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m---------plugingui/lodepng0
-rw-r--r--plugingui/lodepng/lodepng.cpp6260
-rw-r--r--plugingui/lodepng/lodepng.h1716
3 files changed, 0 insertions, 7976 deletions
diff --git a/plugingui/lodepng b/plugingui/lodepng
new file mode 160000
+Subproject a71964ed5fe4f82a32ac7f8201338900f66e855
diff --git a/plugingui/lodepng/lodepng.cpp b/plugingui/lodepng/lodepng.cpp
deleted file mode 100644
index e4f35d7..0000000
--- a/plugingui/lodepng/lodepng.cpp
+++ /dev/null
@@ -1,6260 +0,0 @@
-/*
-LodePNG version 20131222
-
-Copyright (c) 2005-2013 Lode Vandevenne
-
-This software is provided 'as-is', without any express or implied
-warranty. In no event will the authors be held liable for any damages
-arising from the use of this software.
-
-Permission is granted to anyone to use this software for any purpose,
-including commercial applications, and to alter it and redistribute it
-freely, subject to the following restrictions:
-
- 1. The origin of this software must not be misrepresented; you must not
- claim that you wrote the original software. If you use this software
- in a product, an acknowledgment in the product documentation would be
- appreciated but is not required.
-
- 2. Altered source versions must be plainly marked as such, and must not be
- misrepresented as being the original software.
-
- 3. This notice may not be removed or altered from any source
- distribution.
-*/
-
-/*
-The manual and changelog are in the header file "lodepng.h"
-Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for C.
-*/
-
-#include "lodepng.h"
-
-#include <stdio.h>
-#include <stdlib.h>
-
-#ifdef LODEPNG_COMPILE_CPP
-#include <fstream>
-#endif /*LODEPNG_COMPILE_CPP*/
-
-#define VERSION_STRING "20131222"
-
-/*
-This source file is built up in the following large parts. The code sections
-with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way.
--Tools for C and common code for PNG and Zlib
--C Code for Zlib (huffman, deflate, ...)
--C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...)
--The C++ wrapper around all of the above
-*/
-
-/*The malloc, realloc and free functions defined here with "lodepng_" in front
-of the name, so that you can easily change them to others related to your
-platform if needed. Everything else in the code calls these. Pass
--DLODEPNG_NO_COMPILE_ALLOCATORS to the compiler, or comment out
-#define LODEPNG_COMPILE_ALLOCATORS in the header, to disable the ones here and
-define them in your own project's source files without needing to change
-lodepng source code. Don't forget to remove "static" if you copypaste them
-from here.*/
-
-#ifdef LODEPNG_COMPILE_ALLOCATORS
-static void* lodepng_malloc(size_t size)
-{
- return malloc(size);
-}
-
-static void* lodepng_realloc(void* ptr, size_t new_size)
-{
- return realloc(ptr, new_size);
-}
-
-static void lodepng_free(void* ptr)
-{
- free(ptr);
-}
-#else /*LODEPNG_COMPILE_ALLOCATORS*/
-void* lodepng_malloc(size_t size);
-void* lodepng_realloc(void* ptr, size_t new_size);
-void lodepng_free(void* ptr);
-#endif /*LODEPNG_COMPILE_ALLOCATORS*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* // Tools for C, and common code for PNG and Zlib. // */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*
-Often in case of an error a value is assigned to a variable and then it breaks
-out of a loop (to go to the cleanup phase of a function). This macro does that.
-It makes the error handling code shorter and more readable.
-
-Example: if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83);
-*/
-#define CERROR_BREAK(errorvar, code)\
-{\
- errorvar = code;\
- break;\
-}
-
-/*version of CERROR_BREAK that assumes the common case where the error variable is named "error"*/
-#define ERROR_BREAK(code) CERROR_BREAK(error, code)
-
-/*Set error var to the error code, and return it.*/
-#define CERROR_RETURN_ERROR(errorvar, code)\
-{\
- errorvar = code;\
- return code;\
-}
-
-/*Try the code, if it returns error, also return the error.*/
-#define CERROR_TRY_RETURN(call)\
-{\
- unsigned error = call;\
- if(error) return error;\
-}
-
-/*
-About uivector, ucvector and string:
--All of them wrap dynamic arrays or text strings in a similar way.
--LodePNG was originally written in C++. The vectors replace the std::vectors that were used in the C++ version.
--The string tools are made to avoid problems with compilers that declare things like strncat as deprecated.
--They're not used in the interface, only internally in this file as static functions.
--As with many other structs in this file, the init and cleanup functions serve as ctor and dtor.
-*/
-
-#ifdef LODEPNG_COMPILE_ZLIB
-/*dynamic vector of unsigned ints*/
-typedef struct uivector
-{
- unsigned* data;
- size_t size; /*size in number of unsigned longs*/
- size_t allocsize; /*allocated size in bytes*/
-} uivector;
-
-static void uivector_cleanup(void* p)
-{
- ((uivector*)p)->size = ((uivector*)p)->allocsize = 0;
- lodepng_free(((uivector*)p)->data);
- ((uivector*)p)->data = NULL;
-}
-
-/*returns 1 if success, 0 if failure ==> nothing done*/
-static unsigned uivector_resize(uivector* p, size_t size)
-{
- if(size * sizeof(unsigned) > p->allocsize)
- {
- size_t newsize = size * sizeof(unsigned) * 2;
- void* data = lodepng_realloc(p->data, newsize);
- if(data)
- {
- p->allocsize = newsize;
- p->data = (unsigned*)data;
- p->size = size;
- }
- else return 0;
- }
- else p->size = size;
- return 1;
-}
-
-/*resize and give all new elements the value*/
-static unsigned uivector_resizev(uivector* p, size_t size, unsigned value)
-{
- size_t oldsize = p->size, i;
- if(!uivector_resize(p, size)) return 0;
- for(i = oldsize; i < size; i++) p->data[i] = value;
- return 1;
-}
-
-static void uivector_init(uivector* p)
-{
- p->data = NULL;
- p->size = p->allocsize = 0;
-}
-
-#ifdef LODEPNG_COMPILE_ENCODER
-/*returns 1 if success, 0 if failure ==> nothing done*/
-static unsigned uivector_push_back(uivector* p, unsigned c)
-{
- if(!uivector_resize(p, p->size + 1)) return 0;
- p->data[p->size - 1] = c;
- return 1;
-}
-
-/*copy q to p, returns 1 if success, 0 if failure ==> nothing done*/
-static unsigned uivector_copy(uivector* p, const uivector* q)
-{
- size_t i;
- if(!uivector_resize(p, q->size)) return 0;
- for(i = 0; i < q->size; i++) p->data[i] = q->data[i];
- return 1;
-}
-#endif /*LODEPNG_COMPILE_ENCODER*/
-#endif /*LODEPNG_COMPILE_ZLIB*/
-
-/* /////////////////////////////////////////////////////////////////////////// */
-
-/*dynamic vector of unsigned chars*/
-typedef struct ucvector
-{
- unsigned char* data;
- size_t size; /*used size*/
- size_t allocsize; /*allocated size*/
-} ucvector;
-
-/*returns 1 if success, 0 if failure ==> nothing done*/
-static unsigned ucvector_resize(ucvector* p, size_t size)
-{
- if(size * sizeof(unsigned char) > p->allocsize)
- {
- size_t newsize = size * sizeof(unsigned char) * 2;
- void* data = lodepng_realloc(p->data, newsize);
- if(data)
- {
- p->allocsize = newsize;
- p->data = (unsigned char*)data;
- p->size = size;
- }
- else return 0; /*error: not enough memory*/
- }
- else p->size = size;
- return 1;
-}
-
-#ifdef LODEPNG_COMPILE_PNG
-
-static void ucvector_cleanup(void* p)
-{
- ((ucvector*)p)->size = ((ucvector*)p)->allocsize = 0;
- lodepng_free(((ucvector*)p)->data);
- ((ucvector*)p)->data = NULL;
-}
-
-static void ucvector_init(ucvector* p)
-{
- p->data = NULL;
- p->size = p->allocsize = 0;
-}
-
-#ifdef LODEPNG_COMPILE_DECODER
-/*resize and give all new elements the value*/
-static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value)
-{
- size_t oldsize = p->size, i;
- if(!ucvector_resize(p, size)) return 0;
- for(i = oldsize; i < size; i++) p->data[i] = value;
- return 1;
-}
-#endif /*LODEPNG_COMPILE_DECODER*/
-#endif /*LODEPNG_COMPILE_PNG*/
-
-#ifdef LODEPNG_COMPILE_ZLIB
-/*you can both convert from vector to buffer&size and vica versa. If you use
-init_buffer to take over a buffer and size, it is not needed to use cleanup*/
-static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size)
-{
- p->data = buffer;
- p->allocsize = p->size = size;
-}
-#endif /*LODEPNG_COMPILE_ZLIB*/
-
-#if (defined(LODEPNG_COMPILE_PNG) && defined(LODEPNG_COMPILE_ANCILLARY_CHUNKS)) || defined(LODEPNG_COMPILE_ENCODER)
-/*returns 1 if success, 0 if failure ==> nothing done*/
-static unsigned ucvector_push_back(ucvector* p, unsigned char c)
-{
- if(!ucvector_resize(p, p->size + 1)) return 0;
- p->data[p->size - 1] = c;
- return 1;
-}
-#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/
-
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef LODEPNG_COMPILE_PNG
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-/*returns 1 if success, 0 if failure ==> nothing done*/
-static unsigned string_resize(char** out, size_t size)
-{
- char* data = (char*)lodepng_realloc(*out, size + 1);
- if(data)
- {
- data[size] = 0; /*null termination char*/
- *out = data;
- }
- return data != 0;
-}
-
-/*init a {char*, size_t} pair for use as string*/
-static void string_init(char** out)
-{
- *out = NULL;
- string_resize(out, 0);
-}
-
-/*free the above pair again*/
-static void string_cleanup(char** out)
-{
- lodepng_free(*out);
- *out = NULL;
-}
-
-static void string_set(char** out, const char* in)
-{
- size_t insize = strlen(in), i = 0;
- if(string_resize(out, insize))
- {
- for(i = 0; i < insize; i++)
- {
- (*out)[i] = in[i];
- }
- }
-}
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-#endif /*LODEPNG_COMPILE_PNG*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-unsigned lodepng_read32bitInt(const unsigned char* buffer)
-{
- return (buffer[0] << 24) | (buffer[1] << 16) | (buffer[2] << 8) | buffer[3];
-}
-
-#if defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)
-/*buffer must have at least 4 allocated bytes available*/
-static void lodepng_set32bitInt(unsigned char* buffer, unsigned value)
-{
- buffer[0] = (unsigned char)((value >> 24) & 0xff);
- buffer[1] = (unsigned char)((value >> 16) & 0xff);
- buffer[2] = (unsigned char)((value >> 8) & 0xff);
- buffer[3] = (unsigned char)((value ) & 0xff);
-}
-#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/
-
-#ifdef LODEPNG_COMPILE_ENCODER
-static void lodepng_add32bitInt(ucvector* buffer, unsigned value)
-{
- ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/
- lodepng_set32bitInt(&buffer->data[buffer->size - 4], value);
-}
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / File IO / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef LODEPNG_COMPILE_DISK
-
-unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename)
-{
- FILE* file;
- long size;
-
- /*provide some proper output values if error will happen*/
- *out = 0;
- *outsize = 0;
-
- file = fopen(filename, "rb");
- if(!file) return 78;
-
- /*get filesize:*/
- fseek(file , 0 , SEEK_END);
- size = ftell(file);
- rewind(file);
-
- /*read contents of the file into the vector*/
- *outsize = 0;
- *out = (unsigned char*)lodepng_malloc((size_t)size);
- if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file);
-
- fclose(file);
- if(!(*out) && size) return 83; /*the above malloc failed*/
- return 0;
-}
-
-/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
-unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename)
-{
- FILE* file;
- file = fopen(filename, "wb" );
- if(!file) return 79;
- fwrite((char*)buffer , 1 , buffersize, file);
- fclose(file);
- return 0;
-}
-
-#endif /*LODEPNG_COMPILE_DISK*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* // End of common code and tools. Begin of Zlib related code. // */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef LODEPNG_COMPILE_ZLIB
-#ifdef LODEPNG_COMPILE_ENCODER
-/*TODO: this ignores potential out of memory errors*/
-#define addBitToStream(/*size_t**/ bitpointer, /*ucvector**/ bitstream, /*unsigned char*/ bit)\
-{\
- /*add a new byte at the end*/\
- if(((*bitpointer) & 7) == 0) ucvector_push_back(bitstream, (unsigned char)0);\
- /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/\
- (bitstream->data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7));\
- (*bitpointer)++;\
-}
-
-static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
-{
- size_t i;
- for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> i) & 1));
-}
-
-static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits)
-{
- size_t i;
- for(i = 0; i < nbits; i++) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> (nbits - 1 - i)) & 1));
-}
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-#ifdef LODEPNG_COMPILE_DECODER
-
-#define READBIT(bitpointer, bitstream) ((bitstream[bitpointer >> 3] >> (bitpointer & 0x7)) & (unsigned char)1)
-
-static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream)
-{
- unsigned char result = (unsigned char)(READBIT(*bitpointer, bitstream));
- (*bitpointer)++;
- return result;
-}
-
-static unsigned readBitsFromStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
-{
- unsigned result = 0, i;
- for(i = 0; i < nbits; i++)
- {
- result += ((unsigned)READBIT(*bitpointer, bitstream)) << i;
- (*bitpointer)++;
- }
- return result;
-}
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Deflate - Huffman / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#define FIRST_LENGTH_CODE_INDEX 257
-#define LAST_LENGTH_CODE_INDEX 285
-/*256 literals, the end code, some length codes, and 2 unused codes*/
-#define NUM_DEFLATE_CODE_SYMBOLS 288
-/*the distance codes have their own symbols, 30 used, 2 unused*/
-#define NUM_DISTANCE_SYMBOLS 32
-/*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/
-#define NUM_CODE_LENGTH_CODES 19
-
-/*the base lengths represented by codes 257-285*/
-static const unsigned LENGTHBASE[29]
- = {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
- 67, 83, 99, 115, 131, 163, 195, 227, 258};
-
-/*the extra bits used by codes 257-285 (added to base length)*/
-static const unsigned LENGTHEXTRA[29]
- = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3,
- 4, 4, 4, 4, 5, 5, 5, 5, 0};
-
-/*the base backwards distances (the bits of distance codes appear after length codes and use their own huffman tree)*/
-static const unsigned DISTANCEBASE[30]
- = {1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
- 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
-
-/*the extra bits of backwards distances (added to base)*/
-static const unsigned DISTANCEEXTRA[30]
- = {0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8,
- 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13};
-
-/*the order in which "code length alphabet code lengths" are stored, out of this
-the huffman tree of the dynamic huffman tree lengths is generated*/
-static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES]
- = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*
-Huffman tree struct, containing multiple representations of the tree
-*/
-typedef struct HuffmanTree
-{
- unsigned* tree2d;
- unsigned* tree1d;
- unsigned* lengths; /*the lengths of the codes of the 1d-tree*/
- unsigned maxbitlen; /*maximum number of bits a single code can get*/
- unsigned numcodes; /*number of symbols in the alphabet = number of codes*/
-} HuffmanTree;
-
-/*function used for debug purposes to draw the tree in ascii art with C++*/
-/*
-static void HuffmanTree_draw(HuffmanTree* tree)
-{
- std::cout << "tree. length: " << tree->numcodes << " maxbitlen: " << tree->maxbitlen << std::endl;
- for(size_t i = 0; i < tree->tree1d.size; i++)
- {
- if(tree->lengths.data[i])
- std::cout << i << " " << tree->tree1d.data[i] << " " << tree->lengths.data[i] << std::endl;
- }
- std::cout << std::endl;
-}*/
-
-static void HuffmanTree_init(HuffmanTree* tree)
-{
- tree->tree2d = 0;
- tree->tree1d = 0;
- tree->lengths = 0;
-}
-
-static void HuffmanTree_cleanup(HuffmanTree* tree)
-{
- lodepng_free(tree->tree2d);
- lodepng_free(tree->tree1d);
- lodepng_free(tree->lengths);
-}
-
-/*the tree representation used by the decoder. return value is error*/
-static unsigned HuffmanTree_make2DTree(HuffmanTree* tree)
-{
- unsigned nodefilled = 0; /*up to which node it is filled*/
- unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/
- unsigned n, i;
-
- tree->tree2d = (unsigned*)lodepng_malloc(tree->numcodes * 2 * sizeof(unsigned));
- if(!tree->tree2d) return 83; /*alloc fail*/
-
- /*
- convert tree1d[] to tree2d[][]. In the 2D array, a value of 32767 means
- uninited, a value >= numcodes is an address to another bit, a value < numcodes
- is a code. The 2 rows are the 2 possible bit values (0 or 1), there are as
- many columns as codes - 1.
- A good huffmann tree has N * 2 - 1 nodes, of which N - 1 are internal nodes.
- Here, the internal nodes are stored (what their 0 and 1 option point to).
- There is only memory for such good tree currently, if there are more nodes
- (due to too long length codes), error 55 will happen
- */
- for(n = 0; n < tree->numcodes * 2; n++)
- {
- tree->tree2d[n] = 32767; /*32767 here means the tree2d isn't filled there yet*/
- }
-
- for(n = 0; n < tree->numcodes; n++) /*the codes*/
- {
- for(i = 0; i < tree->lengths[n]; i++) /*the bits for this code*/
- {
- unsigned char bit = (unsigned char)((tree->tree1d[n] >> (tree->lengths[n] - i - 1)) & 1);
- if(treepos > tree->numcodes - 2) return 55; /*oversubscribed, see comment in lodepng_error_text*/
- if(tree->tree2d[2 * treepos + bit] == 32767) /*not yet filled in*/
- {
- if(i + 1 == tree->lengths[n]) /*last bit*/
- {
- tree->tree2d[2 * treepos + bit] = n; /*put the current code in it*/
- treepos = 0;
- }
- else
- {
- /*put address of the next step in here, first that address has to be found of course
- (it's just nodefilled + 1)...*/
- nodefilled++;
- /*addresses encoded with numcodes added to it*/
- tree->tree2d[2 * treepos + bit] = nodefilled + tree->numcodes;
- treepos = nodefilled;
- }
- }
- else treepos = tree->tree2d[2 * treepos + bit] - tree->numcodes;
- }
- }
-
- for(n = 0; n < tree->numcodes * 2; n++)
- {
- if(tree->tree2d[n] == 32767) tree->tree2d[n] = 0; /*remove possible remaining 32767's*/
- }
-
- return 0;
-}
-
-/*
-Second step for the ...makeFromLengths and ...makeFromFrequencies functions.
-numcodes, lengths and maxbitlen must already be filled in correctly. return
-value is error.
-*/
-static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree)
-{
- uivector blcount;
- uivector nextcode;
- unsigned bits, n, error = 0;
-
- uivector_init(&blcount);
- uivector_init(&nextcode);
-
- tree->tree1d = (unsigned*)lodepng_malloc(tree->numcodes * sizeof(unsigned));
- if(!tree->tree1d) error = 83; /*alloc fail*/
-
- if(!uivector_resizev(&blcount, tree->maxbitlen + 1, 0)
- || !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0))
- error = 83; /*alloc fail*/
-
- if(!error)
- {
- /*step 1: count number of instances of each code length*/
- for(bits = 0; bits < tree->numcodes; bits++) blcount.data[tree->lengths[bits]]++;
- /*step 2: generate the nextcode values*/
- for(bits = 1; bits <= tree->maxbitlen; bits++)
- {
- nextcode.data[bits] = (nextcode.data[bits - 1] + blcount.data[bits - 1]) << 1;
- }
- /*step 3: generate all the codes*/
- for(n = 0; n < tree->numcodes; n++)
- {
- if(tree->lengths[n] != 0) tree->tree1d[n] = nextcode.data[tree->lengths[n]]++;
- }
- }
-
- uivector_cleanup(&blcount);
- uivector_cleanup(&nextcode);
-
- if(!error) return HuffmanTree_make2DTree(tree);
- else return error;
-}
-
-/*
-given the code lengths (as stored in the PNG file), generate the tree as defined
-by Deflate. maxbitlen is the maximum bits that a code in the tree can have.
-return value is error.
-*/
-static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen,
- size_t numcodes, unsigned maxbitlen)
-{
- unsigned i;
- tree->lengths = (unsigned*)lodepng_malloc(numcodes * sizeof(unsigned));
- if(!tree->lengths) return 83; /*alloc fail*/
- for(i = 0; i < numcodes; i++) tree->lengths[i] = bitlen[i];
- tree->numcodes = (unsigned)numcodes; /*number of symbols*/
- tree->maxbitlen = maxbitlen;
- return HuffmanTree_makeFromLengths2(tree);
-}
-
-#ifdef LODEPNG_COMPILE_ENCODER
-
-/*
-A coin, this is the terminology used for the package-merge algorithm and the
-coin collector's problem. This is used to generate the huffman tree.
-A coin can be multiple coins (when they're merged)
-*/
-typedef struct Coin
-{
- uivector symbols;
- float weight; /*the sum of all weights in this coin*/
-} Coin;
-
-static void coin_init(Coin* c)
-{
- uivector_init(&c->symbols);
-}
-
-/*argument c is void* so that this dtor can be given as function pointer to the vector resize function*/
-static void coin_cleanup(void* c)
-{
- uivector_cleanup(&((Coin*)c)->symbols);
-}
-
-static void coin_copy(Coin* c1, const Coin* c2)
-{
- c1->weight = c2->weight;
- uivector_copy(&c1->symbols, &c2->symbols);
-}
-
-static void add_coins(Coin* c1, const Coin* c2)
-{
- size_t i;
- for(i = 0; i < c2->symbols.size; i++) uivector_push_back(&c1->symbols, c2->symbols.data[i]);
- c1->weight += c2->weight;
-}
-
-static void init_coins(Coin* coins, size_t num)
-{
- size_t i;
- for(i = 0; i < num; i++) coin_init(&coins[i]);
-}
-
-static void cleanup_coins(Coin* coins, size_t num)
-{
- size_t i;
- for(i = 0; i < num; i++) coin_cleanup(&coins[i]);
-}
-
-static int coin_compare(const void* a, const void* b) {
- float wa = ((const Coin*)a)->weight;
- float wb = ((const Coin*)b)->weight;
- return wa > wb ? 1 : wa < wb ? -1 : 0;
-}
-
-static unsigned append_symbol_coins(Coin* coins, const unsigned* frequencies, unsigned numcodes, size_t sum)
-{
- unsigned i;
- unsigned j = 0; /*index of present symbols*/
- for(i = 0; i < numcodes; i++)
- {
- if(frequencies[i] != 0) /*only include symbols that are present*/
- {
- coins[j].weight = frequencies[i] / (float)sum;
- uivector_push_back(&coins[j].symbols, i);
- j++;
- }
- }
- return 0;
-}
-
-unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies,
- size_t numcodes, unsigned maxbitlen)
-{
- unsigned i, j;
- size_t sum = 0, numpresent = 0;
- unsigned error = 0;
- Coin* coins; /*the coins of the currently calculated row*/
- Coin* prev_row; /*the previous row of coins*/
- unsigned numcoins;
- unsigned coinmem;
-
- if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/
-
- for(i = 0; i < numcodes; i++)
- {
- if(frequencies[i] > 0)
- {
- numpresent++;
- sum += frequencies[i];
- }
- }
-
- for(i = 0; i < numcodes; i++) lengths[i] = 0;
-
- /*ensure at least two present symbols. There should be at least one symbol
- according to RFC 1951 section 3.2.7. To decoders incorrectly require two. To
- make these work as well ensure there are at least two symbols. The
- Package-Merge code below also doesn't work correctly if there's only one
- symbol, it'd give it the theoritical 0 bits but in practice zlib wants 1 bit*/
- if(numpresent == 0)
- {
- lengths[0] = lengths[1] = 1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/
- }
- else if(numpresent == 1)
- {
- for(i = 0; i < numcodes; i++)
- {
- if(frequencies[i])
- {
- lengths[i] = 1;
- lengths[i == 0 ? 1 : 0] = 1;
- break;
- }
- }
- }
- else
- {
- /*Package-Merge algorithm represented by coin collector's problem
- For every symbol, maxbitlen coins will be created*/
-
- coinmem = numpresent * 2; /*max amount of coins needed with the current algo*/
- coins = (Coin*)lodepng_malloc(sizeof(Coin) * coinmem);
- prev_row = (Coin*)lodepng_malloc(sizeof(Coin) * coinmem);
- if(!coins || !prev_row)
- {
- lodepng_free(coins);
- lodepng_free(prev_row);
- return 83; /*alloc fail*/
- }
- init_coins(coins, coinmem);
- init_coins(prev_row, coinmem);
-
- /*first row, lowest denominator*/
- error = append_symbol_coins(coins, frequencies, numcodes, sum);
- numcoins = numpresent;
- qsort(coins, numcoins, sizeof(Coin), coin_compare);
- if(!error)
- {
- unsigned numprev = 0;
- for(j = 1; j <= maxbitlen && !error; j++) /*each of the remaining rows*/
- {
- unsigned tempnum;
- Coin* tempcoins;
- /*swap prev_row and coins, and their amounts*/
- tempcoins = prev_row; prev_row = coins; coins = tempcoins;
- tempnum = numprev; numprev = numcoins; numcoins = tempnum;
-
- cleanup_coins(coins, numcoins);
- init_coins(coins, numcoins);
-
- numcoins = 0;
-
- /*fill in the merged coins of the previous row*/
- for(i = 0; i + 1 < numprev; i += 2)
- {
- /*merge prev_row[i] and prev_row[i + 1] into new coin*/
- Coin* coin = &coins[numcoins++];
- coin_copy(coin, &prev_row[i]);
- add_coins(coin, &prev_row[i + 1]);
- }
- /*fill in all the original symbols again*/
- if(j < maxbitlen)
- {
- error = append_symbol_coins(coins + numcoins, frequencies, numcodes, sum);
- numcoins += numpresent;
- }
- qsort(coins, numcoins, sizeof(Coin), coin_compare);
- }
- }
-
- if(!error)
- {
- /*calculate the lenghts of each symbol, as the amount of times a coin of each symbol is used*/
- for(i = 0; i < numpresent - 1; i++)
- {
- Coin* coin = &coins[i];
- for(j = 0; j < coin->symbols.size; j++) lengths[coin->symbols.data[j]]++;
- }
- }
-
- cleanup_coins(coins, coinmem);
- lodepng_free(coins);
- cleanup_coins(prev_row, coinmem);
- lodepng_free(prev_row);
- }
-
- return error;
-}
-
-/*Create the Huffman tree given the symbol frequencies*/
-static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies,
- size_t mincodes, size_t numcodes, unsigned maxbitlen)
-{
- unsigned error = 0;
- while(!frequencies[numcodes - 1] && numcodes > mincodes) numcodes--; /*trim zeroes*/
- tree->maxbitlen = maxbitlen;
- tree->numcodes = (unsigned)numcodes; /*number of symbols*/
- tree->lengths = (unsigned*)lodepng_realloc(tree->lengths, numcodes * sizeof(unsigned));
- if(!tree->lengths) return 83; /*alloc fail*/
- /*initialize all lengths to 0*/
- memset(tree->lengths, 0, numcodes * sizeof(unsigned));
-
- error = lodepng_huffman_code_lengths(tree->lengths, frequencies, numcodes, maxbitlen);
- if(!error) error = HuffmanTree_makeFromLengths2(tree);
- return error;
-}
-
-static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index)
-{
- return tree->tree1d[index];
-}
-
-static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index)
-{
- return tree->lengths[index];
-}
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-/*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/
-static unsigned generateFixedLitLenTree(HuffmanTree* tree)
-{
- unsigned i, error = 0;
- unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
- if(!bitlen) return 83; /*alloc fail*/
-
- /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
- for(i = 0; i <= 143; i++) bitlen[i] = 8;
- for(i = 144; i <= 255; i++) bitlen[i] = 9;
- for(i = 256; i <= 279; i++) bitlen[i] = 7;
- for(i = 280; i <= 287; i++) bitlen[i] = 8;
-
- error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DEFLATE_CODE_SYMBOLS, 15);
-
- lodepng_free(bitlen);
- return error;
-}
-
-/*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/
-static unsigned generateFixedDistanceTree(HuffmanTree* tree)
-{
- unsigned i, error = 0;
- unsigned* bitlen = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
- if(!bitlen) return 83; /*alloc fail*/
-
- /*there are 32 distance codes, but 30-31 are unused*/
- for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen[i] = 5;
- error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DISTANCE_SYMBOLS, 15);
-
- lodepng_free(bitlen);
- return error;
-}
-
-#ifdef LODEPNG_COMPILE_DECODER
-
-/*
-returns the code, or (unsigned)(-1) if error happened
-inbitlength is the length of the complete buffer, in bits (so its byte length times 8)
-*/
-static unsigned huffmanDecodeSymbol(const unsigned char* in, size_t* bp,
- const HuffmanTree* codetree, size_t inbitlength)
-{
- unsigned treepos = 0, ct;
- for(;;)
- {
- if(*bp >= inbitlength) return (unsigned)(-1); /*error: end of input memory reached without endcode*/
- /*
- decode the symbol from the tree. The "readBitFromStream" code is inlined in
- the expression below because this is the biggest bottleneck while decoding
- */
- ct = codetree->tree2d[(treepos << 1) + READBIT(*bp, in)];
- (*bp)++;
- if(ct < codetree->numcodes) return ct; /*the symbol is decoded, return it*/
- else treepos = ct - codetree->numcodes; /*symbol not yet decoded, instead move tree position*/
-
- if(treepos >= codetree->numcodes) return (unsigned)(-1); /*error: it appeared outside the codetree*/
- }
-}
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-#ifdef LODEPNG_COMPILE_DECODER
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Inflator (Decompressor) / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/
-static void getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d)
-{
- /*TODO: check for out of memory errors*/
- generateFixedLitLenTree(tree_ll);
- generateFixedDistanceTree(tree_d);
-}
-
-/*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/
-static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d,
- const unsigned char* in, size_t* bp, size_t inlength)
-{
- /*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/
- unsigned error = 0;
- unsigned n, HLIT, HDIST, HCLEN, i;
- size_t inbitlength = inlength * 8;
-
- /*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/
- unsigned* bitlen_ll = 0; /*lit,len code lengths*/
- unsigned* bitlen_d = 0; /*dist code lengths*/
- /*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/
- unsigned* bitlen_cl = 0;
- HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/
-
- if((*bp) >> 3 >= inlength - 2) return 49; /*error: the bit pointer is or will go past the memory*/
-
- /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/
- HLIT = readBitsFromStream(bp, in, 5) + 257;
- /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/
- HDIST = readBitsFromStream(bp, in, 5) + 1;
- /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/
- HCLEN = readBitsFromStream(bp, in, 4) + 4;
-
- HuffmanTree_init(&tree_cl);
-
- while(!error)
- {
- /*read the code length codes out of 3 * (amount of code length codes) bits*/
-
- bitlen_cl = (unsigned*)lodepng_malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned));
- if(!bitlen_cl) ERROR_BREAK(83 /*alloc fail*/);
-
- for(i = 0; i < NUM_CODE_LENGTH_CODES; i++)
- {
- if(i < HCLEN) bitlen_cl[CLCL_ORDER[i]] = readBitsFromStream(bp, in, 3);
- else bitlen_cl[CLCL_ORDER[i]] = 0; /*if not, it must stay 0*/
- }
-
- error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7);
- if(error) break;
-
- /*now we can use this tree to read the lengths for the tree that this function will return*/
- bitlen_ll = (unsigned*)lodepng_malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
- bitlen_d = (unsigned*)lodepng_malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
- if(!bitlen_ll || !bitlen_d) ERROR_BREAK(83 /*alloc fail*/);
- for(i = 0; i < NUM_DEFLATE_CODE_SYMBOLS; i++) bitlen_ll[i] = 0;
- for(i = 0; i < NUM_DISTANCE_SYMBOLS; i++) bitlen_d[i] = 0;
-
- /*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/
- i = 0;
- while(i < HLIT + HDIST)
- {
- unsigned code = huffmanDecodeSymbol(in, bp, &tree_cl, inbitlength);
- if(code <= 15) /*a length code*/
- {
- if(i < HLIT) bitlen_ll[i] = code;
- else bitlen_d[i - HLIT] = code;
- i++;
- }
- else if(code == 16) /*repeat previous*/
- {
- unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/
- unsigned value; /*set value to the previous code*/
-
- if(*bp >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
- if (i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/
-
- replength += readBitsFromStream(bp, in, 2);
-
- if(i < HLIT + 1) value = bitlen_ll[i - 1];
- else value = bitlen_d[i - HLIT - 1];
- /*repeat this value in the next lengths*/
- for(n = 0; n < replength; n++)
- {
- if(i >= HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/
- if(i < HLIT) bitlen_ll[i] = value;
- else bitlen_d[i - HLIT] = value;
- i++;
- }
- }
- else if(code == 17) /*repeat "0" 3-10 times*/
- {
- unsigned replength = 3; /*read in the bits that indicate repeat length*/
- if(*bp >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
-
- replength += readBitsFromStream(bp, in, 3);
-
- /*repeat this value in the next lengths*/
- for(n = 0; n < replength; n++)
- {
- if(i >= HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/
-
- if(i < HLIT) bitlen_ll[i] = 0;
- else bitlen_d[i - HLIT] = 0;
- i++;
- }
- }
- else if(code == 18) /*repeat "0" 11-138 times*/
- {
- unsigned replength = 11; /*read in the bits that indicate repeat length*/
- if(*bp >= inbitlength) ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
-
- replength += readBitsFromStream(bp, in, 7);
-
- /*repeat this value in the next lengths*/
- for(n = 0; n < replength; n++)
- {
- if(i >= HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/
-
- if(i < HLIT) bitlen_ll[i] = 0;
- else bitlen_d[i - HLIT] = 0;
- i++;
- }
- }
- else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
- {
- if(code == (unsigned)(-1))
- {
- /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
- (10=no endcode, 11=wrong jump outside of tree)*/
- error = (*bp) > inbitlength ? 10 : 11;
- }
- else error = 16; /*unexisting code, this can never happen*/
- break;
- }
- }
- if(error) break;
-
- if(bitlen_ll[256] == 0) ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/
-
- /*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/
- error = HuffmanTree_makeFromLengths(tree_ll, bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 15);
- if(error) break;
- error = HuffmanTree_makeFromLengths(tree_d, bitlen_d, NUM_DISTANCE_SYMBOLS, 15);
-
- break; /*end of error-while*/
- }
-
- lodepng_free(bitlen_cl);
- lodepng_free(bitlen_ll);
- lodepng_free(bitlen_d);
- HuffmanTree_cleanup(&tree_cl);
-
- return error;
-}
-
-/*inflate a block with dynamic of fixed Huffman tree*/
-static unsigned inflateHuffmanBlock(ucvector* out, const unsigned char* in, size_t* bp,
- size_t* pos, size_t inlength, unsigned btype)
-{
- unsigned error = 0;
- HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/
- HuffmanTree tree_d; /*the huffman tree for distance codes*/
- size_t inbitlength = inlength * 8;
-
- HuffmanTree_init(&tree_ll);
- HuffmanTree_init(&tree_d);
-
- if(btype == 1) getTreeInflateFixed(&tree_ll, &tree_d);
- else if(btype == 2) error = getTreeInflateDynamic(&tree_ll, &tree_d, in, bp, inlength);
-
- while(!error) /*decode all symbols until end reached, breaks at end code*/
- {
- /*code_ll is literal, length or end code*/
- unsigned code_ll = huffmanDecodeSymbol(in, bp, &tree_ll, inbitlength);
- if(code_ll <= 255) /*literal symbol*/
- {
- if((*pos) >= out->size)
- {
- /*reserve more room at once*/
- if(!ucvector_resize(out, ((*pos) + 1) * 2)) ERROR_BREAK(83 /*alloc fail*/);
- }
- out->data[(*pos)] = (unsigned char)(code_ll);
- (*pos)++;
- }
- else if(code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/
- {
- unsigned code_d, distance;
- unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/
- size_t start, forward, backward, length;
-
- /*part 1: get length base*/
- length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX];
-
- /*part 2: get extra bits and add the value of that to length*/
- numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX];
- if(*bp >= inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
- length += readBitsFromStream(bp, in, numextrabits_l);
-
- /*part 3: get distance code*/
- code_d = huffmanDecodeSymbol(in, bp, &tree_d, inbitlength);
- if(code_d > 29)
- {
- if(code_ll == (unsigned)(-1)) /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
- {
- /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
- (10=no endcode, 11=wrong jump outside of tree)*/
- error = (*bp) > inlength * 8 ? 10 : 11;
- }
- else error = 18; /*error: invalid distance code (30-31 are never used)*/
- break;
- }
- distance = DISTANCEBASE[code_d];
-
- /*part 4: get extra bits from distance*/
- numextrabits_d = DISTANCEEXTRA[code_d];
- if(*bp >= inbitlength) ERROR_BREAK(51); /*error, bit pointer will jump past memory*/
-
- distance += readBitsFromStream(bp, in, numextrabits_d);
-
- /*part 5: fill in all the out[n] values based on the length and dist*/
- start = (*pos);
- if(distance > start) ERROR_BREAK(52); /*too long backward distance*/
- backward = start - distance;
- if((*pos) + length >= out->size)
- {
- /*reserve more room at once*/
- if(!ucvector_resize(out, ((*pos) + length) * 2)) ERROR_BREAK(83 /*alloc fail*/);
- }
-
- for(forward = 0; forward < length; forward++)
- {
- out->data[(*pos)] = out->data[backward];
- (*pos)++;
- backward++;
- if(backward >= start) backward = start - distance;
- }
- }
- else if(code_ll == 256)
- {
- break; /*end code, break the loop*/
- }
- else /*if(code == (unsigned)(-1))*/ /*huffmanDecodeSymbol returns (unsigned)(-1) in case of error*/
- {
- /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
- (10=no endcode, 11=wrong jump outside of tree)*/
- error = (*bp) > inlength * 8 ? 10 : 11;
- break;
- }
- }
-
- HuffmanTree_cleanup(&tree_ll);
- HuffmanTree_cleanup(&tree_d);
-
- return error;
-}
-
-static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength)
-{
- /*go to first boundary of byte*/
- size_t p;
- unsigned LEN, NLEN, n, error = 0;
- while(((*bp) & 0x7) != 0) (*bp)++;
- p = (*bp) / 8; /*byte position*/
-
- /*read LEN (2 bytes) and NLEN (2 bytes)*/
- if(p >= inlength - 4) return 52; /*error, bit pointer will jump past memory*/
- LEN = in[p] + 256 * in[p + 1]; p += 2;
- NLEN = in[p] + 256 * in[p + 1]; p += 2;
-
- /*check if 16-bit NLEN is really the one's complement of LEN*/
- if(LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/
-
- if((*pos) + LEN >= out->size)
- {
- if(!ucvector_resize(out, (*pos) + LEN)) return 83; /*alloc fail*/
- }
-
- /*read the literal data: LEN bytes are now stored in the out buffer*/
- if(p + LEN > inlength) return 23; /*error: reading outside of in buffer*/
- for(n = 0; n < LEN; n++) out->data[(*pos)++] = in[p++];
-
- (*bp) = p * 8;
-
- return error;
-}
-
-static unsigned lodepng_inflatev(ucvector* out,
- const unsigned char* in, size_t insize,
- const LodePNGDecompressSettings* settings)
-{
- /*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/
- size_t bp = 0;
- unsigned BFINAL = 0;
- size_t pos = 0; /*byte position in the out buffer*/
-
- unsigned error = 0;
-
- (void)settings;
-
- while(!BFINAL)
- {
- unsigned BTYPE;
- if(bp + 2 >= insize * 8) return 52; /*error, bit pointer will jump past memory*/
- BFINAL = readBitFromStream(&bp, in);
- BTYPE = 1 * readBitFromStream(&bp, in);
- BTYPE += 2 * readBitFromStream(&bp, in);
-
- if(BTYPE == 3) return 20; /*error: invalid BTYPE*/
- else if(BTYPE == 0) error = inflateNoCompression(out, in, &bp, &pos, insize); /*no compression*/
- else error = inflateHuffmanBlock(out, in, &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/
-
- if(error) return error;
- }
-
- /*Only now we know the true size of out, resize it to that*/
- if(!ucvector_resize(out, pos)) error = 83; /*alloc fail*/
-
- return error;
-}
-
-unsigned lodepng_inflate(unsigned char** out, size_t* outsize,
- const unsigned char* in, size_t insize,
- const LodePNGDecompressSettings* settings)
-{
- unsigned error;
- ucvector v;
- ucvector_init_buffer(&v, *out, *outsize);
- error = lodepng_inflatev(&v, in, insize, settings);
- *out = v.data;
- *outsize = v.size;
- return error;
-}
-
-static unsigned inflate(unsigned char** out, size_t* outsize,
- const unsigned char* in, size_t insize,
- const LodePNGDecompressSettings* settings)
-{
- if(settings->custom_inflate)
- {
- return settings->custom_inflate(out, outsize, in, insize, settings);
- }
- else
- {
- return lodepng_inflate(out, outsize, in, insize, settings);
- }
-}
-
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-#ifdef LODEPNG_COMPILE_ENCODER
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Deflator (Compressor) / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258;
-
-/*bitlen is the size in bits of the code*/
-static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen)
-{
- addBitsToStreamReversed(bp, compressed, code, bitlen);
-}
-
-/*search the index in the array, that has the largest value smaller than or equal to the given value,
-given array must be sorted (if no value is smaller, it returns the size of the given array)*/
-static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value)
-{
- /*linear search implementation*/
- /*for(size_t i = 1; i < array_size; i++) if(array[i] > value) return i - 1;
- return array_size - 1;*/
-
- /*binary search implementation (not that much faster) (precondition: array_size > 0)*/
- size_t left = 1;
- size_t right = array_size - 1;
- while(left <= right)
- {
- size_t mid = (left + right) / 2;
- if(array[mid] <= value) left = mid + 1; /*the value to find is more to the right*/
- else if(array[mid - 1] > value) right = mid - 1; /*the value to find is more to the left*/
- else return mid - 1;
- }
- return array_size - 1;
-}
-
-static void addLengthDistance(uivector* values, size_t length, size_t distance)
-{
- /*values in encoded vector are those used by deflate:
- 0-255: literal bytes
- 256: end
- 257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits)
- 286-287: invalid*/
-
- unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length);
- unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]);
- unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance);
- unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]);
-
- uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX);
- uivector_push_back(values, extra_length);
- uivector_push_back(values, dist_code);
- uivector_push_back(values, extra_distance);
-}
-
-static const unsigned HASH_BIT_MASK = 65535;
-static const unsigned HASH_NUM_VALUES = 65536;
-static const unsigned HASH_NUM_CHARACTERS = 3;
-static const unsigned HASH_SHIFT = 2;
-/*
-The HASH_NUM_CHARACTERS value is used to make encoding faster by using longer
-sequences to generate a hash value from the stream bytes. Setting it to 3
-gives exactly the same compression as the brute force method, since deflate's
-run length encoding starts with lengths of 3. Setting it to higher values,
-like 6, can make the encoding faster (not always though!), but will cause the
-encoding to miss any length between 3 and this value, so that the compression
-may be worse (but this can vary too depending on the image, sometimes it is
-even a bit better instead).
-The HASH_NUM_VALUES is the amount of unique possible hash values that
-combinations of bytes can give, the higher it is the more memory is needed, but
-if it's too low the advantage of hashing is gone.
-*/
-
-typedef struct Hash
-{
- int* head; /*hash value to head circular pos*/
- int* val; /*circular pos to hash value*/
- /*circular pos to prev circular pos*/
- unsigned short* chain;
- unsigned short* zeros;
-} Hash;
-
-static unsigned hash_init(Hash* hash, unsigned windowsize)
-{
- unsigned i;
- hash->head = (int*)lodepng_malloc(sizeof(int) * HASH_NUM_VALUES);
- hash->val = (int*)lodepng_malloc(sizeof(int) * windowsize);
- hash->chain = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
- hash->zeros = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize);
-
- if(!hash->head || !hash->val || !hash->chain || !hash->zeros) return 83; /*alloc fail*/
-
- /*initialize hash table*/
- for(i = 0; i < HASH_NUM_VALUES; i++) hash->head[i] = -1;
- for(i = 0; i < windowsize; i++) hash->val[i] = -1;
- for(i = 0; i < windowsize; i++) hash->chain[i] = i; /*same value as index indicates uninitialized*/
-
- return 0;
-}
-
-static void hash_cleanup(Hash* hash)
-{
- lodepng_free(hash->head);
- lodepng_free(hash->val);
- lodepng_free(hash->chain);
- lodepng_free(hash->zeros);
-}
-
-static unsigned getHash(const unsigned char* data, size_t size, size_t pos)
-{
- unsigned result = 0;
- if (HASH_NUM_CHARACTERS == 3 && pos + 2 < size) {
- result ^= (data[pos + 0] << (0 * HASH_SHIFT));
- result ^= (data[pos + 1] << (1 * HASH_SHIFT));
- result ^= (data[pos + 2] << (2 * HASH_SHIFT));
- } else {
- size_t amount, i;
- if(pos >= size) return 0;
- amount = HASH_NUM_CHARACTERS;
- if(pos + amount >= size) amount = size - pos;
- for(i = 0; i < amount; i++) result ^= (data[pos + i] << (i * HASH_SHIFT));
- }
- return result & HASH_BIT_MASK;
-}
-
-static unsigned countZeros(const unsigned char* data, size_t size, size_t pos)
-{
- const unsigned char* start = data + pos;
- const unsigned char* end = start + MAX_SUPPORTED_DEFLATE_LENGTH;
- if(end > data + size) end = data + size;
- data = start;
- while (data != end && *data == 0) data++;
- /*subtracting two addresses returned as 32-bit number (max value is MAX_SUPPORTED_DEFLATE_LENGTH)*/
- return (unsigned)(data - start);
-}
-
-/*wpos = pos & (windowsize - 1)*/
-static void updateHashChain(Hash* hash, size_t wpos, int hashval)
-{
- hash->val[wpos] = hashval;
- if(hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval];
- hash->head[hashval] = wpos;
-}
-
-/*
-LZ77-encode the data. Return value is error code. The input are raw bytes, the output
-is in the form of unsigned integers with codes representing for example literal bytes, or
-length/distance pairs.
-It uses a hash table technique to let it encode faster. When doing LZ77 encoding, a
-sliding window (of windowsize) is used, and all past bytes in that window can be used as
-the "dictionary". A brute force search through all possible distances would be slow, and
-this hash technique is one out of several ways to speed this up.
-*/
-static unsigned encodeLZ77(uivector* out, Hash* hash,
- const unsigned char* in, size_t inpos, size_t insize, unsigned windowsize,
- unsigned minmatch, unsigned nicematch, unsigned lazymatching)
-{
- unsigned pos, i, error = 0;
- /*for large window lengths, assume the user wants no compression loss. Otherwise, max hash chain length speedup.*/
- unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8;
- unsigned maxlazymatch = windowsize >= 8192 ? MAX_SUPPORTED_DEFLATE_LENGTH : 64;
-
- unsigned usezeros = 1; /*not sure if setting it to false for windowsize < 8192 is better or worse*/
- unsigned numzeros = 0;
-
- unsigned offset; /*the offset represents the distance in LZ77 terminology*/
- unsigned length;
- unsigned lazy = 0;
- unsigned lazylength = 0, lazyoffset = 0;
- unsigned hashval;
- unsigned current_offset, current_length;
- const unsigned char *lastptr, *foreptr, *backptr;
- unsigned hashpos, prevpos;
-
- if(windowsize <= 0 || windowsize > 32768) return 60; /*error: windowsize smaller/larger than allowed*/
- if((windowsize & (windowsize - 1)) != 0) return 90; /*error: must be power of two*/
-
- if(nicematch > MAX_SUPPORTED_DEFLATE_LENGTH) nicematch = MAX_SUPPORTED_DEFLATE_LENGTH;
-
- for(pos = inpos; pos < insize; pos++)
- {
- size_t wpos = pos & (windowsize - 1); /*position for in 'circular' hash buffers*/
- unsigned chainlength = 0;
-
- hashval = getHash(in, insize, pos);
- updateHashChain(hash, wpos, hashval);
-
- if(usezeros && hashval == 0)
- {
- if (numzeros == 0) numzeros = countZeros(in, insize, pos);
- else if (pos + numzeros >= insize || in[pos + numzeros - 1] != 0) numzeros--;
- hash->zeros[wpos] = numzeros;
- }
- else
- {
- numzeros = 0;
- }
-
- /*the length and offset found for the current position*/
- length = 0;
- offset = 0;
-
- prevpos = hash->head[hashval];
- hashpos = hash->chain[prevpos];
-
- lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH];
-
- /*search for the longest string*/
- for(;;)
- {
- /*stop when went completely around the circular buffer*/
- if(prevpos < wpos && hashpos > prevpos && hashpos <= wpos) break;
- if(prevpos > wpos && (hashpos <= wpos || hashpos > prevpos)) break;
- if(chainlength++ >= maxchainlength) break;
-
- current_offset = hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize;
- if(current_offset > 0)
- {
- /*test the next characters*/
- foreptr = &in[pos];
- backptr = &in[pos - current_offset];
-
- /*common case in PNGs is lots of zeros. Quickly skip over them as a speedup*/
- if(usezeros && hashval == 0 && hash->val[hashpos] == 0 /*hashval[hashpos] may be out of date*/)
- {
- unsigned skip = hash->zeros[hashpos];
- if(skip > numzeros) skip = numzeros;
- backptr += skip;
- foreptr += skip;
- }
-
- while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/
- {
- ++backptr;
- ++foreptr;
- }
- current_length = (unsigned)(foreptr - &in[pos]);
-
- if(current_length > length)
- {
- length = current_length; /*the longest length*/
- offset = current_offset; /*the offset that is related to this longest length*/
- /*jump out once a length of max length is found (speed gain). This also jumps
- out if length is MAX_SUPPORTED_DEFLATE_LENGTH*/
- if(current_length >= nicematch) break;
- }
- }
-
- if(hashpos == hash->chain[hashpos]) break;
-
- prevpos = hashpos;
- hashpos = hash->chain[hashpos];
- }
-
- if(lazymatching)
- {
- if(!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH)
- {
- lazy = 1;
- lazylength = length;
- lazyoffset = offset;
- continue; /*try the next byte*/
- }
- if(lazy)
- {
- lazy = 0;
- if(pos == 0) ERROR_BREAK(81);
- if(length > lazylength + 1)
- {
- /*push the previous character as literal*/
- if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(83 /*alloc fail*/);
- }
- else
- {
- length = lazylength;
- offset = lazyoffset;
- hash->head[hashval] = -1; /*the same hashchain update will be done, this ensures no wrong alteration*/
- pos--;
- }
- }
- }
- if(length >= 3 && offset > windowsize) ERROR_BREAK(86 /*too big (or overflown negative) offset*/);
-
- /*encode it as length/distance pair or literal value*/
- if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/
- {
- if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/);
- }
- else if(length < minmatch || (length == 3 && offset > 4096))
- {
- /*compensate for the fact that longer offsets have more extra bits, a
- length of only 3 may be not worth it then*/
- if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/);
- }
- else
- {
- addLengthDistance(out, length, offset);
- for(i = 1; i < length; i++)
- {
- pos++;
- wpos = pos & (windowsize - 1);
- hashval = getHash(in, insize, pos);
- updateHashChain(hash, wpos, hashval);
- if(usezeros && hashval == 0)
- {
- if (numzeros == 0) numzeros = countZeros(in, insize, pos);
- else if (pos + numzeros >= insize || in[pos + numzeros - 1] != 0) numzeros--;
- hash->zeros[wpos] = numzeros;
- }
- else
- {
- numzeros = 0;
- }
- }
- }
- } /*end of the loop through each character of input*/
-
- return error;
-}
-
-/* /////////////////////////////////////////////////////////////////////////// */
-
-static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize)
-{
- /*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte,
- 2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/
-
- size_t i, j, numdeflateblocks = (datasize + 65534) / 65535;
- unsigned datapos = 0;
- for(i = 0; i < numdeflateblocks; i++)
- {
- unsigned BFINAL, BTYPE, LEN, NLEN;
- unsigned char firstbyte;
-
- BFINAL = (i == numdeflateblocks - 1);
- BTYPE = 0;
-
- firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1));
- ucvector_push_back(out, firstbyte);
-
- LEN = 65535;
- if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos;
- NLEN = 65535 - LEN;
-
- ucvector_push_back(out, (unsigned char)(LEN % 256));
- ucvector_push_back(out, (unsigned char)(LEN / 256));
- ucvector_push_back(out, (unsigned char)(NLEN % 256));
- ucvector_push_back(out, (unsigned char)(NLEN / 256));
-
- /*Decompressed data*/
- for(j = 0; j < 65535 && datapos < datasize; j++)
- {
- ucvector_push_back(out, data[datapos++]);
- }
- }
-
- return 0;
-}
-
-/*
-write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees.
-tree_ll: the tree for lit and len codes.
-tree_d: the tree for distance codes.
-*/
-static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded,
- const HuffmanTree* tree_ll, const HuffmanTree* tree_d)
-{
- size_t i = 0;
- for(i = 0; i < lz77_encoded->size; i++)
- {
- unsigned val = lz77_encoded->data[i];
- addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_ll, val), HuffmanTree_getLength(tree_ll, val));
- if(val > 256) /*for a length code, 3 more things have to be added*/
- {
- unsigned length_index = val - FIRST_LENGTH_CODE_INDEX;
- unsigned n_length_extra_bits = LENGTHEXTRA[length_index];
- unsigned length_extra_bits = lz77_encoded->data[++i];
-
- unsigned distance_code = lz77_encoded->data[++i];
-
- unsigned distance_index = distance_code;
- unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index];
- unsigned distance_extra_bits = lz77_encoded->data[++i];
-
- addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits);
- addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_d, distance_code),
- HuffmanTree_getLength(tree_d, distance_code));
- addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits);
- }
- }
-}
-
-/*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/
-static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash,
- const unsigned char* data, size_t datapos, size_t dataend,
- const LodePNGCompressSettings* settings, int final)
-{
- unsigned error = 0;
-
- /*
- A block is compressed as follows: The PNG data is lz77 encoded, resulting in
- literal bytes and length/distance pairs. This is then huffman compressed with
- two huffman trees. One huffman tree is used for the lit and len values ("ll"),
- another huffman tree is used for the dist values ("d"). These two trees are
- stored using their code lengths, and to compress even more these code lengths
- are also run-length encoded and huffman compressed. This gives a huffman tree
- of code lengths "cl". The code lenghts used to describe this third tree are
- the code length code lengths ("clcl").
- */
-
- /*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/
- uivector lz77_encoded;
- HuffmanTree tree_ll; /*tree for lit,len values*/
- HuffmanTree tree_d; /*tree for distance codes*/
- HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/
- uivector frequencies_ll; /*frequency of lit,len codes*/
- uivector frequencies_d; /*frequency of dist codes*/
- uivector frequencies_cl; /*frequency of code length codes*/
- uivector bitlen_lld; /*lit,len,dist code lenghts (int bits), literally (without repeat codes).*/
- uivector bitlen_lld_e; /*bitlen_lld encoded with repeat codes (this is a rudemtary run length compression)*/
- /*bitlen_cl is the code length code lengths ("clcl"). The bit lengths of codes to represent tree_cl
- (these are written as is in the file, it would be crazy to compress these using yet another huffman
- tree that needs to be represented by yet another set of code lengths)*/
- uivector bitlen_cl;
- size_t datasize = dataend - datapos;
-
- /*
- Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies:
- bitlen_lld is to tree_cl what data is to tree_ll and tree_d.
- bitlen_lld_e is to bitlen_lld what lz77_encoded is to data.
- bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded.
- */
-
- unsigned BFINAL = final;
- size_t numcodes_ll, numcodes_d, i;
- unsigned HLIT, HDIST, HCLEN;
-
- uivector_init(&lz77_encoded);
- HuffmanTree_init(&tree_ll);
- HuffmanTree_init(&tree_d);
- HuffmanTree_init(&tree_cl);
- uivector_init(&frequencies_ll);
- uivector_init(&frequencies_d);
- uivector_init(&frequencies_cl);
- uivector_init(&bitlen_lld);
- uivector_init(&bitlen_lld_e);
- uivector_init(&bitlen_cl);
-
- /*This while loop never loops due to a break at the end, it is here to
- allow breaking out of it to the cleanup phase on error conditions.*/
- while(!error)
- {
- if(settings->use_lz77)
- {
- error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
- settings->minmatch, settings->nicematch, settings->lazymatching);
- if(error) break;
- }
- else
- {
- if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83 /*alloc fail*/);
- for(i = datapos; i < dataend; i++) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/
- }
-
- if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83 /*alloc fail*/);
- if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(83 /*alloc fail*/);
-
- /*Count the frequencies of lit, len and dist codes*/
- for(i = 0; i < lz77_encoded.size; i++)
- {
- unsigned symbol = lz77_encoded.data[i];
- frequencies_ll.data[symbol]++;
- if(symbol > 256)
- {
- unsigned dist = lz77_encoded.data[i + 2];
- frequencies_d.data[dist]++;
- i += 3;
- }
- }
- frequencies_ll.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/
-
- /*Make both huffman trees, one for the lit and len codes, one for the dist codes*/
- error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll.data, 257, frequencies_ll.size, 15);
- if(error) break;
- /*2, not 1, is chosen for mincodes: some buggy PNG decoders require at least 2 symbols in the dist tree*/
- error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, 2, frequencies_d.size, 15);
- if(error) break;
-
- numcodes_ll = tree_ll.numcodes; if(numcodes_ll > 286) numcodes_ll = 286;
- numcodes_d = tree_d.numcodes; if(numcodes_d > 30) numcodes_d = 30;
- /*store the code lengths of both generated trees in bitlen_lld*/
- for(i = 0; i < numcodes_ll; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_ll, (unsigned)i));
- for(i = 0; i < numcodes_d; i++) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_d, (unsigned)i));
-
- /*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times),
- 17 (3-10 zeroes), 18 (11-138 zeroes)*/
- for(i = 0; i < (unsigned)bitlen_lld.size; i++)
- {
- unsigned j = 0; /*amount of repititions*/
- while(i + j + 1 < (unsigned)bitlen_lld.size && bitlen_lld.data[i + j + 1] == bitlen_lld.data[i]) j++;
-
- if(bitlen_lld.data[i] == 0 && j >= 2) /*repeat code for zeroes*/
- {
- j++; /*include the first zero*/
- if(j <= 10) /*repeat code 17 supports max 10 zeroes*/
- {
- uivector_push_back(&bitlen_lld_e, 17);
- uivector_push_back(&bitlen_lld_e, j - 3);
- }
- else /*repeat code 18 supports max 138 zeroes*/
- {
- if(j > 138) j = 138;
- uivector_push_back(&bitlen_lld_e, 18);
- uivector_push_back(&bitlen_lld_e, j - 11);
- }
- i += (j - 1);
- }
- else if(j >= 3) /*repeat code for value other than zero*/
- {
- size_t k;
- unsigned num = j / 6, rest = j % 6;
- uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
- for(k = 0; k < num; k++)
- {
- uivector_push_back(&bitlen_lld_e, 16);
- uivector_push_back(&bitlen_lld_e, 6 - 3);
- }
- if(rest >= 3)
- {
- uivector_push_back(&bitlen_lld_e, 16);
- uivector_push_back(&bitlen_lld_e, rest - 3);
- }
- else j -= rest;
- i += j;
- }
- else /*too short to benefit from repeat code*/
- {
- uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]);
- }
- }
-
- /*generate tree_cl, the huffmantree of huffmantrees*/
-
- if(!uivector_resizev(&frequencies_cl, NUM_CODE_LENGTH_CODES, 0)) ERROR_BREAK(83 /*alloc fail*/);
- for(i = 0; i < bitlen_lld_e.size; i++)
- {
- frequencies_cl.data[bitlen_lld_e.data[i]]++;
- /*after a repeat code come the bits that specify the number of repetitions,
- those don't need to be in the frequencies_cl calculation*/
- if(bitlen_lld_e.data[i] >= 16) i++;
- }
-
- error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data,
- frequencies_cl.size, frequencies_cl.size, 7);
- if(error) break;
-
- if(!uivector_resize(&bitlen_cl, tree_cl.numcodes)) ERROR_BREAK(83 /*alloc fail*/);
- for(i = 0; i < tree_cl.numcodes; i++)
- {
- /*lenghts of code length tree is in the order as specified by deflate*/
- bitlen_cl.data[i] = HuffmanTree_getLength(&tree_cl, CLCL_ORDER[i]);
- }
- while(bitlen_cl.data[bitlen_cl.size - 1] == 0 && bitlen_cl.size > 4)
- {
- /*remove zeros at the end, but minimum size must be 4*/
- if(!uivector_resize(&bitlen_cl, bitlen_cl.size - 1)) ERROR_BREAK(83 /*alloc fail*/);
- }
- if(error) break;
-
- /*
- Write everything into the output
-
- After the BFINAL and BTYPE, the dynamic block consists out of the following:
- - 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN
- - (HCLEN+4)*3 bits code lengths of code length alphabet
- - HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length
- alphabet, + possible repetition codes 16, 17, 18)
- - HDIST + 1 code lengths of distance alphabet (encoded using the code length
- alphabet, + possible repetition codes 16, 17, 18)
- - compressed data
- - 256 (end code)
- */
-
- /*Write block type*/
- addBitToStream(bp, out, BFINAL);
- addBitToStream(bp, out, 0); /*first bit of BTYPE "dynamic"*/
- addBitToStream(bp, out, 1); /*second bit of BTYPE "dynamic"*/
-
- /*write the HLIT, HDIST and HCLEN values*/
- HLIT = (unsigned)(numcodes_ll - 257);
- HDIST = (unsigned)(numcodes_d - 1);
- HCLEN = (unsigned)bitlen_cl.size - 4;
- /*trim zeroes for HCLEN. HLIT and HDIST were already trimmed at tree creation*/
- while(!bitlen_cl.data[HCLEN + 4 - 1] && HCLEN > 0) HCLEN--;
- addBitsToStream(bp, out, HLIT, 5);
- addBitsToStream(bp, out, HDIST, 5);
- addBitsToStream(bp, out, HCLEN, 4);
-
- /*write the code lenghts of the code length alphabet*/
- for(i = 0; i < HCLEN + 4; i++) addBitsToStream(bp, out, bitlen_cl.data[i], 3);
-
- /*write the lenghts of the lit/len AND the dist alphabet*/
- for(i = 0; i < bitlen_lld_e.size; i++)
- {
- addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_cl, bitlen_lld_e.data[i]),
- HuffmanTree_getLength(&tree_cl, bitlen_lld_e.data[i]));
- /*extra bits of repeat codes*/
- if(bitlen_lld_e.data[i] == 16) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 2);
- else if(bitlen_lld_e.data[i] == 17) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 3);
- else if(bitlen_lld_e.data[i] == 18) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 7);
- }
-
- /*write the compressed data symbols*/
- writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d);
- /*error: the length of the end code 256 must be larger than 0*/
- if(HuffmanTree_getLength(&tree_ll, 256) == 0) ERROR_BREAK(64);
-
- /*write the end code*/
- addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256));
-
- break; /*end of error-while*/
- }
-
- /*cleanup*/
- uivector_cleanup(&lz77_encoded);
- HuffmanTree_cleanup(&tree_ll);
- HuffmanTree_cleanup(&tree_d);
- HuffmanTree_cleanup(&tree_cl);
- uivector_cleanup(&frequencies_ll);
- uivector_cleanup(&frequencies_d);
- uivector_cleanup(&frequencies_cl);
- uivector_cleanup(&bitlen_lld_e);
- uivector_cleanup(&bitlen_lld);
- uivector_cleanup(&bitlen_cl);
-
- return error;
-}
-
-static unsigned deflateFixed(ucvector* out, size_t* bp, Hash* hash,
- const unsigned char* data,
- size_t datapos, size_t dataend,
- const LodePNGCompressSettings* settings, int final)
-{
- HuffmanTree tree_ll; /*tree for literal values and length codes*/
- HuffmanTree tree_d; /*tree for distance codes*/
-
- unsigned BFINAL = final;
- unsigned error = 0;
- size_t i;
-
- HuffmanTree_init(&tree_ll);
- HuffmanTree_init(&tree_d);
-
- generateFixedLitLenTree(&tree_ll);
- generateFixedDistanceTree(&tree_d);
-
- addBitToStream(bp, out, BFINAL);
- addBitToStream(bp, out, 1); /*first bit of BTYPE*/
- addBitToStream(bp, out, 0); /*second bit of BTYPE*/
-
- if(settings->use_lz77) /*LZ77 encoded*/
- {
- uivector lz77_encoded;
- uivector_init(&lz77_encoded);
- error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize,
- settings->minmatch, settings->nicematch, settings->lazymatching);
- if(!error) writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d);
- uivector_cleanup(&lz77_encoded);
- }
- else /*no LZ77, but still will be Huffman compressed*/
- {
- for(i = datapos; i < dataend; i++)
- {
- addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, data[i]), HuffmanTree_getLength(&tree_ll, data[i]));
- }
- }
- /*add END code*/
- if(!error) addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256));
-
- /*cleanup*/
- HuffmanTree_cleanup(&tree_ll);
- HuffmanTree_cleanup(&tree_d);
-
- return error;
-}
-
-static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t insize,
- const LodePNGCompressSettings* settings)
-{
- unsigned error = 0;
- size_t i, blocksize, numdeflateblocks;
- size_t bp = 0; /*the bit pointer*/
- Hash hash;
-
- if(settings->btype > 2) return 61;
- else if(settings->btype == 0) return deflateNoCompression(out, in, insize);
- else if(settings->btype == 1) blocksize = insize;
- else /*if(settings->btype == 2)*/
- {
- blocksize = insize / 8 + 8;
- if(blocksize < 65535) blocksize = 65535;
- }
-
- numdeflateblocks = (insize + blocksize - 1) / blocksize;
- if(numdeflateblocks == 0) numdeflateblocks = 1;
-
- error = hash_init(&hash, settings->windowsize);
- if(error) return error;
-
- for(i = 0; i < numdeflateblocks && !error; i++)
- {
- int final = i == numdeflateblocks - 1;
- size_t start = i * blocksize;
- size_t end = start + blocksize;
- if(end > insize) end = insize;
-
- if(settings->btype == 1) error = deflateFixed(out, &bp, &hash, in, start, end, settings, final);
- else if(settings->btype == 2) error = deflateDynamic(out, &bp, &hash, in, start, end, settings, final);
- }
-
- hash_cleanup(&hash);
-
- return error;
-}
-
-unsigned lodepng_deflate(unsigned char** out, size_t* outsize,
- const unsigned char* in, size_t insize,
- const LodePNGCompressSettings* settings)
-{
- unsigned error;
- ucvector v;
- ucvector_init_buffer(&v, *out, *outsize);
- error = lodepng_deflatev(&v, in, insize, settings);
- *out = v.data;
- *outsize = v.size;
- return error;
-}
-
-static unsigned deflate(unsigned char** out, size_t* outsize,
- const unsigned char* in, size_t insize,
- const LodePNGCompressSettings* settings)
-{
- if(settings->custom_deflate)
- {
- return settings->custom_deflate(out, outsize, in, insize, settings);
- }
- else
- {
- return lodepng_deflate(out, outsize, in, insize, settings);
- }
-}
-
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Adler32 */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len)
-{
- unsigned s1 = adler & 0xffff;
- unsigned s2 = (adler >> 16) & 0xffff;
-
- while(len > 0)
- {
- /*at least 5550 sums can be done before the sums overflow, saving a lot of module divisions*/
- unsigned amount = len > 5550 ? 5550 : len;
- len -= amount;
- while(amount > 0)
- {
- s1 += (*data++);
- s2 += s1;
- amount--;
- }
- s1 %= 65521;
- s2 %= 65521;
- }
-
- return (s2 << 16) | s1;
-}
-
-/*Return the adler32 of the bytes data[0..len-1]*/
-static unsigned adler32(const unsigned char* data, unsigned len)
-{
- return update_adler32(1L, data, len);
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Zlib / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef LODEPNG_COMPILE_DECODER
-
-unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
- size_t insize, const LodePNGDecompressSettings* settings)
-{
- unsigned error = 0;
- unsigned CM, CINFO, FDICT;
-
- if(insize < 2) return 53; /*error, size of zlib data too small*/
- /*read information from zlib header*/
- if((in[0] * 256 + in[1]) % 31 != 0)
- {
- /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/
- return 24;
- }
-
- CM = in[0] & 15;
- CINFO = (in[0] >> 4) & 15;
- /*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/
- FDICT = (in[1] >> 5) & 1;
- /*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/
-
- if(CM != 8 || CINFO > 7)
- {
- /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/
- return 25;
- }
- if(FDICT != 0)
- {
- /*error: the specification of PNG says about the zlib stream:
- "The additional flags shall not specify a preset dictionary."*/
- return 26;
- }
-
- error = inflate(out, outsize, in + 2, insize - 2, settings);
- if(error) return error;
-
- if(!settings->ignore_adler32)
- {
- unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]);
- unsigned checksum = adler32(*out, (unsigned)(*outsize));
- if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/
- }
-
- return 0; /*no error*/
-}
-
-static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
- size_t insize, const LodePNGDecompressSettings* settings)
-{
- if(settings->custom_zlib)
- {
- return settings->custom_zlib(out, outsize, in, insize, settings);
- }
- else
- {
- return lodepng_zlib_decompress(out, outsize, in, insize, settings);
- }
-}
-
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-#ifdef LODEPNG_COMPILE_ENCODER
-
-unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
- size_t insize, const LodePNGCompressSettings* settings)
-{
- /*initially, *out must be NULL and outsize 0, if you just give some random *out
- that's pointing to a non allocated buffer, this'll crash*/
- ucvector outv;
- size_t i;
- unsigned error;
- unsigned char* deflatedata = 0;
- size_t deflatesize = 0;
-
- unsigned ADLER32;
- /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/
- unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/
- unsigned FLEVEL = 0;
- unsigned FDICT = 0;
- unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64;
- unsigned FCHECK = 31 - CMFFLG % 31;
- CMFFLG += FCHECK;
-
- /*ucvector-controlled version of the output buffer, for dynamic array*/
- ucvector_init_buffer(&outv, *out, *outsize);
-
- ucvector_push_back(&outv, (unsigned char)(CMFFLG / 256));
- ucvector_push_back(&outv, (unsigned char)(CMFFLG % 256));
-
- error = deflate(&deflatedata, &deflatesize, in, insize, settings);
-
- if(!error)
- {
- ADLER32 = adler32(in, (unsigned)insize);
- for(i = 0; i < deflatesize; i++) ucvector_push_back(&outv, deflatedata[i]);
- lodepng_free(deflatedata);
- lodepng_add32bitInt(&outv, ADLER32);
- }
-
- *out = outv.data;
- *outsize = outv.size;
-
- return error;
-}
-
-/* compress using the default or custom zlib function */
-static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
- size_t insize, const LodePNGCompressSettings* settings)
-{
- if(settings->custom_zlib)
- {
- return settings->custom_zlib(out, outsize, in, insize, settings);
- }
- else
- {
- return lodepng_zlib_compress(out, outsize, in, insize, settings);
- }
-}
-
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-#else /*no LODEPNG_COMPILE_ZLIB*/
-
-#ifdef LODEPNG_COMPILE_DECODER
-static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in,
- size_t insize, const LodePNGDecompressSettings* settings)
-{
- if (!settings->custom_zlib) return 87; /*no custom zlib function provided */
- return settings->custom_zlib(out, outsize, in, insize, settings);
-}
-#endif /*LODEPNG_COMPILE_DECODER*/
-#ifdef LODEPNG_COMPILE_ENCODER
-static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in,
- size_t insize, const LodePNGCompressSettings* settings)
-{
- if (!settings->custom_zlib) return 87; /*no custom zlib function provided */
- return settings->custom_zlib(out, outsize, in, insize, settings);
-}
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-#endif /*LODEPNG_COMPILE_ZLIB*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef LODEPNG_COMPILE_ENCODER
-
-/*this is a good tradeoff between speed and compression ratio*/
-#define DEFAULT_WINDOWSIZE 2048
-
-void lodepng_compress_settings_init(LodePNGCompressSettings* settings)
-{
- /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/
- settings->btype = 2;
- settings->use_lz77 = 1;
- settings->windowsize = DEFAULT_WINDOWSIZE;
- settings->minmatch = 3;
- settings->nicematch = 128;
- settings->lazymatching = 1;
-
- settings->custom_zlib = 0;
- settings->custom_deflate = 0;
- settings->custom_context = 0;
-}
-
-const LodePNGCompressSettings lodepng_default_compress_settings = {2, 1, DEFAULT_WINDOWSIZE, 3, 128, 1, 0, 0, 0};
-
-
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-#ifdef LODEPNG_COMPILE_DECODER
-
-void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings)
-{
- settings->ignore_adler32 = 0;
-
- settings->custom_zlib = 0;
- settings->custom_inflate = 0;
- settings->custom_context = 0;
-}
-
-const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0};
-
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* // End of Zlib related code. Begin of PNG related code. // */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef LODEPNG_COMPILE_PNG
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / CRC32 / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/* CRC polynomial: 0xedb88320 */
-static unsigned lodepng_crc32_table[256] = {
- 0u, 1996959894u, 3993919788u, 2567524794u, 124634137u, 1886057615u, 3915621685u, 2657392035u,
- 249268274u, 2044508324u, 3772115230u, 2547177864u, 162941995u, 2125561021u, 3887607047u, 2428444049u,
- 498536548u, 1789927666u, 4089016648u, 2227061214u, 450548861u, 1843258603u, 4107580753u, 2211677639u,
- 325883990u, 1684777152u, 4251122042u, 2321926636u, 335633487u, 1661365465u, 4195302755u, 2366115317u,
- 997073096u, 1281953886u, 3579855332u, 2724688242u, 1006888145u, 1258607687u, 3524101629u, 2768942443u,
- 901097722u, 1119000684u, 3686517206u, 2898065728u, 853044451u, 1172266101u, 3705015759u, 2882616665u,
- 651767980u, 1373503546u, 3369554304u, 3218104598u, 565507253u, 1454621731u, 3485111705u, 3099436303u,
- 671266974u, 1594198024u, 3322730930u, 2970347812u, 795835527u, 1483230225u, 3244367275u, 3060149565u,
- 1994146192u, 31158534u, 2563907772u, 4023717930u, 1907459465u, 112637215u, 2680153253u, 3904427059u,
- 2013776290u, 251722036u, 2517215374u, 3775830040u, 2137656763u, 141376813u, 2439277719u, 3865271297u,
- 1802195444u, 476864866u, 2238001368u, 4066508878u, 1812370925u, 453092731u, 2181625025u, 4111451223u,
- 1706088902u, 314042704u, 2344532202u, 4240017532u, 1658658271u, 366619977u, 2362670323u, 4224994405u,
- 1303535960u, 984961486u, 2747007092u, 3569037538u, 1256170817u, 1037604311u, 2765210733u, 3554079995u,
- 1131014506u, 879679996u, 2909243462u, 3663771856u, 1141124467u, 855842277u, 2852801631u, 3708648649u,
- 1342533948u, 654459306u, 3188396048u, 3373015174u, 1466479909u, 544179635u, 3110523913u, 3462522015u,
- 1591671054u, 702138776u, 2966460450u, 3352799412u, 1504918807u, 783551873u, 3082640443u, 3233442989u,
- 3988292384u, 2596254646u, 62317068u, 1957810842u, 3939845945u, 2647816111u, 81470997u, 1943803523u,
- 3814918930u, 2489596804u, 225274430u, 2053790376u, 3826175755u, 2466906013u, 167816743u, 2097651377u,
- 4027552580u, 2265490386u, 503444072u, 1762050814u, 4150417245u, 2154129355u, 426522225u, 1852507879u,
- 4275313526u, 2312317920u, 282753626u, 1742555852u, 4189708143u, 2394877945u, 397917763u, 1622183637u,
- 3604390888u, 2714866558u, 953729732u, 1340076626u, 3518719985u, 2797360999u, 1068828381u, 1219638859u,
- 3624741850u, 2936675148u, 906185462u, 1090812512u, 3747672003u, 2825379669u, 829329135u, 1181335161u,
- 3412177804u, 3160834842u, 628085408u, 1382605366u, 3423369109u, 3138078467u, 570562233u, 1426400815u,
- 3317316542u, 2998733608u, 733239954u, 1555261956u, 3268935591u, 3050360625u, 752459403u, 1541320221u,
- 2607071920u, 3965973030u, 1969922972u, 40735498u, 2617837225u, 3943577151u, 1913087877u, 83908371u,
- 2512341634u, 3803740692u, 2075208622u, 213261112u, 2463272603u, 3855990285u, 2094854071u, 198958881u,
- 2262029012u, 4057260610u, 1759359992u, 534414190u, 2176718541u, 4139329115u, 1873836001u, 414664567u,
- 2282248934u, 4279200368u, 1711684554u, 285281116u, 2405801727u, 4167216745u, 1634467795u, 376229701u,
- 2685067896u, 3608007406u, 1308918612u, 956543938u, 2808555105u, 3495958263u, 1231636301u, 1047427035u,
- 2932959818u, 3654703836u, 1088359270u, 936918000u, 2847714899u, 3736837829u, 1202900863u, 817233897u,
- 3183342108u, 3401237130u, 1404277552u, 615818150u, 3134207493u, 3453421203u, 1423857449u, 601450431u,
- 3009837614u, 3294710456u, 1567103746u, 711928724u, 3020668471u, 3272380065u, 1510334235u, 755167117u
-};
-
-/*Return the CRC of the bytes buf[0..len-1].*/
-unsigned lodepng_crc32(const unsigned char* buf, size_t len)
-{
- unsigned c = 0xffffffffL;
- size_t n;
-
- for(n = 0; n < len; n++)
- {
- c = lodepng_crc32_table[(c ^ buf[n]) & 0xff] ^ (c >> 8);
- }
- return c ^ 0xffffffffL;
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Reading and writing single bits and bytes from/to stream for LodePNG / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream)
-{
- unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1);
- (*bitpointer)++;
- return result;
-}
-
-static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits)
-{
- unsigned result = 0;
- size_t i;
- for(i = nbits - 1; i < nbits; i--)
- {
- result += (unsigned)readBitFromReversedStream(bitpointer, bitstream) << i;
- }
- return result;
-}
-
-#ifdef LODEPNG_COMPILE_DECODER
-static void setBitOfReversedStream0(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
-{
- /*the current bit in bitstream must be 0 for this to work*/
- if(bit)
- {
- /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/
- bitstream[(*bitpointer) >> 3] |= (bit << (7 - ((*bitpointer) & 0x7)));
- }
- (*bitpointer)++;
-}
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit)
-{
- /*the current bit in bitstream may be 0 or 1 for this to work*/
- if(bit == 0) bitstream[(*bitpointer) >> 3] &= (unsigned char)(~(1 << (7 - ((*bitpointer) & 0x7))));
- else bitstream[(*bitpointer) >> 3] |= (1 << (7 - ((*bitpointer) & 0x7)));
- (*bitpointer)++;
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / PNG chunks / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-unsigned lodepng_chunk_length(const unsigned char* chunk)
-{
- return lodepng_read32bitInt(&chunk[0]);
-}
-
-void lodepng_chunk_type(char type[5], const unsigned char* chunk)
-{
- unsigned i;
- for(i = 0; i < 4; i++) type[i] = chunk[4 + i];
- type[4] = 0; /*null termination char*/
-}
-
-unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type)
-{
- if(strlen(type) != 4) return 0;
- return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]);
-}
-
-unsigned char lodepng_chunk_ancillary(const unsigned char* chunk)
-{
- return((chunk[4] & 32) != 0);
-}
-
-unsigned char lodepng_chunk_private(const unsigned char* chunk)
-{
- return((chunk[6] & 32) != 0);
-}
-
-unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk)
-{
- return((chunk[7] & 32) != 0);
-}
-
-unsigned char* lodepng_chunk_data(unsigned char* chunk)
-{
- return &chunk[8];
-}
-
-const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk)
-{
- return &chunk[8];
-}
-
-unsigned lodepng_chunk_check_crc(const unsigned char* chunk)
-{
- unsigned length = lodepng_chunk_length(chunk);
- unsigned CRC = lodepng_read32bitInt(&chunk[length + 8]);
- /*the CRC is taken of the data and the 4 chunk type letters, not the length*/
- unsigned checksum = lodepng_crc32(&chunk[4], length + 4);
- if(CRC != checksum) return 1;
- else return 0;
-}
-
-void lodepng_chunk_generate_crc(unsigned char* chunk)
-{
- unsigned length = lodepng_chunk_length(chunk);
- unsigned CRC = lodepng_crc32(&chunk[4], length + 4);
- lodepng_set32bitInt(chunk + 8 + length, CRC);
-}
-
-unsigned char* lodepng_chunk_next(unsigned char* chunk)
-{
- unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12;
- return &chunk[total_chunk_length];
-}
-
-const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk)
-{
- unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12;
- return &chunk[total_chunk_length];
-}
-
-unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk)
-{
- unsigned i;
- unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12;
- unsigned char *chunk_start, *new_buffer;
- size_t new_length = (*outlength) + total_chunk_length;
- if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/
-
- new_buffer = (unsigned char*)lodepng_realloc(*out, new_length);
- if(!new_buffer) return 83; /*alloc fail*/
- (*out) = new_buffer;
- (*outlength) = new_length;
- chunk_start = &(*out)[new_length - total_chunk_length];
-
- for(i = 0; i < total_chunk_length; i++) chunk_start[i] = chunk[i];
-
- return 0;
-}
-
-unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
- const char* type, const unsigned char* data)
-{
- unsigned i;
- unsigned char *chunk, *new_buffer;
- size_t new_length = (*outlength) + length + 12;
- if(new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/
- new_buffer = (unsigned char*)lodepng_realloc(*out, new_length);
- if(!new_buffer) return 83; /*alloc fail*/
- (*out) = new_buffer;
- (*outlength) = new_length;
- chunk = &(*out)[(*outlength) - length - 12];
-
- /*1: length*/
- lodepng_set32bitInt(chunk, (unsigned)length);
-
- /*2: chunk name (4 letters)*/
- chunk[4] = type[0];
- chunk[5] = type[1];
- chunk[6] = type[2];
- chunk[7] = type[3];
-
- /*3: the data*/
- for(i = 0; i < length; i++) chunk[8 + i] = data[i];
-
- /*4: CRC (of the chunkname characters and the data)*/
- lodepng_chunk_generate_crc(chunk);
-
- return 0;
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / Color types and such / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*return type is a LodePNG error code*/
-static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) /*bd = bitdepth*/
-{
- switch(colortype)
- {
- case 0: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/
- case 2: if(!( bd == 8 || bd == 16)) return 37; break; /*RGB*/
- case 3: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 )) return 37; break; /*palette*/
- case 4: if(!( bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/
- case 6: if(!( bd == 8 || bd == 16)) return 37; break; /*RGBA*/
- default: return 31;
- }
- return 0; /*allowed color type / bits combination*/
-}
-
-static unsigned getNumColorChannels(LodePNGColorType colortype)
-{
- switch(colortype)
- {
- case 0: return 1; /*grey*/
- case 2: return 3; /*RGB*/
- case 3: return 1; /*palette*/
- case 4: return 2; /*grey + alpha*/
- case 6: return 4; /*RGBA*/
- }
- return 0; /*unexisting color type*/
-}
-
-static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth)
-{
- /*bits per pixel is amount of channels * bits per channel*/
- return getNumColorChannels(colortype) * bitdepth;
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-void lodepng_color_mode_init(LodePNGColorMode* info)
-{
- info->key_defined = 0;
- info->key_r = info->key_g = info->key_b = 0;
- info->colortype = LCT_RGBA;
- info->bitdepth = 8;
- info->palette = 0;
- info->palettesize = 0;
-}
-
-void lodepng_color_mode_cleanup(LodePNGColorMode* info)
-{
- lodepng_palette_clear(info);
-}
-
-unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source)
-{
- size_t i;
- lodepng_color_mode_cleanup(dest);
- *dest = *source;
- if(source->palette)
- {
- dest->palette = (unsigned char*)lodepng_malloc(1024);
- if(!dest->palette && source->palettesize) return 83; /*alloc fail*/
- for(i = 0; i < source->palettesize * 4; i++) dest->palette[i] = source->palette[i];
- }
- return 0;
-}
-
-static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b)
-{
- size_t i;
- if(a->colortype != b->colortype) return 0;
- if(a->bitdepth != b->bitdepth) return 0;
- if(a->key_defined != b->key_defined) return 0;
- if(a->key_defined)
- {
- if(a->key_r != b->key_r) return 0;
- if(a->key_g != b->key_g) return 0;
- if(a->key_b != b->key_b) return 0;
- }
- if(a->palettesize != b->palettesize) return 0;
- for(i = 0; i < a->palettesize * 4; i++)
- {
- if(a->palette[i] != b->palette[i]) return 0;
- }
- return 1;
-}
-
-void lodepng_palette_clear(LodePNGColorMode* info)
-{
- if(info->palette) lodepng_free(info->palette);
- info->palette = 0;
- info->palettesize = 0;
-}
-
-unsigned lodepng_palette_add(LodePNGColorMode* info,
- unsigned char r, unsigned char g, unsigned char b, unsigned char a)
-{
- unsigned char* data;
- /*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with
- the max of 256 colors, it'll have the exact alloc size*/
- if(!info->palette) /*allocate palette if empty*/
- {
- /*room for 256 colors with 4 bytes each*/
- data = (unsigned char*)lodepng_realloc(info->palette, 1024);
- if(!data) return 83; /*alloc fail*/
- else info->palette = data;
- }
- info->palette[4 * info->palettesize + 0] = r;
- info->palette[4 * info->palettesize + 1] = g;
- info->palette[4 * info->palettesize + 2] = b;
- info->palette[4 * info->palettesize + 3] = a;
- info->palettesize++;
- return 0;
-}
-
-unsigned lodepng_get_bpp(const LodePNGColorMode* info)
-{
- /*calculate bits per pixel out of colortype and bitdepth*/
- return lodepng_get_bpp_lct(info->colortype, info->bitdepth);
-}
-
-unsigned lodepng_get_channels(const LodePNGColorMode* info)
-{
- return getNumColorChannels(info->colortype);
-}
-
-unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info)
-{
- return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA;
-}
-
-unsigned lodepng_is_alpha_type(const LodePNGColorMode* info)
-{
- return (info->colortype & 4) != 0; /*4 or 6*/
-}
-
-unsigned lodepng_is_palette_type(const LodePNGColorMode* info)
-{
- return info->colortype == LCT_PALETTE;
-}
-
-unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info)
-{
- size_t i;
- for(i = 0; i < info->palettesize; i++)
- {
- if(info->palette[i * 4 + 3] < 255) return 1;
- }
- return 0;
-}
-
-unsigned lodepng_can_have_alpha(const LodePNGColorMode* info)
-{
- return info->key_defined
- || lodepng_is_alpha_type(info)
- || lodepng_has_palette_alpha(info);
-}
-
-size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color)
-{
- return (w * h * lodepng_get_bpp(color) + 7) / 8;
-}
-
-size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth)
-{
- return (w * h * lodepng_get_bpp_lct(colortype, bitdepth) + 7) / 8;
-}
-
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-
-static void LodePNGUnknownChunks_init(LodePNGInfo* info)
-{
- unsigned i;
- for(i = 0; i < 3; i++) info->unknown_chunks_data[i] = 0;
- for(i = 0; i < 3; i++) info->unknown_chunks_size[i] = 0;
-}
-
-static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info)
-{
- unsigned i;
- for(i = 0; i < 3; i++) lodepng_free(info->unknown_chunks_data[i]);
-}
-
-static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src)
-{
- unsigned i;
-
- LodePNGUnknownChunks_cleanup(dest);
-
- for(i = 0; i < 3; i++)
- {
- size_t j;
- dest->unknown_chunks_size[i] = src->unknown_chunks_size[i];
- dest->unknown_chunks_data[i] = (unsigned char*)lodepng_malloc(src->unknown_chunks_size[i]);
- if(!dest->unknown_chunks_data[i] && dest->unknown_chunks_size[i]) return 83; /*alloc fail*/
- for(j = 0; j < src->unknown_chunks_size[i]; j++)
- {
- dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j];
- }
- }
-
- return 0;
-}
-
-/******************************************************************************/
-
-static void LodePNGText_init(LodePNGInfo* info)
-{
- info->text_num = 0;
- info->text_keys = NULL;
- info->text_strings = NULL;
-}
-
-static void LodePNGText_cleanup(LodePNGInfo* info)
-{
- size_t i;
- for(i = 0; i < info->text_num; i++)
- {
- string_cleanup(&info->text_keys[i]);
- string_cleanup(&info->text_strings[i]);
- }
- lodepng_free(info->text_keys);
- lodepng_free(info->text_strings);
-}
-
-static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source)
-{
- size_t i = 0;
- dest->text_keys = 0;
- dest->text_strings = 0;
- dest->text_num = 0;
- for(i = 0; i < source->text_num; i++)
- {
- CERROR_TRY_RETURN(lodepng_add_text(dest, source->text_keys[i], source->text_strings[i]));
- }
- return 0;
-}
-
-void lodepng_clear_text(LodePNGInfo* info)
-{
- LodePNGText_cleanup(info);
-}
-
-unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str)
-{
- char** new_keys = (char**)(lodepng_realloc(info->text_keys, sizeof(char*) * (info->text_num + 1)));
- char** new_strings = (char**)(lodepng_realloc(info->text_strings, sizeof(char*) * (info->text_num + 1)));
- if(!new_keys || !new_strings)
- {
- lodepng_free(new_keys);
- lodepng_free(new_strings);
- return 83; /*alloc fail*/
- }
-
- info->text_num++;
- info->text_keys = new_keys;
- info->text_strings = new_strings;
-
- string_init(&info->text_keys[info->text_num - 1]);
- string_set(&info->text_keys[info->text_num - 1], key);
-
- string_init(&info->text_strings[info->text_num - 1]);
- string_set(&info->text_strings[info->text_num - 1], str);
-
- return 0;
-}
-
-/******************************************************************************/
-
-static void LodePNGIText_init(LodePNGInfo* info)
-{
- info->itext_num = 0;
- info->itext_keys = NULL;
- info->itext_langtags = NULL;
- info->itext_transkeys = NULL;
- info->itext_strings = NULL;
-}
-
-static void LodePNGIText_cleanup(LodePNGInfo* info)
-{
- size_t i;
- for(i = 0; i < info->itext_num; i++)
- {
- string_cleanup(&info->itext_keys[i]);
- string_cleanup(&info->itext_langtags[i]);
- string_cleanup(&info->itext_transkeys[i]);
- string_cleanup(&info->itext_strings[i]);
- }
- lodepng_free(info->itext_keys);
- lodepng_free(info->itext_langtags);
- lodepng_free(info->itext_transkeys);
- lodepng_free(info->itext_strings);
-}
-
-static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source)
-{
- size_t i = 0;
- dest->itext_keys = 0;
- dest->itext_langtags = 0;
- dest->itext_transkeys = 0;
- dest->itext_strings = 0;
- dest->itext_num = 0;
- for(i = 0; i < source->itext_num; i++)
- {
- CERROR_TRY_RETURN(lodepng_add_itext(dest, source->itext_keys[i], source->itext_langtags[i],
- source->itext_transkeys[i], source->itext_strings[i]));
- }
- return 0;
-}
-
-void lodepng_clear_itext(LodePNGInfo* info)
-{
- LodePNGIText_cleanup(info);
-}
-
-unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
- const char* transkey, const char* str)
-{
- char** new_keys = (char**)(lodepng_realloc(info->itext_keys, sizeof(char*) * (info->itext_num + 1)));
- char** new_langtags = (char**)(lodepng_realloc(info->itext_langtags, sizeof(char*) * (info->itext_num + 1)));
- char** new_transkeys = (char**)(lodepng_realloc(info->itext_transkeys, sizeof(char*) * (info->itext_num + 1)));
- char** new_strings = (char**)(lodepng_realloc(info->itext_strings, sizeof(char*) * (info->itext_num + 1)));
- if(!new_keys || !new_langtags || !new_transkeys || !new_strings)
- {
- lodepng_free(new_keys);
- lodepng_free(new_langtags);
- lodepng_free(new_transkeys);
- lodepng_free(new_strings);
- return 83; /*alloc fail*/
- }
-
- info->itext_num++;
- info->itext_keys = new_keys;
- info->itext_langtags = new_langtags;
- info->itext_transkeys = new_transkeys;
- info->itext_strings = new_strings;
-
- string_init(&info->itext_keys[info->itext_num - 1]);
- string_set(&info->itext_keys[info->itext_num - 1], key);
-
- string_init(&info->itext_langtags[info->itext_num - 1]);
- string_set(&info->itext_langtags[info->itext_num - 1], langtag);
-
- string_init(&info->itext_transkeys[info->itext_num - 1]);
- string_set(&info->itext_transkeys[info->itext_num - 1], transkey);
-
- string_init(&info->itext_strings[info->itext_num - 1]);
- string_set(&info->itext_strings[info->itext_num - 1], str);
-
- return 0;
-}
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-
-void lodepng_info_init(LodePNGInfo* info)
-{
- lodepng_color_mode_init(&info->color);
- info->interlace_method = 0;
- info->compression_method = 0;
- info->filter_method = 0;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- info->background_defined = 0;
- info->background_r = info->background_g = info->background_b = 0;
-
- LodePNGText_init(info);
- LodePNGIText_init(info);
-
- info->time_defined = 0;
- info->phys_defined = 0;
-
- LodePNGUnknownChunks_init(info);
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-}
-
-void lodepng_info_cleanup(LodePNGInfo* info)
-{
- lodepng_color_mode_cleanup(&info->color);
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- LodePNGText_cleanup(info);
- LodePNGIText_cleanup(info);
-
- LodePNGUnknownChunks_cleanup(info);
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-}
-
-unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source)
-{
- lodepng_info_cleanup(dest);
- *dest = *source;
- lodepng_color_mode_init(&dest->color);
- CERROR_TRY_RETURN(lodepng_color_mode_copy(&dest->color, &source->color));
-
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- CERROR_TRY_RETURN(LodePNGText_copy(dest, source));
- CERROR_TRY_RETURN(LodePNGIText_copy(dest, source));
-
- LodePNGUnknownChunks_init(dest);
- CERROR_TRY_RETURN(LodePNGUnknownChunks_copy(dest, source));
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
- return 0;
-}
-
-void lodepng_info_swap(LodePNGInfo* a, LodePNGInfo* b)
-{
- LodePNGInfo temp = *a;
- *a = *b;
- *b = temp;
-}
-
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*index: bitgroup index, bits: bitgroup size(1, 2 or 4), in: bitgroup value, out: octet array to add bits to*/
-static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in)
-{
- unsigned m = bits == 1 ? 7 : bits == 2 ? 3 : 1; /*8 / bits - 1*/
- /*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/
- unsigned p = index & m;
- in &= (1 << bits) - 1; /*filter out any other bits of the input value*/
- in = in << (bits * (m - p));
- if(p == 0) out[index * bits / 8] = in;
- else out[index * bits / 8] |= in;
-}
-
-typedef struct ColorTree ColorTree;
-
-/*
-One node of a color tree
-This is the data structure used to count the number of unique colors and to get a palette
-index for a color. It's like an octree, but because the alpha channel is used too, each
-node has 16 instead of 8 children.
-*/
-struct ColorTree
-{
- ColorTree* children[16]; /*up to 16 pointers to ColorTree of next level*/
- int index; /*the payload. Only has a meaningful value if this is in the last level*/
-};
-
-static void color_tree_init(ColorTree* tree)
-{
- int i;
- for(i = 0; i < 16; i++) tree->children[i] = 0;
- tree->index = -1;
-}
-
-static void color_tree_cleanup(ColorTree* tree)
-{
- int i;
- for(i = 0; i < 16; i++)
- {
- if(tree->children[i])
- {
- color_tree_cleanup(tree->children[i]);
- lodepng_free(tree->children[i]);
- }
- }
-}
-
-/*returns -1 if color not present, its index otherwise*/
-static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a)
-{
- int bit = 0;
- for(bit = 0; bit < 8; bit++)
- {
- int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1);
- if(!tree->children[i]) return -1;
- else tree = tree->children[i];
- }
- return tree ? tree->index : -1;
-}
-
-#ifdef LODEPNG_COMPILE_ENCODER
-static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a)
-{
- return color_tree_get(tree, r, g, b, a) >= 0;
-}
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-/*color is not allowed to already exist.
-Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")*/
-static void color_tree_add(ColorTree* tree,
- unsigned char r, unsigned char g, unsigned char b, unsigned char a, int index)
-{
- int bit;
- for(bit = 0; bit < 8; bit++)
- {
- int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1);
- if(!tree->children[i])
- {
- tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree));
- color_tree_init(tree->children[i]);
- }
- tree = tree->children[i];
- }
- tree->index = index;
-}
-
-/*put a pixel, given its RGBA color, into image of any color type*/
-static unsigned rgba8ToPixel(unsigned char* out, size_t i,
- const LodePNGColorMode* mode, ColorTree* tree /*for palette*/,
- unsigned char r, unsigned char g, unsigned char b, unsigned char a)
-{
- if(mode->colortype == LCT_GREY)
- {
- unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/;
- if(mode->bitdepth == 8) out[i] = grey;
- else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = grey;
- else
- {
- /*take the most significant bits of grey*/
- grey = (grey >> (8 - mode->bitdepth)) & ((1 << mode->bitdepth) - 1);
- addColorBits(out, i, mode->bitdepth, grey);
- }
- }
- else if(mode->colortype == LCT_RGB)
- {
- if(mode->bitdepth == 8)
- {
- out[i * 3 + 0] = r;
- out[i * 3 + 1] = g;
- out[i * 3 + 2] = b;
- }
- else
- {
- out[i * 6 + 0] = out[i * 6 + 1] = r;
- out[i * 6 + 2] = out[i * 6 + 3] = g;
- out[i * 6 + 4] = out[i * 6 + 5] = b;
- }
- }
- else if(mode->colortype == LCT_PALETTE)
- {
- int index = color_tree_get(tree, r, g, b, a);
- if(index < 0) return 82; /*color not in palette*/
- if(mode->bitdepth == 8) out[i] = index;
- else addColorBits(out, i, mode->bitdepth, index);
- }
- else if(mode->colortype == LCT_GREY_ALPHA)
- {
- unsigned char grey = r; /*((unsigned short)r + g + b) / 3*/;
- if(mode->bitdepth == 8)
- {
- out[i * 2 + 0] = grey;
- out[i * 2 + 1] = a;
- }
- else if(mode->bitdepth == 16)
- {
- out[i * 4 + 0] = out[i * 4 + 1] = grey;
- out[i * 4 + 2] = out[i * 4 + 3] = a;
- }
- }
- else if(mode->colortype == LCT_RGBA)
- {
- if(mode->bitdepth == 8)
- {
- out[i * 4 + 0] = r;
- out[i * 4 + 1] = g;
- out[i * 4 + 2] = b;
- out[i * 4 + 3] = a;
- }
- else
- {
- out[i * 8 + 0] = out[i * 8 + 1] = r;
- out[i * 8 + 2] = out[i * 8 + 3] = g;
- out[i * 8 + 4] = out[i * 8 + 5] = b;
- out[i * 8 + 6] = out[i * 8 + 7] = a;
- }
- }
-
- return 0; /*no error*/
-}
-
-/*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/
-static unsigned rgba16ToPixel(unsigned char* out, size_t i,
- const LodePNGColorMode* mode,
- unsigned short r, unsigned short g, unsigned short b, unsigned short a)
-{
- if(mode->bitdepth != 16) return 85; /*must be 16 for this function*/
- if(mode->colortype == LCT_GREY)
- {
- unsigned short grey = r; /*((unsigned)r + g + b) / 3*/;
- out[i * 2 + 0] = (grey >> 8) & 255;
- out[i * 2 + 1] = grey & 255;
- }
- else if(mode->colortype == LCT_RGB)
- {
- out[i * 6 + 0] = (r >> 8) & 255;
- out[i * 6 + 1] = r & 255;
- out[i * 6 + 2] = (g >> 8) & 255;
- out[i * 6 + 3] = g & 255;
- out[i * 6 + 4] = (b >> 8) & 255;
- out[i * 6 + 5] = b & 255;
- }
- else if(mode->colortype == LCT_GREY_ALPHA)
- {
- unsigned short grey = r; /*((unsigned)r + g + b) / 3*/;
- out[i * 4 + 0] = (grey >> 8) & 255;
- out[i * 4 + 1] = grey & 255;
- out[i * 4 + 2] = (a >> 8) & 255;
- out[i * 4 + 3] = a & 255;
- }
- else if(mode->colortype == LCT_RGBA)
- {
- out[i * 8 + 0] = (r >> 8) & 255;
- out[i * 8 + 1] = r & 255;
- out[i * 8 + 2] = (g >> 8) & 255;
- out[i * 8 + 3] = g & 255;
- out[i * 8 + 4] = (b >> 8) & 255;
- out[i * 8 + 5] = b & 255;
- out[i * 8 + 6] = (a >> 8) & 255;
- out[i * 8 + 7] = a & 255;
- }
-
- return 0; /*no error*/
-}
-
-/*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/
-static unsigned getPixelColorRGBA8(unsigned char* r, unsigned char* g,
- unsigned char* b, unsigned char* a,
- const unsigned char* in, size_t i,
- const LodePNGColorMode* mode,
- unsigned fix_png)
-{
- if(mode->colortype == LCT_GREY)
- {
- if(mode->bitdepth == 8)
- {
- *r = *g = *b = in[i];
- if(mode->key_defined && *r == mode->key_r) *a = 0;
- else *a = 255;
- }
- else if(mode->bitdepth == 16)
- {
- *r = *g = *b = in[i * 2 + 0];
- if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
- else *a = 255;
- }
- else
- {
- unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
- size_t j = i * mode->bitdepth;
- unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
- *r = *g = *b = (value * 255) / highest;
- if(mode->key_defined && value == mode->key_r) *a = 0;
- else *a = 255;
- }
- }
- else if(mode->colortype == LCT_RGB)
- {
- if(mode->bitdepth == 8)
- {
- *r = in[i * 3 + 0]; *g = in[i * 3 + 1]; *b = in[i * 3 + 2];
- if(mode->key_defined && *r == mode->key_r && *g == mode->key_g && *b == mode->key_b) *a = 0;
- else *a = 255;
- }
- else
- {
- *r = in[i * 6 + 0];
- *g = in[i * 6 + 2];
- *b = in[i * 6 + 4];
- if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
- && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
- && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
- else *a = 255;
- }
- }
- else if(mode->colortype == LCT_PALETTE)
- {
- unsigned index;
- if(mode->bitdepth == 8) index = in[i];
- else
- {
- size_t j = i * mode->bitdepth;
- index = readBitsFromReversedStream(&j, in, mode->bitdepth);
- }
-
- if(index >= mode->palettesize)
- {
- /*This is an error according to the PNG spec, but fix_png can ignore it*/
- if(!fix_png) return (mode->bitdepth == 8 ? 46 : 47); /*index out of palette*/
- *r = *g = *b = 0;
- *a = 255;
- }
- else
- {
- *r = mode->palette[index * 4 + 0];
- *g = mode->palette[index * 4 + 1];
- *b = mode->palette[index * 4 + 2];
- *a = mode->palette[index * 4 + 3];
- }
- }
- else if(mode->colortype == LCT_GREY_ALPHA)
- {
- if(mode->bitdepth == 8)
- {
- *r = *g = *b = in[i * 2 + 0];
- *a = in[i * 2 + 1];
- }
- else
- {
- *r = *g = *b = in[i * 4 + 0];
- *a = in[i * 4 + 2];
- }
- }
- else if(mode->colortype == LCT_RGBA)
- {
- if(mode->bitdepth == 8)
- {
- *r = in[i * 4 + 0];
- *g = in[i * 4 + 1];
- *b = in[i * 4 + 2];
- *a = in[i * 4 + 3];
- }
- else
- {
- *r = in[i * 8 + 0];
- *g = in[i * 8 + 2];
- *b = in[i * 8 + 4];
- *a = in[i * 8 + 6];
- }
- }
-
- return 0; /*no error*/
-}
-
-/*Similar to getPixelColorRGBA8, but with all the for loops inside of the color
-mode test cases, optimized to convert the colors much faster, when converting
-to RGBA or RGB with 8 bit per cannel. buffer must be RGBA or RGB output with
-enough memory, if has_alpha is true the output is RGBA. mode has the color mode
-of the input buffer.*/
-static unsigned getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels,
- unsigned has_alpha, const unsigned char* in,
- const LodePNGColorMode* mode,
- unsigned fix_png)
-{
- unsigned num_channels = has_alpha ? 4 : 3;
- size_t i;
- if(mode->colortype == LCT_GREY)
- {
- if(mode->bitdepth == 8)
- {
- for(i = 0; i < numpixels; i++, buffer += num_channels)
- {
- buffer[0] = buffer[1] = buffer[2] = in[i];
- if(has_alpha) buffer[3] = mode->key_defined && in[i] == mode->key_r ? 0 : 255;
- }
- }
- else if(mode->bitdepth == 16)
- {
- for(i = 0; i < numpixels; i++, buffer += num_channels)
- {
- buffer[0] = buffer[1] = buffer[2] = in[i * 2];
- if(has_alpha) buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255;
- }
- }
- else
- {
- unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/
- size_t j = 0;
- for(i = 0; i < numpixels; i++, buffer += num_channels)
- {
- unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth);
- buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest;
- if(has_alpha) buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255;
- }
- }
- }
- else if(mode->colortype == LCT_RGB)
- {
- if(mode->bitdepth == 8)
- {
- for(i = 0; i < numpixels; i++, buffer += num_channels)
- {
- buffer[0] = in[i * 3 + 0];
- buffer[1] = in[i * 3 + 1];
- buffer[2] = in[i * 3 + 2];
- if(has_alpha) buffer[3] = mode->key_defined && buffer[0] == mode->key_r
- && buffer[1]== mode->key_g && buffer[2] == mode->key_b ? 0 : 255;
- }
- }
- else
- {
- for(i = 0; i < numpixels; i++, buffer += num_channels)
- {
- buffer[0] = in[i * 6 + 0];
- buffer[1] = in[i * 6 + 2];
- buffer[2] = in[i * 6 + 4];
- if(has_alpha) buffer[3] = mode->key_defined
- && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
- && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
- && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b ? 0 : 255;
- }
- }
- }
- else if(mode->colortype == LCT_PALETTE)
- {
- unsigned index;
- size_t j = 0;
- for(i = 0; i < numpixels; i++, buffer += num_channels)
- {
- if(mode->bitdepth == 8) index = in[i];
- else index = readBitsFromReversedStream(&j, in, mode->bitdepth);
-
- if(index >= mode->palettesize)
- {
- /*This is an error according to the PNG spec, but fix_png can ignore it*/
- if(!fix_png) return (mode->bitdepth == 8 ? 46 : 47); /*index out of palette*/
- buffer[0] = buffer[1] = buffer[2] = 0;
- if(has_alpha) buffer[3] = 255;
- }
- else
- {
- buffer[0] = mode->palette[index * 4 + 0];
- buffer[1] = mode->palette[index * 4 + 1];
- buffer[2] = mode->palette[index * 4 + 2];
- if(has_alpha) buffer[3] = mode->palette[index * 4 + 3];
- }
- }
- }
- else if(mode->colortype == LCT_GREY_ALPHA)
- {
- if(mode->bitdepth == 8)
- {
- for(i = 0; i < numpixels; i++, buffer += num_channels)
- {
- buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0];
- if(has_alpha) buffer[3] = in[i * 2 + 1];
- }
- }
- else
- {
- for(i = 0; i < numpixels; i++, buffer += num_channels)
- {
- buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
- if(has_alpha) buffer[3] = in[i * 4 + 2];
- }
- }
- }
- else if(mode->colortype == LCT_RGBA)
- {
- if(mode->bitdepth == 8)
- {
- for(i = 0; i < numpixels; i++, buffer += num_channels)
- {
- buffer[0] = in[i * 4 + 0];
- buffer[1] = in[i * 4 + 1];
- buffer[2] = in[i * 4 + 2];
- if(has_alpha) buffer[3] = in[i * 4 + 3];
- }
- }
- else
- {
- for(i = 0; i < numpixels; i++, buffer += num_channels)
- {
- buffer[0] = in[i * 8 + 0];
- buffer[1] = in[i * 8 + 2];
- buffer[2] = in[i * 8 + 4];
- if(has_alpha) buffer[3] = in[i * 8 + 6];
- }
- }
- }
-
- return 0; /*no error*/
-}
-
-/*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with
-given color type, but the given color type must be 16-bit itself.*/
-static unsigned getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a,
- const unsigned char* in, size_t i, const LodePNGColorMode* mode)
-{
- if(mode->bitdepth != 16) return 85; /*error: this function only supports 16-bit input*/
-
- if(mode->colortype == LCT_GREY)
- {
- *r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1];
- if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0;
- else *a = 65535;
- }
- else if(mode->colortype == LCT_RGB)
- {
- *r = 256 * in[i * 6 + 0] + in[i * 6 + 1];
- *g = 256 * in[i * 6 + 2] + in[i * 6 + 3];
- *b = 256 * in[i * 6 + 4] + in[i * 6 + 5];
- if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r
- && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g
- && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0;
- else *a = 65535;
- }
- else if(mode->colortype == LCT_GREY_ALPHA)
- {
- *r = *g = *b = 256 * in[i * 4 + 0] + in[i * 4 + 1];
- *a = 256 * in[i * 4 + 2] + in[i * 4 + 3];
- }
- else if(mode->colortype == LCT_RGBA)
- {
- *r = 256 * in[i * 8 + 0] + in[i * 8 + 1];
- *g = 256 * in[i * 8 + 2] + in[i * 8 + 3];
- *b = 256 * in[i * 8 + 4] + in[i * 8 + 5];
- *a = 256 * in[i * 8 + 6] + in[i * 8 + 7];
- }
- else return 85; /*error: this function only supports 16-bit input, not palettes*/
-
- return 0; /*no error*/
-}
-
-/*
-converts from any color type to 24-bit or 32-bit (later maybe more supported). return value = LodePNG error code
-the out buffer must have (w * h * bpp + 7) / 8 bytes, where bpp is the bits per pixel of the output color type
-(lodepng_get_bpp) for < 8 bpp images, there may _not_ be padding bits at the end of scanlines.
-*/
-unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
- LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
- unsigned w, unsigned h, unsigned fix_png)
-{
- unsigned error = 0;
- size_t i;
- ColorTree tree;
- size_t numpixels = w * h;
-
- if(lodepng_color_mode_equal(mode_out, mode_in))
- {
- size_t numbytes = lodepng_get_raw_size(w, h, mode_in);
- for(i = 0; i < numbytes; i++) out[i] = in[i];
- return error;
- }
-
- if(mode_out->colortype == LCT_PALETTE)
- {
- size_t palsize = 1 << mode_out->bitdepth;
- if(mode_out->palettesize < palsize) palsize = mode_out->palettesize;
- color_tree_init(&tree);
- for(i = 0; i < palsize; i++)
- {
- unsigned char* p = &mode_out->palette[i * 4];
- color_tree_add(&tree, p[0], p[1], p[2], p[3], i);
- }
- }
-
- if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16)
- {
- for(i = 0; i < numpixels; i++)
- {
- unsigned short r = 0, g = 0, b = 0, a = 0;
- error = getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in);
- if(error) break;
- error = rgba16ToPixel(out, i, mode_out, r, g, b, a);
- if(error) break;
- }
- }
- else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA)
- {
- error = getPixelColorsRGBA8(out, numpixels, 1, in, mode_in, fix_png);
- }
- else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB)
- {
- error = getPixelColorsRGBA8(out, numpixels, 0, in, mode_in, fix_png);
- }
- else
- {
- unsigned char r = 0, g = 0, b = 0, a = 0;
- for(i = 0; i < numpixels; i++)
- {
- error = getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in, fix_png);
- if(error) break;
- error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a);
- if(error) break;
- }
- }
-
- if(mode_out->colortype == LCT_PALETTE)
- {
- color_tree_cleanup(&tree);
- }
-
- return error;
-}
-
-#ifdef LODEPNG_COMPILE_ENCODER
-
-typedef struct ColorProfile
-{
- unsigned char sixteenbit; /*needs more than 8 bits per channel*/
- unsigned char sixteenbit_done;
-
-
- unsigned char colored; /*not greyscale*/
- unsigned char colored_done;
-
- unsigned char key; /*a color key is required, or more*/
- unsigned short key_r; /*these values are always in 16-bit bitdepth in the profile*/
- unsigned short key_g;
- unsigned short key_b;
- unsigned char alpha; /*alpha channel, or alpha palette, required*/
- unsigned char alpha_done;
-
- unsigned numcolors;
- ColorTree tree; /*for listing the counted colors, up to 256*/
- unsigned char* palette; /*size 1024. Remember up to the first 256 RGBA colors*/
- unsigned maxnumcolors; /*if more than that amount counted*/
- unsigned char numcolors_done;
-
- unsigned greybits; /*amount of bits required for greyscale (1, 2, 4, 8). Does not take 16 bit into account.*/
- unsigned char greybits_done;
-
-} ColorProfile;
-
-static void color_profile_init(ColorProfile* profile, const LodePNGColorMode* mode)
-{
- profile->sixteenbit = 0;
- profile->sixteenbit_done = mode->bitdepth == 16 ? 0 : 1;
-
- profile->colored = 0;
- profile->colored_done = lodepng_is_greyscale_type(mode) ? 1 : 0;
-
- profile->key = 0;
- profile->alpha = 0;
- profile->alpha_done = lodepng_can_have_alpha(mode) ? 0 : 1;
-
- profile->numcolors = 0;
- color_tree_init(&profile->tree);
- profile->palette = (unsigned char*)lodepng_malloc(1024);
- profile->maxnumcolors = 257;
- if(lodepng_get_bpp(mode) <= 8)
- {
- int bpp = lodepng_get_bpp(mode);
- profile->maxnumcolors = bpp == 1 ? 2 : (bpp == 2 ? 4 : (bpp == 4 ? 16 : 256));
- }
- profile->numcolors_done = 0;
-
- profile->greybits = 1;
- profile->greybits_done = lodepng_get_bpp(mode) == 1 ? 1 : 0;
-}
-
-static void color_profile_cleanup(ColorProfile* profile)
-{
- color_tree_cleanup(&profile->tree);
- lodepng_free(profile->palette);
-}
-
-/*function used for debug purposes with C++*/
-/*void printColorProfile(ColorProfile* p)
-{
- std::cout << "sixteenbit: " << (int)p->sixteenbit << std::endl;
- std::cout << "sixteenbit_done: " << (int)p->sixteenbit_done << std::endl;
- std::cout << "colored: " << (int)p->colored << std::endl;
- std::cout << "colored_done: " << (int)p->colored_done << std::endl;
- std::cout << "key: " << (int)p->key << std::endl;
- std::cout << "key_r: " << (int)p->key_r << std::endl;
- std::cout << "key_g: " << (int)p->key_g << std::endl;
- std::cout << "key_b: " << (int)p->key_b << std::endl;
- std::cout << "alpha: " << (int)p->alpha << std::endl;
- std::cout << "alpha_done: " << (int)p->alpha_done << std::endl;
- std::cout << "numcolors: " << (int)p->numcolors << std::endl;
- std::cout << "maxnumcolors: " << (int)p->maxnumcolors << std::endl;
- std::cout << "numcolors_done: " << (int)p->numcolors_done << std::endl;
- std::cout << "greybits: " << (int)p->greybits << std::endl;
- std::cout << "greybits_done: " << (int)p->greybits_done << std::endl;
-}*/
-
-/*Returns how many bits needed to represent given value (max 8 bit)*/
-unsigned getValueRequiredBits(unsigned short value)
-{
- if(value == 0 || value == 255) return 1;
- /*The scaling of 2-bit and 4-bit values uses multiples of 85 and 17*/
- if(value % 17 == 0) return value % 85 == 0 ? 2 : 4;
- return 8;
-}
-
-/*profile must already have been inited with mode.
-It's ok to set some parameters of profile to done already.*/
-static unsigned get_color_profile(ColorProfile* profile,
- const unsigned char* in,
- size_t numpixels /*must be full image size, for certain filesize based choices*/,
- const LodePNGColorMode* mode,
- unsigned fix_png)
-{
- unsigned error = 0;
- size_t i;
-
- if(mode->bitdepth == 16)
- {
- for(i = 0; i < numpixels; i++)
- {
- unsigned short r, g, b, a;
- error = getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode);
- if(error) break;
-
- /*a color is considered good for 8-bit if the first byte and the second byte are equal,
- (so if it's divisible through 257), NOT necessarily if the second byte is 0*/
- if(!profile->sixteenbit_done
- && (((r & 255) != ((r >> 8) & 255))
- || ((g & 255) != ((g >> 8) & 255))
- || ((b & 255) != ((b >> 8) & 255))))
- {
- profile->sixteenbit = 1;
- profile->sixteenbit_done = 1;
- profile->greybits_done = 1; /*greybits is not applicable anymore at 16-bit*/
- profile->numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/
- }
-
- if(!profile->colored_done && (r != g || r != b))
- {
- profile->colored = 1;
- profile->colored_done = 1;
- profile->greybits_done = 1; /*greybits is not applicable anymore*/
- }
-
- if(!profile->alpha_done && a != 65535)
- {
- /*only use color key if numpixels large enough to justify tRNS chunk size*/
- if(a == 0 && numpixels > 16 && !(profile->key && (r != profile->key_r || g != profile->key_g || b != profile->key_b)))
- {
- if(!profile->alpha && !profile->key)
- {
- profile->key = 1;
- profile->key_r = r;
- profile->key_g = g;
- profile->key_b = b;
- }
- }
- else
- {
- profile->alpha = 1;
- profile->alpha_done = 1;
- profile->greybits_done = 1; /*greybits is not applicable anymore*/
- }
- }
-
- /* Color key cannot be used if an opaque pixel also has that RGB color. */
- if(!profile->alpha_done && a == 65535 && profile->key
- && r == profile->key_r && g == profile->key_g && b == profile->key_b)
- {
- profile->alpha = 1;
- profile->alpha_done = 1;
- profile->greybits_done = 1; /*greybits is not applicable anymore*/
- }
-
- if(!profile->greybits_done)
- {
- /*assuming 8-bit r, this test does not care about 16-bit*/
- unsigned bits = getValueRequiredBits(r);
- if(bits > profile->greybits) profile->greybits = bits;
- if(profile->greybits >= 8) profile->greybits_done = 1;
- }
-
- if(!profile->numcolors_done)
- {
- /*assuming 8-bit rgba, this test does not care about 16-bit*/
- if(!color_tree_has(&profile->tree, (unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a))
- {
- color_tree_add(&profile->tree, (unsigned char)r, (unsigned char)g, (unsigned char)b, (unsigned char)a,
- profile->numcolors);
- if(profile->numcolors < 256)
- {
- unsigned char* p = profile->palette;
- unsigned i = profile->numcolors;
- p[i * 4 + 0] = (unsigned char)r;
- p[i * 4 + 1] = (unsigned char)g;
- p[i * 4 + 2] = (unsigned char)b;
- p[i * 4 + 3] = (unsigned char)a;
- }
- profile->numcolors++;
- if(profile->numcolors >= profile->maxnumcolors) profile->numcolors_done = 1;
- }
- }
-
- if(profile->alpha_done && profile->numcolors_done
- && profile->colored_done && profile->sixteenbit_done && profile->greybits_done)
- {
- break;
- }
- };
- }
- else /* < 16-bit */
- {
- for(i = 0; i < numpixels; i++)
- {
- unsigned char r = 0, g = 0, b = 0, a = 0;
- error = getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode, fix_png);
- if(error) break;
-
- if(!profile->colored_done && (r != g || r != b))
- {
- profile->colored = 1;
- profile->colored_done = 1;
- profile->greybits_done = 1; /*greybits is not applicable anymore*/
- }
-
- if(!profile->alpha_done && a != 255)
- {
- if(a == 0 && !(profile->key && (r != profile->key_r || g != profile->key_g || b != profile->key_b)))
- {
- if(!profile->key)
- {
- profile->key = 1;
- profile->key_r = r;
- profile->key_g = g;
- profile->key_b = b;
- }
- }
- else
- {
- profile->alpha = 1;
- profile->alpha_done = 1;
- profile->greybits_done = 1; /*greybits is not applicable anymore*/
- }
- }
-
- /* Color key cannot be used if an opaque pixel also has that RGB color. */
- if(!profile->alpha_done && a == 255 && profile->key
- && r == profile->key_r && g == profile->key_g && b == profile->key_b)
- {
- profile->alpha = 1;
- profile->alpha_done = 1;
- profile->greybits_done = 1; /*greybits is not applicable anymore*/
- }
-
- if(!profile->greybits_done)
- {
- unsigned bits = getValueRequiredBits(r);
- if(bits > profile->greybits) profile->greybits = bits;
- if(profile->greybits >= 8) profile->greybits_done = 1;
- }
-
- if(!profile->numcolors_done)
- {
- if(!color_tree_has(&profile->tree, r, g, b, a))
- {
-
- color_tree_add(&profile->tree, r, g, b, a, profile->numcolors);
- if(profile->numcolors < 256)
- {
- unsigned char* p = profile->palette;
- unsigned i = profile->numcolors;
- p[i * 4 + 0] = r;
- p[i * 4 + 1] = g;
- p[i * 4 + 2] = b;
- p[i * 4 + 3] = a;
- }
- profile->numcolors++;
- if(profile->numcolors >= profile->maxnumcolors) profile->numcolors_done = 1;
- }
- }
-
- if(profile->alpha_done && profile->numcolors_done && profile->colored_done && profile->greybits_done)
- {
- break;
- }
- };
- }
-
- /*make the profile's key always 16-bit for consistency*/
- if(mode->bitdepth < 16)
- {
- /*repeat each byte twice*/
- profile->key_r *= 257;
- profile->key_g *= 257;
- profile->key_b *= 257;
- }
-
- return error;
-}
-
-static void setColorKeyFrom16bit(LodePNGColorMode* mode_out, unsigned r, unsigned g, unsigned b, unsigned bitdepth)
-{
- unsigned mask = (1 << bitdepth) - 1;
- mode_out->key_defined = 1;
- mode_out->key_r = r & mask;
- mode_out->key_g = g & mask;
- mode_out->key_b = b & mask;
-}
-
-/*updates values of mode with a potentially smaller color model. mode_out should
-contain the user chosen color model, but will be overwritten with the new chosen one.*/
-unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out,
- const unsigned char* image, unsigned w, unsigned h,
- const LodePNGColorMode* mode_in,
- LodePNGAutoConvert auto_convert)
-{
- ColorProfile profile;
- unsigned error = 0;
- int no_nibbles = auto_convert == LAC_AUTO_NO_NIBBLES || auto_convert == LAC_AUTO_NO_NIBBLES_NO_PALETTE;
- int no_palette = auto_convert == LAC_AUTO_NO_PALETTE || auto_convert == LAC_AUTO_NO_NIBBLES_NO_PALETTE;
-
- if(auto_convert == LAC_ALPHA)
- {
- if(mode_out->colortype != LCT_RGBA && mode_out->colortype != LCT_GREY_ALPHA) return 0;
- }
-
- color_profile_init(&profile, mode_in);
- if(auto_convert == LAC_ALPHA)
- {
- profile.colored_done = 1;
- profile.greybits_done = 1;
- profile.numcolors_done = 1;
- profile.sixteenbit_done = 1;
- }
- error = get_color_profile(&profile, image, w * h, mode_in, 0 /*fix_png*/);
- if(!error && auto_convert == LAC_ALPHA)
- {
- if(!profile.alpha)
- {
- mode_out->colortype = (mode_out->colortype == LCT_RGBA ? LCT_RGB : LCT_GREY);
- if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth);
- }
- }
- else if(!error && auto_convert != LAC_ALPHA)
- {
- mode_out->key_defined = 0;
-
- if(profile.sixteenbit)
- {
- mode_out->bitdepth = 16;
- if(profile.alpha)
- {
- mode_out->colortype = profile.colored ? LCT_RGBA : LCT_GREY_ALPHA;
- }
- else
- {
- mode_out->colortype = profile.colored ? LCT_RGB : LCT_GREY;
- if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth);
- }
- }
- else /*less than 16 bits per channel*/
- {
- /*don't add palette overhead if image hasn't got a lot of pixels*/
- unsigned n = profile.numcolors;
- int palette_ok = !no_palette && n <= 256 && (n * 2 < w * h);
- unsigned palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8));
- int grey_ok = !profile.colored && !profile.alpha; /*grey without alpha, with potentially low bits*/
- if(palette_ok || grey_ok)
- {
- if(!palette_ok || (grey_ok && profile.greybits <= palettebits))
- {
- unsigned grey = profile.key_r;
- mode_out->colortype = LCT_GREY;
- mode_out->bitdepth = profile.greybits;
- if(profile.key) setColorKeyFrom16bit(mode_out, grey, grey, grey, mode_out->bitdepth);
- }
- else
- {
- /*fill in the palette*/
- unsigned i;
- unsigned char* p = profile.palette;
- /*remove potential earlier palette*/
- lodepng_palette_clear(mode_out);
- for(i = 0; i < profile.numcolors; i++)
- {
- error = lodepng_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2], p[i * 4 + 3]);
- if(error) break;
- }
-
- mode_out->colortype = LCT_PALETTE;
- mode_out->bitdepth = palettebits;
- }
- }
- else /*8-bit per channel*/
- {
- mode_out->bitdepth = 8;
- if(profile.alpha)
- {
- mode_out->colortype = profile.colored ? LCT_RGBA : LCT_GREY_ALPHA;
- }
- else
- {
- mode_out->colortype = profile.colored ? LCT_RGB : LCT_GREY /*LCT_GREY normally won't occur, already done earlier*/;
- if(profile.key) setColorKeyFrom16bit(mode_out, profile.key_r, profile.key_g, profile.key_b, mode_out->bitdepth);
- }
- }
- }
- }
-
- color_profile_cleanup(&profile);
-
- if(mode_out->colortype == LCT_PALETTE && mode_in->palettesize == mode_out->palettesize)
- {
- /*In this case keep the palette order of the input, so that the user can choose an optimal one*/
- size_t i;
- for(i = 0; i < mode_in->palettesize * 4; i++)
- {
- mode_out->palette[i] = mode_in->palette[i];
- }
- }
-
- if(no_nibbles && mode_out->bitdepth < 8)
- {
- /*palette can keep its small amount of colors, as long as no indices use it*/
- mode_out->bitdepth = 8;
- }
-
- return error;
-}
-
-#endif /* #ifdef LODEPNG_COMPILE_ENCODER */
-
-/*
-Paeth predicter, used by PNG filter type 4
-The parameters are of type short, but should come from unsigned chars, the shorts
-are only needed to make the paeth calculation correct.
-*/
-static unsigned char paethPredictor(short a, short b, short c)
-{
- short pa = abs(b - c);
- short pb = abs(a - c);
- short pc = abs(a + b - c - c);
-
- if(pc < pa && pc < pb) return (unsigned char)c;
- else if(pb < pa) return (unsigned char)b;
- else return (unsigned char)a;
-}
-
-/*shared values used by multiple Adam7 related functions*/
-
-static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/
-static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/
-static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/
-static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/
-
-/*
-Outputs various dimensions and positions in the image related to the Adam7 reduced images.
-passw: output containing the width of the 7 passes
-passh: output containing the height of the 7 passes
-filter_passstart: output containing the index of the start and end of each
- reduced image with filter bytes
-padded_passstart output containing the index of the start and end of each
- reduced image when without filter bytes but with padded scanlines
-passstart: output containing the index of the start and end of each reduced
- image without padding between scanlines, but still padding between the images
-w, h: width and height of non-interlaced image
-bpp: bits per pixel
-"padded" is only relevant if bpp is less than 8 and a scanline or image does not
- end at a full byte
-*/
-static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8],
- size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp)
-{
- /*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/
- unsigned i;
-
- /*calculate width and height in pixels of each pass*/
- for(i = 0; i < 7; i++)
- {
- passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i];
- passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i];
- if(passw[i] == 0) passh[i] = 0;
- if(passh[i] == 0) passw[i] = 0;
- }
-
- filter_passstart[0] = padded_passstart[0] = passstart[0] = 0;
- for(i = 0; i < 7; i++)
- {
- /*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/
- filter_passstart[i + 1] = filter_passstart[i]
- + ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0);
- /*bits padded if needed to fill full byte at end of each scanline*/
- padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8);
- /*only padded at end of reduced image*/
- passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8;
- }
-}
-
-#ifdef LODEPNG_COMPILE_DECODER
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / PNG Decoder / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*read the information from the header and store it in the LodePNGInfo. return value is error*/
-unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state,
- const unsigned char* in, size_t insize)
-{
- LodePNGInfo* info = &state->info_png;
- if(insize == 0 || in == 0)
- {
- CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/
- }
- if(insize < 29)
- {
- CERROR_RETURN_ERROR(state->error, 27); /*error: the data length is smaller than the length of a PNG header*/
- }
-
- /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/
- lodepng_info_cleanup(info);
- lodepng_info_init(info);
-
- if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71
- || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10)
- {
- CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/
- }
- if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R')
- {
- CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/
- }
-
- /*read the values given in the header*/
- *w = lodepng_read32bitInt(&in[16]);
- *h = lodepng_read32bitInt(&in[20]);
- info->color.bitdepth = in[24];
- info->color.colortype = (LodePNGColorType)in[25];
- info->compression_method = in[26];
- info->filter_method = in[27];
- info->interlace_method = in[28];
-
- if(!state->decoder.ignore_crc)
- {
- unsigned CRC = lodepng_read32bitInt(&in[29]);
- unsigned checksum = lodepng_crc32(&in[12], 17);
- if(CRC != checksum)
- {
- CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/
- }
- }
-
- /*error: only compression method 0 is allowed in the specification*/
- if(info->compression_method != 0) CERROR_RETURN_ERROR(state->error, 32);
- /*error: only filter method 0 is allowed in the specification*/
- if(info->filter_method != 0) CERROR_RETURN_ERROR(state->error, 33);
- /*error: only interlace methods 0 and 1 exist in the specification*/
- if(info->interlace_method > 1) CERROR_RETURN_ERROR(state->error, 34);
-
- state->error = checkColorValidity(info->color.colortype, info->color.bitdepth);
- return state->error;
-}
-
-static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon,
- size_t bytewidth, unsigned char filterType, size_t length)
-{
- /*
- For PNG filter method 0
- unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte,
- the filter works byte per byte (bytewidth = 1)
- precon is the previous unfiltered scanline, recon the result, scanline the current one
- the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead
- recon and scanline MAY be the same memory address! precon must be disjoint.
- */
-
- size_t i;
- switch(filterType)
- {
- case 0:
- for(i = 0; i < length; i++) recon[i] = scanline[i];
- break;
- case 1:
- for(i = 0; i < bytewidth; i++) recon[i] = scanline[i];
- for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth];
- break;
- case 2:
- if(precon)
- {
- for(i = 0; i < length; i++) recon[i] = scanline[i] + precon[i];
- }
- else
- {
- for(i = 0; i < length; i++) recon[i] = scanline[i];
- }
- break;
- case 3:
- if(precon)
- {
- for(i = 0; i < bytewidth; i++) recon[i] = scanline[i] + precon[i] / 2;
- for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2);
- }
- else
- {
- for(i = 0; i < bytewidth; i++) recon[i] = scanline[i];
- for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth] / 2;
- }
- break;
- case 4:
- if(precon)
- {
- for(i = 0; i < bytewidth; i++)
- {
- recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/
- }
- for(i = bytewidth; i < length; i++)
- {
- recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth]));
- }
- }
- else
- {
- for(i = 0; i < bytewidth; i++)
- {
- recon[i] = scanline[i];
- }
- for(i = bytewidth; i < length; i++)
- {
- /*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/
- recon[i] = (scanline[i] + recon[i - bytewidth]);
- }
- }
- break;
- default: return 36; /*error: unexisting filter type given*/
- }
- return 0;
-}
-
-static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
-{
- /*
- For PNG filter method 0
- this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times)
- out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline
- w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel
- in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes)
- */
-
- unsigned y;
- unsigned char* prevline = 0;
-
- /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
- size_t bytewidth = (bpp + 7) / 8;
- size_t linebytes = (w * bpp + 7) / 8;
-
- for(y = 0; y < h; y++)
- {
- size_t outindex = linebytes * y;
- size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
- unsigned char filterType = in[inindex];
-
- CERROR_TRY_RETURN(unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes));
-
- prevline = &out[outindex];
- }
-
- return 0;
-}
-
-/*
-in: Adam7 interlaced image, with no padding bits between scanlines, but between
- reduced images so that each reduced image starts at a byte.
-out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h
-bpp: bits per pixel
-out has the following size in bits: w * h * bpp.
-in is possibly bigger due to padding bits between reduced images.
-out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation
-(because that's likely a little bit faster)
-NOTE: comments about padding bits are only relevant if bpp < 8
-*/
-static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
-{
- unsigned passw[7], passh[7];
- size_t filter_passstart[8], padded_passstart[8], passstart[8];
- unsigned i;
-
- Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
-
- if(bpp >= 8)
- {
- for(i = 0; i < 7; i++)
- {
- unsigned x, y, b;
- size_t bytewidth = bpp / 8;
- for(y = 0; y < passh[i]; y++)
- for(x = 0; x < passw[i]; x++)
- {
- size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth;
- size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
- for(b = 0; b < bytewidth; b++)
- {
- out[pixeloutstart + b] = in[pixelinstart + b];
- }
- }
- }
- }
- else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
- {
- for(i = 0; i < 7; i++)
- {
- unsigned x, y, b;
- unsigned ilinebits = bpp * passw[i];
- unsigned olinebits = bpp * w;
- size_t obp, ibp; /*bit pointers (for out and in buffer)*/
- for(y = 0; y < passh[i]; y++)
- for(x = 0; x < passw[i]; x++)
- {
- ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
- obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
- for(b = 0; b < bpp; b++)
- {
- unsigned char bit = readBitFromReversedStream(&ibp, in);
- /*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/
- setBitOfReversedStream0(&obp, out, bit);
- }
- }
- }
- }
-}
-
-static void removePaddingBits(unsigned char* out, const unsigned char* in,
- size_t olinebits, size_t ilinebits, unsigned h)
-{
- /*
- After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need
- to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers
- for the Adam7 code, the color convert code and the output to the user.
- in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must
- have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits
- also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7
- only useful if (ilinebits - olinebits) is a value in the range 1..7
- */
- unsigned y;
- size_t diff = ilinebits - olinebits;
- size_t ibp = 0, obp = 0; /*input and output bit pointers*/
- for(y = 0; y < h; y++)
- {
- size_t x;
- for(x = 0; x < olinebits; x++)
- {
- unsigned char bit = readBitFromReversedStream(&ibp, in);
- setBitOfReversedStream(&obp, out, bit);
- }
- ibp += diff;
- }
-}
-
-/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from
-the IDAT chunks (with filter index bytes and possible padding bits)
-return value is error*/
-static unsigned postProcessScanlines(unsigned char* out, unsigned char* in,
- unsigned w, unsigned h, const LodePNGInfo* info_png)
-{
- /*
- This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype.
- Steps:
- *) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8)
- *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace
- NOTE: the in buffer will be overwritten with intermediate data!
- */
- unsigned bpp = lodepng_get_bpp(&info_png->color);
- if(bpp == 0) return 31; /*error: invalid colortype*/
-
- if(info_png->interlace_method == 0)
- {
- if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
- {
- CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp));
- removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h);
- }
- /*we can immediatly filter into the out buffer, no other steps needed*/
- else CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp));
- }
- else /*interlace_method is 1 (Adam7)*/
- {
- unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8];
- unsigned i;
-
- Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
-
- for(i = 0; i < 7; i++)
- {
- CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp));
- /*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline,
- move bytes instead of bits or move not at all*/
- if(bpp < 8)
- {
- /*remove padding bits in scanlines; after this there still may be padding
- bits between the different reduced images: each reduced image still starts nicely at a byte*/
- removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp,
- ((passw[i] * bpp + 7) / 8) * 8, passh[i]);
- }
- }
-
- Adam7_deinterlace(out, in, w, h, bpp);
- }
-
- return 0;
-}
-
-static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength)
-{
- unsigned pos = 0, i;
- if(color->palette) lodepng_free(color->palette);
- color->palettesize = chunkLength / 3;
- color->palette = (unsigned char*)lodepng_malloc(4 * color->palettesize);
- if(!color->palette && color->palettesize)
- {
- color->palettesize = 0;
- return 83; /*alloc fail*/
- }
- if(color->palettesize > 256) return 38; /*error: palette too big*/
-
- for(i = 0; i < color->palettesize; i++)
- {
- color->palette[4 * i + 0] = data[pos++]; /*R*/
- color->palette[4 * i + 1] = data[pos++]; /*G*/
- color->palette[4 * i + 2] = data[pos++]; /*B*/
- color->palette[4 * i + 3] = 255; /*alpha*/
- }
-
- return 0; /* OK */
-}
-
-static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength)
-{
- unsigned i;
- if(color->colortype == LCT_PALETTE)
- {
- /*error: more alpha values given than there are palette entries*/
- if(chunkLength > color->palettesize) return 38;
-
- for(i = 0; i < chunkLength; i++) color->palette[4 * i + 3] = data[i];
- }
- else if(color->colortype == LCT_GREY)
- {
- /*error: this chunk must be 2 bytes for greyscale image*/
- if(chunkLength != 2) return 30;
-
- color->key_defined = 1;
- color->key_r = color->key_g = color->key_b = 256 * data[0] + data[1];
- }
- else if(color->colortype == LCT_RGB)
- {
- /*error: this chunk must be 6 bytes for RGB image*/
- if(chunkLength != 6) return 41;
-
- color->key_defined = 1;
- color->key_r = 256 * data[0] + data[1];
- color->key_g = 256 * data[2] + data[3];
- color->key_b = 256 * data[4] + data[5];
- }
- else return 42; /*error: tRNS chunk not allowed for other color models*/
-
- return 0; /* OK */
-}
-
-
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-/*background color chunk (bKGD)*/
-static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
-{
- if(info->color.colortype == LCT_PALETTE)
- {
- /*error: this chunk must be 1 byte for indexed color image*/
- if(chunkLength != 1) return 43;
-
- info->background_defined = 1;
- info->background_r = info->background_g = info->background_b = data[0];
- }
- else if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA)
- {
- /*error: this chunk must be 2 bytes for greyscale image*/
- if(chunkLength != 2) return 44;
-
- info->background_defined = 1;
- info->background_r = info->background_g = info->background_b
- = 256 * data[0] + data[1];
- }
- else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA)
- {
- /*error: this chunk must be 6 bytes for greyscale image*/
- if(chunkLength != 6) return 45;
-
- info->background_defined = 1;
- info->background_r = 256 * data[0] + data[1];
- info->background_g = 256 * data[2] + data[3];
- info->background_b = 256 * data[4] + data[5];
- }
-
- return 0; /* OK */
-}
-
-/*text chunk (tEXt)*/
-static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
-{
- unsigned error = 0;
- char *key = 0, *str = 0;
- unsigned i;
-
- while(!error) /*not really a while loop, only used to break on error*/
- {
- unsigned length, string2_begin;
-
- length = 0;
- while(length < chunkLength && data[length] != 0) length++;
- /*even though it's not allowed by the standard, no error is thrown if
- there's no null termination char, if the text is empty*/
- if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
-
- key = (char*)lodepng_malloc(length + 1);
- if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
-
- key[length] = 0;
- for(i = 0; i < length; i++) key[i] = data[i];
-
- string2_begin = length + 1; /*skip keyword null terminator*/
-
- length = chunkLength < string2_begin ? 0 : chunkLength - string2_begin;
- str = (char*)lodepng_malloc(length + 1);
- if(!str) CERROR_BREAK(error, 83); /*alloc fail*/
-
- str[length] = 0;
- for(i = 0; i < length; i++) str[i] = data[string2_begin + i];
-
- error = lodepng_add_text(info, key, str);
-
- break;
- }
-
- lodepng_free(key);
- lodepng_free(str);
-
- return error;
-}
-
-/*compressed text chunk (zTXt)*/
-static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
- const unsigned char* data, size_t chunkLength)
-{
- unsigned error = 0;
- unsigned i;
-
- unsigned length, string2_begin;
- char *key = 0;
- ucvector decoded;
-
- ucvector_init(&decoded);
-
- while(!error) /*not really a while loop, only used to break on error*/
- {
- for(length = 0; length < chunkLength && data[length] != 0; length++) ;
- if(length + 2 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
- if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
-
- key = (char*)lodepng_malloc(length + 1);
- if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
-
- key[length] = 0;
- for(i = 0; i < length; i++) key[i] = data[i];
-
- if(data[length + 1] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
-
- string2_begin = length + 2;
- if(string2_begin > chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/
-
- length = chunkLength - string2_begin;
- /*will fail if zlib error, e.g. if length is too small*/
- error = zlib_decompress(&decoded.data, &decoded.size,
- (unsigned char*)(&data[string2_begin]),
- length, zlibsettings);
- if(error) break;
- ucvector_push_back(&decoded, 0);
-
- error = lodepng_add_text(info, key, (char*)decoded.data);
-
- break;
- }
-
- lodepng_free(key);
- ucvector_cleanup(&decoded);
-
- return error;
-}
-
-/*international text chunk (iTXt)*/
-static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings,
- const unsigned char* data, size_t chunkLength)
-{
- unsigned error = 0;
- unsigned i;
-
- unsigned length, begin, compressed;
- char *key = 0, *langtag = 0, *transkey = 0;
- ucvector decoded;
- ucvector_init(&decoded);
-
- while(!error) /*not really a while loop, only used to break on error*/
- {
- /*Quick check if the chunk length isn't too small. Even without check
- it'd still fail with other error checks below if it's too short. This just gives a different error code.*/
- if(chunkLength < 5) CERROR_BREAK(error, 30); /*iTXt chunk too short*/
-
- /*read the key*/
- for(length = 0; length < chunkLength && data[length] != 0; length++) ;
- if(length + 3 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination char, corrupt?*/
- if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/
-
- key = (char*)lodepng_malloc(length + 1);
- if(!key) CERROR_BREAK(error, 83); /*alloc fail*/
-
- key[length] = 0;
- for(i = 0; i < length; i++) key[i] = data[i];
-
- /*read the compression method*/
- compressed = data[length + 1];
- if(data[length + 2] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/
-
- /*even though it's not allowed by the standard, no error is thrown if
- there's no null termination char, if the text is empty for the next 3 texts*/
-
- /*read the langtag*/
- begin = length + 3;
- length = 0;
- for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
-
- langtag = (char*)lodepng_malloc(length + 1);
- if(!langtag) CERROR_BREAK(error, 83); /*alloc fail*/
-
- langtag[length] = 0;
- for(i = 0; i < length; i++) langtag[i] = data[begin + i];
-
- /*read the transkey*/
- begin += length + 1;
- length = 0;
- for(i = begin; i < chunkLength && data[i] != 0; i++) length++;
-
- transkey = (char*)lodepng_malloc(length + 1);
- if(!transkey) CERROR_BREAK(error, 83); /*alloc fail*/
-
- transkey[length] = 0;
- for(i = 0; i < length; i++) transkey[i] = data[begin + i];
-
- /*read the actual text*/
- begin += length + 1;
-
- length = chunkLength < begin ? 0 : chunkLength - begin;
-
- if(compressed)
- {
- /*will fail if zlib error, e.g. if length is too small*/
- error = zlib_decompress(&decoded.data, &decoded.size,
- (unsigned char*)(&data[begin]),
- length, zlibsettings);
- if(error) break;
- if(decoded.allocsize < decoded.size) decoded.allocsize = decoded.size;
- ucvector_push_back(&decoded, 0);
- }
- else
- {
- if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(error, 83 /*alloc fail*/);
-
- decoded.data[length] = 0;
- for(i = 0; i < length; i++) decoded.data[i] = data[begin + i];
- }
-
- error = lodepng_add_itext(info, key, langtag, transkey, (char*)decoded.data);
-
- break;
- }
-
- lodepng_free(key);
- lodepng_free(langtag);
- lodepng_free(transkey);
- ucvector_cleanup(&decoded);
-
- return error;
-}
-
-static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
-{
- if(chunkLength != 7) return 73; /*invalid tIME chunk size*/
-
- info->time_defined = 1;
- info->time.year = 256 * data[0] + data[+ 1];
- info->time.month = data[2];
- info->time.day = data[3];
- info->time.hour = data[4];
- info->time.minute = data[5];
- info->time.second = data[6];
-
- return 0; /* OK */
-}
-
-static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength)
-{
- if(chunkLength != 9) return 74; /*invalid pHYs chunk size*/
-
- info->phys_defined = 1;
- info->phys_x = 16777216 * data[0] + 65536 * data[1] + 256 * data[2] + data[3];
- info->phys_y = 16777216 * data[4] + 65536 * data[5] + 256 * data[6] + data[7];
- info->phys_unit = data[8];
-
- return 0; /* OK */
-}
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-
-/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/
-static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h,
- LodePNGState* state,
- const unsigned char* in, size_t insize)
-{
- unsigned char IEND = 0;
- const unsigned char* chunk;
- size_t i;
- ucvector idat; /*the data from idat chunks*/
- ucvector scanlines;
-
- /*for unknown chunk order*/
- unsigned unknown = 0;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-
- /*provide some proper output values if error will happen*/
- *out = 0;
-
- state->error = lodepng_inspect(w, h, state, in, insize); /*reads header and resets other parameters in state->info_png*/
- if(state->error) return;
-
- ucvector_init(&idat);
- chunk = &in[33]; /*first byte of the first chunk after the header*/
-
- /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk.
- IDAT data is put at the start of the in buffer*/
- while(!IEND && !state->error)
- {
- unsigned chunkLength;
- const unsigned char* data; /*the data in the chunk*/
-
- /*error: size of the in buffer too small to contain next chunk*/
- if((size_t)((chunk - in) + 12) > insize || chunk < in) CERROR_BREAK(state->error, 30);
-
- /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/
- chunkLength = lodepng_chunk_length(chunk);
- /*error: chunk length larger than the max PNG chunk size*/
- if(chunkLength > 2147483647) CERROR_BREAK(state->error, 63);
-
- if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in)
- {
- CERROR_BREAK(state->error, 64); /*error: size of the in buffer too small to contain next chunk*/
- }
-
- data = lodepng_chunk_data_const(chunk);
-
- /*IDAT chunk, containing compressed image data*/
- if(lodepng_chunk_type_equals(chunk, "IDAT"))
- {
- size_t oldsize = idat.size;
- if(!ucvector_resize(&idat, oldsize + chunkLength)) CERROR_BREAK(state->error, 83 /*alloc fail*/);
- for(i = 0; i < chunkLength; i++) idat.data[oldsize + i] = data[i];
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- critical_pos = 3;
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
- }
- /*IEND chunk*/
- else if(lodepng_chunk_type_equals(chunk, "IEND"))
- {
- IEND = 1;
- }
- /*palette chunk (PLTE)*/
- else if(lodepng_chunk_type_equals(chunk, "PLTE"))
- {
- state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength);
- if(state->error) break;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- critical_pos = 2;
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
- }
- /*palette transparency chunk (tRNS)*/
- else if(lodepng_chunk_type_equals(chunk, "tRNS"))
- {
- state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength);
- if(state->error) break;
- }
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- /*background color chunk (bKGD)*/
- else if(lodepng_chunk_type_equals(chunk, "bKGD"))
- {
- state->error = readChunk_bKGD(&state->info_png, data, chunkLength);
- if(state->error) break;
- }
- /*text chunk (tEXt)*/
- else if(lodepng_chunk_type_equals(chunk, "tEXt"))
- {
- if(state->decoder.read_text_chunks)
- {
- state->error = readChunk_tEXt(&state->info_png, data, chunkLength);
- if(state->error) break;
- }
- }
- /*compressed text chunk (zTXt)*/
- else if(lodepng_chunk_type_equals(chunk, "zTXt"))
- {
- if(state->decoder.read_text_chunks)
- {
- state->error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
- if(state->error) break;
- }
- }
- /*international text chunk (iTXt)*/
- else if(lodepng_chunk_type_equals(chunk, "iTXt"))
- {
- if(state->decoder.read_text_chunks)
- {
- state->error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength);
- if(state->error) break;
- }
- }
- else if(lodepng_chunk_type_equals(chunk, "tIME"))
- {
- state->error = readChunk_tIME(&state->info_png, data, chunkLength);
- if(state->error) break;
- }
- else if(lodepng_chunk_type_equals(chunk, "pHYs"))
- {
- state->error = readChunk_pHYs(&state->info_png, data, chunkLength);
- if(state->error) break;
- }
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
- else /*it's not an implemented chunk type, so ignore it: skip over the data*/
- {
- /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/
- if(!lodepng_chunk_ancillary(chunk)) CERROR_BREAK(state->error, 69);
-
- unknown = 1;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- if(state->decoder.remember_unknown_chunks)
- {
- state->error = lodepng_chunk_append(&state->info_png.unknown_chunks_data[critical_pos - 1],
- &state->info_png.unknown_chunks_size[critical_pos - 1], chunk);
- if(state->error) break;
- }
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
- }
-
- if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/
- {
- if(lodepng_chunk_check_crc(chunk)) CERROR_BREAK(state->error, 57); /*invalid CRC*/
- }
-
- if(!IEND) chunk = lodepng_chunk_next_const(chunk);
- }
-
- ucvector_init(&scanlines);
- if(!state->error)
- {
- /*maximum final image length is already reserved in the vector's length - this is not really necessary*/
- if(!ucvector_resize(&scanlines, lodepng_get_raw_size(*w, *h, &state->info_png.color) + *h))
- {
- state->error = 83; /*alloc fail*/
- }
- }
- if(!state->error)
- {
- /*decompress with the Zlib decompressor*/
- state->error = zlib_decompress(&scanlines.data, &scanlines.size, idat.data,
- idat.size, &state->decoder.zlibsettings);
- }
- ucvector_cleanup(&idat);
-
- if(!state->error)
- {
- ucvector outv;
- ucvector_init(&outv);
- if(!ucvector_resizev(&outv,
- lodepng_get_raw_size(*w, *h, &state->info_png.color), 0)) state->error = 83; /*alloc fail*/
- if(!state->error) state->error = postProcessScanlines(outv.data, scanlines.data, *w, *h, &state->info_png);
- *out = outv.data;
- }
- ucvector_cleanup(&scanlines);
-}
-
-unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
- LodePNGState* state,
- const unsigned char* in, size_t insize)
-{
- *out = 0;
- decodeGeneric(out, w, h, state, in, insize);
- if(state->error) return state->error;
- if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color))
- {
- /*same color type, no copying or converting of data needed*/
- /*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype
- the raw image has to the end user*/
- if(!state->decoder.color_convert)
- {
- state->error = lodepng_color_mode_copy(&state->info_raw, &state->info_png.color);
- if(state->error) return state->error;
- }
- }
- else
- {
- /*color conversion needed; sort of copy of the data*/
- unsigned char* data = *out;
- size_t outsize;
-
- /*TODO: check if this works according to the statement in the documentation: "The converter can convert
- from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/
- if(!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA)
- && !(state->info_raw.bitdepth == 8))
- {
- return 56; /*unsupported color mode conversion*/
- }
-
- outsize = lodepng_get_raw_size(*w, *h, &state->info_raw);
- *out = (unsigned char*)lodepng_malloc(outsize);
- if(!(*out))
- {
- state->error = 83; /*alloc fail*/
- }
- else state->error = lodepng_convert(*out, data, &state->info_raw, &state->info_png.color, *w, *h, state->decoder.fix_png);
- lodepng_free(data);
- }
- return state->error;
-}
-
-unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in,
- size_t insize, LodePNGColorType colortype, unsigned bitdepth)
-{
- unsigned error;
- LodePNGState state;
- lodepng_state_init(&state);
- state.info_raw.colortype = colortype;
- state.info_raw.bitdepth = bitdepth;
- error = lodepng_decode(out, w, h, &state, in, insize);
- lodepng_state_cleanup(&state);
- return error;
-}
-
-unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
-{
- return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8);
-}
-
-unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize)
-{
- return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8);
-}
-
-#ifdef LODEPNG_COMPILE_DISK
-unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename,
- LodePNGColorType colortype, unsigned bitdepth)
-{
- unsigned char* buffer;
- size_t buffersize;
- unsigned error;
- error = lodepng_load_file(&buffer, &buffersize, filename);
- if(!error) error = lodepng_decode_memory(out, w, h, buffer, buffersize, colortype, bitdepth);
- lodepng_free(buffer);
- return error;
-}
-
-unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
-{
- return lodepng_decode_file(out, w, h, filename, LCT_RGBA, 8);
-}
-
-unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename)
-{
- return lodepng_decode_file(out, w, h, filename, LCT_RGB, 8);
-}
-#endif /*LODEPNG_COMPILE_DISK*/
-
-void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings)
-{
- settings->color_convert = 1;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- settings->read_text_chunks = 1;
- settings->remember_unknown_chunks = 0;
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
- settings->ignore_crc = 0;
- settings->fix_png = 0;
- lodepng_decompress_settings_init(&settings->zlibsettings);
-}
-
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER)
-
-void lodepng_state_init(LodePNGState* state)
-{
-#ifdef LODEPNG_COMPILE_DECODER
- lodepng_decoder_settings_init(&state->decoder);
-#endif /*LODEPNG_COMPILE_DECODER*/
-#ifdef LODEPNG_COMPILE_ENCODER
- lodepng_encoder_settings_init(&state->encoder);
-#endif /*LODEPNG_COMPILE_ENCODER*/
- lodepng_color_mode_init(&state->info_raw);
- lodepng_info_init(&state->info_png);
- state->error = 1;
-}
-
-void lodepng_state_cleanup(LodePNGState* state)
-{
- lodepng_color_mode_cleanup(&state->info_raw);
- lodepng_info_cleanup(&state->info_png);
-}
-
-void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source)
-{
- lodepng_state_cleanup(dest);
- *dest = *source;
- lodepng_color_mode_init(&dest->info_raw);
- lodepng_info_init(&dest->info_png);
- dest->error = lodepng_color_mode_copy(&dest->info_raw, &source->info_raw); if(dest->error) return;
- dest->error = lodepng_info_copy(&dest->info_png, &source->info_png); if(dest->error) return;
-}
-
-#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */
-
-#ifdef LODEPNG_COMPILE_ENCODER
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* / PNG Encoder / */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-/*chunkName must be string of 4 characters*/
-static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length)
-{
- CERROR_TRY_RETURN(lodepng_chunk_create(&out->data, &out->size, (unsigned)length, chunkName, data));
- out->allocsize = out->size; /*fix the allocsize again*/
- return 0;
-}
-
-static void writeSignature(ucvector* out)
-{
- /*8 bytes PNG signature, aka the magic bytes*/
- ucvector_push_back(out, 137);
- ucvector_push_back(out, 80);
- ucvector_push_back(out, 78);
- ucvector_push_back(out, 71);
- ucvector_push_back(out, 13);
- ucvector_push_back(out, 10);
- ucvector_push_back(out, 26);
- ucvector_push_back(out, 10);
-}
-
-static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h,
- LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method)
-{
- unsigned error = 0;
- ucvector header;
- ucvector_init(&header);
-
- lodepng_add32bitInt(&header, w); /*width*/
- lodepng_add32bitInt(&header, h); /*height*/
- ucvector_push_back(&header, (unsigned char)bitdepth); /*bit depth*/
- ucvector_push_back(&header, (unsigned char)colortype); /*color type*/
- ucvector_push_back(&header, 0); /*compression method*/
- ucvector_push_back(&header, 0); /*filter method*/
- ucvector_push_back(&header, interlace_method); /*interlace method*/
-
- error = addChunk(out, "IHDR", header.data, header.size);
- ucvector_cleanup(&header);
-
- return error;
-}
-
-static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* info)
-{
- unsigned error = 0;
- size_t i;
- ucvector PLTE;
- ucvector_init(&PLTE);
- for(i = 0; i < info->palettesize * 4; i++)
- {
- /*add all channels except alpha channel*/
- if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]);
- }
- error = addChunk(out, "PLTE", PLTE.data, PLTE.size);
- ucvector_cleanup(&PLTE);
-
- return error;
-}
-
-static unsigned addChunk_tRNS(ucvector* out, const LodePNGColorMode* info)
-{
- unsigned error = 0;
- size_t i;
- ucvector tRNS;
- ucvector_init(&tRNS);
- if(info->colortype == LCT_PALETTE)
- {
- size_t amount = info->palettesize;
- /*the tail of palette values that all have 255 as alpha, does not have to be encoded*/
- for(i = info->palettesize; i > 0; i--)
- {
- if(info->palette[4 * (i - 1) + 3] == 255) amount--;
- else break;
- }
- /*add only alpha channel*/
- for(i = 0; i < amount; i++) ucvector_push_back(&tRNS, info->palette[4 * i + 3]);
- }
- else if(info->colortype == LCT_GREY)
- {
- if(info->key_defined)
- {
- ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
- ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
- }
- }
- else if(info->colortype == LCT_RGB)
- {
- if(info->key_defined)
- {
- ucvector_push_back(&tRNS, (unsigned char)(info->key_r / 256));
- ucvector_push_back(&tRNS, (unsigned char)(info->key_r % 256));
- ucvector_push_back(&tRNS, (unsigned char)(info->key_g / 256));
- ucvector_push_back(&tRNS, (unsigned char)(info->key_g % 256));
- ucvector_push_back(&tRNS, (unsigned char)(info->key_b / 256));
- ucvector_push_back(&tRNS, (unsigned char)(info->key_b % 256));
- }
- }
-
- error = addChunk(out, "tRNS", tRNS.data, tRNS.size);
- ucvector_cleanup(&tRNS);
-
- return error;
-}
-
-static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize,
- LodePNGCompressSettings* zlibsettings)
-{
- ucvector zlibdata;
- unsigned error = 0;
-
- /*compress with the Zlib compressor*/
- ucvector_init(&zlibdata);
- error = zlib_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings);
- if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size);
- ucvector_cleanup(&zlibdata);
-
- return error;
-}
-
-static unsigned addChunk_IEND(ucvector* out)
-{
- unsigned error = 0;
- error = addChunk(out, "IEND", 0, 0);
- return error;
-}
-
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-
-static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring)
-{
- unsigned error = 0;
- size_t i;
- ucvector text;
- ucvector_init(&text);
- for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&text, (unsigned char)keyword[i]);
- if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
- ucvector_push_back(&text, 0); /*0 termination char*/
- for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&text, (unsigned char)textstring[i]);
- error = addChunk(out, "tEXt", text.data, text.size);
- ucvector_cleanup(&text);
-
- return error;
-}
-
-static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring,
- LodePNGCompressSettings* zlibsettings)
-{
- unsigned error = 0;
- ucvector data, compressed;
- size_t i, textsize = strlen(textstring);
-
- ucvector_init(&data);
- ucvector_init(&compressed);
- for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
- if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
- ucvector_push_back(&data, 0); /*0 termination char*/
- ucvector_push_back(&data, 0); /*compression method: 0*/
-
- error = zlib_compress(&compressed.data, &compressed.size,
- (unsigned char*)textstring, textsize, zlibsettings);
- if(!error)
- {
- for(i = 0; i < compressed.size; i++) ucvector_push_back(&data, compressed.data[i]);
- error = addChunk(out, "zTXt", data.data, data.size);
- }
-
- ucvector_cleanup(&compressed);
- ucvector_cleanup(&data);
- return error;
-}
-
-static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag,
- const char* transkey, const char* textstring, LodePNGCompressSettings* zlibsettings)
-{
- unsigned error = 0;
- ucvector data;
- size_t i, textsize = strlen(textstring);
-
- ucvector_init(&data);
-
- for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]);
- if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/
- ucvector_push_back(&data, 0); /*null termination char*/
- ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/
- ucvector_push_back(&data, 0); /*compression method*/
- for(i = 0; langtag[i] != 0; i++) ucvector_push_back(&data, (unsigned char)langtag[i]);
- ucvector_push_back(&data, 0); /*null termination char*/
- for(i = 0; transkey[i] != 0; i++) ucvector_push_back(&data, (unsigned char)transkey[i]);
- ucvector_push_back(&data, 0); /*null termination char*/
-
- if(compressed)
- {
- ucvector compressed_data;
- ucvector_init(&compressed_data);
- error = zlib_compress(&compressed_data.data, &compressed_data.size,
- (unsigned char*)textstring, textsize, zlibsettings);
- if(!error)
- {
- for(i = 0; i < compressed_data.size; i++) ucvector_push_back(&data, compressed_data.data[i]);
- }
- ucvector_cleanup(&compressed_data);
- }
- else /*not compressed*/
- {
- for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]);
- }
-
- if(!error) error = addChunk(out, "iTXt", data.data, data.size);
- ucvector_cleanup(&data);
- return error;
-}
-
-static unsigned addChunk_bKGD(ucvector* out, const LodePNGInfo* info)
-{
- unsigned error = 0;
- ucvector bKGD;
- ucvector_init(&bKGD);
- if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA)
- {
- ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
- ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
- }
- else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA)
- {
- ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256));
- ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256));
- ucvector_push_back(&bKGD, (unsigned char)(info->background_g / 256));
- ucvector_push_back(&bKGD, (unsigned char)(info->background_g % 256));
- ucvector_push_back(&bKGD, (unsigned char)(info->background_b / 256));
- ucvector_push_back(&bKGD, (unsigned char)(info->background_b % 256));
- }
- else if(info->color.colortype == LCT_PALETTE)
- {
- ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); /*palette index*/
- }
-
- error = addChunk(out, "bKGD", bKGD.data, bKGD.size);
- ucvector_cleanup(&bKGD);
-
- return error;
-}
-
-static unsigned addChunk_tIME(ucvector* out, const LodePNGTime* time)
-{
- unsigned error = 0;
- unsigned char* data = (unsigned char*)lodepng_malloc(7);
- if(!data) return 83; /*alloc fail*/
- data[0] = (unsigned char)(time->year / 256);
- data[1] = (unsigned char)(time->year % 256);
- data[2] = time->month;
- data[3] = time->day;
- data[4] = time->hour;
- data[5] = time->minute;
- data[6] = time->second;
- error = addChunk(out, "tIME", data, 7);
- lodepng_free(data);
- return error;
-}
-
-static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* info)
-{
- unsigned error = 0;
- ucvector data;
- ucvector_init(&data);
-
- lodepng_add32bitInt(&data, info->phys_x);
- lodepng_add32bitInt(&data, info->phys_y);
- ucvector_push_back(&data, info->phys_unit);
-
- error = addChunk(out, "pHYs", data.data, data.size);
- ucvector_cleanup(&data);
-
- return error;
-}
-
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-
-static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline,
- size_t length, size_t bytewidth, unsigned char filterType)
-{
- size_t i;
- switch(filterType)
- {
- case 0: /*None*/
- for(i = 0; i < length; i++) out[i] = scanline[i];
- break;
- case 1: /*Sub*/
- if(prevline)
- {
- for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
- for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth];
- }
- else
- {
- for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
- for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth];
- }
- break;
- case 2: /*Up*/
- if(prevline)
- {
- for(i = 0; i < length; i++) out[i] = scanline[i] - prevline[i];
- }
- else
- {
- for(i = 0; i < length; i++) out[i] = scanline[i];
- }
- break;
- case 3: /*Average*/
- if(prevline)
- {
- for(i = 0; i < bytewidth; i++) out[i] = scanline[i] - prevline[i] / 2;
- for(i = bytewidth; i < length; i++) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) / 2);
- }
- else
- {
- for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
- for(i = bytewidth; i < length; i++) out[i] = scanline[i] - scanline[i - bytewidth] / 2;
- }
- break;
- case 4: /*Paeth*/
- if(prevline)
- {
- /*paethPredictor(0, prevline[i], 0) is always prevline[i]*/
- for(i = 0; i < bytewidth; i++) out[i] = (scanline[i] - prevline[i]);
- for(i = bytewidth; i < length; i++)
- {
- out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth]));
- }
- }
- else
- {
- for(i = 0; i < bytewidth; i++) out[i] = scanline[i];
- /*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/
- for(i = bytewidth; i < length; i++) out[i] = (scanline[i] - scanline[i - bytewidth]);
- }
- break;
- default: return; /*unexisting filter type given*/
- }
-}
-
-/* log2 approximation. A slight bit faster than std::log. */
-static float flog2(float f)
-{
- float result = 0;
- while(f > 32) { result += 4; f /= 16; }
- while(f > 2) { result++; f /= 2; }
- return result + 1.442695f * (f * f * f / 3 - 3 * f * f / 2 + 3 * f - 1.83333f);
-}
-
-static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h,
- const LodePNGColorMode* info, const LodePNGEncoderSettings* settings)
-{
- /*
- For PNG filter method 0
- out must be a buffer with as size: h + (w * h * bpp + 7) / 8, because there are
- the scanlines with 1 extra byte per scanline
- */
-
- unsigned bpp = lodepng_get_bpp(info);
- /*the width of a scanline in bytes, not including the filter type*/
- size_t linebytes = (w * bpp + 7) / 8;
- /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/
- size_t bytewidth = (bpp + 7) / 8;
- const unsigned char* prevline = 0;
- unsigned x, y;
- unsigned error = 0;
- LodePNGFilterStrategy strategy = settings->filter_strategy;
-
- /*
- There is a heuristic called the minimum sum of absolute differences heuristic, suggested by the PNG standard:
- * If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e.
- use fixed filtering, with the filter None).
- * (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is
- not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply
- all five filters and select the filter that produces the smallest sum of absolute values per row.
- This heuristic is used if filter strategy is LFS_MINSUM and filter_palette_zero is true.
-
- If filter_palette_zero is true and filter_strategy is not LFS_MINSUM, the above heuristic is followed,
- but for "the other case", whatever strategy filter_strategy is set to instead of the minimum sum
- heuristic is used.
- */
- if(settings->filter_palette_zero &&
- (info->colortype == LCT_PALETTE || info->bitdepth < 8)) strategy = LFS_ZERO;
-
- if(bpp == 0) return 31; /*error: invalid color type*/
-
- if(strategy == LFS_ZERO)
- {
- for(y = 0; y < h; y++)
- {
- size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
- size_t inindex = linebytes * y;
- out[outindex] = 0; /*filter type byte*/
- filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, 0);
- prevline = &in[inindex];
- }
- }
- else if(strategy == LFS_MINSUM)
- {
- /*adaptive filtering*/
- size_t sum[5];
- ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
- size_t smallest = 0;
- unsigned type, bestType = 0;
-
- for(type = 0; type < 5; type++)
- {
- ucvector_init(&attempt[type]);
- if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*alloc fail*/
- }
-
- if(!error)
- {
- for(y = 0; y < h; y++)
- {
- /*try the 5 filter types*/
- for(type = 0; type < 5; type++)
- {
- filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
-
- /*calculate the sum of the result*/
- sum[type] = 0;
- if(type == 0)
- {
- for(x = 0; x < linebytes; x++) sum[type] += (unsigned char)(attempt[type].data[x]);
- }
- else
- {
- for(x = 0; x < linebytes; x++)
- {
- /*For differences, each byte should be treated as signed, values above 127 are negative
- (converted to signed char). Filtertype 0 isn't a difference though, so use unsigned there.
- This means filtertype 0 is almost never chosen, but that is justified.*/
- signed char s = (signed char)(attempt[type].data[x]);
- sum[type] += s < 0 ? -s : s;
- }
- }
-
- /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
- if(type == 0 || sum[type] < smallest)
- {
- bestType = type;
- smallest = sum[type];
- }
- }
-
- prevline = &in[y * linebytes];
-
- /*now fill the out values*/
- out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
- for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
- }
- }
-
- for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
- }
- else if(strategy == LFS_ENTROPY)
- {
- float sum[5];
- ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
- float smallest = 0;
- unsigned type, bestType = 0;
- unsigned count[256];
-
- for(type = 0; type < 5; type++)
- {
- ucvector_init(&attempt[type]);
- if(!ucvector_resize(&attempt[type], linebytes)) return 83; /*alloc fail*/
- }
-
- for(y = 0; y < h; y++)
- {
- /*try the 5 filter types*/
- for(type = 0; type < 5; type++)
- {
- filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
- for(x = 0; x < 256; x++) count[x] = 0;
- for(x = 0; x < linebytes; x++) count[attempt[type].data[x]]++;
- count[type]++; /*the filter type itself is part of the scanline*/
- sum[type] = 0;
- for(x = 0; x < 256; x++)
- {
- float p = count[x] / (float)(linebytes + 1);
- sum[type] += count[x] == 0 ? 0 : flog2(1 / p) * p;
- }
- /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/
- if(type == 0 || sum[type] < smallest)
- {
- bestType = type;
- smallest = sum[type];
- }
- }
-
- prevline = &in[y * linebytes];
-
- /*now fill the out values*/
- out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
- for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
- }
-
- for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
- }
- else if(strategy == LFS_PREDEFINED)
- {
- for(y = 0; y < h; y++)
- {
- size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/
- size_t inindex = linebytes * y;
- unsigned type = settings->predefined_filters[y];
- out[outindex] = type; /*filter type byte*/
- filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type);
- prevline = &in[inindex];
- }
- }
- else if(strategy == LFS_BRUTE_FORCE)
- {
- /*brute force filter chooser.
- deflate the scanline after every filter attempt to see which one deflates best.
- This is very slow and gives only slightly smaller, sometimes even larger, result*/
- size_t size[5];
- ucvector attempt[5]; /*five filtering attempts, one for each filter type*/
- size_t smallest = 0;
- unsigned type = 0, bestType = 0;
- unsigned char* dummy;
- LodePNGCompressSettings zlibsettings = settings->zlibsettings;
- /*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose,
- to simulate the true case where the tree is the same for the whole image. Sometimes it gives
- better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare
- cases better compression. It does make this a bit less slow, so it's worth doing this.*/
- zlibsettings.btype = 1;
- /*a custom encoder likely doesn't read the btype setting and is optimized for complete PNG
- images only, so disable it*/
- zlibsettings.custom_zlib = 0;
- zlibsettings.custom_deflate = 0;
- for(type = 0; type < 5; type++)
- {
- ucvector_init(&attempt[type]);
- ucvector_resize(&attempt[type], linebytes); /*todo: give error if resize failed*/
- }
- for(y = 0; y < h; y++) /*try the 5 filter types*/
- {
- for(type = 0; type < 5; type++)
- {
- unsigned testsize = attempt[type].size;
- /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/
-
- filterScanline(attempt[type].data, &in[y * linebytes], prevline, linebytes, bytewidth, type);
- size[type] = 0;
- dummy = 0;
- zlib_compress(&dummy, &size[type], attempt[type].data, testsize, &zlibsettings);
- lodepng_free(dummy);
- /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/
- if(type == 0 || size[type] < smallest)
- {
- bestType = type;
- smallest = size[type];
- }
- }
- prevline = &in[y * linebytes];
- out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/
- for(x = 0; x < linebytes; x++) out[y * (linebytes + 1) + 1 + x] = attempt[bestType].data[x];
- }
- for(type = 0; type < 5; type++) ucvector_cleanup(&attempt[type]);
- }
- else return 88; /* unknown filter strategy */
-
- return error;
-}
-
-static void addPaddingBits(unsigned char* out, const unsigned char* in,
- size_t olinebits, size_t ilinebits, unsigned h)
-{
- /*The opposite of the removePaddingBits function
- olinebits must be >= ilinebits*/
- unsigned y;
- size_t diff = olinebits - ilinebits;
- size_t obp = 0, ibp = 0; /*bit pointers*/
- for(y = 0; y < h; y++)
- {
- size_t x;
- for(x = 0; x < ilinebits; x++)
- {
- unsigned char bit = readBitFromReversedStream(&ibp, in);
- setBitOfReversedStream(&obp, out, bit);
- }
- /*obp += diff; --> no, fill in some value in the padding bits too, to avoid
- "Use of uninitialised value of size ###" warning from valgrind*/
- for(x = 0; x < diff; x++) setBitOfReversedStream(&obp, out, 0);
- }
-}
-
-/*
-in: non-interlaced image with size w*h
-out: the same pixels, but re-ordered according to PNG's Adam7 interlacing, with
- no padding bits between scanlines, but between reduced images so that each
- reduced image starts at a byte.
-bpp: bits per pixel
-there are no padding bits, not between scanlines, not between reduced images
-in has the following size in bits: w * h * bpp.
-out is possibly bigger due to padding bits between reduced images
-NOTE: comments about padding bits are only relevant if bpp < 8
-*/
-static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp)
-{
- unsigned passw[7], passh[7];
- size_t filter_passstart[8], padded_passstart[8], passstart[8];
- unsigned i;
-
- Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
-
- if(bpp >= 8)
- {
- for(i = 0; i < 7; i++)
- {
- unsigned x, y, b;
- size_t bytewidth = bpp / 8;
- for(y = 0; y < passh[i]; y++)
- for(x = 0; x < passw[i]; x++)
- {
- size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth;
- size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth;
- for(b = 0; b < bytewidth; b++)
- {
- out[pixeloutstart + b] = in[pixelinstart + b];
- }
- }
- }
- }
- else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/
- {
- for(i = 0; i < 7; i++)
- {
- unsigned x, y, b;
- unsigned ilinebits = bpp * passw[i];
- unsigned olinebits = bpp * w;
- size_t obp, ibp; /*bit pointers (for out and in buffer)*/
- for(y = 0; y < passh[i]; y++)
- for(x = 0; x < passw[i]; x++)
- {
- ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp;
- obp = (8 * passstart[i]) + (y * ilinebits + x * bpp);
- for(b = 0; b < bpp; b++)
- {
- unsigned char bit = readBitFromReversedStream(&ibp, in);
- setBitOfReversedStream(&obp, out, bit);
- }
- }
- }
- }
-}
-
-/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image.
-return value is error**/
-static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in,
- unsigned w, unsigned h,
- const LodePNGInfo* info_png, const LodePNGEncoderSettings* settings)
-{
- /*
- This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps:
- *) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp < 8) 2) filter
- *) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter
- */
- unsigned bpp = lodepng_get_bpp(&info_png->color);
- unsigned error = 0;
-
- if(info_png->interlace_method == 0)
- {
- *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/
- *out = (unsigned char*)lodepng_malloc(*outsize);
- if(!(*out) && (*outsize)) error = 83; /*alloc fail*/
-
- if(!error)
- {
- /*non multiple of 8 bits per scanline, padding bits needed per scanline*/
- if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8)
- {
- unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7) / 8));
- if(!padded) error = 83; /*alloc fail*/
- if(!error)
- {
- addPaddingBits(padded, in, ((w * bpp + 7) / 8) * 8, w * bpp, h);
- error = filter(*out, padded, w, h, &info_png->color, settings);
- }
- lodepng_free(padded);
- }
- else
- {
- /*we can immediatly filter into the out buffer, no other steps needed*/
- error = filter(*out, in, w, h, &info_png->color, settings);
- }
- }
- }
- else /*interlace_method is 1 (Adam7)*/
- {
- unsigned passw[7], passh[7];
- size_t filter_passstart[8], padded_passstart[8], passstart[8];
- unsigned char* adam7;
-
- Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp);
-
- *outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/
- *out = (unsigned char*)lodepng_malloc(*outsize);
- if(!(*out)) error = 83; /*alloc fail*/
-
- adam7 = (unsigned char*)lodepng_malloc(passstart[7]);
- if(!adam7 && passstart[7]) error = 83; /*alloc fail*/
-
- if(!error)
- {
- unsigned i;
-
- Adam7_interlace(adam7, in, w, h, bpp);
- for(i = 0; i < 7; i++)
- {
- if(bpp < 8)
- {
- unsigned char* padded = (unsigned char*)lodepng_malloc(padded_passstart[i + 1] - padded_passstart[i]);
- if(!padded) ERROR_BREAK(83); /*alloc fail*/
- addPaddingBits(padded, &adam7[passstart[i]],
- ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]);
- error = filter(&(*out)[filter_passstart[i]], padded,
- passw[i], passh[i], &info_png->color, settings);
- lodepng_free(padded);
- }
- else
- {
- error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]],
- passw[i], passh[i], &info_png->color, settings);
- }
-
- if(error) break;
- }
- }
-
- lodepng_free(adam7);
- }
-
- return error;
-}
-
-/*
-palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA...
-returns 0 if the palette is opaque,
-returns 1 if the palette has a single color with alpha 0 ==> color key
-returns 2 if the palette is semi-translucent.
-*/
-static unsigned getPaletteTranslucency(const unsigned char* palette, size_t palettesize)
-{
- size_t i, key = 0;
- unsigned r = 0, g = 0, b = 0; /*the value of the color with alpha 0, so long as color keying is possible*/
- for(i = 0; i < palettesize; i++)
- {
- if(!key && palette[4 * i + 3] == 0)
- {
- r = palette[4 * i + 0]; g = palette[4 * i + 1]; b = palette[4 * i + 2];
- key = 1;
- i = (size_t)(-1); /*restart from beginning, to detect earlier opaque colors with key's value*/
- }
- else if(palette[4 * i + 3] != 255) return 2;
- /*when key, no opaque RGB may have key's RGB*/
- else if(key && r == palette[i * 4 + 0] && g == palette[i * 4 + 1] && b == palette[i * 4 + 2]) return 2;
- }
- return key;
-}
-
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize)
-{
- unsigned char* inchunk = data;
- while((size_t)(inchunk - data) < datasize)
- {
- CERROR_TRY_RETURN(lodepng_chunk_append(&out->data, &out->size, inchunk));
- out->allocsize = out->size; /*fix the allocsize again*/
- inchunk = lodepng_chunk_next(inchunk);
- }
- return 0;
-}
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-
-unsigned lodepng_encode(unsigned char** out, size_t* outsize,
- const unsigned char* image, unsigned w, unsigned h,
- LodePNGState* state)
-{
- LodePNGInfo info;
- ucvector outv;
- unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/
- size_t datasize = 0;
-
- /*provide some proper output values if error will happen*/
- *out = 0;
- *outsize = 0;
- state->error = 0;
-
- lodepng_info_init(&info);
- lodepng_info_copy(&info, &state->info_png);
-
- if((info.color.colortype == LCT_PALETTE || state->encoder.force_palette)
- && (info.color.palettesize == 0 || info.color.palettesize > 256))
- {
- state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/
- return state->error;
- }
-
- if(state->encoder.auto_convert != LAC_NO)
- {
- state->error = lodepng_auto_choose_color(&info.color, image, w, h, &state->info_raw,
- state->encoder.auto_convert);
- }
- if(state->error) return state->error;
-
- if(state->encoder.zlibsettings.btype > 2)
- {
- CERROR_RETURN_ERROR(state->error, 61); /*error: unexisting btype*/
- }
- if(state->info_png.interlace_method > 1)
- {
- CERROR_RETURN_ERROR(state->error, 71); /*error: unexisting interlace mode*/
- }
-
- state->error = checkColorValidity(info.color.colortype, info.color.bitdepth);
- if(state->error) return state->error; /*error: unexisting color type given*/
- state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth);
- if(state->error) return state->error; /*error: unexisting color type given*/
-
- if(!lodepng_color_mode_equal(&state->info_raw, &info.color))
- {
- unsigned char* converted;
- size_t size = (w * h * lodepng_get_bpp(&info.color) + 7) / 8;
-
- converted = (unsigned char*)lodepng_malloc(size);
- if(!converted && size) state->error = 83; /*alloc fail*/
- if(!state->error)
- {
- state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h, 0 /*fix_png*/);
- }
- if(!state->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder);
- lodepng_free(converted);
- }
- else preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder);
-
- ucvector_init(&outv);
- while(!state->error) /*while only executed once, to break on error*/
- {
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- size_t i;
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
- /*write signature and chunks*/
- writeSignature(&outv);
- /*IHDR*/
- addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method);
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- /*unknown chunks between IHDR and PLTE*/
- if(info.unknown_chunks_data[0])
- {
- state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0], info.unknown_chunks_size[0]);
- if(state->error) break;
- }
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
- /*PLTE*/
- if(info.color.colortype == LCT_PALETTE)
- {
- addChunk_PLTE(&outv, &info.color);
- }
- if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA))
- {
- addChunk_PLTE(&outv, &info.color);
- }
- /*tRNS*/
- if(info.color.colortype == LCT_PALETTE && getPaletteTranslucency(info.color.palette, info.color.palettesize) != 0)
- {
- addChunk_tRNS(&outv, &info.color);
- }
- if((info.color.colortype == LCT_GREY || info.color.colortype == LCT_RGB) && info.color.key_defined)
- {
- addChunk_tRNS(&outv, &info.color);
- }
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- /*bKGD (must come between PLTE and the IDAt chunks*/
- if(info.background_defined) addChunk_bKGD(&outv, &info);
- /*pHYs (must come before the IDAT chunks)*/
- if(info.phys_defined) addChunk_pHYs(&outv, &info);
-
- /*unknown chunks between PLTE and IDAT*/
- if(info.unknown_chunks_data[1])
- {
- state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1], info.unknown_chunks_size[1]);
- if(state->error) break;
- }
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
- /*IDAT (multiple IDAT chunks must be consecutive)*/
- state->error = addChunk_IDAT(&outv, data, datasize, &state->encoder.zlibsettings);
- if(state->error) break;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- /*tIME*/
- if(info.time_defined) addChunk_tIME(&outv, &info.time);
- /*tEXt and/or zTXt*/
- for(i = 0; i < info.text_num; i++)
- {
- if(strlen(info.text_keys[i]) > 79)
- {
- state->error = 66; /*text chunk too large*/
- break;
- }
- if(strlen(info.text_keys[i]) < 1)
- {
- state->error = 67; /*text chunk too small*/
- break;
- }
- if(state->encoder.text_compression)
- {
- addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings);
- }
- else
- {
- addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]);
- }
- }
- /*LodePNG version id in text chunk*/
- if(state->encoder.add_id)
- {
- unsigned alread_added_id_text = 0;
- for(i = 0; i < info.text_num; i++)
- {
- if(!strcmp(info.text_keys[i], "LodePNG"))
- {
- alread_added_id_text = 1;
- break;
- }
- }
- if(alread_added_id_text == 0)
- {
- addChunk_tEXt(&outv, "LodePNG", VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/
- }
- }
- /*iTXt*/
- for(i = 0; i < info.itext_num; i++)
- {
- if(strlen(info.itext_keys[i]) > 79)
- {
- state->error = 66; /*text chunk too large*/
- break;
- }
- if(strlen(info.itext_keys[i]) < 1)
- {
- state->error = 67; /*text chunk too small*/
- break;
- }
- addChunk_iTXt(&outv, state->encoder.text_compression,
- info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i],
- &state->encoder.zlibsettings);
- }
-
- /*unknown chunks between IDAT and IEND*/
- if(info.unknown_chunks_data[2])
- {
- state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2], info.unknown_chunks_size[2]);
- if(state->error) break;
- }
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
- addChunk_IEND(&outv);
-
- break; /*this isn't really a while loop; no error happened so break out now!*/
- }
-
- lodepng_info_cleanup(&info);
- lodepng_free(data);
- /*instead of cleaning the vector up, give it to the output*/
- *out = outv.data;
- *outsize = outv.size;
-
- return state->error;
-}
-
-unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsigned char* image,
- unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth)
-{
- unsigned error;
- LodePNGState state;
- lodepng_state_init(&state);
- state.info_raw.colortype = colortype;
- state.info_raw.bitdepth = bitdepth;
- state.info_png.color.colortype = colortype;
- state.info_png.color.bitdepth = bitdepth;
- lodepng_encode(out, outsize, image, w, h, &state);
- error = state.error;
- lodepng_state_cleanup(&state);
- return error;
-}
-
-unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
-{
- return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGBA, 8);
-}
-
-unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h)
-{
- return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGB, 8);
-}
-
-#ifdef LODEPNG_COMPILE_DISK
-unsigned lodepng_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h,
- LodePNGColorType colortype, unsigned bitdepth)
-{
- unsigned char* buffer;
- size_t buffersize;
- unsigned error = lodepng_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth);
- if(!error) error = lodepng_save_file(buffer, buffersize, filename);
- lodepng_free(buffer);
- return error;
-}
-
-unsigned lodepng_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
-{
- return lodepng_encode_file(filename, image, w, h, LCT_RGBA, 8);
-}
-
-unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h)
-{
- return lodepng_encode_file(filename, image, w, h, LCT_RGB, 8);
-}
-#endif /*LODEPNG_COMPILE_DISK*/
-
-void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings)
-{
- lodepng_compress_settings_init(&settings->zlibsettings);
- settings->filter_palette_zero = 1;
- settings->filter_strategy = LFS_MINSUM;
- settings->auto_convert = LAC_AUTO;
- settings->force_palette = 0;
- settings->predefined_filters = 0;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- settings->add_id = 0;
- settings->text_compression = 1;
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-}
-
-#endif /*LODEPNG_COMPILE_ENCODER*/
-#endif /*LODEPNG_COMPILE_PNG*/
-
-#ifdef LODEPNG_COMPILE_ERROR_TEXT
-/*
-This returns the description of a numerical error code in English. This is also
-the documentation of all the error codes.
-*/
-const char* lodepng_error_text(unsigned code)
-{
- switch(code)
- {
- case 0: return "no error, everything went ok";
- case 1: return "nothing done yet"; /*the Encoder/Decoder has done nothing yet, error checking makes no sense yet*/
- case 10: return "end of input memory reached without huffman end code"; /*while huffman decoding*/
- case 11: return "error in code tree made it jump outside of huffman tree"; /*while huffman decoding*/
- case 13: return "problem while processing dynamic deflate block";
- case 14: return "problem while processing dynamic deflate block";
- case 15: return "problem while processing dynamic deflate block";
- case 16: return "unexisting code while processing dynamic deflate block";
- case 17: return "end of out buffer memory reached while inflating";
- case 18: return "invalid distance code while inflating";
- case 19: return "end of out buffer memory reached while inflating";
- case 20: return "invalid deflate block BTYPE encountered while decoding";
- case 21: return "NLEN is not ones complement of LEN in a deflate block";
- /*end of out buffer memory reached while inflating:
- This can happen if the inflated deflate data is longer than the amount of bytes required to fill up
- all the pixels of the image, given the color depth and image dimensions. Something that doesn't
- happen in a normal, well encoded, PNG image.*/
- case 22: return "end of out buffer memory reached while inflating";
- case 23: return "end of in buffer memory reached while inflating";
- case 24: return "invalid FCHECK in zlib header";
- case 25: return "invalid compression method in zlib header";
- case 26: return "FDICT encountered in zlib header while it's not used for PNG";
- case 27: return "PNG file is smaller than a PNG header";
- /*Checks the magic file header, the first 8 bytes of the PNG file*/
- case 28: return "incorrect PNG signature, it's no PNG or corrupted";
- case 29: return "first chunk is not the header chunk";
- case 30: return "chunk length too large, chunk broken off at end of file";
- case 31: return "illegal PNG color type or bpp";
- case 32: return "illegal PNG compression method";
- case 33: return "illegal PNG filter method";
- case 34: return "illegal PNG interlace method";
- case 35: return "chunk length of a chunk is too large or the chunk too small";
- case 36: return "illegal PNG filter type encountered";
- case 37: return "illegal bit depth for this color type given";
- case 38: return "the palette is too big"; /*more than 256 colors*/
- case 39: return "more palette alpha values given in tRNS chunk than there are colors in the palette";
- case 40: return "tRNS chunk has wrong size for greyscale image";
- case 41: return "tRNS chunk has wrong size for RGB image";
- case 42: return "tRNS chunk appeared while it was not allowed for this color type";
- case 43: return "bKGD chunk has wrong size for palette image";
- case 44: return "bKGD chunk has wrong size for greyscale image";
- case 45: return "bKGD chunk has wrong size for RGB image";
- /*Is the palette too small?*/
- case 46: return "a value in indexed image is larger than the palette size (bitdepth = 8)";
- /*Is the palette too small?*/
- case 47: return "a value in indexed image is larger than the palette size (bitdepth < 8)";
- /*the input data is empty, maybe a PNG file doesn't exist or is in the wrong path*/
- case 48: return "empty input or file doesn't exist";
- case 49: return "jumped past memory while generating dynamic huffman tree";
- case 50: return "jumped past memory while generating dynamic huffman tree";
- case 51: return "jumped past memory while inflating huffman block";
- case 52: return "jumped past memory while inflating";
- case 53: return "size of zlib data too small";
- case 54: return "repeat symbol in tree while there was no value symbol yet";
- /*jumped past tree while generating huffman tree, this could be when the
- tree will have more leaves than symbols after generating it out of the
- given lenghts. They call this an oversubscribed dynamic bit lengths tree in zlib.*/
- case 55: return "jumped past tree while generating huffman tree";
- case 56: return "given output image colortype or bitdepth not supported for color conversion";
- case 57: return "invalid CRC encountered (checking CRC can be disabled)";
- case 58: return "invalid ADLER32 encountered (checking ADLER32 can be disabled)";
- case 59: return "requested color conversion not supported";
- case 60: return "invalid window size given in the settings of the encoder (must be 0-32768)";
- case 61: return "invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed)";
- /*LodePNG leaves the choice of RGB to greyscale conversion formula to the user.*/
- case 62: return "conversion from color to greyscale not supported";
- case 63: return "length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk"; /*(2^31-1)*/
- /*this would result in the inability of a deflated block to ever contain an end code. It must be at least 1.*/
- case 64: return "the length of the END symbol 256 in the Huffman tree is 0";
- case 66: return "the length of a text chunk keyword given to the encoder is longer than the maximum of 79 bytes";
- case 67: return "the length of a text chunk keyword given to the encoder is smaller than the minimum of 1 byte";
- case 68: return "tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors";
- case 69: return "unknown chunk type with 'critical' flag encountered by the decoder";
- case 71: return "unexisting interlace mode given to encoder (must be 0 or 1)";
- case 72: return "while decoding, unexisting compression method encountering in zTXt or iTXt chunk (it must be 0)";
- case 73: return "invalid tIME chunk size";
- case 74: return "invalid pHYs chunk size";
- /*length could be wrong, or data chopped off*/
- case 75: return "no null termination char found while decoding text chunk";
- case 76: return "iTXt chunk too short to contain required bytes";
- case 77: return "integer overflow in buffer size";
- case 78: return "failed to open file for reading"; /*file doesn't exist or couldn't be opened for reading*/
- case 79: return "failed to open file for writing";
- case 80: return "tried creating a tree of 0 symbols";
- case 81: return "lazy matching at pos 0 is impossible";
- case 82: return "color conversion to palette requested while a color isn't in palette";
- case 83: return "memory allocation failed";
- case 84: return "given image too small to contain all pixels to be encoded";
- case 85: return "internal color conversion bug";
- case 86: return "impossible offset in lz77 encoding (internal bug)";
- case 87: return "must provide custom zlib function pointer if LODEPNG_COMPILE_ZLIB is not defined";
- case 88: return "invalid filter strategy given for LodePNGEncoderSettings.filter_strategy";
- case 89: return "text chunk keyword too short or long: must have size 1-79";
- /*the windowsize in the LodePNGCompressSettings. Requiring POT(==> & instead of %) makes encoding 12% faster.*/
- case 90: return "windowsize must be a power of two";
- }
- return "unknown error code";
-}
-#endif /*LODEPNG_COMPILE_ERROR_TEXT*/
-
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* // C++ Wrapper // */
-/* ////////////////////////////////////////////////////////////////////////// */
-/* ////////////////////////////////////////////////////////////////////////// */
-
-#ifdef LODEPNG_COMPILE_CPP
-namespace lodepng
-{
-
-#ifdef LODEPNG_COMPILE_DISK
-void load_file(std::vector<unsigned char>& buffer, const std::string& filename)
-{
- std::ifstream file(filename.c_str(), std::ios::in|std::ios::binary|std::ios::ate);
-
- /*get filesize*/
- std::streamsize size = 0;
- if(file.seekg(0, std::ios::end).good()) size = file.tellg();
- if(file.seekg(0, std::ios::beg).good()) size -= file.tellg();
-
- /*read contents of the file into the vector*/
- buffer.resize(size_t(size));
- if(size > 0) file.read((char*)(&buffer[0]), size);
-}
-
-/*write given buffer to the file, overwriting the file, it doesn't append to it.*/
-void save_file(const std::vector<unsigned char>& buffer, const std::string& filename)
-{
- std::ofstream file(filename.c_str(), std::ios::out|std::ios::binary);
- file.write(buffer.empty() ? 0 : (char*)&buffer[0], std::streamsize(buffer.size()));
-}
-#endif //LODEPNG_COMPILE_DISK
-
-#ifdef LODEPNG_COMPILE_ZLIB
-#ifdef LODEPNG_COMPILE_DECODER
-unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
- const LodePNGDecompressSettings& settings)
-{
- unsigned char* buffer = 0;
- size_t buffersize = 0;
- unsigned error = zlib_decompress(&buffer, &buffersize, in, insize, &settings);
- if(buffer)
- {
- out.insert(out.end(), &buffer[0], &buffer[buffersize]);
- lodepng_free(buffer);
- }
- return error;
-}
-
-unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
- const LodePNGDecompressSettings& settings)
-{
- return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings);
-}
-#endif //LODEPNG_COMPILE_DECODER
-
-#ifdef LODEPNG_COMPILE_ENCODER
-unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
- const LodePNGCompressSettings& settings)
-{
- unsigned char* buffer = 0;
- size_t buffersize = 0;
- unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings);
- if(buffer)
- {
- out.insert(out.end(), &buffer[0], &buffer[buffersize]);
- lodepng_free(buffer);
- }
- return error;
-}
-
-unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
- const LodePNGCompressSettings& settings)
-{
- return compress(out, in.empty() ? 0 : &in[0], in.size(), settings);
-}
-#endif //LODEPNG_COMPILE_ENCODER
-#endif //LODEPNG_COMPILE_ZLIB
-
-
-#ifdef LODEPNG_COMPILE_PNG
-
-State::State()
-{
- lodepng_state_init(this);
-}
-
-State::State(const State& other)
-{
- lodepng_state_init(this);
- lodepng_state_copy(this, &other);
-}
-
-State::~State()
-{
- lodepng_state_cleanup(this);
-}
-
-State& State::operator=(const State& other)
-{
- lodepng_state_copy(this, &other);
- return *this;
-}
-
-#ifdef LODEPNG_COMPILE_DECODER
-
-unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in,
- size_t insize, LodePNGColorType colortype, unsigned bitdepth)
-{
- unsigned char* buffer;
- unsigned error = lodepng_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth);
- if(buffer && !error)
- {
- State state;
- state.info_raw.colortype = colortype;
- state.info_raw.bitdepth = bitdepth;
- size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
- out.insert(out.end(), &buffer[0], &buffer[buffersize]);
- lodepng_free(buffer);
- }
- return error;
-}
-
-unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
- const std::vector<unsigned char>& in, LodePNGColorType colortype, unsigned bitdepth)
-{
- return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colortype, bitdepth);
-}
-
-unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
- State& state,
- const unsigned char* in, size_t insize)
-{
- unsigned char* buffer = NULL;
- unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize);
- if(buffer && !error)
- {
- size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw);
- out.insert(out.end(), &buffer[0], &buffer[buffersize]);
- }
- lodepng_free(buffer);
- return error;
-}
-
-unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
- State& state,
- const std::vector<unsigned char>& in)
-{
- return decode(out, w, h, state, in.empty() ? 0 : &in[0], in.size());
-}
-
-#ifdef LODEPNG_COMPILE_DISK
-unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename,
- LodePNGColorType colortype, unsigned bitdepth)
-{
- std::vector<unsigned char> buffer;
- load_file(buffer, filename);
- return decode(out, w, h, buffer, colortype, bitdepth);
-}
-#endif //LODEPNG_COMPILE_DECODER
-#endif //LODEPNG_COMPILE_DISK
-
-#ifdef LODEPNG_COMPILE_ENCODER
-unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h,
- LodePNGColorType colortype, unsigned bitdepth)
-{
- unsigned char* buffer;
- size_t buffersize;
- unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth);
- if(buffer)
- {
- out.insert(out.end(), &buffer[0], &buffer[buffersize]);
- lodepng_free(buffer);
- }
- return error;
-}
-
-unsigned encode(std::vector<unsigned char>& out,
- const std::vector<unsigned char>& in, unsigned w, unsigned h,
- LodePNGColorType colortype, unsigned bitdepth)
-{
- if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84;
- return encode(out, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
-}
-
-unsigned encode(std::vector<unsigned char>& out,
- const unsigned char* in, unsigned w, unsigned h,
- State& state)
-{
- unsigned char* buffer;
- size_t buffersize;
- unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state);
- if(buffer)
- {
- out.insert(out.end(), &buffer[0], &buffer[buffersize]);
- lodepng_free(buffer);
- }
- return error;
-}
-
-unsigned encode(std::vector<unsigned char>& out,
- const std::vector<unsigned char>& in, unsigned w, unsigned h,
- State& state)
-{
- if(lodepng_get_raw_size(w, h, &state.info_raw) > in.size()) return 84;
- return encode(out, in.empty() ? 0 : &in[0], w, h, state);
-}
-
-#ifdef LODEPNG_COMPILE_DISK
-unsigned encode(const std::string& filename,
- const unsigned char* in, unsigned w, unsigned h,
- LodePNGColorType colortype, unsigned bitdepth)
-{
- std::vector<unsigned char> buffer;
- unsigned error = encode(buffer, in, w, h, colortype, bitdepth);
- if(!error) save_file(buffer, filename);
- return error;
-}
-
-unsigned encode(const std::string& filename,
- const std::vector<unsigned char>& in, unsigned w, unsigned h,
- LodePNGColorType colortype, unsigned bitdepth)
-{
- if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84;
- return encode(filename, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth);
-}
-#endif //LODEPNG_COMPILE_DISK
-#endif //LODEPNG_COMPILE_ENCODER
-#endif //LODEPNG_COMPILE_PNG
-} //namespace lodepng
-#endif /*LODEPNG_COMPILE_CPP*/
diff --git a/plugingui/lodepng/lodepng.h b/plugingui/lodepng/lodepng.h
deleted file mode 100644
index c497a5c..0000000
--- a/plugingui/lodepng/lodepng.h
+++ /dev/null
@@ -1,1716 +0,0 @@
-/*
-LodePNG version 20131222
-
-Copyright (c) 2005-2013 Lode Vandevenne
-
-This software is provided 'as-is', without any express or implied
-warranty. In no event will the authors be held liable for any damages
-arising from the use of this software.
-
-Permission is granted to anyone to use this software for any purpose,
-including commercial applications, and to alter it and redistribute it
-freely, subject to the following restrictions:
-
- 1. The origin of this software must not be misrepresented; you must not
- claim that you wrote the original software. If you use this software
- in a product, an acknowledgment in the product documentation would be
- appreciated but is not required.
-
- 2. Altered source versions must be plainly marked as such, and must not be
- misrepresented as being the original software.
-
- 3. This notice may not be removed or altered from any source
- distribution.
-*/
-
-#ifndef LODEPNG_H
-#define LODEPNG_H
-
-#include <string.h> /*for size_t*/
-
-#ifdef __cplusplus
-#include <vector>
-#include <string>
-#endif /*__cplusplus*/
-
-/*
-The following #defines are used to create code sections. They can be disabled
-to disable code sections, which can give faster compile time and smaller binary.
-The "NO_COMPILE" defines are designed to be used to pass as defines to the
-compiler command to disable them without modifying this header, e.g.
--DLODEPNG_NO_COMPILE_ZLIB for gcc.
-*/
-/*deflate & zlib. If disabled, you must specify alternative zlib functions in
-the custom_zlib field of the compress and decompress settings*/
-#ifndef LODEPNG_NO_COMPILE_ZLIB
-#define LODEPNG_COMPILE_ZLIB
-#endif
-/*png encoder and png decoder*/
-#ifndef LODEPNG_NO_COMPILE_PNG
-#define LODEPNG_COMPILE_PNG
-#endif
-/*deflate&zlib decoder and png decoder*/
-#ifndef LODEPNG_NO_COMPILE_DECODER
-#define LODEPNG_COMPILE_DECODER
-#endif
-/*deflate&zlib encoder and png encoder*/
-#ifndef LODEPNG_NO_COMPILE_ENCODER
-#define LODEPNG_COMPILE_ENCODER
-#endif
-/*the optional built in harddisk file loading and saving functions*/
-#ifndef LODEPNG_NO_COMPILE_DISK
-#define LODEPNG_COMPILE_DISK
-#endif
-/*support for chunks other than IHDR, IDAT, PLTE, tRNS, IEND: ancillary and unknown chunks*/
-#ifndef LODEPNG_NO_COMPILE_ANCILLARY_CHUNKS
-#define LODEPNG_COMPILE_ANCILLARY_CHUNKS
-#endif
-/*ability to convert error numerical codes to English text string*/
-#ifndef LODEPNG_NO_COMPILE_ERROR_TEXT
-#define LODEPNG_COMPILE_ERROR_TEXT
-#endif
-/*Compile the default allocators (C's free, malloc and realloc). If you disable this,
-you can define the functions lodepng_free, lodepng_malloc and lodepng_realloc in your
-source files with custom allocators.*/
-#ifndef LODEPNG_NO_COMPILE_ALLOCATORS
-#define LODEPNG_COMPILE_ALLOCATORS
-#endif
-/*compile the C++ version (you can disable the C++ wrapper here even when compiling for C++)*/
-#ifdef __cplusplus
-#ifndef LODEPNG_NO_COMPILE_CPP
-#define LODEPNG_COMPILE_CPP
-#endif
-#endif
-
-#ifdef LODEPNG_COMPILE_PNG
-/*The PNG color types (also used for raw).*/
-typedef enum LodePNGColorType
-{
- LCT_GREY = 0, /*greyscale: 1,2,4,8,16 bit*/
- LCT_RGB = 2, /*RGB: 8,16 bit*/
- LCT_PALETTE = 3, /*palette: 1,2,4,8 bit*/
- LCT_GREY_ALPHA = 4, /*greyscale with alpha: 8,16 bit*/
- LCT_RGBA = 6 /*RGB with alpha: 8,16 bit*/
-} LodePNGColorType;
-
-#ifdef LODEPNG_COMPILE_DECODER
-/*
-Converts PNG data in memory to raw pixel data.
-out: Output parameter. Pointer to buffer that will contain the raw pixel data.
- After decoding, its size is w * h * (bytes per pixel) bytes larger than
- initially. Bytes per pixel depends on colortype and bitdepth.
- Must be freed after usage with free(*out).
- Note: for 16-bit per channel colors, uses big endian format like PNG does.
-w: Output parameter. Pointer to width of pixel data.
-h: Output parameter. Pointer to height of pixel data.
-in: Memory buffer with the PNG file.
-insize: size of the in buffer.
-colortype: the desired color type for the raw output image. See explanation on PNG color types.
-bitdepth: the desired bit depth for the raw output image. See explanation on PNG color types.
-Return value: LodePNG error code (0 means no error).
-*/
-unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h,
- const unsigned char* in, size_t insize,
- LodePNGColorType colortype, unsigned bitdepth);
-
-/*Same as lodepng_decode_memory, but always decodes to 32-bit RGBA raw image*/
-unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h,
- const unsigned char* in, size_t insize);
-
-/*Same as lodepng_decode_memory, but always decodes to 24-bit RGB raw image*/
-unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h,
- const unsigned char* in, size_t insize);
-
-#ifdef LODEPNG_COMPILE_DISK
-/*
-Load PNG from disk, from file with given name.
-Same as the other decode functions, but instead takes a filename as input.
-*/
-unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h,
- const char* filename,
- LodePNGColorType colortype, unsigned bitdepth);
-
-/*Same as lodepng_decode_file, but always decodes to 32-bit RGBA raw image.*/
-unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h,
- const char* filename);
-
-/*Same as lodepng_decode_file, but always decodes to 24-bit RGB raw image.*/
-unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h,
- const char* filename);
-#endif /*LODEPNG_COMPILE_DISK*/
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-
-#ifdef LODEPNG_COMPILE_ENCODER
-/*
-Converts raw pixel data into a PNG image in memory. The colortype and bitdepth
- of the output PNG image cannot be chosen, they are automatically determined
- by the colortype, bitdepth and content of the input pixel data.
- Note: for 16-bit per channel colors, needs big endian format like PNG does.
-out: Output parameter. Pointer to buffer that will contain the PNG image data.
- Must be freed after usage with free(*out).
-outsize: Output parameter. Pointer to the size in bytes of the out buffer.
-image: The raw pixel data to encode. The size of this buffer should be
- w * h * (bytes per pixel), bytes per pixel depends on colortype and bitdepth.
-w: width of the raw pixel data in pixels.
-h: height of the raw pixel data in pixels.
-colortype: the color type of the raw input image. See explanation on PNG color types.
-bitdepth: the bit depth of the raw input image. See explanation on PNG color types.
-Return value: LodePNG error code (0 means no error).
-*/
-unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize,
- const unsigned char* image, unsigned w, unsigned h,
- LodePNGColorType colortype, unsigned bitdepth);
-
-/*Same as lodepng_encode_memory, but always encodes from 32-bit RGBA raw image.*/
-unsigned lodepng_encode32(unsigned char** out, size_t* outsize,
- const unsigned char* image, unsigned w, unsigned h);
-
-/*Same as lodepng_encode_memory, but always encodes from 24-bit RGB raw image.*/
-unsigned lodepng_encode24(unsigned char** out, size_t* outsize,
- const unsigned char* image, unsigned w, unsigned h);
-
-#ifdef LODEPNG_COMPILE_DISK
-/*
-Converts raw pixel data into a PNG file on disk.
-Same as the other encode functions, but instead takes a filename as output.
-NOTE: This overwrites existing files without warning!
-*/
-unsigned lodepng_encode_file(const char* filename,
- const unsigned char* image, unsigned w, unsigned h,
- LodePNGColorType colortype, unsigned bitdepth);
-
-/*Same as lodepng_encode_file, but always encodes from 32-bit RGBA raw image.*/
-unsigned lodepng_encode32_file(const char* filename,
- const unsigned char* image, unsigned w, unsigned h);
-
-/*Same as lodepng_encode_file, but always encodes from 24-bit RGB raw image.*/
-unsigned lodepng_encode24_file(const char* filename,
- const unsigned char* image, unsigned w, unsigned h);
-#endif /*LODEPNG_COMPILE_DISK*/
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-
-#ifdef LODEPNG_COMPILE_CPP
-namespace lodepng
-{
-#ifdef LODEPNG_COMPILE_DECODER
-/*Same as lodepng_decode_memory, but decodes to an std::vector.*/
-unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
- const unsigned char* in, size_t insize,
- LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
-unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
- const std::vector<unsigned char>& in,
- LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
-#ifdef LODEPNG_COMPILE_DISK
-/*
-Converts PNG file from disk to raw pixel data in memory.
-Same as the other decode functions, but instead takes a filename as input.
-*/
-unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
- const std::string& filename,
- LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
-#endif //LODEPNG_COMPILE_DISK
-#endif //LODEPNG_COMPILE_DECODER
-
-#ifdef LODEPNG_COMPILE_ENCODER
-/*Same as lodepng_encode_memory, but encodes to an std::vector.*/
-unsigned encode(std::vector<unsigned char>& out,
- const unsigned char* in, unsigned w, unsigned h,
- LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
-unsigned encode(std::vector<unsigned char>& out,
- const std::vector<unsigned char>& in, unsigned w, unsigned h,
- LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
-#ifdef LODEPNG_COMPILE_DISK
-/*
-Converts 32-bit RGBA raw pixel data into a PNG file on disk.
-Same as the other encode functions, but instead takes a filename as output.
-NOTE: This overwrites existing files without warning!
-*/
-unsigned encode(const std::string& filename,
- const unsigned char* in, unsigned w, unsigned h,
- LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
-unsigned encode(const std::string& filename,
- const std::vector<unsigned char>& in, unsigned w, unsigned h,
- LodePNGColorType colortype = LCT_RGBA, unsigned bitdepth = 8);
-#endif //LODEPNG_COMPILE_DISK
-#endif //LODEPNG_COMPILE_ENCODER
-} //namespace lodepng
-#endif /*LODEPNG_COMPILE_CPP*/
-#endif /*LODEPNG_COMPILE_PNG*/
-
-#ifdef LODEPNG_COMPILE_ERROR_TEXT
-/*Returns an English description of the numerical error code.*/
-const char* lodepng_error_text(unsigned code);
-#endif /*LODEPNG_COMPILE_ERROR_TEXT*/
-
-#ifdef LODEPNG_COMPILE_DECODER
-/*Settings for zlib decompression*/
-typedef struct LodePNGDecompressSettings LodePNGDecompressSettings;
-struct LodePNGDecompressSettings
-{
- unsigned ignore_adler32; /*if 1, continue and don't give an error message if the Adler32 checksum is corrupted*/
-
- /*use custom zlib decoder instead of built in one (default: null)*/
- unsigned (*custom_zlib)(unsigned char**, size_t*,
- const unsigned char*, size_t,
- const LodePNGDecompressSettings*);
- /*use custom deflate decoder instead of built in one (default: null)
- if custom_zlib is used, custom_deflate is ignored since only the built in
- zlib function will call custom_deflate*/
- unsigned (*custom_inflate)(unsigned char**, size_t*,
- const unsigned char*, size_t,
- const LodePNGDecompressSettings*);
-
- const void* custom_context; /*optional custom settings for custom functions*/
-};
-
-extern const LodePNGDecompressSettings lodepng_default_decompress_settings;
-void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings);
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-#ifdef LODEPNG_COMPILE_ENCODER
-/*
-Settings for zlib compression. Tweaking these settings tweaks the balance
-between speed and compression ratio.
-*/
-typedef struct LodePNGCompressSettings LodePNGCompressSettings;
-struct LodePNGCompressSettings /*deflate = compress*/
-{
- /*LZ77 related settings*/
- unsigned btype; /*the block type for LZ (0, 1, 2 or 3, see zlib standard). Should be 2 for proper compression.*/
- unsigned use_lz77; /*whether or not to use LZ77. Should be 1 for proper compression.*/
- unsigned windowsize; /*must be a power of two <= 32768. higher compresses more but is slower. Typical value: 2048.*/
- unsigned minmatch; /*mininum lz77 length. 3 is normally best, 6 can be better for some PNGs. Default: 0*/
- unsigned nicematch; /*stop searching if >= this length found. Set to 258 for best compression. Default: 128*/
- unsigned lazymatching; /*use lazy matching: better compression but a bit slower. Default: true*/
-
- /*use custom zlib encoder instead of built in one (default: null)*/
- unsigned (*custom_zlib)(unsigned char**, size_t*,
- const unsigned char*, size_t,
- const LodePNGCompressSettings*);
- /*use custom deflate encoder instead of built in one (default: null)
- if custom_zlib is used, custom_deflate is ignored since only the built in
- zlib function will call custom_deflate*/
- unsigned (*custom_deflate)(unsigned char**, size_t*,
- const unsigned char*, size_t,
- const LodePNGCompressSettings*);
-
- const void* custom_context; /*optional custom settings for custom functions*/
-};
-
-extern const LodePNGCompressSettings lodepng_default_compress_settings;
-void lodepng_compress_settings_init(LodePNGCompressSettings* settings);
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-#ifdef LODEPNG_COMPILE_PNG
-/*
-Color mode of an image. Contains all information required to decode the pixel
-bits to RGBA colors. This information is the same as used in the PNG file
-format, and is used both for PNG and raw image data in LodePNG.
-*/
-typedef struct LodePNGColorMode
-{
- /*header (IHDR)*/
- LodePNGColorType colortype; /*color type, see PNG standard or documentation further in this header file*/
- unsigned bitdepth; /*bits per sample, see PNG standard or documentation further in this header file*/
-
- /*
- palette (PLTE and tRNS)
-
- Dynamically allocated with the colors of the palette, including alpha.
- When encoding a PNG, to store your colors in the palette of the LodePNGColorMode, first use
- lodepng_palette_clear, then for each color use lodepng_palette_add.
- If you encode an image without alpha with palette, don't forget to put value 255 in each A byte of the palette.
-
- When decoding, by default you can ignore this palette, since LodePNG already
- fills the palette colors in the pixels of the raw RGBA output.
-
- The palette is only supported for color type 3.
- */
- unsigned char* palette; /*palette in RGBARGBA... order. When allocated, must be either 0, or have size 1024*/
- size_t palettesize; /*palette size in number of colors (amount of bytes is 4 * palettesize)*/
-
- /*
- transparent color key (tRNS)
-
- This color uses the same bit depth as the bitdepth value in this struct, which can be 1-bit to 16-bit.
- For greyscale PNGs, r, g and b will all 3 be set to the same.
-
- When decoding, by default you can ignore this information, since LodePNG sets
- pixels with this key to transparent already in the raw RGBA output.
-
- The color key is only supported for color types 0 and 2.
- */
- unsigned key_defined; /*is a transparent color key given? 0 = false, 1 = true*/
- unsigned key_r; /*red/greyscale component of color key*/
- unsigned key_g; /*green component of color key*/
- unsigned key_b; /*blue component of color key*/
-} LodePNGColorMode;
-
-/*init, cleanup and copy functions to use with this struct*/
-void lodepng_color_mode_init(LodePNGColorMode* info);
-void lodepng_color_mode_cleanup(LodePNGColorMode* info);
-/*return value is error code (0 means no error)*/
-unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source);
-
-void lodepng_palette_clear(LodePNGColorMode* info);
-/*add 1 color to the palette*/
-unsigned lodepng_palette_add(LodePNGColorMode* info,
- unsigned char r, unsigned char g, unsigned char b, unsigned char a);
-
-/*get the total amount of bits per pixel, based on colortype and bitdepth in the struct*/
-unsigned lodepng_get_bpp(const LodePNGColorMode* info);
-/*get the amount of color channels used, based on colortype in the struct.
-If a palette is used, it counts as 1 channel.*/
-unsigned lodepng_get_channels(const LodePNGColorMode* info);
-/*is it a greyscale type? (only colortype 0 or 4)*/
-unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info);
-/*has it got an alpha channel? (only colortype 2 or 6)*/
-unsigned lodepng_is_alpha_type(const LodePNGColorMode* info);
-/*has it got a palette? (only colortype 3)*/
-unsigned lodepng_is_palette_type(const LodePNGColorMode* info);
-/*only returns true if there is a palette and there is a value in the palette with alpha < 255.
-Loops through the palette to check this.*/
-unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info);
-/*
-Check if the given color info indicates the possibility of having non-opaque pixels in the PNG image.
-Returns true if the image can have translucent or invisible pixels (it still be opaque if it doesn't use such pixels).
-Returns false if the image can only have opaque pixels.
-In detail, it returns true only if it's a color type with alpha, or has a palette with non-opaque values,
-or if "key_defined" is true.
-*/
-unsigned lodepng_can_have_alpha(const LodePNGColorMode* info);
-/*Returns the byte size of a raw image buffer with given width, height and color mode*/
-size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color);
-
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-/*The information of a Time chunk in PNG.*/
-typedef struct LodePNGTime
-{
- unsigned year; /*2 bytes used (0-65535)*/
- unsigned month; /*1-12*/
- unsigned day; /*1-31*/
- unsigned hour; /*0-23*/
- unsigned minute; /*0-59*/
- unsigned second; /*0-60 (to allow for leap seconds)*/
-} LodePNGTime;
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-
-/*Information about the PNG image, except pixels, width and height.*/
-typedef struct LodePNGInfo
-{
- /*header (IHDR), palette (PLTE) and transparency (tRNS) chunks*/
- unsigned compression_method;/*compression method of the original file. Always 0.*/
- unsigned filter_method; /*filter method of the original file*/
- unsigned interlace_method; /*interlace method of the original file*/
- LodePNGColorMode color; /*color type and bits, palette and transparency of the PNG file*/
-
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- /*
- suggested background color chunk (bKGD)
- This color uses the same color mode as the PNG (except alpha channel), which can be 1-bit to 16-bit.
-
- For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding
- the encoder writes the red one. For palette PNGs: When decoding, the RGB value
- will be stored, not a palette index. But when encoding, specify the index of
- the palette in background_r, the other two are then ignored.
-
- The decoder does not use this background color to edit the color of pixels.
- */
- unsigned background_defined; /*is a suggested background color given?*/
- unsigned background_r; /*red component of suggested background color*/
- unsigned background_g; /*green component of suggested background color*/
- unsigned background_b; /*blue component of suggested background color*/
-
- /*
- non-international text chunks (tEXt and zTXt)
-
- The char** arrays each contain num strings. The actual messages are in
- text_strings, while text_keys are keywords that give a short description what
- the actual text represents, e.g. Title, Author, Description, or anything else.
-
- A keyword is minimum 1 character and maximum 79 characters long. It's
- discouraged to use a single line length longer than 79 characters for texts.
-
- Don't allocate these text buffers yourself. Use the init/cleanup functions
- correctly and use lodepng_add_text and lodepng_clear_text.
- */
- size_t text_num; /*the amount of texts in these char** buffers (there may be more texts in itext)*/
- char** text_keys; /*the keyword of a text chunk (e.g. "Comment")*/
- char** text_strings; /*the actual text*/
-
- /*
- international text chunks (iTXt)
- Similar to the non-international text chunks, but with additional strings
- "langtags" and "transkeys".
- */
- size_t itext_num; /*the amount of international texts in this PNG*/
- char** itext_keys; /*the English keyword of the text chunk (e.g. "Comment")*/
- char** itext_langtags; /*language tag for this text's language, ISO/IEC 646 string, e.g. ISO 639 language tag*/
- char** itext_transkeys; /*keyword translated to the international language - UTF-8 string*/
- char** itext_strings; /*the actual international text - UTF-8 string*/
-
- /*time chunk (tIME)*/
- unsigned time_defined; /*set to 1 to make the encoder generate a tIME chunk*/
- LodePNGTime time;
-
- /*phys chunk (pHYs)*/
- unsigned phys_defined; /*if 0, there is no pHYs chunk and the values below are undefined, if 1 else there is one*/
- unsigned phys_x; /*pixels per unit in x direction*/
- unsigned phys_y; /*pixels per unit in y direction*/
- unsigned phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/
-
- /*
- unknown chunks
- There are 3 buffers, one for each position in the PNG where unknown chunks can appear
- each buffer contains all unknown chunks for that position consecutively
- The 3 buffers are the unknown chunks between certain critical chunks:
- 0: IHDR-PLTE, 1: PLTE-IDAT, 2: IDAT-IEND
- Do not allocate or traverse this data yourself. Use the chunk traversing functions declared
- later, such as lodepng_chunk_next and lodepng_chunk_append, to read/write this struct.
- */
- unsigned char* unknown_chunks_data[3];
- size_t unknown_chunks_size[3]; /*size in bytes of the unknown chunks, given for protection*/
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-} LodePNGInfo;
-
-/*init, cleanup and copy functions to use with this struct*/
-void lodepng_info_init(LodePNGInfo* info);
-void lodepng_info_cleanup(LodePNGInfo* info);
-/*return value is error code (0 means no error)*/
-unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source);
-
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-void lodepng_clear_text(LodePNGInfo* info); /*use this to clear the texts again after you filled them in*/
-unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str); /*push back both texts at once*/
-
-void lodepng_clear_itext(LodePNGInfo* info); /*use this to clear the itexts again after you filled them in*/
-unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag,
- const char* transkey, const char* str); /*push back the 4 texts of 1 chunk at once*/
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-
-/*
-Converts raw buffer from one color type to another color type, based on
-LodePNGColorMode structs to describe the input and output color type.
-See the reference manual at the end of this header file to see which color conversions are supported.
-return value = LodePNG error code (0 if all went ok, an error if the conversion isn't supported)
-The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel
-of the output color type (lodepng_get_bpp)
-The fix_png value works as described in struct LodePNGDecoderSettings.
-Note: for 16-bit per channel colors, uses big endian format like PNG does.
-*/
-unsigned lodepng_convert(unsigned char* out, const unsigned char* in,
- LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in,
- unsigned w, unsigned h, unsigned fix_png);
-
-#ifdef LODEPNG_COMPILE_DECODER
-/*
-Settings for the decoder. This contains settings for the PNG and the Zlib
-decoder, but not the Info settings from the Info structs.
-*/
-typedef struct LodePNGDecoderSettings
-{
- LodePNGDecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/
-
- unsigned ignore_crc; /*ignore CRC checksums*/
- /*
- The fix_png setting, if 1, makes the decoder tolerant towards some PNG images
- that do not correctly follow the PNG specification. This only supports errors
- that are fixable, were found in images that are actually used on the web, and
- are silently tolerated by other decoders as well. Currently only one such fix
- is implemented: if a palette index is out of bounds given the palette size,
- interpret it as opaque black.
- By default this value is 0, which makes it stop with an error on such images.
- */
- unsigned fix_png;
- unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/
-
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- unsigned read_text_chunks; /*if false but remember_unknown_chunks is true, they're stored in the unknown chunks*/
- /*store all bytes from unknown chunks in the LodePNGInfo (off by default, useful for a png editor)*/
- unsigned remember_unknown_chunks;
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-} LodePNGDecoderSettings;
-
-void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings);
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-#ifdef LODEPNG_COMPILE_ENCODER
-/*automatically use color type with less bits per pixel if losslessly possible. Default: AUTO*/
-typedef enum LodePNGFilterStrategy
-{
- /*every filter at zero*/
- LFS_ZERO,
- /*Use filter that gives minumum sum, as described in the official PNG filter heuristic.*/
- LFS_MINSUM,
- /*Use the filter type that gives smallest Shannon entropy for this scanline. Depending
- on the image, this is better or worse than minsum.*/
- LFS_ENTROPY,
- /*
- Brute-force-search PNG filters by compressing each filter for each scanline.
- Experimental, very slow, and only rarely gives better compression than MINSUM.
- */
- LFS_BRUTE_FORCE,
- /*use predefined_filters buffer: you specify the filter type for each scanline*/
- LFS_PREDEFINED
-} LodePNGFilterStrategy;
-
-/*automatically use color type with less bits per pixel if losslessly possible. Default: LAC_AUTO*/
-typedef enum LodePNGAutoConvert
-{
- LAC_NO, /*use color type user requested*/
- LAC_ALPHA, /*use color type user requested, but if only opaque pixels and RGBA or grey+alpha, use RGB or grey*/
- LAC_AUTO, /*use PNG color type that can losslessly represent the uncompressed image the smallest possible*/
- /*
- like AUTO, but do not choose 1, 2 or 4 bit per pixel types.
- sometimes a PNG image compresses worse if less than 8 bits per pixels.
- */
- LAC_AUTO_NO_NIBBLES,
- /*
- like AUTO, but never choose palette color type. For small images, encoding
- the palette may take more bytes than what is gained. Note that AUTO also
- already prevents encoding the palette for extremely small images, but that may
- not be sufficient because due to the compression it cannot predict when to
- switch.
- */
- LAC_AUTO_NO_PALETTE,
- LAC_AUTO_NO_NIBBLES_NO_PALETTE
-} LodePNGAutoConvert;
-
-
-/*
-Automatically chooses color type that gives smallest amount of bits in the
-output image, e.g. grey if there are only greyscale pixels, palette if there
-are less than 256 colors, ...
-The auto_convert parameter allows limiting it to not use palette, ...
-*/
-unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out,
- const unsigned char* image, unsigned w, unsigned h,
- const LodePNGColorMode* mode_in,
- LodePNGAutoConvert auto_convert);
-
-/*Settings for the encoder.*/
-typedef struct LodePNGEncoderSettings
-{
- LodePNGCompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/
-
- LodePNGAutoConvert auto_convert; /*how to automatically choose output PNG color type, if at all*/
-
- /*If true, follows the official PNG heuristic: if the PNG uses a palette or lower than
- 8 bit depth, set all filters to zero. Otherwise use the filter_strategy. Note that to
- completely follow the official PNG heuristic, filter_palette_zero must be true and
- filter_strategy must be LFS_MINSUM*/
- unsigned filter_palette_zero;
- /*Which filter strategy to use when not using zeroes due to filter_palette_zero.
- Set filter_palette_zero to 0 to ensure always using your chosen strategy. Default: LFS_MINSUM*/
- LodePNGFilterStrategy filter_strategy;
- /*used if filter_strategy is LFS_PREDEFINED. In that case, this must point to a buffer with
- the same length as the amount of scanlines in the image, and each value must <= 5. You
- have to cleanup this buffer, LodePNG will never free it. Don't forget that filter_palette_zero
- must be set to 0 to ensure this is also used on palette or low bitdepth images.*/
- const unsigned char* predefined_filters;
-
- /*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette).
- If colortype is 3, PLTE is _always_ created.*/
- unsigned force_palette;
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
- /*add LodePNG identifier and version as a text chunk, for debugging*/
- unsigned add_id;
- /*encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks*/
- unsigned text_compression;
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
-} LodePNGEncoderSettings;
-
-void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings);
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-
-#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER)
-/*The settings, state and information for extended encoding and decoding.*/
-typedef struct LodePNGState
-{
-#ifdef LODEPNG_COMPILE_DECODER
- LodePNGDecoderSettings decoder; /*the decoding settings*/
-#endif /*LODEPNG_COMPILE_DECODER*/
-#ifdef LODEPNG_COMPILE_ENCODER
- LodePNGEncoderSettings encoder; /*the encoding settings*/
-#endif /*LODEPNG_COMPILE_ENCODER*/
- LodePNGColorMode info_raw; /*specifies the format in which you would like to get the raw pixel buffer*/
- LodePNGInfo info_png; /*info of the PNG image obtained after decoding*/
- unsigned error;
-#ifdef LODEPNG_COMPILE_CPP
- //For the lodepng::State subclass.
- virtual ~LodePNGState(){}
-#endif
-} LodePNGState;
-
-/*init, cleanup and copy functions to use with this struct*/
-void lodepng_state_init(LodePNGState* state);
-void lodepng_state_cleanup(LodePNGState* state);
-void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source);
-#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */
-
-#ifdef LODEPNG_COMPILE_DECODER
-/*
-Same as lodepng_decode_memory, but uses a LodePNGState to allow custom settings and
-getting much more information about the PNG image and color mode.
-*/
-unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h,
- LodePNGState* state,
- const unsigned char* in, size_t insize);
-
-/*
-Read the PNG header, but not the actual data. This returns only the information
-that is in the header chunk of the PNG, such as width, height and color type. The
-information is placed in the info_png field of the LodePNGState.
-*/
-unsigned lodepng_inspect(unsigned* w, unsigned* h,
- LodePNGState* state,
- const unsigned char* in, size_t insize);
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-
-#ifdef LODEPNG_COMPILE_ENCODER
-/*This function allocates the out buffer with standard malloc and stores the size in *outsize.*/
-unsigned lodepng_encode(unsigned char** out, size_t* outsize,
- const unsigned char* image, unsigned w, unsigned h,
- LodePNGState* state);
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-/*
-The lodepng_chunk functions are normally not needed, except to traverse the
-unknown chunks stored in the LodePNGInfo struct, or add new ones to it.
-It also allows traversing the chunks of an encoded PNG file yourself.
-
-PNG standard chunk naming conventions:
-First byte: uppercase = critical, lowercase = ancillary
-Second byte: uppercase = public, lowercase = private
-Third byte: must be uppercase
-Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy
-*/
-
-/*get the length of the data of the chunk. Total chunk length has 12 bytes more.*/
-unsigned lodepng_chunk_length(const unsigned char* chunk);
-
-/*puts the 4-byte type in null terminated string*/
-void lodepng_chunk_type(char type[5], const unsigned char* chunk);
-
-/*check if the type is the given type*/
-unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type);
-
-/*0: it's one of the critical chunk types, 1: it's an ancillary chunk (see PNG standard)*/
-unsigned char lodepng_chunk_ancillary(const unsigned char* chunk);
-
-/*0: public, 1: private (see PNG standard)*/
-unsigned char lodepng_chunk_private(const unsigned char* chunk);
-
-/*0: the chunk is unsafe to copy, 1: the chunk is safe to copy (see PNG standard)*/
-unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk);
-
-/*get pointer to the data of the chunk, where the input points to the header of the chunk*/
-unsigned char* lodepng_chunk_data(unsigned char* chunk);
-const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk);
-
-/*returns 0 if the crc is correct, 1 if it's incorrect (0 for OK as usual!)*/
-unsigned lodepng_chunk_check_crc(const unsigned char* chunk);
-
-/*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/
-void lodepng_chunk_generate_crc(unsigned char* chunk);
-
-/*iterate to next chunks. don't use on IEND chunk, as there is no next chunk then*/
-unsigned char* lodepng_chunk_next(unsigned char* chunk);
-const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk);
-
-/*
-Appends chunk to the data in out. The given chunk should already have its chunk header.
-The out variable and outlength are updated to reflect the new reallocated buffer.
-Returns error code (0 if it went ok)
-*/
-unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk);
-
-/*
-Appends new chunk to out. The chunk to append is given by giving its length, type
-and data separately. The type is a 4-letter string.
-The out variable and outlength are updated to reflect the new reallocated buffer.
-Returne error code (0 if it went ok)
-*/
-unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
- const char* type, const unsigned char* data);
-
-
-/*Calculate CRC32 of buffer*/
-unsigned lodepng_crc32(const unsigned char* buf, size_t len);
-#endif /*LODEPNG_COMPILE_PNG*/
-
-
-#ifdef LODEPNG_COMPILE_ZLIB
-/*
-This zlib part can be used independently to zlib compress and decompress a
-buffer. It cannot be used to create gzip files however, and it only supports the
-part of zlib that is required for PNG, it does not support dictionaries.
-*/
-
-#ifdef LODEPNG_COMPILE_DECODER
-/*Inflate a buffer. Inflate is the decompression step of deflate. Out buffer must be freed after use.*/
-unsigned lodepng_inflate(unsigned char** out, size_t* outsize,
- const unsigned char* in, size_t insize,
- const LodePNGDecompressSettings* settings);
-
-/*
-Decompresses Zlib data. Reallocates the out buffer and appends the data. The
-data must be according to the zlib specification.
-Either, *out must be NULL and *outsize must be 0, or, *out must be a valid
-buffer and *outsize its size in bytes. out must be freed by user after usage.
-*/
-unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize,
- const unsigned char* in, size_t insize,
- const LodePNGDecompressSettings* settings);
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-#ifdef LODEPNG_COMPILE_ENCODER
-/*
-Compresses data with Zlib. Reallocates the out buffer and appends the data.
-Zlib adds a small header and trailer around the deflate data.
-The data is output in the format of the zlib specification.
-Either, *out must be NULL and *outsize must be 0, or, *out must be a valid
-buffer and *outsize its size in bytes. out must be freed by user after usage.
-*/
-unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize,
- const unsigned char* in, size_t insize,
- const LodePNGCompressSettings* settings);
-
-/*
-Find length-limited Huffman code for given frequencies. This function is in the
-public interface only for tests, it's used internally by lodepng_deflate.
-*/
-unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies,
- size_t numcodes, unsigned maxbitlen);
-
-/*Compress a buffer with deflate. See RFC 1951. Out buffer must be freed after use.*/
-unsigned lodepng_deflate(unsigned char** out, size_t* outsize,
- const unsigned char* in, size_t insize,
- const LodePNGCompressSettings* settings);
-
-#endif /*LODEPNG_COMPILE_ENCODER*/
-#endif /*LODEPNG_COMPILE_ZLIB*/
-
-#ifdef LODEPNG_COMPILE_DISK
-/*
-Load a file from disk into buffer. The function allocates the out buffer, and
-after usage you should free it.
-out: output parameter, contains pointer to loaded buffer.
-outsize: output parameter, size of the allocated out buffer
-filename: the path to the file to load
-return value: error code (0 means ok)
-*/
-unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename);
-
-/*
-Save a file from buffer to disk. Warning, if it exists, this function overwrites
-the file without warning!
-buffer: the buffer to write
-buffersize: size of the buffer to write
-filename: the path to the file to save to
-return value: error code (0 means ok)
-*/
-unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename);
-#endif /*LODEPNG_COMPILE_DISK*/
-
-#ifdef LODEPNG_COMPILE_CPP
-//The LodePNG C++ wrapper uses std::vectors instead of manually allocated memory buffers.
-namespace lodepng
-{
-#ifdef LODEPNG_COMPILE_PNG
-class State : public LodePNGState
-{
- public:
- State();
- State(const State& other);
- virtual ~State();
- State& operator=(const State& other);
-};
-
-#ifdef LODEPNG_COMPILE_DECODER
-//Same as other lodepng::decode, but using a State for more settings and information.
-unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
- State& state,
- const unsigned char* in, size_t insize);
-unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h,
- State& state,
- const std::vector<unsigned char>& in);
-#endif /*LODEPNG_COMPILE_DECODER*/
-
-#ifdef LODEPNG_COMPILE_ENCODER
-//Same as other lodepng::encode, but using a State for more settings and information.
-unsigned encode(std::vector<unsigned char>& out,
- const unsigned char* in, unsigned w, unsigned h,
- State& state);
-unsigned encode(std::vector<unsigned char>& out,
- const std::vector<unsigned char>& in, unsigned w, unsigned h,
- State& state);
-#endif /*LODEPNG_COMPILE_ENCODER*/
-
-#ifdef LODEPNG_COMPILE_DISK
-/*
-Load a file from disk into an std::vector. If the vector is empty, then either
-the file doesn't exist or is an empty file.
-*/
-void load_file(std::vector<unsigned char>& buffer, const std::string& filename);
-
-/*
-Save the binary data in an std::vector to a file on disk. The file is overwritten
-without warning.
-*/
-void save_file(const std::vector<unsigned char>& buffer, const std::string& filename);
-#endif //LODEPNG_COMPILE_DISK
-#endif //LODEPNG_COMPILE_PNG
-
-#ifdef LODEPNG_COMPILE_ZLIB
-#ifdef LODEPNG_COMPILE_DECODER
-//Zlib-decompress an unsigned char buffer
-unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
- const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings);
-
-//Zlib-decompress an std::vector
-unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
- const LodePNGDecompressSettings& settings = lodepng_default_decompress_settings);
-#endif //LODEPNG_COMPILE_DECODER
-
-#ifdef LODEPNG_COMPILE_ENCODER
-//Zlib-compress an unsigned char buffer
-unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize,
- const LodePNGCompressSettings& settings = lodepng_default_compress_settings);
-
-//Zlib-compress an std::vector
-unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in,
- const LodePNGCompressSettings& settings = lodepng_default_compress_settings);
-#endif //LODEPNG_COMPILE_ENCODER
-#endif //LODEPNG_COMPILE_ZLIB
-} //namespace lodepng
-#endif /*LODEPNG_COMPILE_CPP*/
-
-/*
-TODO:
-[.] test if there are no memory leaks or security exploits - done a lot but needs to be checked often
-[.] check compatibility with vareous compilers - done but needs to be redone for every newer version
-[X] converting color to 16-bit per channel types
-[ ] read all public PNG chunk types (but never let the color profile and gamma ones touch RGB values)
-[ ] make sure encoder generates no chunks with size > (2^31)-1
-[ ] partial decoding (stream processing)
-[X] let the "isFullyOpaque" function check color keys and transparent palettes too
-[X] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl"
-[ ] don't stop decoding on errors like 69, 57, 58 (make warnings)
-[ ] make option to choose if the raw image with non multiple of 8 bits per scanline should have padding bits or not
-[ ] let the C++ wrapper catch exceptions coming from the standard library and return LodePNG error codes
-*/
-
-#endif /*LODEPNG_H inclusion guard*/
-
-/*
-LodePNG Documentation
----------------------
-
-0. table of contents
---------------------
-
- 1. about
- 1.1. supported features
- 1.2. features not supported
- 2. C and C++ version
- 3. security
- 4. decoding
- 5. encoding
- 6. color conversions
- 6.1. PNG color types
- 6.2. color conversions
- 6.3. padding bits
- 6.4. A note about 16-bits per channel and endianness
- 7. error values
- 8. chunks and PNG editing
- 9. compiler support
- 10. examples
- 10.1. decoder C++ example
- 10.2. decoder C example
- 11. changes
- 12. contact information
-
-
-1. about
---------
-
-PNG is a file format to store raster images losslessly with good compression,
-supporting different color types and alpha channel.
-
-LodePNG is a PNG codec according to the Portable Network Graphics (PNG)
-Specification (Second Edition) - W3C Recommendation 10 November 2003.
-
-The specifications used are:
-
-*) Portable Network Graphics (PNG) Specification (Second Edition):
- http://www.w3.org/TR/2003/REC-PNG-20031110
-*) RFC 1950 ZLIB Compressed Data Format version 3.3:
- http://www.gzip.org/zlib/rfc-zlib.html
-*) RFC 1951 DEFLATE Compressed Data Format Specification ver 1.3:
- http://www.gzip.org/zlib/rfc-deflate.html
-
-The most recent version of LodePNG can currently be found at
-http://lodev.org/lodepng/
-
-LodePNG works both in C (ISO C90) and C++, with a C++ wrapper that adds
-extra functionality.
-
-LodePNG exists out of two files:
--lodepng.h: the header file for both C and C++
--lodepng.c(pp): give it the name lodepng.c or lodepng.cpp (or .cc) depending on your usage
-
-If you want to start using LodePNG right away without reading this doc, get the
-examples from the LodePNG website to see how to use it in code, or check the
-smaller examples in chapter 13 here.
-
-LodePNG is simple but only supports the basic requirements. To achieve
-simplicity, the following design choices were made: There are no dependencies
-on any external library. There are functions to decode and encode a PNG with
-a single function call, and extended versions of these functions taking a
-LodePNGState struct allowing to specify or get more information. By default
-the colors of the raw image are always RGB or RGBA, no matter what color type
-the PNG file uses. To read and write files, there are simple functions to
-convert the files to/from buffers in memory.
-
-This all makes LodePNG suitable for loading textures in games, demos and small
-programs, ... It's less suitable for full fledged image editors, loading PNGs
-over network (it requires all the image data to be available before decoding can
-begin), life-critical systems, ...
-
-1.1. supported features
------------------------
-
-The following features are supported by the decoder:
-
-*) decoding of PNGs with any color type, bit depth and interlace mode, to a 24- or 32-bit color raw image,
- or the same color type as the PNG
-*) encoding of PNGs, from any raw image to 24- or 32-bit color, or the same color type as the raw image
-*) Adam7 interlace and deinterlace for any color type
-*) loading the image from harddisk or decoding it from a buffer from other sources than harddisk
-*) support for alpha channels, including RGBA color model, translucent palettes and color keying
-*) zlib decompression (inflate)
-*) zlib compression (deflate)
-*) CRC32 and ADLER32 checksums
-*) handling of unknown chunks, allowing making a PNG editor that stores custom and unknown chunks.
-*) the following chunks are supported (generated/interpreted) by both encoder and decoder:
- IHDR: header information
- PLTE: color palette
- IDAT: pixel data
- IEND: the final chunk
- tRNS: transparency for palettized images
- tEXt: textual information
- zTXt: compressed textual information
- iTXt: international textual information
- bKGD: suggested background color
- pHYs: physical dimensions
- tIME: modification time
-
-1.2. features not supported
----------------------------
-
-The following features are _not_ supported:
-
-*) some features needed to make a conformant PNG-Editor might be still missing.
-*) partial loading/stream processing. All data must be available and is processed in one call.
-*) The following public chunks are not supported but treated as unknown chunks by LodePNG
- cHRM, gAMA, iCCP, sRGB, sBIT, hIST, sPLT
- Some of these are not supported on purpose: LodePNG wants to provide the RGB values
- stored in the pixels, not values modified by system dependent gamma or color models.
-
-
-2. C and C++ version
---------------------
-
-The C version uses buffers allocated with alloc that you need to free()
-yourself. You need to use init and cleanup functions for each struct whenever
-using a struct from the C version to avoid exploits and memory leaks.
-
-The C++ version has extra functions with std::vectors in the interface and the
-lodepng::State class which is a LodePNGState with constructor and destructor.
-
-These files work without modification for both C and C++ compilers because all
-the additional C++ code is in "#ifdef __cplusplus" blocks that make C-compilers
-ignore it, and the C code is made to compile both with strict ISO C90 and C++.
-
-To use the C++ version, you need to rename the source file to lodepng.cpp
-(instead of lodepng.c), and compile it with a C++ compiler.
-
-To use the C version, you need to rename the source file to lodepng.c (instead
-of lodepng.cpp), and compile it with a C compiler.
-
-
-3. Security
------------
-
-Even if carefully designed, it's always possible that LodePNG contains possible
-exploits. If you discover one, please let me know, and it will be fixed.
-
-When using LodePNG, care has to be taken with the C version of LodePNG, as well
-as the C-style structs when working with C++. The following conventions are used
-for all C-style structs:
-
--if a struct has a corresponding init function, always call the init function when making a new one
--if a struct has a corresponding cleanup function, call it before the struct disappears to avoid memory leaks
--if a struct has a corresponding copy function, use the copy function instead of "=".
- The destination must also be inited already.
-
-
-4. Decoding
------------
-
-Decoding converts a PNG compressed image to a raw pixel buffer.
-
-Most documentation on using the decoder is at its declarations in the header
-above. For C, simple decoding can be done with functions such as
-lodepng_decode32, and more advanced decoding can be done with the struct
-LodePNGState and lodepng_decode. For C++, all decoding can be done with the
-various lodepng::decode functions, and lodepng::State can be used for advanced
-features.
-
-When using the LodePNGState, it uses the following fields for decoding:
-*) LodePNGInfo info_png: it stores extra information about the PNG (the input) in here
-*) LodePNGColorMode info_raw: here you can say what color mode of the raw image (the output) you want to get
-*) LodePNGDecoderSettings decoder: you can specify a few extra settings for the decoder to use
-
-LodePNGInfo info_png
---------------------
-
-After decoding, this contains extra information of the PNG image, except the actual
-pixels, width and height because these are already gotten directly from the decoder
-functions.
-
-It contains for example the original color type of the PNG image, text comments,
-suggested background color, etc... More details about the LodePNGInfo struct are
-at its declaration documentation.
-
-LodePNGColorMode info_raw
--------------------------
-
-When decoding, here you can specify which color type you want
-the resulting raw image to be. If this is different from the colortype of the
-PNG, then the decoder will automatically convert the result. This conversion
-always works, except if you want it to convert a color PNG to greyscale or to
-a palette with missing colors.
-
-By default, 32-bit color is used for the result.
-
-LodePNGDecoderSettings decoder
-------------------------------
-
-The settings can be used to ignore the errors created by invalid CRC and Adler32
-chunks, and to disable the decoding of tEXt chunks.
-
-There's also a setting color_convert, true by default. If false, no conversion
-is done, the resulting data will be as it was in the PNG (after decompression)
-and you'll have to puzzle the colors of the pixels together yourself using the
-color type information in the LodePNGInfo.
-
-
-5. Encoding
------------
-
-Encoding converts a raw pixel buffer to a PNG compressed image.
-
-Most documentation on using the encoder is at its declarations in the header
-above. For C, simple encoding can be done with functions such as
-lodepng_encode32, and more advanced decoding can be done with the struct
-LodePNGState and lodepng_encode. For C++, all encoding can be done with the
-various lodepng::encode functions, and lodepng::State can be used for advanced
-features.
-
-Like the decoder, the encoder can also give errors. However it gives less errors
-since the encoder input is trusted, the decoder input (a PNG image that could
-be forged by anyone) is not trusted.
-
-When using the LodePNGState, it uses the following fields for encoding:
-*) LodePNGInfo info_png: here you specify how you want the PNG (the output) to be.
-*) LodePNGColorMode info_raw: here you say what color type of the raw image (the input) has
-*) LodePNGEncoderSettings encoder: you can specify a few settings for the encoder to use
-
-LodePNGInfo info_png
---------------------
-
-When encoding, you use this the opposite way as when decoding: for encoding,
-you fill in the values you want the PNG to have before encoding. By default it's
-not needed to specify a color type for the PNG since it's automatically chosen,
-but it's possible to choose it yourself given the right settings.
-
-The encoder will not always exactly match the LodePNGInfo struct you give,
-it tries as close as possible. Some things are ignored by the encoder. The
-encoder uses, for example, the following settings from it when applicable:
-colortype and bitdepth, text chunks, time chunk, the color key, the palette, the
-background color, the interlace method, unknown chunks, ...
-
-When encoding to a PNG with colortype 3, the encoder will generate a PLTE chunk.
-If the palette contains any colors for which the alpha channel is not 255 (so
-there are translucent colors in the palette), it'll add a tRNS chunk.
-
-LodePNGColorMode info_raw
--------------------------
-
-You specify the color type of the raw image that you give to the input here,
-including a possible transparent color key and palette you happen to be using in
-your raw image data.
-
-By default, 32-bit color is assumed, meaning your input has to be in RGBA
-format with 4 bytes (unsigned chars) per pixel.
-
-LodePNGEncoderSettings encoder
-------------------------------
-
-The following settings are supported (some are in sub-structs):
-*) auto_convert: when this option is enabled, the encoder will
-automatically choose the smallest possible color mode (including color key) that
-can encode the colors of all pixels without information loss.
-*) btype: the block type for LZ77. 0 = uncompressed, 1 = fixed huffman tree,
- 2 = dynamic huffman tree (best compression). Should be 2 for proper
- compression.
-*) use_lz77: whether or not to use LZ77 for compressed block types. Should be
- true for proper compression.
-*) windowsize: the window size used by the LZ77 encoder (1 - 32768). Has value
- 2048 by default, but can be set to 32768 for better, but slow, compression.
-*) force_palette: if colortype is 2 or 6, you can make the encoder write a PLTE
- chunk if force_palette is true. This can used as suggested palette to convert
- to by viewers that don't support more than 256 colors (if those still exist)
-*) add_id: add text chunk "Encoder: LodePNG <version>" to the image.
-*) text_compression: default 1. If 1, it'll store texts as zTXt instead of tEXt chunks.
- zTXt chunks use zlib compression on the text. This gives a smaller result on
- large texts but a larger result on small texts (such as a single program name).
- It's all tEXt or all zTXt though, there's no separate setting per text yet.
-
-
-6. color conversions
---------------------
-
-An important thing to note about LodePNG, is that the color type of the PNG, and
-the color type of the raw image, are completely independent. By default, when
-you decode a PNG, you get the result as a raw image in the color type you want,
-no matter whether the PNG was encoded with a palette, greyscale or RGBA color.
-And if you encode an image, by default LodePNG will automatically choose the PNG
-color type that gives good compression based on the values of colors and amount
-of colors in the image. It can be configured to let you control it instead as
-well, though.
-
-To be able to do this, LodePNG does conversions from one color mode to another.
-It can convert from almost any color type to any other color type, except the
-following conversions: RGB to greyscale is not supported, and converting to a
-palette when the palette doesn't have a required color is not supported. This is
-not supported on purpose: this is information loss which requires a color
-reduction algorithm that is beyong the scope of a PNG encoder (yes, RGB to grey
-is easy, but there are multiple ways if you want to give some channels more
-weight).
-
-By default, when decoding, you get the raw image in 32-bit RGBA or 24-bit RGB
-color, no matter what color type the PNG has. And by default when encoding,
-LodePNG automatically picks the best color model for the output PNG, and expects
-the input image to be 32-bit RGBA or 24-bit RGB. So, unless you want to control
-the color format of the images yourself, you can skip this chapter.
-
-6.1. PNG color types
---------------------
-
-A PNG image can have many color types, ranging from 1-bit color to 64-bit color,
-as well as palettized color modes. After the zlib decompression and unfiltering
-in the PNG image is done, the raw pixel data will have that color type and thus
-a certain amount of bits per pixel. If you want the output raw image after
-decoding to have another color type, a conversion is done by LodePNG.
-
-The PNG specification gives the following color types:
-
-0: greyscale, bit depths 1, 2, 4, 8, 16
-2: RGB, bit depths 8 and 16
-3: palette, bit depths 1, 2, 4 and 8
-4: greyscale with alpha, bit depths 8 and 16
-6: RGBA, bit depths 8 and 16
-
-Bit depth is the amount of bits per pixel per color channel. So the total amount
-of bits per pixel is: amount of channels * bitdepth.
-
-6.2. color conversions
-----------------------
-
-As explained in the sections about the encoder and decoder, you can specify
-color types and bit depths in info_png and info_raw to change the default
-behaviour.
-
-If, when decoding, you want the raw image to be something else than the default,
-you need to set the color type and bit depth you want in the LodePNGColorMode,
-or the parameters of the simple function of LodePNG you're using.
-
-If, when encoding, you use another color type than the default in the input
-image, you need to specify its color type and bit depth in the LodePNGColorMode
-of the raw image, or use the parameters of the simplefunction of LodePNG you're
-using.
-
-If, when encoding, you don't want LodePNG to choose the output PNG color type
-but control it yourself, you need to set auto_convert in the encoder settings
-to LAC_NONE, and specify the color type you want in the LodePNGInfo of the
-encoder.
-
-If you do any of the above, LodePNG may need to do a color conversion, which
-follows the rules below, and may sometimes not be allowed.
-
-To avoid some confusion:
--the decoder converts from PNG to raw image
--the encoder converts from raw image to PNG
--the colortype and bitdepth in LodePNGColorMode info_raw, are those of the raw image
--the colortype and bitdepth in the color field of LodePNGInfo info_png, are those of the PNG
--when encoding, the color type in LodePNGInfo is ignored if auto_convert
- is enabled, it is automatically generated instead
--when decoding, the color type in LodePNGInfo is set by the decoder to that of the original
- PNG image, but it can be ignored since the raw image has the color type you requested instead
--if the color type of the LodePNGColorMode and PNG image aren't the same, a conversion
- between the color types is done if the color types are supported. If it is not
- supported, an error is returned. If the types are the same, no conversion is done.
--even though some conversions aren't supported, LodePNG supports loading PNGs from any
- colortype and saving PNGs to any colortype, sometimes it just requires preparing
- the raw image correctly before encoding.
--both encoder and decoder use the same color converter.
-
-Non supported color conversions:
--color to greyscale: no error is thrown, but the result will look ugly because
-only the red channel is taken
--anything, to palette when that palette does not have that color in it: in this
-case an error is thrown
-
-Supported color conversions:
--anything to 8-bit RGB, 8-bit RGBA, 16-bit RGB, 16-bit RGBA
--any grey or grey+alpha, to grey or grey+alpha
--anything to a palette, as long as the palette has the requested colors in it
--removing alpha channel
--higher to smaller bitdepth, and vice versa
-
-If you want no color conversion to be done:
--In the encoder, you can make it save a PNG with any color type by giving the
-raw color mode and LodePNGInfo the same color mode, and setting auto_convert to
-LAC_NO.
--In the decoder, you can make it store the pixel data in the same color type
-as the PNG has, by setting the color_convert setting to false. Settings in
-info_raw are then ignored.
-
-The function lodepng_convert does the color conversion. It is available in the
-interface but normally isn't needed since the encoder and decoder already call
-it.
-
-6.3. padding bits
------------------
-
-In the PNG file format, if a less than 8-bit per pixel color type is used and the scanlines
-have a bit amount that isn't a multiple of 8, then padding bits are used so that each
-scanline starts at a fresh byte. But that is NOT true for the LodePNG raw input and output.
-The raw input image you give to the encoder, and the raw output image you get from the decoder
-will NOT have these padding bits, e.g. in the case of a 1-bit image with a width
-of 7 pixels, the first pixel of the second scanline will the the 8th bit of the first byte,
-not the first bit of a new byte.
-
-6.4. A note about 16-bits per channel and endianness
-----------------------------------------------------
-
-LodePNG uses unsigned char arrays for 16-bit per channel colors too, just like
-for any other color format. The 16-bit values are stored in big endian (most
-significant byte first) in these arrays. This is the opposite order of the
-little endian used by x86 CPU's.
-
-LodePNG always uses big endian because the PNG file format does so internally.
-Conversions to other formats than PNG uses internally are not supported by
-LodePNG on purpose, there are myriads of formats, including endianness of 16-bit
-colors, the order in which you store R, G, B and A, and so on. Supporting and
-converting to/from all that is outside the scope of LodePNG.
-
-This may mean that, depending on your use case, you may want to convert the big
-endian output of LodePNG to little endian with a for loop. This is certainly not
-always needed, many applications and libraries support big endian 16-bit colors
-anyway, but it means you cannot simply cast the unsigned char* buffer to an
-unsigned short* buffer on x86 CPUs.
-
-
-7. error values
----------------
-
-All functions in LodePNG that return an error code, return 0 if everything went
-OK, or a non-zero code if there was an error.
-
-The meaning of the LodePNG error values can be retrieved with the function
-lodepng_error_text: given the numerical error code, it returns a description
-of the error in English as a string.
-
-Check the implementation of lodepng_error_text to see the meaning of each code.
-
-
-8. chunks and PNG editing
--------------------------
-
-If you want to add extra chunks to a PNG you encode, or use LodePNG for a PNG
-editor that should follow the rules about handling of unknown chunks, or if your
-program is able to read other types of chunks than the ones handled by LodePNG,
-then that's possible with the chunk functions of LodePNG.
-
-A PNG chunk has the following layout:
-
-4 bytes length
-4 bytes type name
-length bytes data
-4 bytes CRC
-
-8.1. iterating through chunks
------------------------------
-
-If you have a buffer containing the PNG image data, then the first chunk (the
-IHDR chunk) starts at byte number 8 of that buffer. The first 8 bytes are the
-signature of the PNG and are not part of a chunk. But if you start at byte 8
-then you have a chunk, and can check the following things of it.
-
-NOTE: none of these functions check for memory buffer boundaries. To avoid
-exploits, always make sure the buffer contains all the data of the chunks.
-When using lodepng_chunk_next, make sure the returned value is within the
-allocated memory.
-
-unsigned lodepng_chunk_length(const unsigned char* chunk):
-
-Get the length of the chunk's data. The total chunk length is this length + 12.
-
-void lodepng_chunk_type(char type[5], const unsigned char* chunk):
-unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type):
-
-Get the type of the chunk or compare if it's a certain type
-
-unsigned char lodepng_chunk_critical(const unsigned char* chunk):
-unsigned char lodepng_chunk_private(const unsigned char* chunk):
-unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk):
-
-Check if the chunk is critical in the PNG standard (only IHDR, PLTE, IDAT and IEND are).
-Check if the chunk is private (public chunks are part of the standard, private ones not).
-Check if the chunk is safe to copy. If it's not, then, when modifying data in a critical
-chunk, unsafe to copy chunks of the old image may NOT be saved in the new one if your
-program doesn't handle that type of unknown chunk.
-
-unsigned char* lodepng_chunk_data(unsigned char* chunk):
-const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk):
-
-Get a pointer to the start of the data of the chunk.
-
-unsigned lodepng_chunk_check_crc(const unsigned char* chunk):
-void lodepng_chunk_generate_crc(unsigned char* chunk):
-
-Check if the crc is correct or generate a correct one.
-
-unsigned char* lodepng_chunk_next(unsigned char* chunk):
-const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk):
-
-Iterate to the next chunk. This works if you have a buffer with consecutive chunks. Note that these
-functions do no boundary checking of the allocated data whatsoever, so make sure there is enough
-data available in the buffer to be able to go to the next chunk.
-
-unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk):
-unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length,
- const char* type, const unsigned char* data):
-
-These functions are used to create new chunks that are appended to the data in *out that has
-length *outlength. The append function appends an existing chunk to the new data. The create
-function creates a new chunk with the given parameters and appends it. Type is the 4-letter
-name of the chunk.
-
-8.2. chunks in info_png
------------------------
-
-The LodePNGInfo struct contains fields with the unknown chunk in it. It has 3
-buffers (each with size) to contain 3 types of unknown chunks:
-the ones that come before the PLTE chunk, the ones that come between the PLTE
-and the IDAT chunks, and the ones that come after the IDAT chunks.
-It's necessary to make the distionction between these 3 cases because the PNG
-standard forces to keep the ordering of unknown chunks compared to the critical
-chunks, but does not force any other ordering rules.
-
-info_png.unknown_chunks_data[0] is the chunks before PLTE
-info_png.unknown_chunks_data[1] is the chunks after PLTE, before IDAT
-info_png.unknown_chunks_data[2] is the chunks after IDAT
-
-The chunks in these 3 buffers can be iterated through and read by using the same
-way described in the previous subchapter.
-
-When using the decoder to decode a PNG, you can make it store all unknown chunks
-if you set the option settings.remember_unknown_chunks to 1. By default, this
-option is off (0).
-
-The encoder will always encode unknown chunks that are stored in the info_png.
-If you need it to add a particular chunk that isn't known by LodePNG, you can
-use lodepng_chunk_append or lodepng_chunk_create to the chunk data in
-info_png.unknown_chunks_data[x].
-
-Chunks that are known by LodePNG should not be added in that way. E.g. to make
-LodePNG add a bKGD chunk, set background_defined to true and add the correct
-parameters there instead.
-
-
-9. compiler support
--------------------
-
-No libraries other than the current standard C library are needed to compile
-LodePNG. For the C++ version, only the standard C++ library is needed on top.
-Add the files lodepng.c(pp) and lodepng.h to your project, include
-lodepng.h where needed, and your program can read/write PNG files.
-
-If performance is important, use optimization when compiling! For both the
-encoder and decoder, this makes a large difference.
-
-Make sure that LodePNG is compiled with the same compiler of the same version
-and with the same settings as the rest of the program, or the interfaces with
-std::vectors and std::strings in C++ can be incompatible.
-
-CHAR_BITS must be 8 or higher, because LodePNG uses unsigned chars for octets.
-
-*) gcc and g++
-
-LodePNG is developed in gcc so this compiler is natively supported. It gives no
-warnings with compiler options "-Wall -Wextra -pedantic -ansi", with gcc and g++
-version 4.7.1 on Linux, 32-bit and 64-bit.
-
-*) Mingw
-
-The Mingw compiler (a port of gcc) for Windows is fully supported by LodePNG.
-
-*) Visual Studio 2005 and up, Visual C++ Express Edition 2005 and up
-
-Visual Studio may give warnings about 'fopen' being deprecated. A multiplatform library
-can't support the proposed Visual Studio alternative however, so LodePNG keeps using
-fopen. If you don't want to see the deprecated warnings, put this on top of lodepng.h
-before the inclusions:
-#define _CRT_SECURE_NO_DEPRECATE
-
-Other than the above warnings, LodePNG should be warning-free with warning
-level 3 (W3). Warning level 4 (W4) will give warnings about integer conversions.
-I'm not planning to resolve these warnings. To get rid of them, let Visual
-Studio use warning level W3 for lodepng.cpp only: right click lodepng.cpp,
-Properties, C/C++, General, Warning Level: Level 3 (/W3).
-
-Visual Studio may want "stdafx.h" files to be included in each source file and
-give an error "unexpected end of file while looking for precompiled header".
-That is not standard C++ and will not be added to the stock LodePNG. You can
-disable it for lodepng.cpp only by right clicking it, Properties, C/C++,
-Precompiled Headers, and set it to Not Using Precompiled Headers there.
-
-*) Visual Studio 6.0
-
-LodePNG support for Visual Studio 6.0 is not guaranteed because VS6 doesn't
-follow the C++ standard correctly.
-
-*) Comeau C/C++
-
-Vesion 20070107 compiles without problems on the Comeau C/C++ Online Test Drive
-at http://www.comeaucomputing.com/tryitout in both C90 and C++ mode.
-
-*) Compilers on Macintosh
-
-LodePNG has been reported to work both with the gcc and LLVM for Macintosh, both
-for C and C++.
-
-*) Other Compilers
-
-If you encounter problems on other compilers, feel free to let me know and I may
-try to fix it if the compiler is modern standards complient.
-
-
-10. examples
-------------
-
-This decoder example shows the most basic usage of LodePNG. More complex
-examples can be found on the LodePNG website.
-
-10.1. decoder C++ example
--------------------------
-
-#include "lodepng.h"
-#include <iostream>
-
-int main(int argc, char *argv[])
-{
- const char* filename = argc > 1 ? argv[1] : "test.png";
-
- //load and decode
- std::vector<unsigned char> image;
- unsigned width, height;
- unsigned error = lodepng::decode(image, width, height, filename);
-
- //if there's an error, display it
- if(error) std::cout << "decoder error " << error << ": " << lodepng_error_text(error) << std::endl;
-
- //the pixels are now in the vector "image", 4 bytes per pixel, ordered RGBARGBA..., use it as texture, draw it, ...
-}
-
-10.2. decoder C example
------------------------
-
-#include "lodepng.h"
-
-int main(int argc, char *argv[])
-{
- unsigned error;
- unsigned char* image;
- size_t width, height;
- const char* filename = argc > 1 ? argv[1] : "test.png";
-
- error = lodepng_decode32_file(&image, &width, &height, filename);
-
- if(error) printf("decoder error %u: %s\n", error, lodepng_error_text(error));
-
- / * use image here * /
-
- free(image);
- return 0;
-}
-
-
-11. changes
------------
-
-The version number of LodePNG is the date of the change given in the format
-yyyymmdd.
-
-Some changes aren't backwards compatible. Those are indicated with a (!)
-symbol.
-
-*) 22 dec 2013: Power of two windowsize required for optimization.
-*) 15 apr 2013: Fixed bug with LAC_ALPHA and color key.
-*) 25 mar 2013: Added an optional feature to ignore some PNG errors (fix_png).
-*) 11 mar 2013 (!): Bugfix with custom free. Changed from "my" to "lodepng_"
- prefix for the custom allocators and made it possible with a new #define to
- use custom ones in your project without needing to change lodepng's code.
-*) 28 jan 2013: Bugfix with color key.
-*) 27 okt 2012: Tweaks in text chunk keyword length error handling.
-*) 8 okt 2012 (!): Added new filter strategy (entropy) and new auto color mode.
- (no palette). Better deflate tree encoding. New compression tweak settings.
- Faster color conversions while decoding. Some internal cleanups.
-*) 23 sep 2012: Reduced warnings in Visual Studio a little bit.
-*) 1 sep 2012 (!): Removed #define's for giving custom (de)compression functions
- and made it work with function pointers instead.
-*) 23 jun 2012: Added more filter strategies. Made it easier to use custom alloc
- and free functions and toggle #defines from compiler flags. Small fixes.
-*) 6 may 2012 (!): Made plugging in custom zlib/deflate functions more flexible.
-*) 22 apr 2012 (!): Made interface more consistent, renaming a lot. Removed
- redundant C++ codec classes. Reduced amount of structs. Everything changed,
- but it is cleaner now imho and functionality remains the same. Also fixed
- several bugs and shrinked the implementation code. Made new samples.
-*) 6 nov 2011 (!): By default, the encoder now automatically chooses the best
- PNG color model and bit depth, based on the amount and type of colors of the
- raw image. For this, autoLeaveOutAlphaChannel replaced by auto_choose_color.
-*) 9 okt 2011: simpler hash chain implementation for the encoder.
-*) 8 sep 2011: lz77 encoder lazy matching instead of greedy matching.
-*) 23 aug 2011: tweaked the zlib compression parameters after benchmarking.
- A bug with the PNG filtertype heuristic was fixed, so that it chooses much
- better ones (it's quite significant). A setting to do an experimental, slow,
- brute force search for PNG filter types is added.
-*) 17 aug 2011 (!): changed some C zlib related function names.
-*) 16 aug 2011: made the code less wide (max 120 characters per line).
-*) 17 apr 2011: code cleanup. Bugfixes. Convert low to 16-bit per sample colors.
-*) 21 feb 2011: fixed compiling for C90. Fixed compiling with sections disabled.
-*) 11 dec 2010: encoding is made faster, based on suggestion by Peter Eastman
- to optimize long sequences of zeros.
-*) 13 nov 2010: added LodePNG_InfoColor_hasPaletteAlpha and
- LodePNG_InfoColor_canHaveAlpha functions for convenience.
-*) 7 nov 2010: added LodePNG_error_text function to get error code description.
-*) 30 okt 2010: made decoding slightly faster
-*) 26 okt 2010: (!) changed some C function and struct names (more consistent).
- Reorganized the documentation and the declaration order in the header.
-*) 08 aug 2010: only changed some comments and external samples.
-*) 05 jul 2010: fixed bug thanks to warnings in the new gcc version.
-*) 14 mar 2010: fixed bug where too much memory was allocated for char buffers.
-*) 02 sep 2008: fixed bug where it could create empty tree that linux apps could
- read by ignoring the problem but windows apps couldn't.
-*) 06 jun 2008: added more error checks for out of memory cases.
-*) 26 apr 2008: added a few more checks here and there to ensure more safety.
-*) 06 mar 2008: crash with encoding of strings fixed
-*) 02 feb 2008: support for international text chunks added (iTXt)
-*) 23 jan 2008: small cleanups, and #defines to divide code in sections
-*) 20 jan 2008: support for unknown chunks allowing using LodePNG for an editor.
-*) 18 jan 2008: support for tIME and pHYs chunks added to encoder and decoder.
-*) 17 jan 2008: ability to encode and decode compressed zTXt chunks added
- Also vareous fixes, such as in the deflate and the padding bits code.
-*) 13 jan 2008: Added ability to encode Adam7-interlaced images. Improved
- filtering code of encoder.
-*) 07 jan 2008: (!) changed LodePNG to use ISO C90 instead of C++. A
- C++ wrapper around this provides an interface almost identical to before.
- Having LodePNG be pure ISO C90 makes it more portable. The C and C++ code
- are together in these files but it works both for C and C++ compilers.
-*) 29 dec 2007: (!) changed most integer types to unsigned int + other tweaks
-*) 30 aug 2007: bug fixed which makes this Borland C++ compatible
-*) 09 aug 2007: some VS2005 warnings removed again
-*) 21 jul 2007: deflate code placed in new namespace separate from zlib code
-*) 08 jun 2007: fixed bug with 2- and 4-bit color, and small interlaced images
-*) 04 jun 2007: improved support for Visual Studio 2005: crash with accessing
- invalid std::vector element [0] fixed, and level 3 and 4 warnings removed
-*) 02 jun 2007: made the encoder add a tag with version by default
-*) 27 may 2007: zlib and png code separated (but still in the same file),
- simple encoder/decoder functions added for more simple usage cases
-*) 19 may 2007: minor fixes, some code cleaning, new error added (error 69),
- moved some examples from here to lodepng_examples.cpp
-*) 12 may 2007: palette decoding bug fixed
-*) 24 apr 2007: changed the license from BSD to the zlib license
-*) 11 mar 2007: very simple addition: ability to encode bKGD chunks.
-*) 04 mar 2007: (!) tEXt chunk related fixes, and support for encoding
- palettized PNG images. Plus little interface change with palette and texts.
-*) 03 mar 2007: Made it encode dynamic Huffman shorter with repeat codes.
- Fixed a bug where the end code of a block had length 0 in the Huffman tree.
-*) 26 feb 2007: Huffman compression with dynamic trees (BTYPE 2) now implemented
- and supported by the encoder, resulting in smaller PNGs at the output.
-*) 27 jan 2007: Made the Adler-32 test faster so that a timewaste is gone.
-*) 24 jan 2007: gave encoder an error interface. Added color conversion from any
- greyscale type to 8-bit greyscale with or without alpha.
-*) 21 jan 2007: (!) Totally changed the interface. It allows more color types
- to convert to and is more uniform. See the manual for how it works now.
-*) 07 jan 2007: Some cleanup & fixes, and a few changes over the last days:
- encode/decode custom tEXt chunks, separate classes for zlib & deflate, and
- at last made the decoder give errors for incorrect Adler32 or Crc.
-*) 01 jan 2007: Fixed bug with encoding PNGs with less than 8 bits per channel.
-*) 29 dec 2006: Added support for encoding images without alpha channel, and
- cleaned out code as well as making certain parts faster.
-*) 28 dec 2006: Added "Settings" to the encoder.
-*) 26 dec 2006: The encoder now does LZ77 encoding and produces much smaller files now.
- Removed some code duplication in the decoder. Fixed little bug in an example.
-*) 09 dec 2006: (!) Placed output parameters of public functions as first parameter.
- Fixed a bug of the decoder with 16-bit per color.
-*) 15 okt 2006: Changed documentation structure
-*) 09 okt 2006: Encoder class added. It encodes a valid PNG image from the
- given image buffer, however for now it's not compressed.
-*) 08 sep 2006: (!) Changed to interface with a Decoder class
-*) 30 jul 2006: (!) LodePNG_InfoPng , width and height are now retrieved in different
- way. Renamed decodePNG to decodePNGGeneric.
-*) 29 jul 2006: (!) Changed the interface: image info is now returned as a
- struct of type LodePNG::LodePNG_Info, instead of a vector, which was a bit clumsy.
-*) 28 jul 2006: Cleaned the code and added new error checks.
- Corrected terminology "deflate" into "inflate".
-*) 23 jun 2006: Added SDL example in the documentation in the header, this
- example allows easy debugging by displaying the PNG and its transparency.
-*) 22 jun 2006: (!) Changed way to obtain error value. Added
- loadFile function for convenience. Made decodePNG32 faster.
-*) 21 jun 2006: (!) Changed type of info vector to unsigned.
- Changed position of palette in info vector. Fixed an important bug that
- happened on PNGs with an uncompressed block.
-*) 16 jun 2006: Internally changed unsigned into unsigned where
- needed, and performed some optimizations.
-*) 07 jun 2006: (!) Renamed functions to decodePNG and placed them
- in LodePNG namespace. Changed the order of the parameters. Rewrote the
- documentation in the header. Renamed files to lodepng.cpp and lodepng.h
-*) 22 apr 2006: Optimized and improved some code
-*) 07 sep 2005: (!) Changed to std::vector interface
-*) 12 aug 2005: Initial release (C++, decoder only)
-
-
-12. contact information
------------------------
-
-Feel free to contact me with suggestions, problems, comments, ... concerning
-LodePNG. If you encounter a PNG image that doesn't work properly with this
-decoder, feel free to send it and I'll use it to find and fix the problem.
-
-My email address is (puzzle the account and domain together with an @ symbol):
-Domain: gmail dot com.
-Account: lode dot vandevenne.
-
-
-Copyright (c) 2005-2013 Lode Vandevenne
-*/