup(&tree_d); |
| HuffmanTree_cleanup(&tree_cl); |
| uivector_cleanup(&frequencies_ll); |
| uivector_cleanup(&frequencies_d); |
| uivector_cleanup(&frequencies_cl); |
| uivector_cleanup(&bitlen_lld_e); |
| uivector_cleanup(&bitlen_lld); |
| uivector_cleanup(&bitlen_cl); |
| |
| return error; |
| } |
| |
| static unsigned deflateFixed(ucvector* out, size_t* bp, Hash* hash, |
| const unsigned char* data, |
| size_t datapos, size_t dataend, |
| const LodePNGCompressSettings* settings, int final) |
| { |
| HuffmanTree tree_ll; /*tree for literal values and length codes*/ |
| HuffmanTree tree_d; /*tree for distance codes*/ |
| |
| unsigned BFINAL = final; |
| unsigned error = 0; |
| size_t i; |
| |
| HuffmanTree_init(&tree_ll); |
| HuffmanTree_init(&tree_d); |
| |
| generateFixedLitLenTree(&tree_ll); |
| generateFixedDistanceTree(&tree_d); |
| |
| addBitToStream(bp, out, BFINAL); |
| addBitToStream(bp, out, 1); /*first bit of BTYPE*/ |
| addBitToStream(bp, out, 0); /*second bit of BTYPE*/ |
| |
| if(settings->use_lz77) /*LZ77 encoded*/ |
| { |
| uivector lz77_encoded; |
| uivector_init(&lz77_encoded); |
| error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize, |
| settings->minmatch, settings->nicematch, settings->lazymatching); |
| if(!error) writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d); |
| uivector_cleanup(&lz77_encoded); |
| } |
| else /*no LZ77, but still will be Huffman compressed*/ |
| { |
| for(i = datapos; i < dataend; i++) |
| { |
| addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, data[i]), HuffmanTree_getLength(&tree_ll, data[i])); |
| } |
| } |
| /*add END code*/ |
| if(!error) addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256)); |
| |
| /*cleanup*/ |
| HuffmanTree_cleanup(&tree_ll); |
| HuffmanTree_cleanup(&tree_d); |
| |
| return error; |
| } |
| |
| static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t insize, |
| const LodePNGCompressSettings* settings) |
| { |
| unsigned error = 0; |
| size_t i, blocksize, numdeflateblocks; |
| size_t bp = 0; /*the bit pointer*/ |
| Hash hash; |
| |
| if(settings->btype > 2) return 61; |
| else if(settings->btype == 0) return deflateNoCompression(out, in, insize); |
| else if(settings->btype == 1) blocksize = insize; |
| else /*if(settings->btype == 2)*/ |
| { |
| blocksize = insize / 8 + 8; |
| if(blocksize < 65535) blocksize = 65535; |
| } |
| |
| numdeflateblocks = (insize + blocksize - 1) / blocksize; |
| if(numdeflateblocks == 0) numdeflateblocks = 1; |
| |
| error = hash_init(&hash, settings->windowsize); |
| if(error) return error; |
| |
| for(i = 0; i < numdeflateblocks && !error; i++) |
| { |
| int final = i == numdeflateblocks - 1; |
| size_t start = i * blocksize; |
| size_t end = start + blocksize; |
| if(end > insize) end = insize; |
| |
| if(settings->btype == 1) error = deflateFixed(out, &bp, &hash, in, start, end, settings, final); |
| else if(settings->btype == 2) error = deflateDynamic(out, &bp, &hash, in, start, end, settings, final); |
| } |
| |
| hash_cleanup(&hash); |
| |
| return error; |
| } |
| |
| unsigned lodepng_deflate(unsigned char** out, size_t* outsize, |
| const unsigned char* in, size_t insize, |
| const LodePNGCompressSettings* settings) |
| { |
| unsigned error; |
| ucvector v; |
| ucvector_init_buffer(&v, *out, *outsize); |
| error = lodepng_deflatev(&v, in, insize, settings); |
| *out = v.data; |
| *outsize = v.size; |
| return error; |
| } |
| |
| static unsigned deflate(unsigned char** out, size_t* outsize, |
| const unsigned char* in, size_t insize, |
| const LodePNGCompressSettings* settings) |
| { |
| if(settings->custom_deflate) |
| { |
| return settings->custom_deflate(out, outsize, in, insize, settings); |
| } |
| else |
| { |
| return lodepng_deflate(out, outsize, in, insize, settings); |
| } |
| } |
| |
| #endif /*LODEPNG_COMPILE_DECODER*/ |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* / Adler32 */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len) |
| { |
| unsigned s1 = adler & 0xffff; |
| unsigned s2 = (adler >> 16) & 0xffff; |
| |
| while(len > 0) |
| { |
| /*at least 5550 sums can be done before the sums overflow, saving a lot of module divisions*/ |
| unsigned amount = len > 5550 ? 5550 : len; |
| len -= amount; |
| while(amount > 0) |
| { |
| s1 += (*data++); |
| s2 += s1; |
| amount--; |
| } |
| s1 %= 65521; |
| s2 %= 65521; |
| } |
| |
| return (s2 << 16) | s1; |
| } |
| |
| /*Return the adler32 of the bytes data[0..len-1]*/ |
| static unsigned adler32(const unsigned char* data, unsigned len) |
| { |
| return update_adler32(1L, data, len); |
| } |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* / Zlib / */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| #ifdef LODEPNG_COMPILE_DECODER |
| |
| unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, |
| size_t insize, const LodePNGDecompressSettings* settings) |
| { |
| unsigned error = 0; |
| unsigned CM, CINFO, FDICT; |
| |
| if(insize < 2) return 53; /*error, size of zlib data too small*/ |
| /*read information from zlib header*/ |
| if((in[0] * 256 + in[1]) % 31 != 0) |
| { |
| /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/ |
| return 24; |
| } |
| |
| CM = in[0] & 15; |
| CINFO = (in[0] >> 4) & 15; |
| /*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/ |
| FDICT = (in[1] >> 5) & 1; |
| /*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/ |
| |
| if(CM != 8 || CINFO > 7) |
| { |
| /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/ |
| return 25; |
| } |
| if(FDICT != 0) |
| { |
| /*error: the specification of PNG says about the zlib stream: |
| "The additional flags shall not specify a preset dictionary."*/ |
| return 26; |
| } |
| |
| error = inflate(out, outsize, in + 2, insize - 2, settings); |
| if(error) return error; |
| |
| if(!settings->ignore_adler32) |
| { |
| unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]); |
| unsigned checksum = adler32(*out, (unsigned)(*outsize)); |
| if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/ |
| } |
| |
| return 0; /*no error*/ |
| } |
| |
| static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, |
| size_t insize, const LodePNGDecompressSettings* settings) |
| { |
| if(settings->custom_zlib) |
| return settings->custom_zlib(out, outsize, in, insize, settings); |
| else |
| return lodepng_zlib_decompress(out, outsize, in, insize, settings); |
| } |
| |
| #endif /*LODEPNG_COMPILE_DECODER*/ |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| |
| unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, |
| size_t insize, const LodePNGCompressSettings* settings) |
| { |
| /*initially, *out must be NULL and outsize 0, if you just give some random *out |
| that's pointing to a non allocated buffer, this'll crash*/ |
| ucvector outv; |
| size_t i; |
| unsigned error; |
| unsigned char* deflatedata = 0; |
| size_t deflatesize = 0; |
| |
| unsigned ADLER32; |
| /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/ |
| unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/ |
| unsigned FLEVEL = 0; |
| unsigned FDICT = 0; |
| unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64; |
| unsigned FCHECK = 31 - CMFFLG % 31; |
| CMFFLG += FCHECK; |
| |
| /*ucvector-controlled version of the output buffer, for dynamic array*/ |
| ucvector_init_buffer(&outv, *out, *outsize); |
| |
| ucvector_push_back(&outv, (unsigned char)(CMFFLG / 256)); |
| ucvector_push_back(&outv, (unsigned char)(CMFFLG % 256)); |
| |
| error = deflate(&deflatedata, &deflatesize, in, insize, settings); |
| |
| if(!error) |
| { |
| ADLER32 = adler32(in, (unsigned)insize); |
| for(i = 0; i < deflatesize; i++) ucvector_push_back(&outv, deflatedata[i]); |
| lodepng_free(deflatedata); |
| lodepng_add32bitInt(&outv, ADLER32); |
| } |
| |
| *out = outv.data; |
| *outsize = outv.size; |
| |
| return error; |
| } |
| |
| /* compress using the default or custom zlib function */ |
| static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, |
| size_t insize, const LodePNGCompressSettings* settings) |
| { |
| if(settings->custom_zlib) |
| { |
| return settings->custom_zlib(out, outsize, in, insize, settings); |
| } |
| else |
| { |
| return lodepng_zlib_compress(out, outsize, in, insize, settings); |
| } |
| } |
| |
| #endif /*LODEPNG_COMPILE_ENCODER*/ |
| |
| #else /*no LODEPNG_COMPILE_ZLIB*/ |
| |
| #ifdef LODEPNG_COMPILE_DECODER |
| static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, |
| size_t insize, const LodePNGDecompressSettings* settings) |
| { |
| if (!settings->custom_zlib) return 87; /*no custom zlib function provided */ |
| return settings->custom_zlib(out, outsize, in, insize, settings); |
| } |
| #endif /*LODEPNG_COMPILE_DECODER*/ |
| #ifdef LODEPNG_COMPILE_ENCODER |
| static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, |
| size_t insize, const LodePNGCompressSettings* settings) |
| { |
| if (!settings->custom_zlib) return 87; /*no custom zlib function provided */ |
| return settings->custom_zlib(out, outsize, in, insize, settings); |
| } |
| #endif /*LODEPNG_COMPILE_ENCODER*/ |
| |
| #endif /*LODEPNG_COMPILE_ZLIB*/ |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| |
| /*this is a good tradeoff between speed and compression ratio*/ |
| #define DEFAULT_WINDOWSIZE 2048 |
| |
| void lodepng_compress_settings_init(LodePNGCompressSettings* settings) |
| { |
| /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/ |
| settings->btype = 2; |
| settings->use_lz77 = 1; |
| settings->windowsize = DEFAULT_WINDOWSIZE; |
| settings->minmatch = 3; |
| settings->nicematch = 128; |
| settings->lazymatching = 1; |
| |
| settings->custom_zlib = 0; |
| settings->custom_deflate = 0; |
| settings->custom_context = 0; |
| } |
| |
| const LodePNGCompressSettings lodepng_default_compress_settings = {2, 1, DEFAULT_WINDOWSIZE, 3, 128, 1, 0, 0, 0}; |
| |
| |
| #endif /*LODEPNG_COMPILE_ENCODER*/ |
| |
| #ifdef LODEPNG_COMPILE_DECODER |
| |
| void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings) |
| { |
| settings->ignore_adler32 = 0; |
| |
| settings->custom_zlib = 0; |
| settings->custom_inflate = 0; |
| settings->custom_context = 0; |
| } |
| |
| const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0}; |
| |
| #endif /*LODEPNG_COMPILE_DECODER*/ |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* // End of Zlib related code. Begin of PNG related code. // */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| #ifdef LODEPNG_COMPILE_PNG |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* / CRC32 / */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| 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].*/ |
| unsigned lodepng_crc32(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_ancillary(const unsigned char* chunk) |
| { |
| return((chunk[4] & 32) != 0); |
| } |
| |
| unsigned char lodepng_chunk_private(const unsigned char* chunk) |
| { |
| return((chunk[6] & 32) != 0); |
| } |
| |
| unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk) |
| { |
| return((chunk[7] & 32) != 0); |
| } |
| |
| unsigned char* lodepng_chunk_data(unsigned char* chunk) |
| { |
| return &chunk[8]; |
| } |
| |
| const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk) |
| { |
| return &chunk[8]; |
| } |
| |
| unsigned lodepng_chunk_check_crc(const unsigned char* chunk) |
| { |
| unsigned length = lodepng_chunk_length(chunk); |
| unsigned CRC = lodepng_read32bitInt(&chunk[length + 8]); |
| /*the CRC is taken of the data and the 4 chunk type letters, not the length*/ |
| unsigned checksum = lodepng_crc32(&chunk[4], length + 4); |
| if(CRC != checksum) return 1; |
| else return 0; |
| } |
| |
| void lodepng_chunk_generate_crc(unsigned char* chunk) |
| { |
| unsigned length = lodepng_chunk_length(chunk); |
| unsigned CRC = lodepng_crc32(&chunk[4], length + 4); |
| lodepng_set32bitInt(chunk + 8 + length, CRC); |
| } |
| |
| unsigned char* lodepng_chunk_next(unsigned char* chunk) |
| { |
| unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; |
| return &chunk[total_chunk_length]; |
| } |
| |
| const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk) |
| { |
| unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; |
| return &chunk[total_chunk_length]; |
| } |
| |
| unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk) |
| { |
| unsigned i; |
| unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; |
| unsigned char *chunk_start, *new_buffer; |
| size_t new_length = (*outlength) + total_chunk_length; |
| if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/ |
| |
| new_buffer = (unsigned char*)lodepng_realloc(*out, new_length); |
| if(!new_buffer) return 83; /*alloc fail*/ |
| (*out) = new_buffer; |
| (*outlength) = new_length; |
| chunk_start = &(*out)[new_length - total_chunk_length]; |
| |
| for(i = 0; i < total_chunk_length; i++) chunk_start[i] = chunk[i]; |
| |
| return 0; |
| } |
| |
| unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length, |
| const char* type, const unsigned char* data) |
| { |
| unsigned i; |
| unsigned char *chunk, *new_buffer; |
| size_t new_length = (*outlength) + length + 12; |
| if(new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/ |
| new_buffer = (unsigned char*)lodepng_realloc(*out, new_length); |
| if(!new_buffer) return 83; /*alloc fail*/ |
| (*out) = new_buffer; |
| (*outlength) = new_length; |
| chunk = &(*out)[(*outlength) - length - 12]; |
| |
| /*1: length*/ |
| lodepng_set32bitInt(chunk, (unsigned)length); |
| |
| /*2: chunk name (4 letters)*/ |
| chunk[4] = type[0]; |
| chunk[5] = type[1]; |
| chunk[6] = type[2]; |
| chunk[7] = type[3]; |
| |
| /*3: the data*/ |
| for(i = 0; i < length; i++) chunk[8 + i] = data[i]; |
| |
| /*4: CRC (of the chunkname characters and the data)*/ |
| lodepng_chunk_generate_crc(chunk); |
| |
| return 0; |
| } |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* / Color types and such / */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| /*return type is a LodePNG error code*/ |
| static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) /*bd = bitdepth*/ |
| { |
| switch(colortype) |
| { |
| case 0: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/ |
| case 2: if(!( bd == 8 || bd == 16)) return 37; break; /*RGB*/ |
| case 3: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 )) return 37; break; /*palette*/ |
| case 4: if(!( bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/ |
| case 6: if(!( bd == 8 || bd == 16)) return 37; break; /*RGBA*/ |
| default: return 31; |
| } |
| return 0; /*allowed color type / bits combination*/ |
| } |
| |
| static unsigned getNumColorChannels(LodePNGColorType colortype) |
| { |
| switch(colortype) |
| { |
| case 0: return 1; /*grey*/ |
| case 2: return 3; /*RGB*/ |
| case 3: return 1; /*palette*/ |
| case 4: return 2; /*grey + alpha*/ |
| case 6: return 4; /*RGBA*/ |
| } |
| return 0; /*unexisting color type*/ |
| } |
| |
| static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth) |
| { |
| /*bits per pixel is amount of channels * bits per channel*/ |
| return getNumColorChannels(colortype) * bitdepth; |
| } |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| void lodepng_color_mode_init(LodePNGColorMode* info) |
| { |
| info->key_defined = 0; |
| info->key_r = info->key_g = info->key_b = 0; |
| info->colortype = LCT_RGBA; |
| info->bitdepth = 8; |
| info->palette = 0; |
| info->palettesize = 0; |
| } |
| |
| void lodepng_color_mode_cleanup(LodePNGColorMode* info) |
| { |
| lodepng_palette_clear(info); |
| } |
| |
| unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source) |
| { |
| size_t i; |
| lodepng_color_mode_cleanup(dest); |
| *dest = *source; |
| if(source->palette) |
| { |
| dest->palette = (unsigned char*)lodepng_malloc(1024); |
| if(!dest->palette && source->palettesize) return 83; /*alloc fail*/ |
| for(i = 0; i < source->palettesize * 4; i++) dest->palette[i] = source->palette[i]; |
| } |
| return 0; |
| } |
| |
| static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b) |
| { |
| size_t i; |
| if(a->colortype != b->colortype) return 0; |
| if(a->bitdepth != b->bitdepth) return 0; |
| if(a->key_defined != b->key_defined) return 0; |
| if(a->key_defined) |
| { |
| if(a->key_r != b->key_r) return 0; |
| if(a->key_g != b->key_g) return 0; |
| if(a->key_b != b->key_b) return 0; |
| } |
| if(a->palettesize != b->palettesize) return 0; |
| for(i = 0; i < a->palettesize * 4; i++) |
| { |
| if(a->palette[i] != b->palette[i]) return 0; |
| } |
| return 1; |
| } |
| |
| void lodepng_palette_clear(LodePNGColorMode* info) |
| { |
| if(info->palette) lodepng_free(info->palette); |
| info->palette = 0; |
| info->palettesize = 0; |
| } |
| |
| unsigned lodepng_palette_add(LodePNGColorMode* info, |
| unsigned char r, unsigned char g, unsigned char b, unsigned char a) |
| { |
| unsigned char* data; |
| /*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with |
| the max of 256 colors, it'll have the exact alloc size*/ |
| if(!info->palette) /*allocate palette if empty*/ |
| { |
| /*room for 256 colors with 4 bytes each*/ |
| data = (unsigned char*)lodepng_realloc(info->palette, 1024); |
| if(!data) return 83; /*alloc fail*/ |
| else info->palette = data; |
| } |
| info->palette[4 * info->palettesize + 0] = r; |
| info->palette[4 * info->palettesize + 1] = g; |
| info->palette[4 * info->palettesize + 2] = b; |
| info->palette[4 * info->palettesize + 3] = a; |
| info->palettesize++; |
| return 0; |
| } |
| |
| unsigned lodepng_get_bpp(const LodePNGColorMode* info) |
| { |
| /*calculate bits per pixel out of colortype and bitdepth*/ |
| return lodepng_get_bpp_lct(info->colortype, info->bitdepth); |
| } |
| |
| unsigned lodepng_get_channels(const LodePNGColorMode* info) |
| { |
| return getNumColorChannels(info->colortype); |
| } |
| |
| unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info) |
| { |
| return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA; |
| } |
| |
| unsigned lodepng_is_alpha_type(const LodePNGColorMode* info) |
| { |
| return (info->colortype & 4) != 0; /*4 or 6*/ |
| } |
| |
| unsigned lodepng_is_palette_type(const LodePNGColorMode* info) |
| { |
| return info->colortype == LCT_PALETTE; |
| } |
| |
| unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info) |
| { |
| size_t i; |
| for(i = 0; i < info->palettesize; i++) |
| { |
| if(info->palette[i * 4 + 3] < 255) return 1; |
| } |
| return 0; |
| } |
| |
| unsigned lodepng_can_have_alpha(const LodePNGColorMode* info) |
| { |
| return info->key_defined |
| || lodepng_is_alpha_type(info) |
| || lodepng_has_palette_alpha(info); |
| } |
| |
| size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color) |
| { |
| return (w * h * lodepng_get_bpp(color) + 7) / 8; |
| } |
| |
| size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) |
| { |
| return (w * h * lodepng_get_bpp_lct(colortype, bitdepth) + 7) / 8; |
| } |
| |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| |
| static void LodePNGUnknownChunks_init(LodePNGInfo* info) |
| { |
| unsigned i; |
| for(i = 0; i < 3; i++) info->unknown_chunks_data[i] = 0; |
| for(i = 0; i < 3; i++) info->unknown_chunks_size[i] = 0; |
| } |
| |
| static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info) |
| { |
| unsigned i; |
| for(i = 0; i < 3; i++) lodepng_free(info->unknown_chunks_data[i]); |
| } |
| |
| static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src) |
| { |
| unsigned i; |
| |
| LodePNGUnknownChunks_cleanup(dest); |
| |
| for(i = 0; i < 3; i++) |
| { |
| size_t j; |
| dest->unknown_chunks_size[i] = src->unknown_chunks_size[i]; |
| dest->unknown_chunks_data[i] = (unsigned char*)lodepng_malloc(src->unknown_chunks_size[i]); |
| if(!dest->unknown_chunks_data[i] && dest->unknown_chunks_size[i]) return 83; /*alloc fail*/ |
| for(j = 0; j < src->unknown_chunks_size[i]; j++) |
| { |
| dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j]; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /******************************************************************************/ |
| |
| static void LodePNGText_init(LodePNGInfo* info) |
| { |
| info->text_num = 0; |
| info->text_keys = NULL; |
| info->text_strings = NULL; |
| } |
| |
| static void LodePNGText_cleanup(LodePNGInfo* info) |
| { |
| size_t i; |
| for(i = 0; i < info->text_num; i++) |
| { |
| string_cleanup(&info->text_keys[i]); |
| string_cleanup(&info->text_strings[i]); |
| } |
| lodepng_free(info->text_keys); |
| lodepng_free(info->text_strings); |
| } |
| |
| static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source) |
| { |
| size_t i = 0; |
| dest->text_keys = 0; |
| dest->text_strings = 0; |
| dest->text_num = 0; |
| for(i = 0; i < source->text_num; i++) |
| { |
| CERROR_TRY_RETURN(lodepng_add_text(dest, source->text_keys[i], source->text_strings[i])); |
| } |
| return 0; |
| } |
| |
| void lodepng_clear_text(LodePNGInfo* info) |
| { |
| LodePNGText_cleanup(info); |
| } |
| |
| unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str) |
| { |
| char** new_keys = (char**)(lodepng_realloc(info->text_keys, sizeof(char*) * (info->text_num + 1))); |
| char** new_strings = (char**)(lodepng_realloc(info->text_strings, sizeof(char*) * (info->text_num + 1))); |
| if(!new_keys || !new_strings) |
| { |
| lodepng_free(new_keys); |
| lodepng_free(new_strings); |
| return 83; /*alloc fail*/ |
| } |
| |
| info->text_num++; |
| info->text_keys = new_keys; |
| info->text_strings = new_strings; |
| |
| string_init(&info->text_keys[info->text_num - 1]); |
| string_set(&info->text_keys[info->text_num - 1], key); |
| |
| string_init(&info->text_strings[info->text_num - 1]); |
| string_set(&info->text_strings[info->text_num - 1], str); |
| |
| return 0; |
| } |
| |
| /******************************************************************************/ |
| |
| static void LodePNGIText_init(LodePNGInfo* info) |
| { |
| info->itext_num = 0; |
| info->itext_keys = NULL; |
| info->itext_langtags = NULL; |
| info->itext_transkeys = NULL; |
| info->itext_strings = NULL; |
| } |
| |
| static void LodePNGIText_cleanup(LodePNGInfo* info) |
| { |
| size_t i; |
| for(i = 0; i < info->itext_num; i++) |
| { |
| string_cleanup(&info->itext_keys[i]); |
| string_cleanup(&info->itext_langtags[i]); |
| string_cleanup(&info->itext_transkeys[i]); |
| string_cleanup(&info->itext_strings[i]); |
| } |
| lodepng_free(info->itext_keys); |
| lodepng_free(info->itext_langtags); |
| lodepng_free(info->itext_transkeys); |
| lodepng_free(info->itext_strings); |
| } |
| |
| static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source) |
| { |
| size_t i = 0; |
| dest->itext_keys = 0; |
| dest->itext_langtags = 0; |
| dest->itext_transkeys = 0; |
| dest->itext_strings = 0; |
| dest->itext_num = 0; |
| for(i = 0; i < source->itext_num; i++) |
| { |
| CERROR_TRY_RETURN(lodepng_add_itext(dest, source->itext_keys[i], source->itext_langtags[i], |
| source->itext_transkeys[i], source->itext_strings[i])); |
| } |
| return 0; |
| } |
| |
| void lodepng_clear_itext(LodePNGInfo* info) |
| { |
| LodePNGIText_cleanup(info); |
| } |
| |
| unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag, |
| const char* transkey, const char* str) |
| { |
| char** new_keys = (char**)(lodepng_realloc(info->itext_keys, sizeof(char*) * (info->itext_num + 1))); |
| char** new_langtags = (char**)(lodepng_realloc(info->itext_langtags, sizeof(char*) * (info->itext_num + 1))); |
| char** new_transkeys = (char**)(lodepng_realloc(info->itext_transkeys, sizeof(char*) * (info->itext_num + 1))); |
| char** new_strings = (char**)(lodepng_realloc(info->itext_strings, sizeof(char*) * (info->itext_num + 1))); |
| if(!new_keys || !new_langtags || !new_transkeys || !new_strings) |
| { |
| lodepng_free(new_keys); |
| lodepng_free(new_langtags); |
| lodepng_free(new_transkeys); |
| lodepng_free(new_strings); |
| return 83; /*alloc fail*/ |
| } |
| |
| info->itext_num++; |
| info->itext_keys = new_keys; |
| info->itext_langtags = new_langtags; |
| info->itext_transkeys = new_transkeys; |
| info->itext_strings = new_strings; |
| |
| string_init(&info->itext_keys[info->itext_num - 1]); |
| string_set(&info->itext_keys[info->itext_num - 1], key); |
| |
| string_init(&info->itext_langtags[info->itext_num - 1]); |
| string_set(&info->itext_langtags[info->itext_num - 1], langtag); |
| |
| string_init(&info->itext_transkeys[info->itext_num - 1]); |
| string_set(&info->itext_transkeys[info->itext_num - 1], transkey); |
| |
| string_init(&info->itext_strings[info->itext_num - 1]); |
| string_set(&info->itext_strings[info->itext_num - 1], str); |
| |
| return 0; |
| } |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| |
| void lodepng_info_init(LodePNGInfo* info) |
| { |
| lodepng_color_mode_init(&info->color); |
| info->interlace_method = 0; |
| info->compression_method = 0; |
| info->filter_method = 0; |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| info->background_defined = 0; |
| info->background_r = info->background_g = info->background_b = 0; |
| |
| LodePNGText_init(info); |
| LodePNGIText_init(info); |
| |
| info->time_defined = 0; |
| info->phys_defined = 0; |
| |
| LodePNGUnknownChunks_init(info); |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| } |
| |
| void lodepng_info_cleanup(LodePNGInfo* info) |
| { |
| lodepng_color_mode_cleanup(&info->color); |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| LodePNGText_cleanup(info); |
| LodePNGIText_cleanup(info); |
| |
| LodePNGUnknownChunks_cleanup(info); |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| } |
| |
| unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) |
| { |
| lodepng_info_cleanup(dest); |
| *dest = *source; |
| lodepng_color_mode_init(&dest->color); |
| CERROR_TRY_RETURN(lodepng_color_mode_copy(&dest->color, &source->color)); |
| |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| CERROR_TRY_RETURN(LodePNGText_copy(dest, source)); |
| CERROR_TRY_RETURN(LodePNGIText_copy(dest, source)); |
| |
| LodePNGUnknownChunks_init(dest); |
| CERROR_TRY_RETURN(LodePNGUnknownChunks_copy(dest, source)); |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| return 0; |
| } |
| |
| void lodepng_info_swap(LodePNGInfo* a, LodePNGInfo* b) |
| { |
| LodePNGInfo temp = *a; |
| *a = *b; |
| *b = temp; |
| } |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| /*index: bitgroup index, bits: bitgroup size(1, 2 or 4, in: bitgroup value, out: octet array to add bits to*/ |
| static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in) |
| { |
| /*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/ |
| unsigned p = index % (8 / bits); |
| in &= (1 << bits) - 1; /*filter out any other bits of the input value*/ |
| in = in << (bits * (8 / bits - p - 1)); |
| if(p == 0) out[index * bits / 8] = in; |
| else out[index * bits / 8] |= in; |
| } |
| |
| typedef struct ColorTree ColorTree; |
| |
| /* |
| One node of a color tree |
| This is the data structure used to count the number of unique colors and to get a palette |
| index for a color. It's like an octree, but because the alpha channel is used too, each |
| node has 16 instead of 8 children. |
| */ |
| struct ColorTree |
| { |
| ColorTree* children[16]; /*up to 16 pointers to ColorTree of next level*/ |
| int index; /*the payload. Only has a meaningful value if this is in the last level*/ |
| }; |
| |
| static void color_tree_init(ColorTree* tree) |
| { |
| int i; |
| for(i = 0; i < 16; i++) tree->children[i] = 0; |
| tree->index = -1; |
| } |
| |
| static void color_tree_cleanup(ColorTree* tree) |
| { |
| int i; |
| for(i = 0; i < 16; i++) |
| { |
| if(tree->children[i]) |
| { |
| color_tree_cleanup(tree->children[i]); |
| lodepng_free(tree->children[i]); |
| } |
| } |
| } |
| |
| /*returns -1 if color not present, its index otherwise*/ |
| static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) |
| { |
| int bit = 0; |
| for(bit = 0; bit < 8; bit++) |
| { |
| int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1); |
| if(!tree->children[i]) return -1; |
| else tree = tree->children[i]; |
| } |
| return tree ? tree->index : -1; |
| } |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) |
| { |
| return color_tree_get(tree, r, g, b, a) >= 0; |
| } |
| #endif /*LODEPNG_COMPILE_ENCODER*/ |
| |
| /*color is not allowed to already exist. |
| Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")*/ |
| static void color_tree_add(ColorTree* tree, |
| unsigned char r, unsigned char g, unsigned char b, unsigned char a, int index) |
| { |
| int bit; |
| for(bit = 0; bit < 8; bit++) |
| { |
| int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1); |
| if(!tree->children[i]) |
| { |
| tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree)); |
| color_tree_init(tree->children[i]); |
| } |
| tree = tree->children[i]; |
| } |
| tree->index = index; |
| } |
| |
| /*put a pixel, given its RGBA color, into image of any color type*/ |
| static unsigned rgba8ToPixel(unsigned char* out, size_t i, |
| const LodePNGColorMode* mode, ColorTree* tree /*for palette*/, |
| unsigned char r, unsigned char g, unsigned char b, unsigned char a) |
| { |
| if(mode->colortype == LCT_GREY) |
| { |
| unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/; |
| if(mode->bitdepth == 8) out[i] = grey; |
| else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = grey; |
| else |
| { |
| /*take the most significant bits of grey*/ |
| grey = (grey >> (8 - mode->bitdepth)) & ((1 << mode->bitdepth) - 1); |
| addColorBits(out, i, mode->bitdepth, grey); |
| } |
| } |
| else if(mode->colortype == LCT_RGB) |
| { |
| if(mode->bitdepth == 8) |
| { |
| out[i * 3 + 0] = r; |
| out[i * 3 + 1] = g; |
| out[i * 3 + 2] = b; |
| } |
| else |
| { |
| out[i * 6 + 0] = out[i * 6 + 1] = r; |
| out[i * 6 + 2] = out[i * 6 + 3] = g; |
| out[i * 6 + 4] = out[i * 6 + 5] = b; |
| } |
| } |
| else if(mode->colortype == LCT_PALETTE) |
| { |
| int index = color_tree_get(tree, r, g, b, a); |
| if(index < 0) return 82; /*color not in palette*/ |
| if(mode->bitdepth == 8) out[i] = index; |
| else addColorBits(out, i, mode->bitdepth, index); |
| } |
| else if(mode->colortype == LCT_GREY_ALPHA) |
| { |
| unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/; |
| if(mode->bitdepth == 8) |
| { |
| out[i * 2 + 0] = grey; |
| out[i * 2 + 1] = a; |
| } |
| else if(mode->bitdepth == 16) |
| { |
| out[i * 4 + 0] = out[i * 4 + 1] = grey; |
| out[i * 4 + 2] = out[i * 4 + 3] = a; |
| } |
| } |
| else if(mode->colortype == LCT_RGBA) |
| { |
| if(mode->bitdepth == 8) |
| { |
| out[i * 4 + 0] = r; |
| out[i * 4 + 1] = g; |
| out[i * 4 + 2] = b; |
| out[i * 4 + 3] = a; |
| } |
| else |
| { |
| out[i * 8 + 0] = out[i * 8 + 1] = r; |
| out[i * 8 + 2] = out[i * 8 + 3] = g; |
| out[i * 8 + 4] = out[i * 8 + 5] = b; |
| out[i * 8 + 6] = out[i * 8 + 7] = a; |
| } |
| } |
| |
| return 0; /*no error*/ |
| } |
| |
| /*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/ |
| static unsigned rgba16ToPixel(unsigned char* out, size_t i, |
| const LodePNGColorMode* mode, |
| unsigned short r, unsigned short g, unsigned short b, unsigned short a) |
| { |
| if(mode->bitdepth != 16) return 85; /*must be 16 for this function*/ |
| if(mode->colortype == LCT_GREY) |
| { |
| unsigned short grey = r; /*((unsigned)r + g + b) / 3*/; |
| out[i * 2 + 0] = (grey >> 8) & 255; |
| out[i * 2 + 1] = grey & 255; |
| } |
| else if(mode->colortype == LCT_RGB) |
| { |
| out[i * 6 + 0] = (r >> 8) & 255; |
| out[i * 6 + 1] = r & 255; |
| out[i * 6 + 2] = (g >> 8) & 255; |
| out[i * 6 + 3] = g & 255; |
| out[i * 6 + 4] = (b >> 8) & 255; |
| out[i * 6 + 5] = b & 255; |
| } |
| else if(mode->colortype == LCT_GREY_ALPHA) |
| { |
| unsigned short grey = r; /*((unsigned)r + g + b) / 3*/; |
| out[i * 4 + 0] = (grey >> 8) & 255; |
| out[i * 4 + 1] = grey & 255; |
| out[i * 4 + 2] = (a >> 8) & 255; |
| out[i * 4 + 3] = a & 255; |
| } |
| else if(mode->colortype == LCT_RGBA) |
| { |
| out[i * 8 + 0] = (r >> 8) & 255; |
| out[i * 8 + 1] = r & 255; |
| out[i * 8 + 2] = (g >> 8) & 255; |
| out[i * 8 + 3] = g & 255; |
| out[i * 8 + 4] = (b >> 8) & 255; |
| out[i * 8 + 5] = b & 255; |
| out[i * 8 + 6] = (a >> 8) & 255; |
| out[i * 8 + 7] = a & 255; |
| } |
| |
| return 0; /*no error*/ |
| } |
| |
| /*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/ |
| static unsigned getPixelColorRGBA8(unsigned char* r, unsigned char* g, |
| unsigned char* b, unsigned char* a, |
| const unsigned char* in, size_t i, |
| const LodePNGColorMode* mode, |
| unsigned fix_png) |
| { |
| if(mode->colortype == LCT_GREY) |
| { |
| if(mode->bitdepth == 8) |
| { |
| *r = *g = *b = in[i]; |
| if(mode->key_defined && *r == mode->key_r) *a = 0; |
| else *a = 255; |
| } |
| else if(mode->bitdepth == 16) |
| { |
| *r = *g = *b = in[i * 2 + 0]; |
| if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0; |
| else *a = 255; |
| } |
| else |
| { |
| unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ |
| size_t j = i * mode->bitdepth; |
| unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); |
| *r = *g = *b = (value * 255) / highest; |
| if(mode->key_defined && value == mode->key_r) *a = 0; |
| else *a = 255; |
| } |
| } |
| else if(mode->colortype == LCT_RGB) |
| { |
| if(mode->bitdepth == 8) |
| { |
| *r = in[i * 3 + 0]; *g = in[i * 3 + 1]; *b = in[i * 3 + 2]; |
| if(mode->key_defined && *r == mode->key_r && *g == mode->key_g && *b == mode->key_b) *a = 0; |
| else *a = 255; |
| } |
| else |
| { |
| *r = in[i * 6 + 0]; |
| *g = in[i * 6 + 2]; |
| *b = in[i * 6 + 4]; |
| if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r |
| && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g |
| && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0; |
| else *a = 255; |
| } |
| } |
| else if(mode->colortype == LCT_PALETTE) |
| { |
| unsigned index; |
| if(mode->bitdepth == 8) index = in[i]; |
| else |
| { |
| size_t j = i * mode->bitdepth; |
| index = readBitsFromReversedStream(&j, in, mode->bitdepth); |
| } |
| |
| if(index >= mode->palettesize) |
| { |
| /*This is an error according to the PNG spec, but fix_png can ignore it*/ |
| if(!fix_png) return (mode->bitdepth == 8 ? 46 : 47); /*index out of palette*/ |
| *r = *g = *b = 0; |
| *a = 255; |
| } |
| else |
| { |
| *r = mode->palette[index * 4 + 0]; |
| *g = mode->palette[index * 4 + 1]; |
| *b = mode->palette[index * 4 + 2]; |
| *a = mode->palette[index * 4 + 3]; |
| } |
| } |
| else if(mode->colortype == LCT_GREY_ALPHA) |
| { |
| if(mode->bitdepth == 8) |
| { |
| *r = *g = *b = in[i * 2 + 0]; |
| *a = in[i * 2 + 1]; |
| } |
| else |
| { |
| *r = *g = *b = in[i * 4 + 0]; |
| *a = in[i * 4 + 2]; |
| } |
| } |
| else if(mode->colortype == LCT_RGBA) |
| { |
| if(mode->bitdepth == 8) |
| { |
| *r = in[i * 4 + 0]; |
| *g = in[i * 4 + 1]; |
| *b = in[i * 4 + 2]; |
| *a = in[i * 4 + 3]; |
| } |
| else |
| { |
| *r = in[i * 8 + 0]; |
| *g = in[i * 8 + 2]; |
| *b = in[i * 8 + 4]; |
| *a = in[i * 8 + 6]; |
| } |
| } |
| |
| return 0; /*no error*/ |
| } |
| |
| /*Similar to getPixelColorRGBA8, but with all the for loops inside of the color |
| mode test cases, optimized to convert the colors much faster, when converting |
| to RGBA or RGB with 8 bit per cannel. buffer must be RGBA or RGB output with |
| enough memory, if has_alpha is true the output is RGBA. mode has the color mode |
| of the input buffer.*/ |
| static unsigned getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels, |
| unsigned has_alpha, const unsigned char* in, |
| const LodePNGColorMode* mode, |
| unsigned fix_png) |
| { |
| unsigned num_channels = has_alpha ? 4 : 3; |
| size_t i; |
| if(mode->colortype == LCT_GREY) |
| { |
| if(mode->bitdepth == 8) |
| { |
| for(i = 0; i < numpixels; i++, buffer += num_channels) |
| { |
| buffer[0] = buffer[1] = buffer[2] = in[i]; |
| if(has_alpha) buffer[3] = mode->key_defined && in[i] == mode->key_r ? 0 : 255; |
| } |
| } |
| else if(mode->bitdepth == 16) |
| { |
| for(i = 0; i < numpixels; i++, buffer += num_channels) |
| { |
| buffer[0] = buffer[1] = buffer[2] = in[i * 2]; |
| if(has_alpha) buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255; |
| } |
| } |
| else |
| { |
| unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ |
| size_t j = 0; |
| for(i = 0; i < numpixels; i++, buffer += num_channels) |
| { |
| unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); |
| buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest; |
| if(has_alpha) buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255; |
| } |
| } |
| } |
| else if(mode->colortype == LCT_RGB) |
| { |
| if(mode->bitdepth == 8) |
| { |
| for(i = 0; i < numpixels; i++, buffer += num_channels) |
| { |
| buffer[0] = in[i * 3 + 0]; |
| buffer[1] = in[i * 3 + 1]; |
| buffer[2] = in[i * 3 + 2]; |
| if(has_alpha) buffer[3] = mode->key_defined && buffer[0] == mode->key_r |
| && buffer[1]== mode->key_g && buffer[2] == mode->key_b ? 0 : 255; |
| } |
| } |
| else |
| { |
| for(i = 0; i < numpixels; i++, buffer += num_channels) |
| { |
| buffer[0] = in[i * 6 + 0]; |
| buffer[1] = in[i * 6 + 2]; |
| buffer[2] = in[i * 6 + 4]; |
| if(has_alpha) buffer[3] = mode->key_defined |
| && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r |
| && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g |
| && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b ? 0 : 255; |
| } |
| } |
| } |
| else if(mode->colortype == LCT_PALETTE) |
| { |
| unsigned index; |
| size_t j = 0; |
| for(i = 0; i < numpixels; i++, buffer += num_channels) |
| { |
| if(mode->bitdepth == 8) index = in[i]; |
| else index = readBitsFromReversedStream(&j, in, mode->bitdepth); |
| |
| if(index >= mode->palettesize) |
| { |
| /*This is an error according to the PNG spec, but fix_png can ignore it*/ |
| if(!fix_png) return (mode->bitdepth == 8 ? 46 : 47); /*index out of palette*/ |
| buffer[0] = buffer[1] = buffer[2] = 0; |
| if(has_alpha) buffer[3] = 255; |
| } |
| else |
| { |
| buffer[0] = mode->palette[index * 4 + 0]; |
| buffer[1] = mode->palette[index * 4 + 1]; |
| buffer[2] = mode->palette[index * 4 + 2]; |
| if(has_alpha) buffer[3] = mode->palette[index * 4 + 3]; |
| } |
| } |
| } |
| else if(mode->colortype == LCT_GREY_ALPHA) |
| { |
| if(mode->bitdepth == 8) |
| { |
| for(i = 0; i < numpixels; i++, buffer += num_channels) |
| { |
| buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0]; |
| if(has_alpha) buffer[3] = in[i * 2 + 1]; |
| } |
| } |
| else |
| { |
| for(i = 0; i < numpixels; i++, buffer += num_channels) |
| { |
| buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0]; |
| if(has_alpha) buffer[3] = in[i * 4 + 2]; |
| } |
| } |
| } |
| else if(mode->colortype == LCT_RGBA) |
| { |
| if(mode->bitdepth == 8) |
| { |
| for(i = 0; i < numpixels; i++, buffer += num_channels) |
| { |
| buffer[0] = in[i * 4 + 0]; |
| buffer[1] = in[i * 4 + 1]; |
| buffer[2] = in[i * 4 + 2]; |
| if(has_alpha) buffer[3] = in[i * 4 + 3]; |
| } |
| } |
| else |
| { |
| for(i = 0; i < numpixels; i++, buffer += num_channels) |
| { |
| buffer[0] = in[i * 8 + 0]; |
| buffer[1] = in[i * 8 + 2]; |
| buffer[2] = in[i * 8 + 4]; |
| if(has_alpha) buffer[3] = in[i * 8 + 6]; |
| } |
| } |
| } |
| |
| return 0; /*no error*/ |
| } |
| |
| /*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with |
| given color type, but the given color type must be 16-bit itself.*/ |
| static unsigned getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a, |
| const unsigned char* in, size_t i, const LodePNGColorMode* mode) |
| { |
| if(mode->bitdepth != 16) return 85; /*error: this function only supports 16-bit input*/ |
| |
| if(mode->colortype == LCT_GREY) |
| { |
| *r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1]; |
| if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0; |
| else *a = 65535; |
| } |
| else if(mode->colortype == LCT_RGB) |
| { |
| *r = 256 * in[i * 6 + 0] + in[i * 6 + 1]; |
| *g = 256 * in[i * 6 + 2] + in[i * 6 + 3]; |
| *b = 256 * in[i * 6 + 4] + in[i * 6 + 5]; |
| if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r |
| && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g |
| && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0; |
| else *a = 65535; |
| } |
| else if(mode->colortype == LCT_GREY_ALPHA) |
| { |
| *r = *g = *b = 256 * in[i * 4 + 0] + in[i * 4 + 1]; |
| *a = 256 * in[i * 4 + 2] + in[i * 4 + 3]; |
| } |
| else if(mode->colortype == LCT_RGBA) |
| { |
| *r = 256 * in[i * 8 + 0] + in[i * 8 + 1]; |
| *g = 256 * in[i * 8 + 2] + in[i * 8 + 3]; |
| *b = 256 * in[i * 8 + 4] + in[i * 8 + 5]; |
| *a = 256 * in[i * 8 + 6] + in[i * 8 + 7]; |
| } |
| else return 85; /*error: this function only supports 16-bit input, not palettes*/ |
| |
| return 0; /*no error*/ |
| } |
| |
| /* |
| converts from any color type to 24-bit or 32-bit (later maybe more supported). return value = LodePNG error code |
| the out buffer must have (w * h * bpp + 7) / 8 bytes, where bpp is the bits per pixel of the output color type |
| (lodepng_get_bpp) for < 8 bpp images, there may _not_ be padding bits at the end of scanlines. |
| */ |
| unsigned lodepng_convert(unsigned char* out, const unsigned char* in, |
| LodePNGColorMode* mode_out, LodePNGColorMode* mode_in, |
| unsigned w, unsigned h, unsigned fix_png) |
| { |
| unsigned error = 0; |
| size_t i; |
| ColorTree tree; |
| size_t numpixels = w * h; |
| |
| if(lodepng_color_mode_equal(mode_out, mode_in)) |
| { |
| size_t numbytes = lodepng_get_raw_size(w, h, mode_in); |
| for(i = 0; i < numbytes; i++) out[i] = in[i]; |
| return error; |
| } |
| |
| if(mode_out->colortype == LCT_PALETTE) |
| { |
| size_t palsize = 1 << mode_out->bitdepth; |
| if(mode_out->palettesize < palsize) palsize = mode_out->palettesize; |
| color_tree_init(&tree); |
| for(i = 0; i < palsize; i++) |
| { |
| unsigned char* p = &mode_out->palette[i * 4]; |
| color_tree_add(&tree, p[0], p[1], p[2], p[3], i); |
| } |
| } |
| |
| if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16) |
| { |
| for(i = 0; i < numpixels; i++) |
| { |
| unsigned short r = 0, g = 0, b = 0, a = 0; |
| error = getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); |
| if(error) break; |
| error = rgba16ToPixel(out, i, mode_out, r, g, b, a); |
| if(error) break; |
| } |
| } |
| else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA) |
| { |
| error = getPixelColorsRGBA8(out, numpixels, 1, in, mode_in, fix_png); |
| } |
| else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) |
| { |
| error = getPixelColorsRGBA8(out, numpixels, 0, in, mode_in, fix_png); |
| } |
| else |
| { |
| unsigned char r = 0, g = 0, b = 0, a = 0; |
| for(i = 0; i < numpixels; i++) |
| { |
| error = getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in, fix_png); |
| if(error) break; |
| error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a); |
| if(error) break; |
| } |
| } |
| |
| if(mode_out->colortype == LCT_PALETTE) |
| { |
| color_tree_cleanup(&tree); |
| } |
| |
| return error; |
| } |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| |
| typedef struct ColorProfile |
| { |
| unsigned char sixteenbit; /*needs more than 8 bits per channel*/ |
| unsigned char sixteenbit_done; |
| |
| |
| unsigned char colored; /*not greyscale*/ |
| unsigned char colored_done; |
| |
| unsigned char key; /*a color key is required, or more*/ |
| unsigned short key_r; /*these values are always in 16-bit bitdepth in the profile*/ |
| unsigned short key_g; |
| unsigned short key_b; |
| unsigned char alpha; /*alpha channel, or alpha palette, required*/ |
| unsigned char alpha_done; |
| |
| unsigned numcolors; |
| ColorTree tree; /*for listing the counted colors, up to 256*/ |
| unsigned char* palette; /*size 1024. Remember up to the first 256 RGBA colors*/ |
| unsigned maxnumcolors; /*if more than that amount counted*/ |
| unsigned char numcolors_done; |
| |
| unsigned greybits; /*amount of bits required for greyscale (1, 2, 4, 8). Does not take 16 bit into account.*/ |
| unsigned char greybits_done; |
| |
| } ColorProfile; |
| |
| static void color_profile_init(ColorProfile* profile, LodePNGColorMode* mode) |
| { |
| profile->sixteenbit = 0; |
| profile->sixteenbit_done = mode->bitdepth == 16 ? 0 : 1; |
| |
| profile->colored = 0; |
| profile->colored_done = lodepng_is_greyscale_type(mode) ? 1 : 0; |
| |
| profile->key = 0; |
| profile->alpha = 0; |
| profile->alpha_done = lodepng_can_have_alpha(mode) ? 0 : 1; |
| |
| profile->numcolors = 0; |
| color_tree_init(&profile->tree); |
| profile->palette = (unsigned char*)lodepng_malloc(1024); |
| profile->maxnumcolors = 257; |
| if(lodepng_get_bpp(mode) <= 8) |
| { |
| int bpp = lodepng_get_bpp(mode); |
| profile->maxnumcolors = bpp == 1 ? 2 : (bpp == 2 ? 4 : (bpp == 4 ? 16 : 256)); |
| } |
| profile->numcolors_done = 0; |
| |
| profile->greybits = 1; |
| profile->greybits_done = lodepng_get_bpp(mode) == 1 ? 1 : 0; |
| } |
| |
| static void color_profile_cleanup(ColorProfile* profile) |
| { |
| color_tree_cleanup(&profile->tree); |
| lodepng_free(profile->palette); |
| } |
| |
| /*function used for debug purposes with C++*/ |
| /*void printColorProfile(ColorProfile* p) |
| { |
| std::cout << "sixteenbit: " << (int)p->sixteenbit << std::endl; |
| std::cout << "sixteenbit_done: " << (int)p->sixteenbit_done << std::endl; |
| std::cout << "colored: " << (int)p->colored << std::endl; |
| std::cout << "colored_done: " << (int)p->colored_done << std::endl; |
| std::cout << "key: " << (int)p->key << std::endl; |
| std::cout << "key_r: " << (int)p->key_r << std::endl; |
| std::cout << "key_g: " << (int)p->key_g << std::endl; |
| std::cout << "key_b: " << (int)p->key_b << std::endl; |
| std::cout << "alpha: " << (int)p->alpha << std::endl; |
| std::cout << "alpha_done: " << (int)p->alpha_done << std::endl; |
| std::cout << "numcolors: " << (int)p->numcolors << std::endl; |
| std::cout << "maxnumcolors: " << (int)p->maxnumcolors << std::endl; |
| std::cout << "numcolors_done: " << (int)p->numcolors_done << std::endl; |
| std::cout << "greybits: " << (int)p->greybits << std::endl; |
| std::cout << "greybits_done: " << (int)p->greybits_done << std::endl; |
| }*/ |
| |
| /*Returns how many bits needed to represent given value (max 8 bit)*/ |
| unsigned getValueRequiredBits(unsigned short value) |
| { |
| if(value == 0 || value == 255) return 1; |
| /*The scaling of 2-bit and 4-bit values uses multiples of 85 and 17*/ |
| if(value % 17 == 0) return value % 85 == 0 ? 2 : 4; |
| return 8; |
| } |
| |
| /*profile must already have been inited with mode. |
| It's ok to set some parameters of profile to done already.*/ |
| static unsigned get_color_profile(ColorProfile* profile, |
| const unsigned char* in, size_t numpixels, |
| LodePNGColorMode* mode, |
| unsigned fix_png) |
| { |
| unsigned error = 0; |
| size_t i; |
| |
| if(mode->bitdepth == 16) |
| { |
| for(i = 0; i < numpixels; i++) |
| { |
| unsigned short r, g, b, a; |
| error = getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode); |
| if(error) break; |
| |
| /*a color is considered good for 8-bit if the first byte and the second byte are equal, |
| (so if it's divisible through 257), NOT necessarily if the second byte is 0*/ |
| if(!profile->sixteenbit_done |
| && (((r & 255) != ((r >> 8) & 255)) |
| || ((g & 255) != ((g >> 8) & 255)) |
| || ((b & 255) != ((b >> 8) & 255)))) |
| { |
| profile->sixteenbit = 1; |
| profile->sixteenbit_done = 1; |
| profile->greybits_done = 1; /*greybits is not applicable anymore at 16-bit*/ |
| profile->numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/ |
| } |
| |
| if(!profile->colored_done && (r != g || r != b)) |
| { |
| profile->colored = 1; |
| profile->colored_done = 1; |
| profile->greybits_done = 1; /*greybits is not applicable anymore*/ |
| } |
| |
| if(!profile->alpha_done && a != 65535) |
| { |
| if(a == 0 && !(profile->key && (r != profile->key_r || g != profile->key_g || b != profile->key_b))) |
| { |
| if(!profile->key) |
| { |
| profile->key = 1; |
| profile->key_r = r; |
| profile->key_g = g; |
| profile->key_b = b; |
| } |
| } |
| else |
| { |
| profile->alpha = 1; |
| profile->alpha_done = 1; |
| profile->greybits_done = 1; /*greybits is not applicable anymore*/ |
| } |
| } |
| |
| /* Color key cannot be used if an opaque pixel also has that RGB color. */ |
| if(!profile->alpha_done && a == 65535 && profile->key |
| && r == profile->key_r && g == profile->key_g && b == profile->key_b) |
| { |
| profile->alpha = 1; |
| profile->alpha_done = 1; |
| profile->greybits_done = 1; /*greybits is not applicable anymore*/ |
| } |
| |
| if(!profile->greybits_done) |
| { |
| /*assuming 8-bit r, this test does not care about 16-bit*/ |
| unsigned bits = getValueRequiredBits(r); |
| if(bits > profile->greybits) profile->greybits = bits; |
| if(profile->greybits >= 8) profile->greybits_done = 1; |
| } |
| |
| if(!profile->numcolors_done) |
| { |
| /*assuming 8-bit rgba, this test does not care about 16-bit*/ |
| if(!color_tree_has(&profile->tree, (unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a)) |
| { |
| color_tree_add(&profile->tree, (unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a, |
| profile->numcolors); |
| if(profile->numcolors < 256) |
| { |
| unsigned char* p = profile->palette; |
| unsigned i = profile->numcolors; |
| p[i * 4 + 0] = (unsigned char)r; |
| p[i * 4 + 1] = (unsigned char)g; |
| p[i * 4 + 2] = (unsigned char)b; |
| p[i * 4 + 3] = (unsigned char)a; |
| } |
| profile->numcolors++; |
| if(profile->numcolors >= profile->maxnumcolors) profile->numcolors_done = 1; |
| } |
| } |
| |
| if(profile->alpha_done && profile->numcolors_done |
| && profile->colored_done && profile->sixteenbit_done && profile->greybits_done) |
| { |
| break; |
| } |
| }; |
| } |
| else /* < 16-bit */ |
| { |
| for(i = 0; i < numpixels; i++) |
| { |
| unsigned char r = 0, g = 0, b = 0, a = 0; |
| error = getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode, fix_png); |
| if(error) break; |
| |
| if(!profile->colored_done && (r != g || r != b)) |
| { |
| profile->colored = 1; |
| profile->colored_done = 1; |
| profile->greybits_done = 1; /*greybits is not applicable anymore*/ |
| } |
| |
| if(!profile->alpha_done && a != 255) |
| { |
| if(a == 0 && !(profile->key && (r != profile->key_r || g != profile->key_g || b != profile->key_b))) |
| { |
| if(!profile->key) |
| { |
| profile->key = 1; |
| profile->key_r = r; |
| profile->key_g = g; |
| profile->key_b = b; |
| } |
| } |
| else |
| { |
| profile->alpha = 1; |
| profile->alpha_done = 1; |
| profile->greybits_done = 1; /*greybits is not applicable anymore*/ |
| } |
| } |
| |
| /* Color key cannot be used if an opaque pixel also has that RGB color. */ |
| if(!profile->alpha_done && a == 255 && profile->key |
| && r == profile->key_r && g == profile->key_g && b == profile->key_b) |
| { |
| profile->alpha = 1; |
| profile->alpha_done = 1; |
| profile->greybits_done = 1; /*greybits is not applicable anymore*/ |
| } |
| |
| if(!profile->greybits_done) |
| { |
| unsigned bits = getValueRequiredBits(r); |
| if(bits > profile->greybits) profile->greybits = bits; |
| if(profile->greybits >= 8) profile->greybits_done = 1; |
| } |
| |
| if(!profile->numcolors_done) |
| { |
| if(!color_tree_has(&profile->tree, r, g, b, a)) |
| { |
| |
| color_tree_add(&profile->tree, r, g, b, a, profile->numcolors); |
| if(profile->numcolors < 256) |
| { |
| unsigned char* p = profile->palette; |
| unsigned i = profile->numcolors; |
| p[i * 4 + 0] = r; |
| p[i * 4 + 1] = g; |
| p[i * 4 + 2] = b; |
| p[i * 4 + 3] = a; |
| } |
| profile->numcolors++; |
| if(profile->numcolors >= profile->maxnumcolors) profile->numcolors_done = 1; |
| } |
| } |
| |
| if(profile->alpha_done && profile->numcolors_done && profile->colored_done && profile->greybits_done) |
| { |
| break; |
| } |
| }; |
| } |
| |
| /*make the profile's key always 16-bit for consistency*/ |
| if(mode->bitdepth < 16) |
| { |
| /*repeat each byte twice*/ |
| profile->key_r *= 257; |
| profile->key_g *= 257; |
| profile->key_b *= 257; |
| } |
| |
| return error; |
| } |
| |
| static void setColorKeyFrom16bit(LodePNGColorMode* mode_out, unsigned r, unsigned g, unsigned b, unsigned bitdepth) |
| { |
| unsigned mask = (1 << bitdepth) - 1; |
| mode_out->key_defined = 1; |
| mode_out->key_r = r & mask; |
| mode_out->key_g = g & mask; |
| mode_out->key_b = b & mask; |
| } |
| |
| /*updates values of mode with a potentially smaller color model. mode_out should |
| contain the user chosen color model, but will be overwritten with the new chosen one.*/ |
| static unsigned doAutoChooseColor(LodePNGColorMode* mode_out, |
| const unsigned char* image, unsigned w, unsigned h, LodePNGColorMode* mode_in, |
| LodePNGAutoConvert auto_convert) |
| { |
| ColorProfile profile; |
| unsigned error = 0; |
| int no_nibbles = auto_convert == LAC_AUTO_NO_NIBBLES || auto_convert == LAC_AUTO_NO_NIBBLES_NO_PALETTE; |
| int no_palette = auto_convert == LAC_AUTO_NO_PALETTE || auto_convert == LAC_AUTO_NO_NIBBLES_NO_PALETTE; |
| |
| if(auto_convert == LAC_ALPHA) |
| { |
| if(mode_out->colortype != LCT_RGBA && mode_out->colortype != LCT_GREY_ALPHA) return 0; |
| } |
| |
| color_profile_init(&profile, mode_in); |
| if(auto_convert == LAC_ALPHA) |
| { |
| profile.colored_done = 1; |
| profile.greybits_done = 1; |
| profile.numcolors_done = 1; |
| profile.sixteenbit_done = 1; |
| } |
| error = get_color_profile(&profile, image, w * h, mode_in, 0 /*fix_png*/); |
| if(!error && auto_convert == LAC_ALPHA) |
| { |
| if(!profile.alpha) |
| { |
| mode_out->colortype = (mode_out->colortype == LCT_RGBA ? LCT_RGB : LCT_GREY); |
| if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth); |
| } |
| } |
| else if(!error && auto_convert != LAC_ALPHA) |
| { |
| mode_out->key_defined = 0; |
| |
| if(profile.sixteenbit) |
| { |
| mode_out->bitdepth = 16; |
| if(profile.alpha) |
| { |
| mode_out->colortype = profile.colored ? LCT_RGBA : LCT_GREY_ALPHA; |
| } |
| else |
| { |
| mode_out->colortype = profile.colored ? LCT_RGB : LCT_GREY; |
| if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth); |
| } |
| } |
| else /*less than 16 bits per channel*/ |
| { |
| /*don't add palette overhead if image hasn't got a lot of pixels*/ |
| unsigned n = profile.numcolors; |
| int palette_ok = !no_palette && n <= 256 && (n * 2 < w * h); |
| unsigned palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8)); |
| int grey_ok = !profile.colored && !profile.alpha; /*grey without alpha, with potentially low bits*/ |
| if(palette_ok || grey_ok) |
| { |
| if(!palette_ok || (grey_ok && profile.greybits <= palettebits)) |
| { |
| mode_out->colortype = LCT_GREY; |
| mode_out->bitdepth = profile.greybits; |
| unsigned grey = profile.key_r; |
| if(profile.key) setColorKeyFrom16bit(mode_out, grey, grey, grey, mode_out->bitdepth); |
| } |
| else |
| { |
| /*fill in the palette*/ |
| unsigned i; |
| unsigned char* p = profile.palette; |
| /*remove potential earlier palette*/ |
| lodepng_palette_clear(mode_out); |
| for(i = 0; i < profile.numcolors; i++) |
| { |
| error = lodepng_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2], p[i * 4 + 3]); |
| if(error) break; |
| } |
| |
| mode_out->colortype = LCT_PALETTE; |
| mode_out->bitdepth = palettebits; |
| } |
| } |
| else /*8-bit per channel*/ |
| { |
| mode_out->bitdepth = 8; |
| if(profile.alpha) |
| { |
| mode_out->colortype = profile.colored ? LCT_RGBA : LCT_GREY_ALPHA; |
| } |
| else |
| { |
| mode_out->colortype = profile.colored ? LCT_RGB : LCT_GREY /*LCT_GREY normally won't occur, already done earlier*/; |
| if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth); |
| } |
| } |
| } |
| } |
| |
| color_profile_cleanup(&profile); |
| |
| if(mode_out->colortype == LCT_PALETTE && mode_in->palettesize == mode_out->palettesize) |
| { |
| /*In this case keep the palette order of the input, so that the user can choose an optimal one*/ |
| size_t i; |
| for(i = 0; i < mode_in->palettesize * 4; i++) |
| { |
| mode_out->palette[i] = mode_in->palette[i]; |
| } |
| } |
| |
| if(no_nibbles && mode_out->bitdepth < 8) |
| { |
| /*palette can keep its small amount of colors, as long as no indices use it*/ |
| mode_out->bitdepth = 8; |
| } |
| |
| return error; |
| } |
| |
| #endif /* #ifdef LODEPNG_COMPILE_ENCODER */ |
| |
| /* |
| Paeth predicter, used by PNG filter type 4 |
| The parameters are of type short, but should come from unsigned chars, the shorts |
| are only needed to make the paeth calculation correct. |
| */ |
| static unsigned char paethPredictor(short a, short b, short c) |
| { |
| short pa = abs(b - c); |
| short pb = abs(a - c); |
| short pc = abs(a + b - c - c); |
| |
| if(pc < pa && pc < pb) return (unsigned char)c; |
| else if(pb < pa) return (unsigned char)b; |
| else return (unsigned char)a; |
| } |
| |
| /*shared values used by multiple Adam7 related functions*/ |
| |
| static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/ |
| static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/ |
| static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/ |
| static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/ |
| |
| /* |
| Outputs various dimensions and positions in the image related to the Adam7 reduced images. |
| passw: output containing the width of the 7 passes |
| passh: output containing the height of the 7 passes |
| filter_passstart: output containing the index of the start and end of each |
| reduced image with filter bytes |
| padded_passstart output containing the index of the start and end of each |
| reduced image when without filter bytes but with padded scanlines |
| passstart: output containing the index of the start and end of each reduced |
| image without padding between scanlines, but still padding between the images |
| w, h: width and height of non-interlaced image |
| bpp: bits per pixel |
| "padded" is only relevant if bpp is less than 8 and a scanline or image does not |
| end at a full byte |
| */ |
| static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8], |
| size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp) |
| { |
| /*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/ |
| unsigned i; |
| |
| /*calculate width and height in pixels of each pass*/ |
| for(i = 0; i < 7; i++) |
| { |
| passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i]; |
| passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i]; |
| if(passw[i] == 0) passh[i] = 0; |
| if(passh[i] == 0) passw[i] = 0; |
| } |
| |
| filter_passstart[0] = padded_passstart[0] = passstart[0] = 0; |
| for(i = 0; i < 7; i++) |
| { |
| /*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/ |
| filter_passstart[i + 1] = filter_passstart[i] |
| + ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0); |
| /*bits padded if needed to fill full byte at end of each scanline*/ |
| padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8); |
| /*only padded at end of reduced image*/ |
| passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8; |
| } |
| } |
| |
| #ifdef LODEPNG_COMPILE_DECODER |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* / PNG Decoder / */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| /*read the information from the header and store it in the LodePNGInfo. return value is error*/ |
| unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state, |
| const unsigned char* in, size_t insize) |
| { |
| LodePNGInfo* info = &state->info_png; |
| if(insize == 0 || in == 0) |
| { |
| CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/ |
| } |
| if(insize < 29) |
| { |
| CERROR_RETURN_ERROR(state->error, 27); /*error: the data length is smaller than the length of a PNG header*/ |
| } |
| |
| /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/ |
| lodepng_info_cleanup(info); |
| lodepng_info_init(info); |
| |
| if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71 |
| || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) |
| { |
| CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/ |
| } |
| if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R') |
| { |
| CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/ |
| } |
| |
| /*read the values given in the header*/ |
| *w = lodepng_read32bitInt(&in[16]); |
| *h = lodepng_read32bitInt(&in[20]); |
| info->color.bitdepth = in[24]; |
| info->color.colortype = (LodePNGColorType)in[25]; |
| info->compression_method = in[26]; |
| info->filter_method = in[27]; |
| info->interlace_method = in[28]; |
| |
| if(!state->decoder.ignore_crc) |
| { |
| unsigned CRC = lodepng_read32bitInt(&in[29]); |
| unsigned checksum = lodepng_crc32(&in[12], 17); |
| if(CRC != checksum) |
| { |
| CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/ |
| } |
| } |
| |
| /*error: only compression method 0 is allowed in the specification*/ |
| if(info->compression_method != 0) CERROR_RETURN_ERROR(state->error, 32); |
| /*error: only filter method 0 is allowed in the specification*/ |
| if(info->filter_method != 0) CERROR_RETURN_ERROR(state->error, 33); |
| /*error: only interlace methods 0 and 1 exist in the specification*/ |
| if(info->interlace_method > 1) CERROR_RETURN_ERROR(state->error, 34); |
| |
| state->error = checkColorValidity(info->color.colortype, info->color.bitdepth); |
| return state->error; |
| } |
| |
| static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon, |
| size_t bytewidth, unsigned char filterType, size_t length) |
| { |
| /* |
| For PNG filter method 0 |
| unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte, |
| the filter works byte per byte (bytewidth = 1) |
| precon is the previous unfiltered scanline, recon the result, scanline the current one |
| the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead |
| recon and scanline MAY be the same memory address! precon must be disjoint. |
| */ |
| |
| size_t i; |
| switch(filterType) |
| { |
| case 0: |
| for(i = 0; i < length; i++) recon[i] = scanline[i]; |
| break; |
| case 1: |
| for(i = 0; i < bytewidth; i++) recon[i] = scanline[i]; |
| for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth]; |
| break; |
| case 2: |
| if(precon) |
| { |
| for(i = 0; i < length; i++) recon[i] = scanline[i] + precon[i]; |
| } |
| else |
| { |
| for(i = 0; i < length; i++) recon[i] = scanline[i]; |
| } |
| break; |
| case 3: |
| if(precon) |
| { |
| for(i = 0; i < bytewidth; i++) recon[i] = scanline[i] + precon[i] / 2; |
| for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2); |
| } |
| else |
| { |
| for(i = 0; i < bytewidth; i++) recon[i] = scanline[i]; |
| for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth] / 2; |
| } |
| break; |
| case 4: |
| if(precon) |
| { |
| for(i = 0; i < bytewidth; i++) |
| { |
| recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/ |
| } |
| for(i = bytewidth; i < length; i++) |
| { |
| recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth])); |
| } |
| } |
| else |
| { |
| for(i = 0; i < bytewidth; i++) |
| { |
| recon[i] = scanline[i]; |
| } |
| for(i = bytewidth; i < length; i++) |
| { |
| /*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/ |
| recon[i] = (scanline[i] + recon[i - bytewidth]); |
| } |
| } |
| break; |
| default: return 36; /*error: unexisting filter type given*/ |
| } |
| return 0; |
| } |
| |
| static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) |
| { |
| /* |
| For PNG filter method 0 |
| this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times) |
| out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline |
| w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel |
| in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes) |
| */ |
| |
| unsigned y; |
| unsigned char* prevline = 0; |
| |
| /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ |
| size_t bytewidth = (bpp + 7) / 8; |
| size_t linebytes = (w * bpp + 7) / 8; |
| |
| for(y = 0; y < h; y++) |
| { |
| size_t outindex = linebytes * y; |
| size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ |
| unsigned char filterType = in[inindex]; |
| |
| CERROR_TRY_RETURN(unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes)); |
| |
| prevline = &out[outindex]; |
| } |
| |
| return 0; |
| } |
| |
| /* |
| in: Adam7 interlaced image, with no padding bits between scanlines, but between |
| reduced images so that each reduced image starts at a byte. |
| out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h |
| bpp: bits per pixel |
| out has the following size in bits: w * h * bpp. |
| in is possibly bigger due to padding bits between reduced images. |
| out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation |
| (because that's likely a little bit faster) |
| NOTE: comments about padding bits are only relevant if bpp < 8 |
| */ |
| static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) |
| { |
| unsigned passw[7], passh[7]; |
| size_t filter_passstart[8], padded_passstart[8], passstart[8]; |
| unsigned i; |
| |
| Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); |
| |
| if(bpp >= 8) |
| { |
| for(i = 0; i < 7; i++) |
| { |
| unsigned x, y, b; |
| size_t bytewidth = bpp / 8; |
| for(y = 0; y < passh[i]; y++) |
| for(x = 0; x < passw[i]; x++) |
| { |
| size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth; |
| size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth; |
| for(b = 0; b < bytewidth; b++) |
| { |
| out[pixeloutstart + b] = in[pixelinstart + b]; |
| } |
| } |
| } |
| } |
| else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ |
| { |
| for(i = 0; i < 7; i++) |
| { |
| unsigned x, y, b; |
| unsigned ilinebits = bpp * passw[i]; |
| unsigned olinebits = bpp * w; |
| size_t obp, ibp; /*bit pointers (for out and in buffer)*/ |
| for(y = 0; y < passh[i]; y++) |
| for(x = 0; x < passw[i]; x++) |
| { |
| ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp); |
| obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp; |
| for(b = 0; b < bpp; b++) |
| { |
| unsigned char bit = readBitFromReversedStream(&ibp, in); |
| /*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/ |
| setBitOfReversedStream0(&obp, out, bit); |
| } |
| } |
| } |
| } |
| } |
| |
| static void removePaddingBits(unsigned char* out, const unsigned char* in, |
| size_t olinebits, size_t ilinebits, unsigned h) |
| { |
| /* |
| After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need |
| to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers |
| for the Adam7 code, the color convert code and the output to the user. |
| in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must |
| have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits |
| also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7 |
| only useful if (ilinebits - olinebits) is a value in the range 1..7 |
| */ |
| unsigned y; |
| size_t diff = ilinebits - olinebits; |
| size_t ibp = 0, obp = 0; /*input and output bit pointers*/ |
| for(y = 0; y < h; y++) |
| { |
| size_t x; |
| for(x = 0; x < olinebits; x++) |
| { |
| unsigned char bit = readBitFromReversedStream(&ibp, in); |
| setBitOfReversedStream(&obp, out, bit); |
| } |
| ibp += diff; |
| } |
| } |
| |
| /*out must be buffer big enough to contain full image, and in must contain the full decompressed data from |
| the IDAT chunks (with filter index bytes and possible padding bits) |
| return value is error*/ |
| static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, |
| unsigned w, unsigned h, const LodePNGInfo* info_png) |
| { |
| /* |
| This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype. |
| Steps: |
| *) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8) |
| *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace |
| NOTE: the in buffer will be overwritten with intermediate data! |
| */ |
| unsigned bpp = lodepng_get_bpp(&info_png->color); |
| if(bpp == 0) return 31; /*error: invalid colortype*/ |
| |
| if(info_png->interlace_method == 0) |
| { |
| if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) |
| { |
| CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp)); |
| removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h); |
| } |
| /*we can immediatly filter into the out buffer, no other steps needed*/ |
| else CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp)); |
| } |
| else /*interlace_method is 1 (Adam7)*/ |
| { |
| unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; |
| unsigned i; |
| |
| Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); |
| |
| for(i = 0; i < 7; i++) |
| { |
| CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp)); |
| /*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline, |
| move bytes instead of bits or move not at all*/ |
| if(bpp < 8) |
| { |
| /*remove padding bits in scanlines; after this there still may be padding |
| bits between the different reduced images: each reduced image still starts nicely at a byte*/ |
| removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp, |
| ((passw[i] * bpp + 7) / 8) * 8, passh[i]); |
| } |
| } |
| |
| Adam7_deinterlace(out, in, w, h, bpp); |
| } |
| |
| return 0; |
| } |
| |
| static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) |
| { |
| unsigned pos = 0, i; |
| if(color->palette) lodepng_free(color->palette); |
| color->palettesize = chunkLength / 3; |
| color->palette = (unsigned char*)lodepng_malloc(4 * color->palettesize); |
| if(!color->palette && color->palettesize) |
| { |
| color->palettesize = 0; |
| return 83; /*alloc fail*/ |
| } |
| if(color->palettesize > 256) return 38; /*error: palette too big*/ |
| |
| for(i = 0; i < color->palettesize; i++) |
| { |
| color->palette[4 * i + 0] = data[pos++]; /*R*/ |
| color->palette[4 * i + 1] = data[pos++]; /*G*/ |
| color->palette[4 * i + 2] = data[pos++]; /*B*/ |
| color->palette[4 * i + 3] = 255; /*alpha*/ |
| } |
| |
| return 0; /* OK */ |
| } |
| |
| static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) |
| { |
| unsigned i; |
| if(color->colortype == LCT_PALETTE) |
| { |
| /*error: more alpha values given than there are palette entries*/ |
| if(chunkLength > color->palettesize) return 38; |
| |
| for(i = 0; i < chunkLength; i++) color->palette[4 * i + 3] = data[i]; |
| } |
| else if(color->colortype == LCT_GREY) |
| { |
| /*error: this chunk must be 2 bytes for greyscale image*/ |
| if(chunkLength != 2) return 30; |
| |
| color->key_defined = 1; |
| color->key_r = color->key_g = color->key_b = 256 * data[0] + data[1]; |
| } |
| else if(color->colortype == LCT_RGB) |
| { |
| /*error: this chunk must be 6 bytes for RGB image*/ |
| if(chunkLength != 6) return 41; |
| |
| color->key_defined = 1; |
| color->key_r = 256 * data[0] + data[1]; |
| color->key_g = 256 * data[2] + data[3]; |
| color->key_b = 256 * data[4] + data[5]; |
| } |
| else return 42; /*error: tRNS chunk not allowed for other color models*/ |
| |
| return 0; /* OK */ |
| } |
| |
| |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| /*background color chunk (bKGD)*/ |
| static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) |
| { |
| if(info->color.colortype == LCT_PALETTE) |
| { |
| /*error: this chunk must be 1 byte for indexed color image*/ |
| if(chunkLength != 1) return 43; |
| |
| info->background_defined = 1; |
| info->background_r = info->background_g = info->background_b = data[0]; |
| } |
| else if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) |
| { |
| /*error: this chunk must be 2 bytes for greyscale image*/ |
| if(chunkLength != 2) return 44; |
| |
| info->background_defined = 1; |
| info->background_r = info->background_g = info->background_b |
| = 256 * data[0] + data[1]; |
| } |
| else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) |
| { |
| /*error: this chunk must be 6 bytes for greyscale image*/ |
| if(chunkLength != 6) return 45; |
| |
| info->background_defined = 1; |
| info->background_r = 256 * data[0] + data[1]; |
| info->background_g = 256 * data[2] + data[3]; |
| info->background_b = 256 * data[4] + data[5]; |
| } |
| |
| return 0; /* OK */ |
| } |
| |
| /*text chunk (tEXt)*/ |
| static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) |
| { |
| unsigned error = 0; |
| char *key = 0, *str = 0; |
| unsigned i; |
| |
| while(!error) /*not really a while loop, only used to break on error*/ |
| { |
| unsigned length, string2_begin; |
| |
| length = 0; |
| while(length < chunkLength && data[length] != 0) length++; |
| /*even though it's not allowed by the standard, no error is thrown if |
| there's no null termination char, if the text is empty*/ |
| if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ |
| |
| key = (char*)lodepng_malloc(length + 1); |
| if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ |
| |
| key[length] = 0; |
| for(i = 0; i < length; i++) key[i] = data[i]; |
| |
| string2_begin = length + 1; /*skip keyword null terminator*/ |
| |
| length = chunkLength < string2_begin ? 0 : chunkLength - string2_begin; |
| str = (char*)lodepng_malloc(length + 1); |
| if(!str) CERROR_BREAK(error, 83); /*alloc fail*/ |
| |
| str[length] = 0; |
| for(i = 0; i < length; i++) str[i] = data[string2_begin + i]; |
| |
| error = lodepng_add_text(info, key, str); |
| |
| break; |
| } |
| |
| lodepng_free(key); |
| lodepng_free(str); |
| |
| return error; |
| } |
| |
| /*compressed text chunk (zTXt)*/ |
| static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, |
| const unsigned char* data, size_t chunkLength) |
| { |
| unsigned error = 0; |
| unsigned i; |
| |
| unsigned length, string2_begin; |
| char *key = 0; |
| ucvector decoded; |
| |
| ucvector_init(&decoded); |
| |
| while(!error) /*not really a while loop, only used to break on error*/ |
| { |
| for(length = 0; length < chunkLength && data[length] != 0; length++) ; |
| if(length + 2 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/ |
| if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ |
| |
| key = (char*)lodepng_malloc(length + 1); |
| if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ |
| |
| key[length] = 0; |
| for(i = 0; i < length; i++) key[i] = data[i]; |
| |
| if(data[length + 1] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/ |
| |
| string2_begin = length + 2; |
| if(string2_begin > chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/ |
| |
| length = chunkLength - string2_begin; |
| /*will fail if zlib error, e.g. if length is too small*/ |
| error = zlib_decompress(&decoded.data, &decoded.size, |
| (unsigned char*)(&data[string2_begin]), |
| length, zlibsettings); |
| if(error) break; |
| ucvector_push_back(&decoded, 0); |
| |
| error = lodepng_add_text(info, key, (char*)decoded.data); |
| |
| break; |
| } |
| |
| lodepng_free(key); |
| ucvector_cleanup(&decoded); |
| |
| return error; |
| } |
| |
| /*international text chunk (iTXt)*/ |
| static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, |
| const unsigned char* data, size_t chunkLength) |
| { |
| unsigned error = 0; |
| unsigned i; |
| |
| unsigned length, begin, compressed; |
| char *key = 0, *langtag = 0, *transkey = 0; |
| ucvector decoded; |
| ucvector_init(&decoded); |
| |
| while(!error) /*not really a while loop, only used to break on error*/ |
| { |
| /*Quick check if the chunk length isn't too small. Even without check |
| it'd still fail with other error checks below if it's too short. This just gives a different error code.*/ |
| if(chunkLength < 5) CERROR_BREAK(error, 30); /*iTXt chunk too short*/ |
| |
| /*read the key*/ |
| for(length = 0; length < chunkLength && data[length] != 0; length++) ; |
| if(length + 3 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination char, corrupt?*/ |
| if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ |
| |
| key = (char*)lodepng_malloc(length + 1); |
| if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ |
| |
| key[length] = 0; |
| for(i = 0; i < length; i++) key[i] = data[i]; |
| |
| /*read the compression method*/ |
| compressed = data[length + 1]; |
| if(data[length + 2] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/ |
| |
| /*even though it's not allowed by the standard, no error is thrown if |
| there's no null termination char, if the text is empty for the next 3 texts*/ |
| |
| /*read the langtag*/ |
| begin = length + 3; |
| length = 0; |
| for(i = begin; i < chunkLength && data[i] != 0; i++) length++; |
| |
| langtag = (char*)lodepng_malloc(length + 1); |
| if(!langtag) CERROR_BREAK(error, 83); /*alloc fail*/ |
| |
| langtag[length] = 0; |
| for(i = 0; i < length; i++) langtag[i] = data[begin + i]; |
| |
| /*read the transkey*/ |
| begin += length + 1; |
| length = 0; |
| for(i = begin; i < chunkLength && data[i] != 0; i++) length++; |
| |
| transkey = (char*)lodepng_malloc(length + 1); |
| if(!transkey) CERROR_BREAK(error, 83); /*alloc fail*/ |
| |
| transkey[length] = 0; |
| for(i = 0; i < length; i++) transkey[i] = data[begin + i]; |
| |
| /*read the actual text*/ |
| begin += length + 1; |
| |
| length = chunkLength < begin ? 0 : chunkLength - begin; |
| |
| if(compressed) |
| { |
| /*will fail if zlib error, e.g. if length is too small*/ |
| error = zlib_decompress(&decoded.data, &decoded.size, |
| (unsigned char*)(&data[begin]), |
| length, zlibsettings); |
| if(error) break; |
| if(decoded.allocsize < decoded.size) decoded.allocsize = decoded.size; |
| ucvector_push_back(&decoded, 0); |
| } |
| else |
| { |
| if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(error, 83 /*alloc fail*/); |
| |
| decoded.data[length] = 0; |
| for(i = 0; i < length; i++) decoded.data[i] = data[begin + i]; |
| } |
| |
| error = lodepng_add_itext(info, key, langtag, transkey, (char*)decoded.data); |
| |
| break; |
| } |
| |
| lodepng_free(key); |
| lodepng_free(langtag); |
| lodepng_free(transkey); |
| ucvector_cleanup(&decoded); |
| |
| return error; |
| } |
| |
| static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) |
| { |
| if(chunkLength != 7) return 73; /*invalid tIME chunk size*/ |
| |
| info->time_defined = 1; |
| info->time.year = 256 * data[0] + data[+ 1]; |
| info->time.month = data[2]; |
| info->time.day = data[3]; |
| info->time.hour = data[4]; |
| info->time.minute = data[5]; |
| info->time.second = data[6]; |
| |
| return 0; /* OK */ |
| } |
| |
| static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) |
| { |
| if(chunkLength != 9) return 74; /*invalid pHYs chunk size*/ |
| |
| info->phys_defined = 1; |
| info->phys_x = 16777216 * data[0] + 65536 * data[1] + 256 * data[2] + data[3]; |
| info->phys_y = 16777216 * data[4] + 65536 * data[5] + 256 * data[6] + data[7]; |
| info->phys_unit = data[8]; |
| |
| return 0; /* OK */ |
| } |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| |
| /*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/ |
| static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h, |
| LodePNGState* state, |
| const unsigned char* in, size_t insize) |
| { |
| unsigned char IEND = 0; |
| const unsigned char* chunk; |
| size_t i; |
| ucvector idat; /*the data from idat chunks*/ |
| |
| /*for unknown chunk order*/ |
| unsigned unknown = 0; |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/ |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| |
| /*provide some proper output values if error will happen*/ |
| *out = 0; |
| |
| state->error = lodepng_inspect(w, h, state, in, insize); /*reads header and resets other parameters in state->info_png*/ |
| if(state->error) return; |
| |
| ucvector_init(&idat); |
| chunk = &in[33]; /*first byte of the first chunk after the header*/ |
| |
| /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk. |
| IDAT data is put at the start of the in buffer*/ |
| while(!IEND && !state->error) |
| { |
| unsigned chunkLength; |
| const unsigned char* data; /*the data in the chunk*/ |
| |
| /*error: size of the in buffer too small to contain next chunk*/ |
| if((size_t)((chunk - in) + 12) > insize || chunk < in) CERROR_BREAK(state->error, 30); |
| |
| /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/ |
| chunkLength = lodepng_chunk_length(chunk); |
| /*error: chunk length larger than the max PNG chunk size*/ |
| if(chunkLength > 2147483647) CERROR_BREAK(state->error, 63); |
| |
| if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in) |
| { |
| CERROR_BREAK(state->error, 64); /*error: size of the in buffer too small to contain next chunk*/ |
| } |
| |
| data = lodepng_chunk_data_const(chunk); |
| |
| /*IDAT chunk, containing compressed image data*/ |
| if(lodepng_chunk_type_equals(chunk, "IDAT")) |
| { |
| size_t oldsize = idat.size; |
| if(!ucvector_resize(&idat, oldsize + chunkLength)) CERROR_BREAK(state->error, 83 /*alloc fail*/); |
| for(i = 0; i < chunkLength; i++) idat.data[oldsize + i] = data[i]; |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| critical_pos = 3; |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| } |
| /*IEND chunk*/ |
| else if(lodepng_chunk_type_equals(chunk, "IEND")) |
| { |
| IEND = 1; |
| } |
| /*palette chunk (PLTE)*/ |
| else if(lodepng_chunk_type_equals(chunk, "PLTE")) |
| { |
| state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength); |
| if(state->error) break; |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| critical_pos = 2; |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| } |
| /*palette transparency chunk (tRNS)*/ |
| else if(lodepng_chunk_type_equals(chunk, "tRNS")) |
| { |
| state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength); |
| if(state->error) break; |
| } |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| /*background color chunk (bKGD)*/ |
| else if(lodepng_chunk_type_equals(chunk, "bKGD")) |
| { |
| state->error = readChunk_bKGD(&state->info_png, data, chunkLength); |
| if(state->error) break; |
| } |
| /*text chunk (tEXt)*/ |
| else if(lodepng_chunk_type_equals(chunk, "tEXt")) |
| { |
| if(state->decoder.read_text_chunks) |
| { |
| state->error = readChunk_tEXt(&state->info_png, data, chunkLength); |
| if(state->error) break; |
| } |
| } |
| /*compressed text chunk (zTXt)*/ |
| else if(lodepng_chunk_type_equals(chunk, "zTXt")) |
| { |
| if(state->decoder.read_text_chunks) |
| { |
| state->error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); |
| if(state->error) break; |
| } |
| } |
| /*international text chunk (iTXt)*/ |
| else if(lodepng_chunk_type_equals(chunk, "iTXt")) |
| { |
| if(state->decoder.read_text_chunks) |
| { |
| state->error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); |
| if(state->error) break; |
| } |
| } |
| else if(lodepng_chunk_type_equals(chunk, "tIME")) |
| { |
| state->error = readChunk_tIME(&state->info_png, data, chunkLength); |
| if(state->error) break; |
| } |
| else if(lodepng_chunk_type_equals(chunk, "pHYs")) |
| { |
| state->error = readChunk_pHYs(&state->info_png, data, chunkLength); |
| if(state->error) break; |
| } |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| else /*it's not an implemented chunk type, so ignore it: skip over the data*/ |
| { |
| /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/ |
| if(!lodepng_chunk_ancillary(chunk)) CERROR_BREAK(state->error, 69); |
| |
| unknown = 1; |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| if(state->decoder.remember_unknown_chunks) |
| { |
| state->error = lodepng_chunk_append(&state->info_png.unknown_chunks_data[critical_pos - 1], |
| &state->info_png.unknown_chunks_size[critical_pos - 1], chunk); |
| if(state->error) break; |
| } |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| } |
| |
| if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/ |
| { |
| if(lodepng_chunk_check_crc(chunk)) CERROR_BREAK(state->error, 57); /*invalid CRC*/ |
| } |
| |
| if(!IEND) chunk = lodepng_chunk_next_const(chunk); |
| } |
| |
| if(!state->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, lodepng_get_raw_size(*w, *h, &state->info_png.color) + *h)) |
| { |
| state->error = 83; /*alloc fail*/ |
| } |
| if(!state->error) |
| { |
| /*decompress with the Zlib decompressor*/ |
| state->error = zlib_decompress(&scanlines.data, &scanlines.size, idat.data, |
| idat.size, &state->decoder.zlibsettings); |
| } |
| |
| if(!state->error) |
| { |
| ucvector outv; |
| ucvector_init(&outv); |
| if(!ucvector_resizev(&outv, |
| lodepng_get_raw_size(*w, *h, &state->info_png.color), 0)) state->error = 83; /*alloc fail*/ |
| if(!state->error) state->error = postProcessScanlines(outv.data, scanlines.data, *w, *h, &state->info_png); |
| *out = outv.data; |
| } |
| ucvector_cleanup(&scanlines); |
| } |
| |
| ucvector_cleanup(&idat); |
| } |
| |
| unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h, |
| LodePNGState* state, |
| const unsigned char* in, size_t insize) |
| { |
| *out = 0; |
| decodeGeneric(out, w, h, state, in, insize); |
| if(state->error) return state->error; |
| if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color)) |
| { |
| /*same color type, no copying or converting of data needed*/ |
| /*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype |
| the raw image has to the end user*/ |
| if(!state->decoder.color_convert) |
| { |
| state->error = lodepng_color_mode_copy(&state->info_raw, &state->info_png.color); |
| if(state->error) return state->error; |
| } |
| } |
| else |
| { |
| /*color conversion needed; sort of copy of the data*/ |
| unsigned char* data = *out; |
| size_t outsize; |
| |
| /*TODO: check if this works according to the statement in the documentation: "The converter can convert |
| from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/ |
| if(!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA) |
| && !(state->info_raw.bitdepth == 8)) |
| { |
| return 56; /*unsupported color mode conversion*/ |
| } |
| |
| outsize = lodepng_get_raw_size(*w, *h, &state->info_raw); |
| *out = (unsigned char*)lodepng_malloc(outsize); |
| if(!(*out)) |
| { |
| state->error = 83; /*alloc fail*/ |
| } |
| else state->error = lodepng_convert(*out, data, &state->info_raw, &state->info_png.color, *w, *h, state->decoder.fix_png); |
| lodepng_free(data); |
| } |
| return state->error; |
| } |
| |
| unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, |
| size_t insize, LodePNGColorType colortype, unsigned bitdepth) |
| { |
| unsigned error; |
| LodePNGState state; |
| lodepng_state_init(&state); |
| state.info_raw.colortype = colortype; |
| state.info_raw.bitdepth = bitdepth; |
| error = lodepng_decode(out, w, h, &state, in, insize); |
| lodepng_state_cleanup(&state); |
| return error; |
| } |
| |
| unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) |
| { |
| return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8); |
| } |
| |
| unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) |
| { |
| return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8); |
| } |
| |
| #ifdef LODEPNG_COMPILE_DISK |
| unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename, |
| LodePNGColorType colortype, unsigned bitdepth) |
| { |
| unsigned char* buffer; |
| size_t buffersize; |
| unsigned error; |
| error = lodepng_load_file(&buffer, &buffersize, filename); |
| if(!error) error = lodepng_decode_memory(out, w, h, buffer, buffersize, colortype, bitdepth); |
| lodepng_free(buffer); |
| return error; |
| } |
| |
| unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) |
| { |
| return lodepng_decode_file(out, w, h, filename, LCT_RGBA, 8); |
| } |
| |
| unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) |
| { |
| return lodepng_decode_file(out, w, h, filename, LCT_RGB, 8); |
| } |
| #endif /*LODEPNG_COMPILE_DISK*/ |
| |
| void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) |
| { |
| settings->color_convert = 1; |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| settings->read_text_chunks = 1; |
| settings->remember_unknown_chunks = 0; |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| settings->ignore_crc = 0; |
| settings->fix_png = 0; |
| lodepng_decompress_settings_init(&settings->zlibsettings); |
| } |
| |
| #endif /*LODEPNG_COMPILE_DECODER*/ |
| |
| #if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) |
| |
| void lodepng_state_init(LodePNGState* state) |
| { |
| #ifdef LODEPNG_COMPILE_DECODER |
| lodepng_decoder_settings_init(&state->decoder); |
| #endif /*LODEPNG_COMPILE_DECODER*/ |
| #ifdef LODEPNG_COMPILE_ENCODER |
| lodepng_encoder_settings_init(&state->encoder); |
| #endif /*LODEPNG_COMPILE_ENCODER*/ |
| lodepng_color_mode_init(&state->info_raw); |
| lodepng_info_init(&state->info_png); |
| state->error = 1; |
| } |
| |
| void lodepng_state_cleanup(LodePNGState* state) |
| { |
| lodepng_color_mode_cleanup(&state->info_raw); |
| lodepng_info_cleanup(&state->info_png); |
| } |
| |
| void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source) |
| { |
| lodepng_state_cleanup(dest); |
| *dest = *source; |
| lodepng_color_mode_init(&dest->info_raw); |
| lodepng_info_init(&dest->info_png); |
| dest->error = lodepng_color_mode_copy(&dest->info_raw, &source->info_raw); if(dest->error) return; |
| dest->error = lodepng_info_copy(&dest->info_png, &source->info_png); if(dest->error) return; |
| } |
| |
| #endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */ |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* / PNG Encoder / */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| /*chunkName must be string of 4 characters*/ |
| static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length) |
| { |
| CERROR_TRY_RETURN(lodepng_chunk_create(&out->data, &out->size, (unsigned)length, chunkName, data)); |
| out->allocsize = out->size; /*fix the allocsize again*/ |
| return 0; |
| } |
| |
| static void writeSignature(ucvector* out) |
| { |
| /*8 bytes PNG signature, aka the magic bytes*/ |
| ucvector_push_back(out, 137); |
| ucvector_push_back(out, 80); |
| ucvector_push_back(out, 78); |
| ucvector_push_back(out, 71); |
| ucvector_push_back(out, 13); |
| ucvector_push_back(out, 10); |
| ucvector_push_back(out, 26); |
| ucvector_push_back(out, 10); |
| } |
| |
| static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h, |
| LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method) |
| { |
| unsigned error = 0; |
| ucvector header; |
| ucvector_init(&header); |
| |
| lodepng_add32bitInt(&header, w); /*width*/ |
| lodepng_add32bitInt(&header, h); /*height*/ |
| ucvector_push_back(&header, (unsigned char)bitdepth); /*bit depth*/ |
| ucvector_push_back(&header, (unsigned char)colortype); /*color type*/ |
| ucvector_push_back(&header, 0); /*compression method*/ |
| ucvector_push_back(&header, 0); /*filter method*/ |
| ucvector_push_back(&header, interlace_method); /*interlace method*/ |
| |
| error = addChunk(out, "IHDR", header.data, header.size); |
| ucvector_cleanup(&header); |
| |
| return error; |
| } |
| |
| static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* info) |
| { |
| unsigned error = 0; |
| size_t i; |
| ucvector PLTE; |
| ucvector_init(&PLTE); |
| for(i = 0; i < info->palettesize * 4; i++) |
| { |
| /*add all channels except alpha channel*/ |
| if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]); |
| } |
| error = addChunk(out, "PLTE", PLTE.data, PLTE.size); |
| ucvector_cleanup(&PLTE); |
| |
| return error; |
| } |
| |
| static unsigned addChunk_tRNS(ucvector* out, const LodePNGColorMode* info) |
| { |
| unsigned error = 0; |
| size_t i; |
| ucvector tRNS; |
| ucvector_init(&tRNS); |
| if(info->colortype == LCT_PALETTE) |
| { |
| size_t amount = info->palettesize; |
| /*the tail of palette values that all have 255 as alpha, does not have to be encoded*/ |
| for(i = info->palettesize; i > 0; i--) |
| { |
| if(info->palette[4 * (i - 1) + 3] == 255) amount--; |
| else break; |
| } |
| /*add only alpha channel*/ |
| for(i = 0; i < amount; i++) ucvector_push_back(&tRNS, info->palette[4 * i + 3]); |
| } |
| else if(info->colortype == LCT_GREY) |
| { |
| if(info->key_defined) |
| { |
| ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256)); |
| ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256)); |
| } |
| } |
| else if(info->colortype == LCT_RGB) |
| { |
| if(info->key_defined) |
| { |
| ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256)); |
| ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256)); |
| ucvector_push_back(&tRNS, (unsigned char)(info->key_g / 256)); |
| ucvector_push_back(&tRNS, (unsigned char)(info->key_g % 256)); |
| ucvector_push_back(&tRNS, (unsigned char)(info->key_b / 256)); |
| ucvector_push_back(&tRNS, (unsigned char)(info->key_b % 256)); |
| } |
| } |
| |
| error = addChunk(out, "tRNS", tRNS.data, tRNS.size); |
| ucvector_cleanup(&tRNS); |
| |
| return error; |
| } |
| |
| static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize, |
| LodePNGCompressSettings* zlibsettings) |
| { |
| ucvector zlibdata; |
| unsigned error = 0; |
| |
| /*compress with the Zlib compressor*/ |
| ucvector_init(&zlibdata); |
| error = zlib_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings); |
| if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size); |
| ucvector_cleanup(&zlibdata); |
| |
| return error; |
| } |
| |
| static unsigned addChunk_IEND(ucvector* out) |
| { |
| unsigned error = 0; |
| error = addChunk(out, "IEND", 0, 0); |
| return error; |
| } |
| |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| |
| static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring) |
| { |
| unsigned error = 0; |
| size_t i; |
| ucvector text; |
| ucvector_init(&text); |
| for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&text, (unsigned char)keyword[i]); |
| if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/ |
| ucvector_push_back(&text, 0); /*0 termination char*/ |
| for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&text, (unsigned char)textstring[i]); |
| error = addChunk(out, "tEXt", text.data, text.size); |
| ucvector_cleanup(&text); |
| |
| return error; |
| } |
| |
| static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring, |
| LodePNGCompressSettings* zlibsettings) |
| { |
| unsigned error = 0; |
| ucvector data, compressed; |
| size_t i, textsize = strlen(textstring); |
| |
| ucvector_init(&data); |
| ucvector_init(&compressed); |
| for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]); |
| if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/ |
| ucvector_push_back(&data, 0); /*0 termination char*/ |
| ucvector_push_back(&data, 0); /*compression method: 0*/ |
| |
| error = zlib_compress(&compressed.data, &compressed.size, |
| (unsigned char*)textstring, textsize, zlibsettings); |
| if(!error) |
| { |
| for(i = 0; i < compressed.size; i++) ucvector_push_back(&data, compressed.data[i]); |
| error = addChunk(out, "zTXt", data.data, data.size); |
| } |
| |
| ucvector_cleanup(&compressed); |
| ucvector_cleanup(&data); |
| return error; |
| } |
| |
| static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag, |
| const char* transkey, const char* textstring, LodePNGCompressSettings* zlibsettings) |
| { |
| unsigned error = 0; |
| ucvector data; |
| size_t i, textsize = strlen(textstring); |
| |
| ucvector_init(&data); |
| |
| for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]); |
| if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/ |
| ucvector_push_back(&data, 0); /*null termination char*/ |
| ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/ |
| ucvector_push_back(&data, 0); /*compression method*/ |
| for(i = 0; langtag[i] != 0; i++) ucvector_push_back(&data, (unsigned char)langtag[i]); |
| ucvector_push_back(&data, 0); /*null termination char*/ |
| for(i = 0; transkey[i] != 0; i++) ucvector_push_back(&data, (unsigned char)transkey[i]); |
| ucvector_push_back(&data, 0); /*null termination char*/ |
| |
| if(compressed) |
| { |
| ucvector compressed_data; |
| ucvector_init(&compressed_data); |
| error = zlib_compress(&compressed_data.data, &compressed_data.size, |
| (unsigned char*)textstring, textsize, zlibsettings); |
| if(!error) |
| { |
| for(i = 0; i < compressed_data.size; i++) ucvector_push_back(&data, compressed_data.data[i]); |
| } |
| ucvector_cleanup(&compressed_data); |
| } |
| else /*not compressed*/ |
| { |
| for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]); |
| } |
| |
| if(!error) error = addChunk(out, "iTXt", data.data, data.size); |
| ucvector_cleanup(&data); |
| return error; |
| } |
| |
| static unsigned addChunk_bKGD(ucvector* out, const LodePNGInfo* info) |
| { |
| unsigned error = 0; |
| ucvector bKGD; |
| ucvector_init(&bKGD); |
| if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) |
| { |
| ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256)); |
| ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); |
| } |
| else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) |
| { |
| ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256)); |
| ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); |
| ucvector_push_back(&bKGD, (unsigned char)(info->background_g / 256)); |
| ucvector_push_back(&bKGD, (unsigned char)(info->background_g % 256)); |
| ucvector_push_back(&bKGD, (unsigned char)(info->background_b / 256)); |
| ucvector_push_back(&bKGD, (unsigned char)(info->background_b % 256)); |
| } |
| else if(info->color.colortype == LCT_PALETTE) |
| { |
| ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); /*palette index*/ |
| } |
| |
| error = addChunk(out, "bKGD", bKGD.data, bKGD.size); |
| ucvector_cleanup(&bKGD); |
| |
| return error; |
| } |
| |
| static unsigned addChunk_tIME(ucvector* out, const LodePNGTime* time) |
| { |
| unsigned error = 0; |
| unsigned char* data = (unsigned char*)lodepng_malloc(7); |
| if(!data) return 83; /*alloc fail*/ |
| data[0] = (unsigned char)(time->year / 256); |
| data[1] = (unsigned char)(time->year % 256); |
| data[2] = time->month; |
| data[3] = time->day; |
| data[4] = time->hour; |
| data[5] = time->minute; |
| data[6] = time->second; |
| error = addChunk(out, "tIME", data, 7); |
| lodepng_free(data); |
| return error; |
| } |
| |
| static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* info) |
| { |
| unsigned error = 0; |
| ucvector data; |
| ucvector_init(&data); |
| |
| lodepng_add32bitInt(&data, info->phys_x); |
| lodepng_add32bitInt(&data, info->phys_y); |
| ucvector_push_back(&data, info->phys_unit); |
| |
| error = addChunk(out, "pHYs", data.data, data.size); |
| ucvector_cleanup(&data); |
| |
| return error; |
| } |
| |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| |
| static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline, |
| size_t length, size_t bytewidth, unsigned char filterType) |
| { |
| size_t i; |
| switch(filterType) |
| { |
| case 0: /*None*/ |
| for(i = 0; i < length; i++) out[i] = scanline[i]; |
| break; |
| case 1: /*Sub*/ |
| if(prevline) |
| { |
| for(i = 0; i < bytewidth; i++) out[i] = scanline[i]; |
| for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth]; |
| } |
| else |
| { |
| for(i = 0; i < bytewidth; i++) out[i] = scanline[i]; |
| for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth]; |
| } |
| break; |
| case 2: /*Up*/ |
| if(prevline) |
| { |
| for(i = 0; i < length; i++) out[i] = scanline[i] - prevline[i]; |
| } |
| else |
| { |
| for(i = 0; i < length; i++) out[i] = scanline[i]; |
| } |
| break; |
| case 3: /*Average*/ |
| if(prevline) |
| { |
| for(i = 0; i < bytewidth; i++) out[i] = scanline[i] - prevline[i] / 2; |
| for(i = bytewidth; i < length; i++) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) / 2); |
| } |
| else |
| { |
| for(i = 0; i < bytewidth; i++) out[i] = scanline[i]; |
| for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth] / 2; |
| } |
| break; |
| case 4: /*Paeth*/ |
| if(prevline) |
| { |
| /*paethPredictor(0, prevline[i], 0) is always prevline[i]*/ |
| for(i = 0; i < bytewidth; i++) out[i] = (scanline[i] - prevline[i]); |
| for(i = bytewidth; i < length; i++) |
| { |
| out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth])); |
| } |
| } |
| else |
| { |
| for(i = 0; i < bytewidth; i++) out[i] = scanline[i]; |
| /*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/ |
| for(i = bytewidth; i < length; i++) out[i] = (scanline[i] - scanline[i - bytewidth]); |
| } |
| break; |
| default: return; /*unexisting filter type given*/ |
| } |
| } |
| |
| /* log2 approximation. A slight bit faster than std::log. */ |
| static float flog2(float f) |
| { |
| float result = 0; |
| while(f > 32) { result += 4; f /= 16; } |
| while(f > 2) { result++; f /= 2; } |
| return result + 1.442695f * (f * f * f / 3 - 3 * f * f / 2 + 3 * f - 1.83333f); |
| } |
| |
| static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, |
| const LodePNGColorMode* info, const LodePNGEncoderSettings* settings) |
| { |
| /* |
| For PNG filter method 0 |
| out must be a buffer with as size: h + (w * h * bpp + 7) / 8, because there are |
| the scanlines with 1 extra byte per scanline |
| */ |
| |
| unsigned bpp = lodepng_get_bpp(info); |
| /*the width of a scanline in bytes, not including the filter type*/ |
| size_t linebytes = (w * bpp + 7) / 8; |
| /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ |
| size_t bytewidth = (bpp + 7) / 8; |
| const unsigned char* prevline = 0; |
| unsigned x, y; |
| unsigned error = 0; |
| LodePNGFilterStrategy strategy = settings->filter_strategy; |
| |
| /* |
| There is a heuristic called the minimum sum of absolute differences heuristic, suggested by the PNG standard: |
| * If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e. |
| use fixed filtering, with the filter None). |
| * (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is |
| not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply |
| all five filters and select the filter that produces the smallest sum of absolute values per row. |
| This heuristic is used if filter strategy is LFS_MINSUM and filter_palette_zero is true. |
| |
| If filter_palette_zero is true and filter_strategy is not LFS_MINSUM, the above heuristic is followed, |
| but for "the other case", whatever strategy filter_strategy is set to instead of the minimum sum |
| heuristic is used. |
| */ |
| if(settings->filter_palette_zero && |
| (info->colortype == LCT_PALETTE || info->bitdepth < 8)) strategy = LFS_ZERO; |
| |
| if(bpp == 0) return 31; /*error: invalid color type*/ |
| |
| if(strategy == LFS_ZERO) |
| { |
| for(y = 0; y < h; y++) |
| { |
| size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ |
| size_t inindex = linebytes * y; |
| out[outindex] = 0; /*filter type byte*/ |
| filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, 0); |
| prevline = &in[inindex]; |
| } |
| } |
| else if(strategy == LFS_MINSUM) |
| { |
| /*adaptive filtering*/ |
| size_t sum[5]; |
| ucvector attempt[5]; /*five filtering attempts, one for each filter type*/ |
| size_t smallest = 0; |
| unsigned type, bestType = 0; |
| |
| for(type = 0; type < 5; type++) |
| { |
| ucvector_init(&attempt[type]); |
| if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*alloc fail*/ |
| } |
| |
| if(!error) |
| { |
| for(y = 0; y < h; y++) |
| { |
| /*try the 5 filter types*/ |
| for(type = 0; type < 5; type++) |
| { |
| filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type); |
| |
| /*calculate the sum of the result*/ |
| sum[type] = 0; |
| if(type == 0) |
| { |
| for(x = 0; x < linebytes; x++) sum[type] += (unsigned char)(attempt[type].data[x]); |
| } |
| else |
| { |
| for(x = 0; x < linebytes; x++) |
| { |
| /*For differences, each byte should be treated as signed, values above 127 are negative |
| (converted to signed char). Filtertype 0 isn't a difference though, so use unsigned there. |
| This means filtertype 0 is almost never chosen, but that is justified.*/ |
| signed char s = (signed char)(attempt[type].data[x]); |
| sum[type] += s < 0 ? -s : s; |
| } |
| } |
| |
| /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/ |
| if(type == 0 || sum[type] < smallest) |
| { |
| bestType = type; |
| smallest = sum[type]; |
| } |
| } |
| |
| prevline = &in[y * linebytes]; |
| |
| /*now fill the out values*/ |
| out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ |
| for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x]; |
| } |
| } |
| |
| for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]); |
| } |
| else if(strategy == LFS_ENTROPY) |
| { |
| float sum[5]; |
| ucvector attempt[5]; /*five filtering attempts, one for each filter type*/ |
| float smallest = 0; |
| unsigned type, bestType = 0; |
| unsigned count[256]; |
| |
| for(type = 0; type < 5; type++) |
| { |
| ucvector_init(&attempt[type]); |
| if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*alloc fail*/ |
| } |
| |
| for(y = 0; y < h; y++) |
| { |
| /*try the 5 filter types*/ |
| for(type = 0; type < 5; type++) |
| { |
| filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type); |
| for(x = 0; x < 256; x++) count[x] = 0; |
| for(x = 0; x < linebytes; x++) count[attempt[type].data[x]]++; |
| count[type]++; /*the filter type itself is part of the scanline*/ |
| sum[type] = 0; |
| for(x = 0; x < 256; x++) |
| { |
| float p = count[x] / (float)(linebytes + 1); |
| sum[type] += count[x] == 0 ? 0 : flog2(1 / p) * p; |
| } |
| /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/ |
| if(type == 0 || sum[type] < smallest) |
| { |
| bestType = type; |
| smallest = sum[type]; |
| } |
| } |
| |
| prevline = &in[y * linebytes]; |
| |
| /*now fill the out values*/ |
| out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ |
| for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x]; |
| } |
| |
| for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]); |
| } |
| else if(strategy == LFS_PREDEFINED) |
| { |
| for(y = 0; y < h; y++) |
| { |
| size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ |
| size_t inindex = linebytes * y; |
| unsigned type = settings->predefined_filters[y]; |
| out[outindex] = type; /*filter type byte*/ |
| filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type); |
| prevline = &in[inindex]; |
| } |
| } |
| else if(strategy == LFS_BRUTE_FORCE) |
| { |
| /*brute force filter chooser. |
| deflate the scanline after every filter attempt to see which one deflates best. |
| This is very slow and gives only slightly smaller, sometimes even larger, result*/ |
| size_t size[5]; |
| ucvector attempt[5]; /*five filtering attempts, one for each filter type*/ |
| size_t smallest = 0; |
| unsigned type = 0, bestType = 0; |
| unsigned char* dummy; |
| LodePNGCompressSettings zlibsettings = settings->zlibsettings; |
| /*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose, |
| to simulate the true case where the tree is the same for the whole image. Sometimes it gives |
| better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare |
| cases better compression. It does make this a bit less slow, so it's worth doing this.*/ |
| zlibsettings.btype = 1; |
| /*a custom encoder likely doesn't read the btype setting and is optimized for complete PNG |
| images only, so disable it*/ |
| zlibsettings.custom_zlib = 0; |
| zlibsettings.custom_deflate = 0; |
| for(type = 0; type < 5; type++) |
| { |
| ucvector_init(&attempt[type]); |
| ucvector_resize(&attempt[type], linebytes); /*todo: give error if resize failed*/ |
| } |
| for(y = 0; y < h; y++) /*try the 5 filter types*/ |
| { |
| for(type = 0; type < 5; type++) |
| { |
| unsigned testsize = attempt[type].size; |
| /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/ |
| |
| filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type); |
| size[type] = 0; |
| dummy = 0; |
| zlib_compress(&dummy, &size[type], attempt[type].data, testsize, &zlibsettings); |
| lodepng_free(dummy); |
| /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/ |
| if(type == 0 || size[type] < smallest) |
| { |
| bestType = type; |
| smallest = size[type]; |
| } |
| } |
| prevline = &in[y * linebytes]; |
| out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ |
| for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x]; |
| } |
| for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]); |
| } |
| else return 88; /* unknown filter strategy */ |
| |
| return error; |
| } |
| |
| static void addPaddingBits(unsigned char* out, const unsigned char* in, |
| size_t olinebits, size_t ilinebits, unsigned h) |
| { |
| /*The opposite of the removePaddingBits function |
| olinebits must be >= ilinebits*/ |
| unsigned y; |
| size_t diff = olinebits - ilinebits; |
| size_t obp = 0, ibp = 0; /*bit pointers*/ |
| for(y = 0; y < h; y++) |
| { |
| size_t x; |
| for(x = 0; x < ilinebits; x++) |
| { |
| unsigned char bit = readBitFromReversedStream(&ibp, in); |
| setBitOfReversedStream(&obp, out, bit); |
| } |
| /*obp += diff; --> no, fill in some value in the padding bits too, to avoid |
| "Use of uninitialised value of size ###" warning from valgrind*/ |
| for(x = 0; x < diff; x++) setBitOfReversedStream(&obp, out, 0); |
| } |
| } |
| |
| /* |
| in: non-interlaced image with size w*h |
| out: the same pixels, but re-ordered according to PNG's Adam7 interlacing, with |
| no padding bits between scanlines, but between reduced images so that each |
| reduced image starts at a byte. |
| bpp: bits per pixel |
| there are no padding bits, not between scanlines, not between reduced images |
| in has the following size in bits: w * h * bpp. |
| out is possibly bigger due to padding bits between reduced images |
| NOTE: comments about padding bits are only relevant if bpp < 8 |
| */ |
| static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) |
| { |
| unsigned passw[7], passh[7]; |
| size_t filter_passstart[8], padded_passstart[8], passstart[8]; |
| unsigned i; |
| |
| Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); |
| |
| if(bpp >= 8) |
| { |
| for(i = 0; i < 7; i++) |
| { |
| unsigned x, y, b; |
| size_t bytewidth = bpp / 8; |
| for(y = 0; y < passh[i]; y++) |
| for(x = 0; x < passw[i]; x++) |
| { |
| size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth; |
| size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth; |
| for(b = 0; b < bytewidth; b++) |
| { |
| out[pixeloutstart + b] = in[pixelinstart + b]; |
| } |
| } |
| } |
| } |
| else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ |
| { |
| for(i = 0; i < 7; i++) |
| { |
| unsigned x, y, b; |
| unsigned ilinebits = bpp * passw[i]; |
| unsigned olinebits = bpp * w; |
| size_t obp, ibp; /*bit pointers (for out and in buffer)*/ |
| for(y = 0; y < passh[i]; y++) |
| for(x = 0; x < passw[i]; x++) |
| { |
| ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp; |
| obp = (8 * passstart[i]) + (y * ilinebits + x * bpp); |
| for(b = 0; b < bpp; b++) |
| { |
| unsigned char bit = readBitFromReversedStream(&ibp, in); |
| setBitOfReversedStream(&obp, out, bit); |
| } |
| } |
| } |
| } |
| } |
| |
| /*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image. |
| return value is error**/ |
| static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in, |
| unsigned w, unsigned h, |
| const LodePNGInfo* info_png, const LodePNGEncoderSettings* settings) |
| { |
| /* |
| This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps: |
| *) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp < 8) 2) filter |
| *) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter |
| */ |
| unsigned bpp = lodepng_get_bpp(&info_png->color); |
| unsigned error = 0; |
| |
| if(info_png->interlace_method == 0) |
| { |
| *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/ |
| *out = (unsigned char*)lodepng_malloc(*outsize); |
| if(!(*out) && (*outsize)) error = 83; /*alloc fail*/ |
| |
| if(!error) |
| { |
| /*non multiple of 8 bits per scanline, padding bits needed per scanline*/ |
| if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) |
| { |
| unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7) / 8)); |
| if(!padded) error = 83; /*alloc fail*/ |
| if(!error) |
| { |
| addPaddingBits(padded, in, ((w * bpp + 7) / 8) * 8, w * bpp, h); |
| error = filter(*out, padded, w, h, &info_png->color, settings); |
| } |
| lodepng_free(padded); |
| } |
| else |
| { |
| /*we can immediatly filter into the out buffer, no other steps needed*/ |
| error = filter(*out, in, w, h, &info_png->color, settings); |
| } |
| } |
| } |
| else /*interlace_method is 1 (Adam7)*/ |
| { |
| unsigned passw[7], passh[7]; |
| size_t filter_passstart[8], padded_passstart[8], passstart[8]; |
| unsigned char* adam7; |
| |
| Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); |
| |
| *outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/ |
| *out = (unsigned char*)lodepng_malloc(*outsize); |
| if(!(*out)) error = 83; /*alloc fail*/ |
| |
| adam7 = (unsigned char*)lodepng_malloc(passstart[7]); |
| if(!adam7 && passstart[7]) error = 83; /*alloc fail*/ |
| |
| if(!error) |
| { |
| unsigned i; |
| |
| Adam7_interlace(adam7, in, w, h, bpp); |
| for(i = 0; i < 7; i++) |
| { |
| if(bpp < 8) |
| { |
| unsigned char* padded = (unsigned char*)lodepng_malloc(padded_passstart[i + 1] - padded_passstart[i]); |
| if(!padded) ERROR_BREAK(83); /*alloc fail*/ |
| addPaddingBits(padded, &adam7[passstart[i]], |
| ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]); |
| error = filter(&(*out)[filter_passstart[i]], padded, |
| passw[i], passh[i], &info_png->color, settings); |
| lodepng_free(padded); |
| } |
| else |
| { |
| error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]], |
| passw[i], passh[i], &info_png->color, settings); |
| } |
| |
| if(error) break; |
| } |
| } |
| |
| lodepng_free(adam7); |
| } |
| |
| return error; |
| } |
| |
| /* |
| palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA... |
| returns 0 if the palette is opaque, |
| returns 1 if the palette has a single color with alpha 0 ==> color key |
| returns 2 if the palette is semi-translucent. |
| */ |
| static unsigned getPaletteTranslucency(const unsigned char* palette, size_t palettesize) |
| { |
| size_t i, key = 0; |
| unsigned r = 0, g = 0, b = 0; /*the value of the color with alpha 0, so long as color keying is possible*/ |
| for(i = 0; i < palettesize; i++) |
| { |
| if(!key && palette[4 * i + 3] == 0) |
| { |
| r = palette[4 * i + 0]; g = palette[4 * i + 1]; b = palette[4 * i + 2]; |
| key = 1; |
| i = (size_t)(-1); /*restart from beginning, to detect earlier opaque colors with key's value*/ |
| } |
| else if(palette[4 * i + 3] != 255) return 2; |
| /*when key, no opaque RGB may have key's RGB*/ |
| else if(key && r == palette[i * 4 + 0] && g == palette[i * 4 + 1] && b == palette[i * 4 + 2]) return 2; |
| } |
| return key; |
| } |
| |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize) |
| { |
| unsigned char* inchunk = data; |
| while((size_t)(inchunk - data) < datasize) |
| { |
| CERROR_TRY_RETURN(lodepng_chunk_append(&out->data, &out->size, inchunk)); |
| out->allocsize = out->size; /*fix the allocsize again*/ |
| inchunk = lodepng_chunk_next(inchunk); |
| } |
| return 0; |
| } |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| |
| unsigned lodepng_encode(unsigned char** out, size_t* outsize, |
| const unsigned char* image, unsigned w, unsigned h, |
| LodePNGState* state) |
| { |
| LodePNGInfo info; |
| ucvector outv; |
| unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/ |
| size_t datasize = 0; |
| |
| /*provide some proper output values if error will happen*/ |
| *out = 0; |
| *outsize = 0; |
| state->error = 0; |
| |
| lodepng_info_init(&info); |
| lodepng_info_copy(&info, &state->info_png); |
| |
| if((info.color.colortype == LCT_PALETTE || state->encoder.force_palette) |
| && (info.color.palettesize == 0 || info.color.palettesize > 256)) |
| { |
| state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/ |
| return state->error; |
| } |
| |
| if(state->encoder.auto_convert != LAC_NO) |
| { |
| state->error = doAutoChooseColor(&info.color, image, w, h, &state->info_raw, |
| state->encoder.auto_convert); |
| } |
| if(state->error) return state->error; |
| |
| if(state->encoder.zlibsettings.windowsize > 32768) |
| { |
| CERROR_RETURN_ERROR(state->error, 60); /*error: windowsize larger than allowed*/ |
| } |
| if(state->encoder.zlibsettings.btype > 2) |
| { |
| CERROR_RETURN_ERROR(state->error, 61); /*error: unexisting btype*/ |
| } |
| if(state->info_png.interlace_method > 1) |
| { |
| CERROR_RETURN_ERROR(state->error, 71); /*error: unexisting interlace mode*/ |
| } |
| |
| state->error = checkColorValidity(info.color.colortype, info.color.bitdepth); |
| if(state->error) return state->error; /*error: unexisting color type given*/ |
| state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth); |
| if(state->error) return state->error; /*error: unexisting color type given*/ |
| |
| if(!lodepng_color_mode_equal(&state->info_raw, &info.color)) |
| { |
| unsigned char* converted; |
| size_t size = (w * h * lodepng_get_bpp(&info.color) + 7) / 8; |
| |
| converted = (unsigned char*)lodepng_malloc(size); |
| if(!converted && size) state->error = 83; /*alloc fail*/ |
| if(!state->error) |
| { |
| state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h, 0 /*fix_png*/); |
| } |
| if(!state->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder); |
| lodepng_free(converted); |
| } |
| else preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder); |
| |
| ucvector_init(&outv); |
| while(!state->error) /*while only executed once, to break on error*/ |
| { |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| size_t i; |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| /*write signature and chunks*/ |
| writeSignature(&outv); |
| /*IHDR*/ |
| addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method); |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| /*unknown chunks between IHDR and PLTE*/ |
| if(info.unknown_chunks_data[0]) |
| { |
| state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0], info.unknown_chunks_size[0]); |
| if(state->error) break; |
| } |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| /*PLTE*/ |
| if(info.color.colortype == LCT_PALETTE) |
| { |
| addChunk_PLTE(&outv, &info.color); |
| } |
| if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA)) |
| { |
| addChunk_PLTE(&outv, &info.color); |
| } |
| /*tRNS*/ |
| if(info.color.colortype == LCT_PALETTE && getPaletteTranslucency(info.color.palette, info.color.palettesize) != 0) |
| { |
| addChunk_tRNS(&outv, &info.color); |
| } |
| if((info.color.colortype == LCT_GREY || info.color.colortype == LCT_RGB) && info.color.key_defined) |
| { |
| addChunk_tRNS(&outv, &info.color); |
| } |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| /*bKGD (must come between PLTE and the IDAt chunks*/ |
| if(info.background_defined) addChunk_bKGD(&outv, &info); |
| /*pHYs (must come before the IDAT chunks)*/ |
| if(info.phys_defined) addChunk_pHYs(&outv, &info); |
| |
| /*unknown chunks between PLTE and IDAT*/ |
| if(info.unknown_chunks_data[1]) |
| { |
| state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1], info.unknown_chunks_size[1]); |
| if(state->error) break; |
| } |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| /*IDAT (multiple IDAT chunks must be consecutive)*/ |
| state->error = addChunk_IDAT(&outv, data, datasize, &state->encoder.zlibsettings); |
| if(state->error) break; |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| /*tIME*/ |
| if(info.time_defined) addChunk_tIME(&outv, &info.time); |
| /*tEXt and/or zTXt*/ |
| for(i = 0; i < info.text_num; i++) |
| { |
| if(strlen(info.text_keys[i]) > 79) |
| { |
| state->error = 66; /*text chunk too large*/ |
| break; |
| } |
| if(strlen(info.text_keys[i]) < 1) |
| { |
| state->error = 67; /*text chunk too small*/ |
| break; |
| } |
| if(state->encoder.text_compression) |
| addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings); |
| else |
| addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]); |
| } |
| /*LodePNG version id in text chunk*/ |
| if(state->encoder.add_id) |
| { |
| unsigned alread_added_id_text = 0; |
| for(i = 0; i < info.text_num; i++) |
| { |
| if(!strcmp(info.text_keys[i], "LodePNG")) |
| { |
| alread_added_id_text = 1; |
| break; |
| } |
| } |
| if(alread_added_id_text == 0) |
| addChunk_tEXt(&outv, "LodePNG", VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/ |
| } |
| /*iTXt*/ |
| for(i = 0; i < info.itext_num; i++) |
| { |
| if(strlen(info.itext_keys[i]) > 79) |
| { |
| state->error = 66; /*text chunk too large*/ |
| break; |
| } |
| if(strlen(info.itext_keys[i]) < 1) |
| { |
| state->error = 67; /*text chunk too small*/ |
| break; |
| } |
| addChunk_iTXt(&outv, state->encoder.text_compression, |
| info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i], |
| &state->encoder.zlibsettings); |
| } |
| |
| /*unknown chunks between IDAT and IEND*/ |
| if(info.unknown_chunks_data[2]) |
| { |
| state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2], info.unknown_chunks_size[2]); |
| if(state->error) break; |
| } |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| /*IEND*/ |
| addChunk_IEND(&outv); |
| |
| break; /*this isn't really a while loop; no error happened so break out now!*/ |
| } |
| |
| lodepng_info_cleanup(&info); |
| lodepng_free(data); |
| /*instead of cleaning the vector up, give it to the output*/ |
| *out = outv.data; |
| *outsize = outv.size; |
| |
| return state->error; |
| } |
| |
| unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsigned char* image, |
| unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) |
| { |
| unsigned error; |
| LodePNGState state; |
| lodepng_state_init(&state); |
| state.info_raw.colortype = colortype; |
| state.info_raw.bitdepth = bitdepth; |
| state.info_png.color.colortype = colortype; |
| state.info_png.color.bitdepth = bitdepth; |
| lodepng_encode(out, outsize, image, w, h, &state); |
| error = state.error; |
| lodepng_state_cleanup(&state); |
| return error; |
| } |
| |
| unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) |
| { |
| return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGBA, 8); |
| } |
| |
| unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) |
| { |
| return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGB, 8); |
| } |
| |
| #ifdef LODEPNG_COMPILE_DISK |
| unsigned lodepng_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h, |
| LodePNGColorType colortype, unsigned bitdepth) |
| { |
| unsigned char* buffer; |
| size_t buffersize; |
| unsigned error = lodepng_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth); |
| if(!error) error = lodepng_save_file(buffer, buffersize, filename); |
| lodepng_free(buffer); |
| return error; |
| } |
| |
| unsigned lodepng_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) |
| { |
| return lodepng_encode_file(filename, image, w, h, LCT_RGBA, 8); |
| } |
| |
| unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) |
| { |
| return lodepng_encode_file(filename, image, w, h, LCT_RGB, 8); |
| } |
| #endif /*LODEPNG_COMPILE_DISK*/ |
| |
| void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings) |
| { |
| lodepng_compress_settings_init(&settings->zlibsettings); |
| settings->filter_palette_zero = 1; |
| settings->filter_strategy = LFS_MINSUM; |
| settings->auto_convert = LAC_AUTO; |
| settings->force_palette = 0; |
| settings->predefined_filters = 0; |
| #ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS |
| settings->add_id = 0; |
| settings->text_compression = 1; |
| #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ |
| } |
| |
| #endif /*LODEPNG_COMPILE_ENCODER*/ |
| #endif /*LODEPNG_COMPILE_PNG*/ |
| |
| #ifdef LODEPNG_COMPILE_ERROR_TEXT |
| /* |
| This returns the description of a numerical error code in English. This is also |
| the documentation of all the error codes. |
| */ |
| const char* lodepng_error_text(unsigned code) |
| { |
| switch(code) |
| { |
| case 0: return "no error, everything went ok"; |
| case 1: return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, error checking makes no sense yet*/ |
| case 10: return "end of input memory reached without huffman end code"; /*while huffman decoding*/ |
| case 11: return "error in code tree made it jump outside of huffman tree"; /*while huffman decoding*/ |
| case 13: return "problem while processing dynamic deflate block"; |
| case 14: return "problem while processing dynamic deflate block"; |
| case 15: return "problem while processing dynamic deflate block"; |
| case 16: return "unexisting code while processing dynamic deflate block"; |
| case 17: return "end of out buffer memory reached while inflating"; |
| case 18: return "invalid distance code while inflating"; |
| case 19: return "end of out buffer memory reached while inflating"; |
| case 20: return "invalid deflate block BTYPE encountered while decoding"; |
| case 21: return "NLEN is not ones complement of LEN in a deflate block"; |
| /*end of out buffer memory reached while inflating: |
| This can happen if the inflated deflate data is longer than the amount of bytes required to fill up |
| all the pixels of the image, given the color depth and image dimensions. Something that doesn't |
| happen in a normal, well encoded, PNG image.*/ |
| case 22: return "end of out buffer memory reached while inflating"; |
| case 23: return "end of in buffer memory reached while inflating"; |
| case 24: return "invalid FCHECK in zlib header"; |
| case 25: return "invalid compression method in zlib header"; |
| case 26: return "FDICT encountered in zlib header while it's not used for PNG"; |
| case 27: return "PNG file is smaller than a PNG header"; |
| /*Checks the magic file header, the first 8 bytes of the PNG file*/ |
| case 28: return "incorrect PNG signature, it's no PNG or corrupted"; |
| case 29: return "first chunk is not the header chunk"; |
| case 30: return "chunk length too large, chunk broken off at end of file"; |
| case 31: return "illegal PNG color type or bpp"; |
| case 32: return "illegal PNG compression method"; |
| case 33: return "illegal PNG filter method"; |
| case 34: return "illegal PNG interlace method"; |
| case 35: return "chunk length of a chunk is too large or the chunk too small"; |
| case 36: return "illegal PNG filter type encountered"; |
| case 37: return "illegal bit depth for this color type given"; |
| case 38: return "the palette is too big"; /*more than 256 colors*/ |
| case 39: return "more palette alpha values given in tRNS chunk than there are colors in the palette"; |
| case 40: return "tRNS chunk has wrong size for greyscale image"; |
| case 41: return "tRNS chunk has wrong size for RGB image"; |
| case 42: return "tRNS chunk appeared while it was not allowed for this color type"; |
| case 43: return "bKGD chunk has wrong size for palette image"; |
| case 44: return "bKGD chunk has wrong size for greyscale image"; |
| case 45: return "bKGD chunk has wrong size for RGB image"; |
| /*Is the palette too small?*/ |
| case 46: return "a value in indexed image is larger than the palette size (bitdepth = 8)"; |
| /*Is the palette too small?*/ |
| case 47: return "a value in indexed image is larger than the palette size (bitdepth < 8)"; |
| /*the input data is empty, maybe a PNG file doesn't exist or is in the wrong path*/ |
| case 48: return "empty input or file doesn't exist"; |
| case 49: return "jumped past memory while generating dynamic huffman tree"; |
| case 50: return "jumped past memory while generating dynamic huffman tree"; |
| case 51: return "jumped past memory while inflating huffman block"; |
| case 52: return "jumped past memory while inflating"; |
| case 53: return "size of zlib data too small"; |
| case 54: return "repeat symbol in tree while there was no value symbol yet"; |
| /*jumped past tree while generating huffman tree, this could be when the |
| tree will have more leaves than symbols after generating it out of the |
| given lenghts. They call this an oversubscribed dynamic bit lengths tree in zlib.*/ |
| case 55: return "jumped past tree while generating huffman tree"; |
| case 56: return "given output image colortype or bitdepth not supported for color conversion"; |
| case 57: return "invalid CRC encountered (checking CRC can be disabled)"; |
| case 58: return "invalid ADLER32 encountered (checking ADLER32 can be disabled)"; |
| case 59: return "requested color conversion not supported"; |
| case 60: return "invalid window size given in the settings of the encoder (must be 0-32768)"; |
| case 61: return "invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed)"; |
| /*LodePNG leaves the choice of RGB to greyscale conversion formula to the user.*/ |
| case 62: return "conversion from color to greyscale not supported"; |
| case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk"; /*(2^31-1)*/ |
| /*this would result in the inability of a deflated block to ever contain an end code. It must be at least 1.*/ |
| case 64: return "the length of the END symbol 256 in the Huffman tree is 0"; |
| case 66: return "the length of a text chunk keyword given to the encoder is longer than the maximum of 79 bytes"; |
| case 67: return "the length of a text chunk keyword given to the encoder is smaller than the minimum of 1 byte"; |
| case 68: return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors"; |
| case 69: return "unknown chunk type with 'critical' flag encountered by the decoder"; |
| case 71: return "unexisting interlace mode given to encoder (must be 0 or 1)"; |
| case 72: return "while decoding, unexisting compression method encountering in zTXt or iTXt chunk (it must be 0)"; |
| case 73: return "invalid tIME chunk size"; |
| case 74: return "invalid pHYs chunk size"; |
| /*length could be wrong, or data chopped off*/ |
| case 75: return "no null termination char found while decoding text chunk"; |
| case 76: return "iTXt chunk too short to contain required bytes"; |
| case 77: return "integer overflow in buffer size"; |
| case 78: return "failed to open file for reading"; /*file doesn't exist or couldn't be opened for reading*/ |
| case 79: return "failed to open file for writing"; |
| case 80: return "tried creating a tree of 0 symbols"; |
| case 81: return "lazy matching at pos 0 is impossible"; |
| case 82: return "color conversion to palette requested while a color isn't in palette"; |
| case 83: return "memory allocation failed"; |
| case 84: return "given image too small to contain all pixels to be encoded"; |
| case 85: return "internal color conversion bug"; |
| case 86: return "impossible offset in lz77 encoding (internal bug)"; |
| case 87: return "must provide custom zlib function pointer if LODEPNG_COMPILE_ZLIB is not defined"; |
| case 88: return "invalid filter strategy given for LodePNGEncoderSettings.filter_strategy"; |
| case 89: return "text chunk keyword too short or long: must have size 1-79"; |
| } |
| return "unknown error code"; |
| } |
| #endif /*LODEPNG_COMPILE_ERROR_TEXT*/ |
| |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* // C++ Wrapper // */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| /* ////////////////////////////////////////////////////////////////////////// */ |
| |
| |
| #ifdef LODEPNG_COMPILE_CPP |
| namespace lodepng |
| { |
| |
| #ifdef LODEPNG_COMPILE_DISK |
| void load_file(std::vector<unsigned char>& buffer, const std::string& filename) |
| { |
| std::ifstream file(filename.c_str(), std::ios::in|std::ios::binary|std::ios::ate); |
| |
| /*get filesize*/ |
| std::streamsize size = 0; |
| if(file.seekg(0, std::ios::end).good()) size = file.tellg(); |
| if(file.seekg(0, std::ios::beg).good()) size -= file.tellg(); |
| |
| /*read contents of the file into the vector*/ |
| buffer.resize(size_t(size)); |
| if(size > 0) file.read((char*)(&buffer[0]), size); |
| } |
| |
| /*write given buffer to the file, overwriting the file, it doesn't append to it.*/ |
| void save_file(const std::vector<unsigned char>& buffer, const std::string& filename) |
| { |
| std::ofstream file(filename.c_str(), std::ios::out|std::ios::binary); |
| file.write(buffer.empty() ? 0 : (char*)&buffer[0], std::streamsize(buffer.size())); |
| } |
| #endif //LODEPNG_COMPILE_DISK |
| |
| #ifdef LODEPNG_COMPILE_ZLIB |
| #ifdef LODEPNG_COMPILE_DECODER |
| unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize, |
| const LodePNGDecompressSettings& settings) |
| { |
| unsigned char* buffer = 0; |
| size_t buffersize = 0; |
| unsigned error = zlib_decompress(&buffer, &buffersize, in, insize, &settings); |
| if(buffer) |
| { |
| out.insert(out.end(), &buffer[0], &buffer[buffersize]); |
| lodepng_free(buffer); |
| } |
| return error; |
| } |
| |
| unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, |
| const LodePNGDecompressSettings& settings) |
| { |
| return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings); |
| } |
| #endif //LODEPNG_COMPILE_DECODER |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize, |
| const LodePNGCompressSettings& settings) |
| { |
| unsigned char* buffer = 0; |
| size_t buffersize = 0; |
| unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings); |
| if(buffer) |
| { |
| out.insert(out.end(), &buffer[0], &buffer[buffersize]); |
| lodepng_free(buffer); |
| } |
| return error; |
| } |
| |
| unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, |
| const LodePNGCompressSettings& settings) |
| { |
| return compress(out, in.empty() ? 0 : &in[0], in.size(), settings); |
| } |
| #endif //LODEPNG_COMPILE_ENCODER |
| #endif //LODEPNG_COMPILE_ZLIB |
| |
| |
| #ifdef LODEPNG_COMPILE_PNG |
| |
| State::State() |
| { |
| lodepng_state_init(this); |
| } |
| |
| State::State(const State& other) |
| { |
| lodepng_state_init(this); |
| lodepng_state_copy(this, &other); |
| } |
| |
| State::~State() |
| { |
| lodepng_state_cleanup(this); |
| } |
| |
| State& State::operator=(const State& other) |
| { |
| lodepng_state_copy(this, &other); |
| return *this; |
| } |
| |
| #ifdef LODEPNG_COMPILE_DECODER |
| |
| unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in, |
| size_t insize, LodePNGColorType colortype, unsigned bitdepth) |
| { |
| unsigned char* buffer; |
| unsigned error = lodepng_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth); |
| if(buffer && !error) |
| { |
| State state; |
| state.info_raw.colortype = colortype; |
| state.info_raw.bitdepth = bitdepth; |
| size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw); |
| out.insert(out.end(), &buffer[0], &buffer[buffersize]); |
| lodepng_free(buffer); |
| } |
| return error; |
| } |
| |
| unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, |
| const std::vector<unsigned char>& in, LodePNGColorType colortype, unsigned bitdepth) |
| { |
| return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colortype, bitdepth); |
| } |
| |
| unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, |
| State& state, |
| const unsigned char* in, size_t insize) |
| { |
| unsigned char* buffer; |
| unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize); |
| if(buffer && !error) |
| { |
| size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw); |
| out.insert(out.end(), &buffer[0], &buffer[buffersize]); |
| lodepng_free(buffer); |
| } |
| return error; |
| } |
| |
| unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, |
| State& state, |
| const std::vector<unsigned char>& in) |
| { |
| return decode(out, w, h, state, in.empty() ? 0 : &in[0], in.size()); |
| } |
| |
| #ifdef LODEPNG_COMPILE_DISK |
| unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename, |
| LodePNGColorType colortype, unsigned bitdepth) |
| { |
| std::vector<unsigned char> buffer; |
| load_file(buffer, filename); |
| return decode(out, w, h, buffer, colortype, bitdepth); |
| } |
| #endif //LODEPNG_COMPILE_DECODER |
| #endif //LODEPNG_COMPILE_DISK |
| |
| #ifdef LODEPNG_COMPILE_ENCODER |
| unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h, |
| LodePNGColorType colortype, unsigned bitdepth) |
| { |
| unsigned char* buffer; |
| size_t buffersize; |
| unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth); |
| if(buffer) |
| { |
| out.insert(out.end(), &buffer[0], &buffer[buffersize]); |
| lodepng_free(buffer); |
| } |
| return error; |
| } |
| |
| unsigned encode(std::vector<unsigned char>& out, |
| const std::vector<unsigned char>& in, unsigned w, unsigned h, |
| LodePNGColorType colortype, unsigned bitdepth) |
| { |
| if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84; |
| return encode(out, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth); |
| } |
| |
| unsigned encode(std::vector<unsigned char>& out, |
| const unsigned char* in, unsigned w, unsigned h, |
| State& state) |
| { |
| unsigned char* buffer; |
| size_t buffersize; |
| unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state); |
| if(buffer) |
| { |
| out.insert(out.end(), &buffer[0], &buffer[buffersize]); |
| lodepng_free(buffer); |
| } |
| return error; |
| } |
| |
| unsigned encode(std::vector<unsigned char>& out, |
| const std::vector<unsigned char>& in, unsigned w, unsigned h, |
| State& state) |
| { |
| if(lodepng_get_raw_size(w, h, &state.info_raw) > in.size()) return 84; |
| return encode(out, in.empty() ? 0 : &in[0], w, h, state); |
| } |
| |
| #ifdef LODEPNG_COMPILE_DISK |
| unsigned encode(const std::string& filename, |
| const unsigned char* in, unsigned w, unsigned h, |
| LodePNGColorType colortype, unsigned bitdepth) |
| { |
| std::vector<unsigned char> buffer; |
| unsigned error = encode(buffer, in, w, h, colortype, bitdepth); |
| if(!error) save_file(buffer, filename); |
| return error; |
| } |
| |
| unsigned encode(const std::string& filename, |
| const std::vector<unsigned char>& in, unsigned w, unsigned h, |
| LodePNGColorType colortype, unsigned bitdepth) |
| { |
| if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84; |
| return encode(filename, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth); |
| } |
| #endif //LODEPNG_COMPILE_DISK |
| #endif //LODEPNG_COMPILE_ENCODER |
| #endif //LODEPNG_COMPILE_PNG |
| } //namespace lodepng |
| #endif /*LODEPNG_COMPILE_CPP*/ |