From 64865ad3e91fffe6e50b51b29ae2a54126f80126 Mon Sep 17 00:00:00 2001 From: Dimitri van Heesch Date: Mon, 18 Sep 2017 20:48:53 +0200 Subject: [PATCH] Stripped unused LodePNG code to prevent false positives for coverity --- src/lodepng.cpp | 1989 +++++------------------------------------------ src/lodepng.h | 1458 +--------------------------------- 2 files changed, 215 insertions(+), 3232 deletions(-) diff --git a/src/lodepng.cpp b/src/lodepng.cpp index 66335aa98d6..bdf292d434e 100644 --- a/src/lodepng.cpp +++ b/src/lodepng.cpp @@ -46,8 +46,64 @@ About these tools (vector, uivector, ucvector and string): -They're not used in the interface, only internally in this file, so all their functions are made static. */ -#ifdef LODEPNG_COMPILE_ZLIB -#ifdef LODEPNG_COMPILE_ENCODER +//-------------------------------------------------------------------------------------------- + + +/*LodePNG_chunk functions: These functions need as input a large enough amount of allocated memory.*/ + +static unsigned LodePNG_chunk_length(const unsigned char* chunk); /*get the length of the data of the chunk. Total chunk length has 12 bytes more.*/ + +static void LodePNG_chunk_type(char type[5], const unsigned char* chunk); /*puts the 4-byte type in null terminated string*/ +static unsigned char LodePNG_chunk_type_equals(const unsigned char* chunk, const char* type); /*check if the type is the given type*/ + +/*properties of PNG chunks gotten from capitalization of chunk type name, as defined by the standard*/ +static unsigned char LodePNG_chunk_critical(const unsigned char* chunk); /*0: ancillary chunk, 1: it's one of the critical chunk types*/ +static unsigned char LodePNG_chunk_private(const unsigned char* chunk); /*0: public, 1: private*/ +static unsigned char LodePNG_chunk_safetocopy(const unsigned char* chunk); /*0: the chunk is unsafe to copy, 1: the chunk is safe to copy*/ + +static unsigned char* LodePNG_chunk_data(unsigned char* chunk); /*get pointer to the data of the chunk*/ +static const unsigned char* LodePNG_chunk_data_const(const unsigned char* chunk); /*get pointer to the data of the chunk*/ + +static unsigned LodePNG_chunk_check_crc(const unsigned char* chunk); /*returns 0 if the crc is correct, 1 if it's incorrect*/ +static void LodePNG_chunk_generate_crc(unsigned char* chunk); /*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/ + +/*iterate to next chunks.*/ +static unsigned char* LodePNG_chunk_next(unsigned char* chunk); +static const unsigned char* LodePNG_chunk_next_const(const unsigned char* chunk); + +/*add chunks to out buffer. It reallocs the buffer to append the data. returns error code*/ +static unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk); /*appends chunk that was already created, to the data. Returns pointer to start of appended chunk, or NULL if error happened*/ +static unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned length, const char* type, const unsigned char* data); /*appends new chunk to out. Returns pointer to start of appended chunk, or NULL if error happened; may change memory address of out buffer*/ + +static void LodePNG_InfoColor_init(LodePNG_InfoColor* info); +static void LodePNG_InfoColor_cleanup(LodePNG_InfoColor* info); +static unsigned LodePNG_InfoColor_copy(LodePNG_InfoColor* dest, const LodePNG_InfoColor* source); + +/*Use these functions instead of allocating palette manually*/ +static void LodePNG_InfoColor_clearPalette(LodePNG_InfoColor* info); + +/*additional color info*/ +static unsigned LodePNG_InfoColor_getBpp(const LodePNG_InfoColor* info); /*bits per pixel*/ +static unsigned LodePNG_InfoColor_getChannels(const LodePNG_InfoColor* info); /*amount of channels*/ +static unsigned LodePNG_InfoColor_isGreyscaleType(const LodePNG_InfoColor* info); /*is it a greyscale type? (colorType 0 or 4)*/ +static unsigned LodePNG_InfoColor_isAlphaType(const LodePNG_InfoColor* info); /*has it an alpha channel? (colorType 2 or 6)*/ + +static void LodePNG_InfoPng_init(LodePNG_InfoPng* info); +static void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info); +static unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source); + +static void LodePNG_InfoRaw_init(LodePNG_InfoRaw* info); +static void LodePNG_InfoRaw_cleanup(LodePNG_InfoRaw* info); +static unsigned LodePNG_InfoRaw_copy(LodePNG_InfoRaw* dest, const LodePNG_InfoRaw* source); + +/* +LodePNG_convert: 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, where bpp is the bits per pixel of the output color type (LodePNG_InfoColor_getBpp) +*/ +unsigned LodePNG_convert(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoOut, LodePNG_InfoColor* infoIn, unsigned w, unsigned h); + + +//-------------------------------------------------------------------------------------------- typedef struct vector /*this one is used only by the deflate compressor*/ { @@ -115,12 +171,9 @@ static void* vector_get(vector* p, size_t index) { return &((char*)p->data)[index * p->typesize]; } -#endif /*LODEPNG_COMPILE_ENCODER*/ -#endif /*LODEPNG_COMPILE_ZLIB*/ /* /////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_ZLIB typedef struct uivector { unsigned* data; @@ -167,7 +220,6 @@ static void uivector_init(uivector* p) p->size = p->allocsize = 0; } -#ifdef LODEPNG_COMPILE_ENCODER static unsigned uivector_push_back(uivector* p, unsigned c) /*returns 1 if success, 0 if failure ==> nothing done*/ { if(!uivector_resize(p, p->size + 1)) return 0; @@ -191,8 +243,6 @@ static void uivector_swap(uivector* p, uivector* q) tmp = p->allocsize; p->allocsize = q->allocsize; q->allocsize = tmp; tmpp = p->data; p->data = q->data; q->data = tmpp; } -#endif /*LODEPNG_COMPILE_ENCODER*/ -#endif /*LODEPNG_COMPILE_ZLIB*/ /* /////////////////////////////////////////////////////////////////////////// */ @@ -228,17 +278,6 @@ static unsigned ucvector_resize(ucvector* p, size_t size) /*returns 1 if success return 1; } -#ifdef LODEPNG_COMPILE_DECODER -#ifdef LODEPNG_COMPILE_PNG -static unsigned ucvector_resizev(ucvector* p, size_t size, unsigned char value) /*resize and give all new elements the value*/ -{ - size_t oldsize = p->size, i; - if(!ucvector_resize(p, size)) return 0; - for(i = oldsize; i < size; i++) p->data[i] = value; - return 1; -} -#endif /*LODEPNG_COMPILE_PNG*/ -#endif /*LODEPNG_COMPILE_DECODER*/ static void ucvector_init(ucvector* p) { @@ -246,14 +285,12 @@ static void ucvector_init(ucvector* p) p->size = p->allocsize = 0; } -#ifdef LODEPNG_COMPILE_ZLIB /*you can both convert from vector to buffer&size and vica versa*/ 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*/ static unsigned ucvector_push_back(ucvector* p, unsigned char c) /*returns 1 if success, 0 if failure ==> nothing done*/ { @@ -264,8 +301,6 @@ static unsigned ucvector_push_back(ucvector* p, unsigned char c) /*returns 1 if /* /////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_PNG -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS static unsigned string_resize(char** out, size_t size) /*returns 1 if success, 0 if failure ==> nothing done*/ { char* data = (char*)realloc(*out, size + 1); @@ -294,16 +329,12 @@ 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*/ -#ifdef LODEPNG_COMPILE_ZLIB /* ////////////////////////////////////////////////////////////////////////// */ /* / Reading and writing single bits and bytes from/to stream for Deflate / */ /* ////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_ENCODER static void addBitToStream(size_t* bitpointer, ucvector* bitstream, unsigned char bit) { if((*bitpointer) % 8 == 0) ucvector_push_back(bitstream, 0); /*add a new byte at the end*/ @@ -322,23 +353,7 @@ static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, uns 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 -static unsigned char readBitFromStream(size_t* bitpointer, const unsigned char* bitstream) -{ - unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> ((*bitpointer) & 0x7)) & 1); - (*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)readBitFromStream(bitpointer, bitstream)) << i; - return result; -} -#endif /*LODEPNG_COMPILE_DECODER*/ /* ////////////////////////////////////////////////////////////////////////// */ /* / Deflate - Huffman / */ @@ -363,7 +378,6 @@ static const unsigned CLCL[NUM_CODE_LENGTH_CODES] /*the order in which "code len /* /////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_ENCODER /*terminology used for the package-merge algorithm and the coin collector's problem*/ typedef struct Coin /*a coin can be multiple coins (when they're merged)*/ { @@ -417,7 +431,6 @@ static void Coin_sort(Coin* data, size_t amount) /*combsort*/ } } } -#endif /*LODEPNG_COMPILE_ENCODER*/ typedef struct HuffmanTree { @@ -461,7 +474,7 @@ static unsigned HuffmanTree_make2DTree(HuffmanTree* tree) unsigned nodefilled = 0; /*up to which node it is filled*/ unsigned treepos = 0; /*position in the tree (1 of the numcodes columns)*/ unsigned n, i; - + if(!uivector_resize(&tree->tree2d, tree->numcodes * 2)) return 9901; /*if failed return not enough memory error*/ /*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*/ @@ -489,7 +502,7 @@ static unsigned HuffmanTree_make2DTree(HuffmanTree* tree) else treepos = tree->tree2d.data[2 * treepos + bit] - tree->numcodes; } for(n = 0; n < tree->numcodes * 2; n++) if(tree->tree2d.data[n] == 32767) tree->tree2d.data[n] = 0; /*remove possible remaining 32767's*/ - + return 0; } @@ -498,14 +511,14 @@ static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree) /*given that num uivector blcount; uivector nextcode; unsigned bits, n, error = 0; - + uivector_init(&blcount); uivector_init(&nextcode); if(!uivector_resize(&tree->tree1d, tree->numcodes) || !uivector_resizev(&blcount, tree->maxbitlen + 1, 0) || !uivector_resizev(&nextcode, tree->maxbitlen + 1, 0)) error = 9902; - + if(!error) { /*step 1: count number of instances of each code length*/ @@ -515,10 +528,10 @@ static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree) /*given that num /*step 3: generate all the codes*/ for(n = 0; n < tree->numcodes; n++) if(tree->lengths.data[n] != 0) tree->tree1d.data[n] = nextcode.data[tree->lengths.data[n]]++; } - + uivector_cleanup(&blcount); uivector_cleanup(&nextcode); - + if(!error) return HuffmanTree_make2DTree(tree); else return error; } @@ -534,7 +547,6 @@ static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* b return HuffmanTree_makeFromLengths2(tree); } -#ifdef LODEPNG_COMPILE_ENCODER static unsigned HuffmanTree_fillInCoins(vector* coins, const unsigned* frequencies, unsigned numcodes, size_t sum) { unsigned i; @@ -557,12 +569,12 @@ static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigne unsigned i, j; size_t sum = 0, numpresent = 0; unsigned error = 0; - + vector prev_row; /*type Coin, the previous row of coins*/ vector coins; /*type Coin, the coins of the currently calculated row*/ - + tree->maxbitlen = maxbitlen; - + for(i = 0; i < numcodes; i++) { if(frequencies[i] > 0) @@ -571,12 +583,12 @@ static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigne sum += frequencies[i]; } } - + if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/ tree->numcodes = (unsigned)numcodes; /*number of symbols*/ uivector_resize(&tree->lengths, 0); if(!uivector_resizev(&tree->lengths, tree->numcodes, 0)) return 9905; - + if(numpresent == 0) /*there are no symbols at all, in that case add one symbol of value 0 to the tree (see RFC 1951 section 3.2.7) */ { tree->lengths.data[0] = 1; @@ -587,13 +599,13 @@ static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigne for(i = 0; i < numcodes; i++) if(frequencies[i]) tree->lengths.data[i] = 1; return HuffmanTree_makeFromLengths2(tree); } - + vector_init(&coins, sizeof(Coin)); vector_init(&prev_row, sizeof(Coin)); /*Package-Merge algorithm represented by coin collector's problem For every symbol, maxbitlen coins will be created*/ - + /*first row, lowest denominator*/ error = HuffmanTree_fillInCoins(&coins, frequencies, tree->numcodes, sum); if(!error) @@ -616,31 +628,30 @@ static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigne } } } - + if(!error) { /*keep the coins with lowest weight, so that they add up to the amount of symbols - 1*/ vector_resized(&coins, numpresent - 1, Coin_cleanup); - + /*calculate the lengths of each symbol, as the amount of times a coin of each symbol is used*/ for(i = 0; i < coins.size; i++) { Coin* coin = (Coin*)vector_get(&coins, i); for(j = 0; j < coin->symbols.size; j++) tree->lengths.data[coin->symbols.data[j]]++; } - + error = HuffmanTree_makeFromLengths2(tree); } vector_cleanupd(&coins, Coin_cleanup); vector_cleanupd(&prev_row, Coin_cleanup); - + return error; } static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index) { return tree->tree1d.data[index]; } static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index) { return tree->lengths.data[index]; } -#endif /*LODEPNG_COMPILE_ENCODER*/ /*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/ static unsigned generateFixedTree(HuffmanTree* tree) @@ -649,7 +660,7 @@ static unsigned generateFixedTree(HuffmanTree* tree) uivector bitlen; uivector_init(&bitlen); if(!uivector_resize(&bitlen, NUM_DEFLATE_CODE_SYMBOLS)) error = 9909; - + if(!error) { /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/ @@ -657,10 +668,10 @@ static unsigned generateFixedTree(HuffmanTree* tree) for(i = 144; i <= 255; i++) bitlen.data[i] = 9; for(i = 256; i <= 279; i++) bitlen.data[i] = 7; for(i = 280; i <= 287; i++) bitlen.data[i] = 8; - + error = HuffmanTree_makeFromLengths(tree, bitlen.data, NUM_DEFLATE_CODE_SYMBOLS, 15); } - + uivector_cleanup(&bitlen); return error; } @@ -671,7 +682,7 @@ static unsigned generateDistanceTree(HuffmanTree* tree) uivector bitlen; uivector_init(&bitlen); if(!uivector_resize(&bitlen, NUM_DISTANCE_SYMBOLS)) error = 9910; - + /*there are 32 distance codes, but 30-31 are unused*/ if(!error) { @@ -682,308 +693,6 @@ static unsigned generateDistanceTree(HuffmanTree* tree) return error; } -#ifdef LODEPNG_COMPILE_DECODER -/*Decodes a symbol from the tree -if decoded is true, then result contains the symbol, otherwise it contains something unspecified (because the symbol isn't fully decoded yet) -bit is the bit that was just read from the stream -you have to decode a full symbol (let the decode function return true) before you can try to decode another one, otherwise the state isn't reset -return value is error.*/ -static unsigned HuffmanTree_decode(const HuffmanTree* tree, unsigned* decoded, unsigned* result, unsigned* treepos, unsigned char bit) -{ - if((*treepos) >= tree->numcodes) return 11; /*error: it appeared outside the codetree*/ - - (*result) = tree->tree2d.data[2 * (*treepos) + bit]; - (*decoded) = ((*result) < tree->numcodes); - - if(*decoded) (*treepos) = 0; - else (*treepos) = (*result) - tree->numcodes; - - return 0; -} - -static unsigned huffmanDecodeSymbol(unsigned int* error, const unsigned char* in, size_t* bp, const HuffmanTree* codetree, size_t inlength) -{ - unsigned treepos = 0, decoded, ct; - for(;;) - { - unsigned char bit; - if(((*bp) & 0x07) == 0 && ((*bp) >> 3) > inlength) { *error = 10; return 0; } /*error: end of input memory reached without endcode*/ - bit = readBitFromStream(bp, in); - *error = HuffmanTree_decode(codetree, &decoded, &ct, &treepos, bit); - if(*error) return 0; /*stop, an error happened*/ - if(decoded) return ct; - } -} -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_DECODER - -/* ////////////////////////////////////////////////////////////////////////// */ -/* / Inflator / */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/*get the tree of a deflated block with fixed tree, as specified in the deflate specification*/ -static void getTreeInflateFixed(HuffmanTree* tree, HuffmanTree* treeD) -{ - /*error checking not done, this is fixed stuff, it works, it doesn't depend on the image*/ - generateFixedTree(tree); - generateDistanceTree(treeD); -} - -/*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* codetree, HuffmanTree* codetreeD, HuffmanTree* codelengthcodetree, - 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*/ - /*C-code note: use no "return" between ctor and dtor of an uivector!*/ - unsigned error = 0; - unsigned n, HLIT, HDIST, HCLEN, i; - uivector bitlen; - uivector bitlenD; - uivector codelengthcode; - - if((*bp) >> 3 >= inlength - 2) { return 49; } /*the bit pointer is or will go past the memory*/ - - HLIT = readBitsFromStream(bp, in, 5) + 257; /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/ - HDIST = readBitsFromStream(bp, in, 5) + 1; /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/ - HCLEN = readBitsFromStream(bp, in, 4) + 4; /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/ - - /*read the code length codes out of 3 * (amount of code length codes) bits*/ - uivector_init(&codelengthcode); - if(!uivector_resize(&codelengthcode, NUM_CODE_LENGTH_CODES)) error = 9911; - - if(!error) - { - for(i = 0; i < NUM_CODE_LENGTH_CODES; i++) - { - if(i < HCLEN) codelengthcode.data[CLCL[i]] = readBitsFromStream(bp, in, 3); - else codelengthcode.data[CLCL[i]] = 0; /*if not, it must stay 0*/ - } - - error = HuffmanTree_makeFromLengths(codelengthcodetree, codelengthcode.data, codelengthcode.size, 7); - } - - uivector_cleanup(&codelengthcode); - if(error) return error; - - /*now we can use this tree to read the lengths for the tree that this function will return*/ - uivector_init(&bitlen); - uivector_resizev(&bitlen, NUM_DEFLATE_CODE_SYMBOLS, 0); - uivector_init(&bitlenD); - uivector_resizev(&bitlenD, NUM_DISTANCE_SYMBOLS, 0); - i = 0; - if(!bitlen.data || !bitlenD.data) error = 9912; - else while(i < HLIT + HDIST) /*i is the current symbol we're reading in the part that contains the code lengths of lit/len codes and dist codes*/ - { - unsigned code = huffmanDecodeSymbol(&error, in, bp, codelengthcodetree, inlength); - if(error) break; - - if(code <= 15) /*a length code*/ - { - if(i < HLIT) bitlen.data[i] = code; - else bitlenD.data[i - HLIT] = code; - i++; - } - else if(code == 16) /*repeat previous*/ - { - unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/ - unsigned value; /*set value to the previous code*/ - - if((*bp) >> 3 >= inlength) { error = 50; break; } /*error, bit pointer jumps past memory*/ - - replength += readBitsFromStream(bp, in, 2); - - if((i - 1) < HLIT) value = bitlen.data[i - 1]; - else value = bitlenD.data[i - HLIT - 1]; - /*repeat this value in the next lengths*/ - for(n = 0; n < replength; n++) - { - if(i >= HLIT + HDIST) { error = 13; break; } /*error: i is larger than the amount of codes*/ - if(i < HLIT) bitlen.data[i] = value; - else bitlenD.data[i - HLIT] = value; - i++; - } - } - else if(code == 17) /*repeat "0" 3-10 times*/ - { - unsigned replength = 3; /*read in the bits that indicate repeat length*/ - if((*bp) >> 3 >= inlength) { error = 50; break; } /*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 = 14; break; } /*error: i is larger than the amount of codes*/ - if(i < HLIT) bitlen.data[i] = 0; - else bitlenD.data[i - HLIT] = 0; - i++; - } - } - else if(code == 18) /*repeat "0" 11-138 times*/ - { - unsigned replength = 11; /*read in the bits that indicate repeat length*/ - if((*bp) >> 3 >= inlength) { error = 50; break; } /*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 = 15; break; } /*error: i is larger than the amount of codes*/ - if(i < HLIT) bitlen.data[i] = 0; - else bitlenD.data[i - HLIT] = 0; - i++; - } - } - else { error = 16; break; } /*error: somehow an unexisting code appeared. This can never happen.*/ - } - - if(!error && bitlen.data[256] == 0) { error = 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*/ - if(!error) error = HuffmanTree_makeFromLengths(codetree, &bitlen.data[0], bitlen.size, 15); - if(!error) error = HuffmanTree_makeFromLengths(codetreeD, &bitlenD.data[0], bitlenD.size, 15); - - uivector_cleanup(&bitlen); - uivector_cleanup(&bitlenD); - - 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 endreached = 0, error = 0; - HuffmanTree codetree; /*287, the code tree for Huffman codes*/ - HuffmanTree codetreeD; /*31, the code tree for distance codes*/ - - HuffmanTree_init(&codetree); - HuffmanTree_init(&codetreeD); - - if(btype == 1) getTreeInflateFixed(&codetree, &codetreeD); - else if(btype == 2) - { - HuffmanTree codelengthcodetree; /*18, the code tree for code length codes*/ - HuffmanTree_init(&codelengthcodetree); - error = getTreeInflateDynamic(&codetree, &codetreeD, &codelengthcodetree, in, bp, inlength); - HuffmanTree_cleanup(&codelengthcodetree); - } - - while(!endreached && !error) - { - unsigned code = huffmanDecodeSymbol(&error, in, bp, &codetree, inlength); - if(error) break; /*some error happened in the above function*/ - if(code == 256) endreached = 1; /*end code*/ - else if(code <= 255) /*literal symbol*/ - { - if((*pos) >= out->size) ucvector_resize(out, ((*pos) + 1) * 2); /*reserve more room at once*/ - if((*pos) >= out->size) { error = 9913; break; } /*not enough memory*/ - out->data[(*pos)] = (unsigned char)(code); - (*pos)++; - } - else if(code >= FIRST_LENGTH_CODE_INDEX && code <= LAST_LENGTH_CODE_INDEX) /*length code*/ - { - /*part 1: get length base*/ - size_t length = LENGTHBASE[code - FIRST_LENGTH_CODE_INDEX]; - unsigned codeD, distance, numextrabitsD; - size_t start, forward, backward, numextrabits; - - /*part 2: get extra bits and add the value of that to length*/ - numextrabits = LENGTHEXTRA[code - FIRST_LENGTH_CODE_INDEX]; - if(((*bp) >> 3) >= inlength) { error = 51; break; } /*error, bit pointer will jump past memory*/ - length += readBitsFromStream(bp, in, numextrabits); - - /*part 3: get distance code*/ - codeD = huffmanDecodeSymbol(&error, in, bp, &codetreeD, inlength); - if(error) break; - if(codeD > 29) { error = 18; break; } /*error: invalid distance code (30-31 are never used)*/ - distance = DISTANCEBASE[codeD]; - - /*part 4: get extra bits from distance*/ - numextrabitsD = DISTANCEEXTRA[codeD]; - if(((*bp) >> 3) >= inlength) { error = 51; break; } /*error, bit pointer will jump past memory*/ - distance += readBitsFromStream(bp, in, numextrabitsD); - - /*part 5: fill in all the out[n] values based on the length and dist*/ - start = (*pos); - backward = start - distance; - if((*pos) + length >= out->size) ucvector_resize(out, ((*pos) + length) * 2); /*reserve more room at once*/ - if((*pos) + length >= out->size) { error = 9914; break; } /*not enough memory*/ - - for(forward = 0; forward < length; forward++) - { - out->data[(*pos)] = out->data[backward]; - (*pos)++; - backward++; - if(backward >= start) backward = start - distance; - } - } - } - - HuffmanTree_cleanup(&codetree); - HuffmanTree_cleanup(&codetreeD); - - return error; -} - -static unsigned inflateNoCompression(ucvector* out, const unsigned char* in, size_t* bp, size_t* pos, size_t inlength) -{ - /*go to first boundary of byte*/ - size_t p; - unsigned LEN, NLEN, n, error = 0; - while(((*bp) & 0x7) != 0) (*bp)++; - p = (*bp) / 8; /*byte position*/ - - /*read LEN (2 bytes) and NLEN (2 bytes)*/ - if(p >= inlength - 4) return 52; /*error, bit pointer will jump past memory*/ - LEN = in[p] + 256 * in[p + 1]; p += 2; - NLEN = in[p] + 256 * in[p + 1]; p += 2; - - /*check if 16-bit NLEN is really the one's complement of LEN*/ - if(LEN + NLEN != 65535) return 21; /*error: NLEN is not one's complement of LEN*/ - - if((*pos) + LEN >= out->size) { if(!ucvector_resize(out, (*pos) + LEN)) return 9915; } - - /*read the literal data: LEN bytes are now stored in the out buffer*/ - if(p + LEN > inlength) return 23; /*error: reading outside of in buffer*/ - for(n = 0; n < LEN; n++) out->data[(*pos)++] = in[p++]; - - (*bp) = p * 8; - - return error; -} - -/*inflate the deflated data (cfr. deflate spec); return value is the error*/ -unsigned LodeFlate_inflate(ucvector* out, const unsigned char* in, size_t insize, size_t inpos) -{ - size_t bp = 0; /*bit pointer in the "in" data, current byte is bp >> 3, current bit is bp & 0x7 (from lsb to msb of the byte)*/ - unsigned BFINAL = 0; - size_t pos = 0; /*byte position in the out buffer*/ - - unsigned error = 0; - - while(!BFINAL) - { - unsigned BTYPE; - if((bp >> 3) >= insize) return 52; /*error, bit pointer will jump past memory*/ - BFINAL = readBitFromStream(&bp, &in[inpos]); - BTYPE = 1 * readBitFromStream(&bp, &in[inpos]); BTYPE += 2 * readBitFromStream(&bp, &in[inpos]); - - if(BTYPE == 3) return 20; /*error: invalid BTYPE*/ - else if(BTYPE == 0) error = inflateNoCompression(out, &in[inpos], &bp, &pos, insize); /*no compression*/ - else error = inflateHuffmanBlock(out, &in[inpos], &bp, &pos, insize, BTYPE); /*compression, BTYPE 01 or 10*/ - if(error) return error; - } - - if(!ucvector_resize(out, pos)) error = 9916; /*Only now we know the true size of out, resize it to that*/ - - return error; -} - -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER - /* ////////////////////////////////////////////////////////////////////////// */ /* / Deflator / */ /* ////////////////////////////////////////////////////////////////////////// */ @@ -1002,7 +711,7 @@ static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t v /*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; @@ -1028,7 +737,7 @@ static void addLengthDistance(uivector* values, size_t length, size_t distance) 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); @@ -1044,26 +753,26 @@ static unsigned encodeLZ77_brute(uivector* out, const unsigned char* in, size_t /*using pointer instead of vector for input makes it faster when NOT using optimization when compiling; no influence if optimization is used*/ for(pos = 0; pos < size; pos++) { - /*Phase 1: doxygen images often have long runs of the same color, try to find them*/ + /*Phase 1: doxygen images often have long runs of the same color, try to find them*/ const int minLength = 4; // Minimum length for a run to make sense - + if(pos < size - minLength * 4) { size_t p, fp; size_t current_length; - + /*RGBA pixel run?*/ p = pos; fp = pos + 4; current_length = 0; - + while(fp < size && in[p] == in[fp] && current_length < MAX_SUPPORTED_DEFLATE_LENGTH) { ++p; ++fp; ++current_length; } - + if (current_length > (minLength - 1 ) * 4) /*worth using?*/ { uivector_push_back(out, in[pos ]); @@ -1071,30 +780,30 @@ static unsigned encodeLZ77_brute(uivector* out, const unsigned char* in, size_t uivector_push_back(out, in[pos + 2]); uivector_push_back(out, in[pos + 3]); addLengthDistance(out, current_length, 4); - + pos += current_length + 4 - 1; /*-1 for loop's pos++*/ continue; } - + /*RGB pixel run?*/ p = pos; fp = pos + 3; current_length = 0; - + while(fp < size && in[p] == in[fp] && current_length < MAX_SUPPORTED_DEFLATE_LENGTH) { ++p; ++fp; ++current_length; } - + if (current_length > (minLength - 1 ) * 3) /*worth using?*/ { uivector_push_back(out, in[pos ]); uivector_push_back(out, in[pos + 1]); uivector_push_back(out, in[pos + 2]); addLengthDistance(out, current_length, 3); - + pos += current_length + 3 - 1; /*-1 for loop's pos++*/ continue; } @@ -1103,7 +812,7 @@ static unsigned encodeLZ77_brute(uivector* out, const unsigned char* in, size_t size_t length = 0, offset = 0; /*the length and offset found for the current position*/ size_t max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/ size_t current_offset; - + /**search for the longest string**/ for(current_offset = 1; current_offset < max_offset; current_offset++) /*search backwards through all possible distances (=offsets)*/ { @@ -1129,7 +838,7 @@ static unsigned encodeLZ77_brute(uivector* out, const unsigned char* in, size_t } } } - + /**encode it as length/distance pair or literal value**/ if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/ { @@ -1173,7 +882,7 @@ static unsigned encodeLZ77(uivector* out, const unsigned char* in, size_t size, vector table; /*HASH_NUM_VALUES uivectors; this represents what would be an std::vector > in C++*/ uivector tablepos1, tablepos2; unsigned pos, i, error = 0; - + vector_init(&table, sizeof(uivector)); if(!vector_resize(&table, HASH_NUM_VALUES)) return 9917; for(i = 0; i < HASH_NUM_VALUES; i++) @@ -1187,7 +896,7 @@ static unsigned encodeLZ77(uivector* out, const unsigned char* in, size_t size, uivector_init(&tablepos2); if(!uivector_resizev(&tablepos1, HASH_NUM_VALUES, 0)) error = 9918; if(!uivector_resizev(&tablepos2, HASH_NUM_VALUES, 0)) error = 9919; - + if(!error) { for(pos = 0; pos < size; pos++) @@ -1195,12 +904,12 @@ static unsigned encodeLZ77(uivector* out, const unsigned char* in, size_t size, unsigned length = 0, offset = 0; /*the length and offset found for the current position*/ unsigned max_offset = pos < windowSize ? pos : windowSize; /*how far back to test*/ unsigned tablepos; - + /*/search for the longest string*/ /*first find out where in the table to start (the first value that is in the range from "pos - max_offset" to "pos")*/ unsigned hash = getHash(in, size, pos); if(!uivector_push_back((uivector*)vector_get(&table, hash), pos)) { error = 9920; break; } - + while(((uivector*)vector_get(&table, hash))->data[tablepos1.data[hash]] < pos - max_offset) tablepos1.data[hash]++; /*it now points to the first value in the table for which the index is larger than or equal to pos - max_offset*/ while(((uivector*)vector_get(&table, hash))->data[tablepos2.data[hash]] < pos) tablepos2.data[hash]++; /*it now points to the first value in the table for which the index is larger than or equal to pos*/ @@ -1227,7 +936,7 @@ static unsigned encodeLZ77(uivector* out, const unsigned char* in, size_t size, if(current_length == MAX_SUPPORTED_DEFLATE_LENGTH) break; /*you can jump out of this for loop once a length of max length is found (gives significant speed gain)*/ } } - + /**encode it as length/distance pair or literal value**/ if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/ { @@ -1245,7 +954,7 @@ static unsigned encodeLZ77(uivector* out, const unsigned char* in, size_t size, } } /*end of the loop through each character of input*/ } /*end of "if(!error)"*/ - + /*cleanup*/ for(i = 0; i < table.size; i++) { @@ -1264,24 +973,24 @@ static unsigned encodeLZ77(uivector* out, const unsigned char* in, size_t size, static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize) { /*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte, 2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/ - + size_t i, j, numdeflateblocks = datasize / 65536 + 1; unsigned datapos = 0; for(i = 0; i < numdeflateblocks; i++) { unsigned BFINAL, BTYPE, LEN, NLEN; unsigned char firstbyte; - + BFINAL = (i == numdeflateblocks - 1); BTYPE = 0; - + firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1)); ucvector_push_back(out, firstbyte); - + LEN = 65535; if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos; NLEN = 65535 - LEN; - + ucvector_push_back(out, (unsigned char)(LEN % 256)); ucvector_push_back(out, (unsigned char)(LEN / 256)); ucvector_push_back(out, (unsigned char)(NLEN % 256)); @@ -1293,7 +1002,7 @@ static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, s ucvector_push_back(out, data[datapos++]); } } - + return 0; } @@ -1310,13 +1019,13 @@ static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encode 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(codesD, distance_code), HuffmanTree_getLength(codesD, distance_code)); addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits); @@ -1335,9 +1044,9 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t - compressed data - 256 (end code) */ - + unsigned error = 0; - + uivector lz77_encoded; HuffmanTree codes; /*tree for literal values and length codes*/ HuffmanTree codesD; /*tree for distance codes*/ @@ -1348,11 +1057,11 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t uivector lldl; uivector lldll; /*lit/len & dist code lengths*/ uivector clcls; - + unsigned BFINAL = 1; /*make only one block... the first and final one*/ size_t numcodes, numcodesD, i, bp = 0; /*the bit pointer*/ unsigned HLIT, HDIST, HCLEN; - + uivector_init(&lz77_encoded); HuffmanTree_init(&codes); HuffmanTree_init(&codesD); @@ -1363,7 +1072,7 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t uivector_init(&lldl); uivector_init(&lldll); uivector_init(&clcls); - + while(!error) /*the goto-avoiding while construct: break out to go to the cleanup phase, a break at the end makes sure the while is never repeated*/ { if(settings->useLZ77) @@ -1376,7 +1085,7 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t if(!uivector_resize(&lz77_encoded, datasize)) { error = 9923; break; } for(i = 0; i < datasize; i++) lz77_encoded.data[i] = data[i]; /*no LZ77, but still will be Huffman compressed*/ } - + if(!uivector_resizev(&frequencies, 286, 0)) { error = 9924; break; } if(!uivector_resizev(&frequenciesD, 30, 0)) { error = 9925; break; } for(i = 0; i < lz77_encoded.size; i++) @@ -1391,27 +1100,27 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t } } frequencies.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/ - + error = HuffmanTree_makeFromFrequencies(&codes, frequencies.data, frequencies.size, 15); if(error) break; error = HuffmanTree_makeFromFrequencies(&codesD, frequenciesD.data, frequenciesD.size, 15); if(error) break; - + addBitToStream(&bp, out, BFINAL); addBitToStream(&bp, out, 0); /*first bit of BTYPE "dynamic"*/ addBitToStream(&bp, out, 1); /*second bit of BTYPE "dynamic"*/ - + numcodes = codes.numcodes; if(numcodes > 286) numcodes = 286; numcodesD = codesD.numcodes; if(numcodesD > 30) numcodesD = 30; for(i = 0; i < numcodes; i++) uivector_push_back(&lldll, HuffmanTree_getLength(&codes, (unsigned)i)); for(i = 0; i < numcodesD; i++) uivector_push_back(&lldll, HuffmanTree_getLength(&codesD, (unsigned)i)); - + /*make lldl smaller by using repeat codes 16 (copy length 3-6 times), 17 (3-10 zeros), 18 (11-138 zeros)*/ for(i = 0; i < (unsigned)lldll.size; i++) { unsigned j = 0; while(i + j + 1 < (unsigned)lldll.size && lldll.data[i + j + 1] == lldll.data[i]) j++; - + if(lldll.data[i] == 0 && j >= 2) { j++; /*include the first zero*/ @@ -1435,7 +1144,7 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t } else uivector_push_back(&lldl, lldll.data[i]); } - + /*generate huffmantree for the length codes of lit/len and dist codes*/ if(!uivector_resizev(&amounts, 19, 0)) { error = 9926; break; } /*16 possible lengths (0-15) and 3 repeat codes (16, 17 and 18)*/ for(i = 0; i < lldl.size; i++) @@ -1443,10 +1152,10 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t amounts.data[lldl.data[i]]++; if(lldl.data[i] >= 16) i++; /*after a repeat code come the bits that specify the amount, those don't need to be in the amounts calculation*/ } - + error = HuffmanTree_makeFromFrequencies(&codelengthcodes, amounts.data, amounts.size, 7); if(error) break; - + if(!uivector_resize(&clcls, 19)) { error = 9927; break; } for(i = 0; i < 19; i++) clcls.data[i] = HuffmanTree_getLength(&codelengthcodes, CLCL[i]); /*lengths of code length tree is in the order as specified by deflate*/ while(clcls.data[clcls.size - 1] == 0 && clcls.size > 4) @@ -1454,7 +1163,7 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t if(!uivector_resize(&clcls, clcls.size - 1)) { error = 9928; break; } /*remove zeros at the end, but minimum size must be 4*/ } if(error) break; - + /*write the HLIT, HDIST and HCLEN values*/ HLIT = (unsigned)(numcodes - 257); HDIST = (unsigned)(numcodesD - 1); @@ -1462,10 +1171,10 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t addBitsToStream(&bp, out, HLIT, 5); addBitsToStream(&bp, out, HDIST, 5); addBitsToStream(&bp, out, HCLEN, 4); - + /*write the code lengths of the code length alphabet*/ for(i = 0; i < HCLEN + 4; i++) addBitsToStream(&bp, out, clcls.data[i], 3); - + /*write the lengths of the lit/len AND the dist alphabet*/ for(i = 0; i < lldl.size; i++) { @@ -1475,15 +1184,15 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t else if(lldl.data[i] == 17) addBitsToStream(&bp, out, lldl.data[++i], 3); else if(lldl.data[i] == 18) addBitsToStream(&bp, out, lldl.data[++i], 7); } - + /*write the compressed data symbols*/ writeLZ77data(&bp, out, &lz77_encoded, &codes, &codesD); if(HuffmanTree_getLength(&codes, 256) == 0) { error = 64; break; } /*the length of the end code 256 must be larger than 0*/ addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&codes, 256), HuffmanTree_getLength(&codes, 256)); /*end code*/ - + break; /*end of error-while*/ } - + /*cleanup*/ uivector_cleanup(&lz77_encoded); HuffmanTree_cleanup(&codes); @@ -1495,7 +1204,7 @@ static unsigned deflateDynamic(ucvector* out, const unsigned char* data, size_t uivector_cleanup(&lldl); uivector_cleanup(&lldll); uivector_cleanup(&clcls); - + return error; } @@ -1503,21 +1212,21 @@ static unsigned deflateFixed(ucvector* out, const unsigned char* data, size_t da { HuffmanTree codes; /*tree for literal values and length codes*/ HuffmanTree codesD; /*tree for distance codes*/ - + unsigned BFINAL = 1; /*make only one block... the first and final one*/ unsigned error = 0; size_t i, bp = 0; /*the bit pointer*/ - + HuffmanTree_init(&codes); HuffmanTree_init(&codesD); - + generateFixedTree(&codes); generateDistanceTree(&codesD); - + addBitToStream(&bp, out, BFINAL); addBitToStream(&bp, out, 1); /*first bit of BTYPE*/ addBitToStream(&bp, out, 0); /*second bit of BTYPE*/ - + if(settings->useLZ77) /*LZ77 encoded*/ { uivector lz77_encoded; @@ -1531,11 +1240,11 @@ static unsigned deflateFixed(ucvector* out, const unsigned char* data, size_t da for(i = 0; i < datasize; i++) addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&codes, data[i]), HuffmanTree_getLength(&codes, data[i])); } if(!error) addHuffmanSymbol(&bp, out, HuffmanTree_getCode(&codes, 256), HuffmanTree_getLength(&codes, 256)); /*"end" code*/ - + /*cleanup*/ HuffmanTree_cleanup(&codes); HuffmanTree_cleanup(&codesD); - + return error; } @@ -1549,7 +1258,6 @@ unsigned LodeFlate_deflate(ucvector* out, const unsigned char* data, size_t data return error; } -#endif /*LODEPNG_COMPILE_DECODER*/ /* ////////////////////////////////////////////////////////////////////////// */ /* / Adler32 */ @@ -1559,7 +1267,7 @@ static unsigned update_adler32(unsigned adler, const unsigned char* data, unsign { unsigned s1 = adler & 0xffff; unsigned s2 = (adler >> 16) & 0xffff; - + while(len > 0) { /*at least 5550 sums can be done before the sums overflow, saving us from a lot of module divisions*/ @@ -1574,7 +1282,7 @@ static unsigned update_adler32(unsigned adler, const unsigned char* data, unsign s1 %= 65521; s2 %= 65521; } - + return (s2 << 16) | s1; } @@ -1588,7 +1296,6 @@ static unsigned adler32(const unsigned char* data, unsigned len) /* / Reading and writing single bits and bytes from/to stream for Zlib / */ /* ////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_ENCODER void LodeZlib_add32bitInt(ucvector* buffer, unsigned value) { ucvector_push_back(buffer, (unsigned char)((value >> 24) & 0xff)); @@ -1596,7 +1303,6 @@ void LodeZlib_add32bitInt(ucvector* buffer, unsigned value) ucvector_push_back(buffer, (unsigned char)((value >> 8) & 0xff)); ucvector_push_back(buffer, (unsigned char)((value ) & 0xff)); } -#endif /*LODEPNG_COMPILE_ENCODER*/ unsigned LodeZlib_read32bitInt(const unsigned char* buffer) { @@ -1607,46 +1313,6 @@ unsigned LodeZlib_read32bitInt(const unsigned char* buffer) /* / Zlib / */ /* ////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_DECODER - -unsigned LodeZlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DecompressSettings* settings) -{ - unsigned error = 0; - unsigned CM, CINFO, FDICT; - ucvector outv; - - if(insize < 2) { error = 53; return error; } /*error, size of zlib data too small*/ - /*read information from zlib header*/ - if((in[0] * 256 + in[1]) % 31 != 0) { error = 24; return error; } /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/ - - 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; //not really important, all it does it to give a compiler warning about unused variable, we don't care what encoding setting the encoder used*/ - - if(CM != 8 || CINFO > 7) { error = 25; return error; } /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/ - if(FDICT != 0) { error = 26; return error; } /*error: the specification of PNG says about the zlib stream: "The additional flags shall not specify a preset dictionary."*/ - - ucvector_init_buffer(&outv, *out, *outsize); /*ucvector-controlled version of the output buffer, for dynamic array*/ - error = LodeFlate_inflate(&outv, in, insize, 2); - *out = outv.data; - *outsize = outv.size; - if(error) return error; - - if(!settings->ignoreAdler32) - { - unsigned ADLER32 = LodeZlib_read32bitInt(&in[insize - 4]); - unsigned checksum = adler32(outv.data, (unsigned)outv.size); - if(checksum != ADLER32) { error = 58; return error; } - } - - return error; -} - -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER unsigned LodeZlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DeflateSettings* settings) { @@ -1654,7 +1320,7 @@ unsigned LodeZlib_compress(unsigned char** out, size_t* outsize, const unsigned ucvector deflatedata, outv; size_t i; unsigned error; - + unsigned ADLER32; /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/ unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/ @@ -1663,15 +1329,15 @@ unsigned LodeZlib_compress(unsigned char** out, size_t* outsize, const unsigned unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64; unsigned FCHECK = 31 - CMFFLG % 31; CMFFLG += FCHECK; - + ucvector_init_buffer(&outv, *out, *outsize); /*ucvector-controlled version of the output buffer, for dynamic array*/ - + ucvector_push_back(&outv, (unsigned char)(CMFFLG / 256)); ucvector_push_back(&outv, (unsigned char)(CMFFLG % 256)); - + ucvector_init(&deflatedata); error = LodeFlate_deflate(&deflatedata, in, insize, settings); - + if(!error) { ADLER32 = adler32(in, (unsigned)insize); @@ -1679,21 +1345,15 @@ unsigned LodeZlib_compress(unsigned char** out, size_t* outsize, const unsigned ucvector_cleanup(&deflatedata); LodeZlib_add32bitInt(&outv, ADLER32); } - + *out = outv.data; *outsize = outv.size; - + return error; } -#endif /*LODEPNG_COMPILE_ENCODER*/ - -#endif /*LODEPNG_COMPILE_ZLIB*/ - /* ////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_ENCODER - void LodeZlib_DeflateSettings_init(LodeZlib_DeflateSettings* settings) { settings->btype = 2; /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/ @@ -1703,19 +1363,6 @@ void LodeZlib_DeflateSettings_init(LodeZlib_DeflateSettings* settings) const LodeZlib_DeflateSettings LodeZlib_defaultDeflateSettings = {2, 1, 2048}; -#endif /*LODEPNG_COMPILE_ENCODER*/ - -#ifdef LODEPNG_COMPILE_DECODER - -void LodeZlib_DecompressSettings_init(LodeZlib_DecompressSettings* settings) -{ - settings->ignoreAdler32 = 0; -} - -const LodeZlib_DecompressSettings LodeZlib_defaultDecompressSettings = {0}; - -#endif /*LODEPNG_COMPILE_DECODER*/ - /* ////////////////////////////////////////////////////////////////////////// */ /* ////////////////////////////////////////////////////////////////////////// */ /* ////////////////////////////////////////////////////////////////////////// */ @@ -1728,8 +1375,6 @@ const LodeZlib_DecompressSettings LodeZlib_defaultDecompressSettings = {0}; /* ////////////////////////////////////////////////////////////////////////// */ /* ////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_PNG - /* The two functions below (LodePNG_decompress and LodePNG_compress) directly call the LodeZlib_decompress and LodeZlib_compress functions. The only purpose of the functions @@ -1742,18 +1387,10 @@ in the other LodePNG functions. be the size of the useful data in bytes, not the alloc size. */ -#ifdef LODEPNG_COMPILE_DECODER -static unsigned LodePNG_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DecompressSettings* settings) -{ - return LodeZlib_decompress(out, outsize, in, insize, settings); -} -#endif /*LODEPNG_COMPILE_DECODER*/ -#ifdef LODEPNG_COMPILE_ENCODER static unsigned LodePNG_compress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DeflateSettings* settings) { return LodeZlib_compress(out, outsize, in, insize, settings); } -#endif /*LODEPNG_COMPILE_ENCODER*/ /* ////////////////////////////////////////////////////////////////////////// */ /* / CRC32 / */ @@ -1779,7 +1416,7 @@ static void Crc32_make_crc_table(void) Crc32_crc_table_computed = 1; } -/*Update a running CRC with the bytes buf[0..len-1]--the CRC should be +/*Update a running CRC with the bytes buf[0..len-1]--the CRC should be initialized to all 1's, and the transmitted value is the 1's complement of the final running CRC (see the crc() routine below).*/ static unsigned Crc32_update_crc(const unsigned char* buf, unsigned int crc, size_t len) @@ -1820,15 +1457,6 @@ static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned ch 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) bitstream[(*bitpointer) >> 3] |= (bit << (7 - ((*bitpointer) & 0x7))); /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/ - (*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*/ @@ -1850,13 +1478,11 @@ static void LodePNG_set32bitInt(unsigned char* buffer, unsigned value) /*buffer buffer[3] = (unsigned char)((value ) & 0xff); } -#ifdef LODEPNG_COMPILE_ENCODER static void LodePNG_add32bitInt(ucvector* buffer, unsigned value) { ucvector_resize(buffer, buffer->size + 4); LodePNG_set32bitInt(&buffer->data[buffer->size - 4], value); } -#endif /*LODEPNG_COMPILE_ENCODER*/ /* ////////////////////////////////////////////////////////////////////////// */ /* / PNG chunks / */ @@ -1941,15 +1567,15 @@ unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsi unsigned char *chunk_start, *new_buffer; size_t new_length = (*outlength) + total_chunk_length; if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/ - + new_buffer = (unsigned char*)realloc(*out, new_length); if(!new_buffer) return 9929; (*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; } @@ -1964,22 +1590,22 @@ unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned l (*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; } @@ -2074,242 +1700,28 @@ unsigned LodePNG_InfoColor_equal(const LodePNG_InfoColor* info1, const LodePNG_I && info1->bitDepth == info2->bitDepth; /*palette and color key not compared*/ } -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - -void LodePNG_UnknownChunks_init(LodePNG_UnknownChunks* chunks) -{ - unsigned i; - for(i = 0; i < 3; i++) chunks->data[i] = 0; - for(i = 0; i < 3; i++) chunks->datasize[i] = 0; -} -void LodePNG_UnknownChunks_cleanup(LodePNG_UnknownChunks* chunks) +void LodePNG_InfoPng_init(LodePNG_InfoPng* info) { - unsigned i; - for(i = 0; i < 3; i++) free(chunks->data[i]); + info->width = info->height = 0; + LodePNG_InfoColor_init(&info->color); + info->interlaceMethod = 0; + info->compressionMethod = 0; + info->filterMethod = 0; } -unsigned LodePNG_UnknownChunks_copy(LodePNG_UnknownChunks* dest, const LodePNG_UnknownChunks* src) +void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info) { - unsigned i; - - LodePNG_UnknownChunks_cleanup(dest); - - for(i = 0; i < 3; i++) - { - size_t j; - dest->datasize[i] = src->datasize[i]; - dest->data[i] = (unsigned char*)malloc(src->datasize[i]); - if(!dest->data[i] && dest->datasize[i]) return 9932; - for(j = 0; j < src->datasize[i]; j++) dest->data[i][j] = src->data[i][j]; - } - - return 0; + LodePNG_InfoColor_cleanup(&info->color); } -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - -void LodePNG_Text_init(LodePNG_Text* text) -{ - text->num = 0; - text->keys = NULL; - text->strings = NULL; -} - -void LodePNG_Text_cleanup(LodePNG_Text* text) -{ - LodePNG_Text_clear(text); -} - -unsigned LodePNG_Text_copy(LodePNG_Text* dest, const LodePNG_Text* source) -{ - size_t i = 0; - dest->keys = 0; - dest->strings = 0; - dest->num = 0; - for(i = 0; i < source->num; i++) - { - unsigned error = LodePNG_Text_add(dest, source->keys[i], source->strings[i]); - if(error) return error; - } - return 0; -} - -void LodePNG_Text_clear(LodePNG_Text* text) -{ - size_t i; - for(i = 0; i < text->num; i++) - { - string_cleanup(&text->keys[i]); - string_cleanup(&text->strings[i]); - } - free(text->keys); - free(text->strings); -} - -unsigned LodePNG_Text_add(LodePNG_Text* text, const char* key, const char* str) -{ - char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1))); - char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1))); - if(!new_keys || !new_strings) - { - free(new_keys); - free(new_strings); - return 9933; - } - - text->num++; - text->keys = new_keys; - text->strings = new_strings; - - string_init(&text->keys[text->num - 1]); - string_set(&text->keys[text->num - 1], key); - - string_init(&text->strings[text->num - 1]); - string_set(&text->strings[text->num - 1], str); - - return 0; -} - -/******************************************************************************/ - -void LodePNG_IText_init(LodePNG_IText* text) -{ - text->num = 0; - text->keys = NULL; - text->langtags = NULL; - text->transkeys = NULL; - text->strings = NULL; -} - -void LodePNG_IText_cleanup(LodePNG_IText* text) -{ - LodePNG_IText_clear(text); -} - -unsigned LodePNG_IText_copy(LodePNG_IText* dest, const LodePNG_IText* source) -{ - size_t i = 0; - dest->keys = 0; - dest->langtags = 0; - dest->transkeys = 0; - dest->strings = 0; - dest->num = 0; - for(i = 0; i < source->num; i++) - { - unsigned error = LodePNG_IText_add(dest, source->keys[i], source->langtags[i], source->transkeys[i], source->strings[i]); - if(error) return error; - } - return 0; -} - -void LodePNG_IText_clear(LodePNG_IText* text) -{ - size_t i; - for(i = 0; i < text->num; i++) - { - string_cleanup(&text->keys[i]); - string_cleanup(&text->langtags[i]); - string_cleanup(&text->transkeys[i]); - string_cleanup(&text->strings[i]); - } - free(text->keys); - free(text->langtags); - free(text->transkeys); - free(text->strings); -} - -unsigned LodePNG_IText_add(LodePNG_IText* text, const char* key, const char* langtag, const char* transkey, const char* str) -{ - char** new_keys = (char**)(realloc(text->keys, sizeof(char*) * (text->num + 1))); - char** new_langtags = (char**)(realloc(text->langtags, sizeof(char*) * (text->num + 1))); - char** new_transkeys = (char**)(realloc(text->transkeys, sizeof(char*) * (text->num + 1))); - char** new_strings = (char**)(realloc(text->strings, sizeof(char*) * (text->num + 1))); - if(!new_keys || !new_langtags || !new_transkeys || !new_strings) - { - free(new_keys); - free(new_langtags); - free(new_transkeys); - free(new_strings); - return 9934; - } - - text->num++; - text->keys = new_keys; - text->langtags = new_langtags; - text->transkeys = new_transkeys; - text->strings = new_strings; - - string_init(&text->keys[text->num - 1]); - string_set(&text->keys[text->num - 1], key); - - string_init(&text->langtags[text->num - 1]); - string_set(&text->langtags[text->num - 1], langtag); - - string_init(&text->transkeys[text->num - 1]); - string_set(&text->transkeys[text->num - 1], transkey); - - string_init(&text->strings[text->num - 1]); - string_set(&text->strings[text->num - 1], str); - - return 0; -} - -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -void LodePNG_InfoPng_init(LodePNG_InfoPng* info) -{ - info->width = info->height = 0; - LodePNG_InfoColor_init(&info->color); - info->interlaceMethod = 0; - info->compressionMethod = 0; - info->filterMethod = 0; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - info->background_defined = 0; - info->background_r = info->background_g = info->background_b = 0; - - LodePNG_Text_init(&info->text); - LodePNG_IText_init(&info->itext); - - info->time_defined = 0; - info->phys_defined = 0; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - LodePNG_UnknownChunks_init(&info->unknown_chunks); -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ -} - -void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info) -{ - LodePNG_InfoColor_cleanup(&info->color); -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - LodePNG_Text_cleanup(&info->text); - LodePNG_IText_cleanup(&info->itext); -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - LodePNG_UnknownChunks_cleanup(&info->unknown_chunks); -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ -} - -unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source) +unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source) { unsigned error = 0; LodePNG_InfoPng_cleanup(dest); *dest = *source; LodePNG_InfoColor_init(&dest->color); error = LodePNG_InfoColor_copy(&dest->color, &source->color); if(error) return error; - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - error = LodePNG_Text_copy(&dest->text, &source->text); if(error) return error; - error = LodePNG_IText_copy(&dest->itext, &source->itext); if(error) return error; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - LodePNG_UnknownChunks_init(&dest->unknown_chunks); - error = LodePNG_UnknownChunks_copy(&dest->unknown_chunks, &source->unknown_chunks); if(error) return error; -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ return error; } @@ -2364,7 +1776,7 @@ unsigned LodePNG_convert(unsigned char* out, const unsigned char* in, LodePNG_In const unsigned OUT_BYTES = LodePNG_InfoColor_getBpp(infoOut) / 8; /*bytes per pixel in the output image*/ const unsigned OUT_ALPHA = LodePNG_InfoColor_isAlphaType(infoOut); /*use 8-bit alpha channel*/ size_t i, c, bp = 0; /*bitpointer, used by less-than-8-bit color types*/ - + /*cases where in and out already have the same format*/ if(LodePNG_InfoColor_equal(infoIn, infoOut)) { @@ -2543,7 +1955,7 @@ unsigned LodePNG_convert(unsigned char* out, const unsigned char* in, LodePNG_In } } else return 59; - + return 0; } @@ -2554,7 +1966,7 @@ static int paethPredictor(int a, int b, int c) int pa = p > a ? p - a : a - p; int pb = p > b ? p - b : b - p; int pc = p > c ? p - c : c - p; - + if(pa <= pb && pa <= pc) return a; else if(pb <= pc) return b; else return c; @@ -2571,7 +1983,7 @@ static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t fil { /*the passstart values have 8 values: the 8th one actually 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++) { @@ -2580,7 +1992,7 @@ static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t fil 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++) { @@ -2590,684 +2002,6 @@ static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t fil } } -#ifdef LODEPNG_COMPILE_DECODER - -/* ////////////////////////////////////////////////////////////////////////// */ -/* / PNG Decoder / */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/*read the information from the header and store it in the LodePNG_Info. return value is error*/ -void LodePNG_inspect(LodePNG_Decoder* decoder, const unsigned char* in, size_t inlength) -{ - if(inlength == 0 || in == 0) { decoder->error = 48; return; } /*the given data is empty*/ - if(inlength < 29) { decoder->error = 27; return; } /*error: the data length is smaller than the length of the header*/ - - /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/ - LodePNG_InfoPng_cleanup(&decoder->infoPng); - LodePNG_InfoPng_init(&decoder->infoPng); - decoder->error = 0; - - if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71 || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) { decoder->error = 28; return; } /*error: the first 8 bytes are not the correct PNG signature*/ - if(in[12] != 'I' || in[13] != 'H' || in[14] != 'D' || in[15] != 'R') { decoder->error = 29; return; } /*error: it doesn't start with a IHDR chunk!*/ - - /*read the values given in the header*/ - decoder->infoPng.width = LodePNG_read32bitInt(&in[16]); - decoder->infoPng.height = LodePNG_read32bitInt(&in[20]); - decoder->infoPng.color.bitDepth = in[24]; - decoder->infoPng.color.colorType = in[25]; - decoder->infoPng.compressionMethod = in[26]; - decoder->infoPng.filterMethod = in[27]; - decoder->infoPng.interlaceMethod = in[28]; - - if(!decoder->settings.ignoreCrc) - { - unsigned CRC = LodePNG_read32bitInt(&in[29]); - unsigned checksum = Crc32_crc(&in[12], 17); - if(CRC != checksum) { decoder->error = 57; return; } - } - - if(decoder->infoPng.compressionMethod != 0) { decoder->error = 32; return; } /*error: only compression method 0 is allowed in the specification*/ - if(decoder->infoPng.filterMethod != 0) { decoder->error = 33; return; } /*error: only filter method 0 is allowed in the specification*/ - if(decoder->infoPng.interlaceMethod > 1) { decoder->error = 34; return; } /*error: only interlace methods 0 and 1 exist in the specification*/ - - decoder->error = checkColorValidity(decoder->infoPng.color.colorType, decoder->infoPng.color.bitDepth); -} - -static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon, size_t bytewidth, unsigned char filterType, size_t length) -{ - /* - For PNG filter method 0 - unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte, the filter works byte per byte (bytewidth = 1) - precon is the previous unfiltered scanline, recon the result, scanline the current one - the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead - recon and scanline MAY be the same memory address! precon must be disjoint. - */ - - size_t i; - switch(filterType) - { - case 0: - for(i = 0; i < length; i++) recon[i] = scanline[i]; - break; - case 1: - for(i = 0; i < bytewidth; i++) recon[i] = scanline[i]; - for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth]; - break; - case 2: - if(precon) for(i = 0; i < length; i++) recon[i] = scanline[i] + precon[i]; - else for(i = 0; i < length; i++) recon[i] = scanline[i]; - break; - case 3: - if(precon) - { - for(i = 0; i < bytewidth; i++) recon[i] = scanline[i] + precon[i] / 2; - for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) / 2); - } - else - { - for(i = 0; i < bytewidth; i++) recon[i] = scanline[i]; - for(i = bytewidth; i < length; i++) recon[i] = scanline[i] + recon[i - bytewidth] / 2; - } - break; - case 4: - if(precon) - { - for(i = 0; i < bytewidth; i++) recon[i] = (unsigned char)(scanline[i] + paethPredictor(0, precon[i], 0)); - for(i = bytewidth; i < length; i++) recon[i] = (unsigned char)(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++) recon[i] = (unsigned char)(scanline[i] + paethPredictor(recon[i - bytewidth], 0, 0)); - } - 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 it's called 7 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! - */ - - unsigned y; - unsigned char* prevline = 0; - - size_t bytewidth = (bpp + 7) / 8; /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ - size_t linebytes = (w * bpp + 7) / 8; - - for(y = 0; y < h; y++) - { - size_t outindex = linebytes * y; - size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ - unsigned char filterType = in[inindex]; - - unsigned error = unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes); - if(error) return error; - - prevline = &out[outindex]; - } - - return 0; -} - -static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) -{ - /*Note: this function works on image buffers WITHOUT padding bits at end of scanlines with non-multiple-of-8 bit amounts, only between reduced images is padding - out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation (because that's likely a little bit faster)*/ - unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; - unsigned i; - - Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); - - if(bpp >= 8) - { - for(i = 0; i < 7; i++) - { - unsigned x, y, b; - size_t bytewidth = bpp / 8; - for(y = 0; y < passh[i]; y++) - for(x = 0; x < passw[i]; x++) - { - size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth; - size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth; - for(b = 0; b < bytewidth; b++) - { - out[pixeloutstart + b] = in[pixelinstart + b]; - } - } - } - } - else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ - { - for(i = 0; i < 7; i++) - { - unsigned x, y, b; - unsigned ilinebits = bpp * passw[i]; - unsigned olinebits = bpp * w; - size_t obp, ibp; /*bit pointers (for out and in buffer)*/ - for(y = 0; y < passh[i]; y++) - for(x = 0; x < passw[i]; x++) - { - ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp); - obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp; - for(b = 0; b < bpp; b++) - { - unsigned char bit = readBitFromReversedStream(&ibp, in); - setBitOfReversedStream0(&obp, out, bit); /*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/ - } - } - } - } -} - -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 obp = 0, ibp = 0; /*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*/ -static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, const LodePNG_InfoPng* infoPng) /*return value is error*/ -{ - /* - 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 (= possible extra bits per scanline if bpp < 8) - *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace - NOTE: the in buffer will be overwritten with intermediate data! - */ - unsigned bpp = LodePNG_InfoColor_getBpp(&infoPng->color); - unsigned w = infoPng->width; - unsigned h = infoPng->height; - unsigned error = 0; - if(bpp == 0) return 31; /*error: invalid colortype*/ - - if(infoPng->interlaceMethod == 0) - { - if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) - { - error = unfilter(in, in, w, h, bpp); - if(error) return error; - removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h); - } - else error = unfilter(out, in, w, h, bpp); /*we can immediately filter into the out buffer, no other steps needed*/ - } - else /*interlaceMethod is 1 (Adam7)*/ - { - unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; - unsigned i; - - Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); - - for(i = 0; i < 7; i++) - { - error = unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp); - if(error) return error; - if(bpp < 8) /*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*/ - { - /*remove padding bits in scanlines; after this there still may be padding bits between the different reduced images: each reduced image still starts nicely at a byte*/ - removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp, ((passw[i] * bpp + 7) / 8) * 8, passh[i]); - } - } - - Adam7_deinterlace(out, in, w, h, bpp); - } - - return error; -} - -/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/ -static void decodeGeneric(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize, const unsigned char* in, size_t size) -{ - unsigned char IEND = 0; - const unsigned char* chunk; - size_t i; - ucvector idat; /*the data from idat chunks*/ - - /*for unknown chunk order*/ - unsigned unknown = 0; - unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/ - - /*provide some proper output values if error will happen*/ - *out = 0; - *outsize = 0; - - if(size == 0 || in == 0) { decoder->error = 48; return; } /*the given data is empty*/ - - LodePNG_inspect(decoder, in, size); /*reads header and resets other parameters in decoder->infoPng*/ - if(decoder->error) return; - - ucvector_init(&idat); - - chunk = &in[33]; /*first byte of the first chunk after the header*/ - - while(!IEND) /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk. IDAT data is put at the start of the in buffer*/ - { - unsigned chunkLength; - const unsigned char* data; /*the data in the chunk*/ - - if((size_t)((chunk - in) + 12) > size || chunk < in) { decoder->error = 30; break; } /*error: size of the in buffer too small to contain next chunk*/ - chunkLength = LodePNG_chunk_length(chunk); /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/ - if(chunkLength > 2147483647) { decoder->error = 63; break; } - if((size_t)((chunk - in) + chunkLength + 12) > size || (chunk + chunkLength + 12) < in) { decoder->error = 35; break; } /*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)) { decoder->error = 9936; break; } - for(i = 0; i < chunkLength; i++) idat.data[oldsize + i] = data[i]; - critical_pos = 3; - } - /*IEND chunk*/ - else if(LodePNG_chunk_type_equals(chunk, "IEND")) - { - IEND = 1; - } - /*palette chunk (PLTE)*/ - else if(LodePNG_chunk_type_equals(chunk, "PLTE")) - { - unsigned pos = 0; - if(decoder->infoPng.color.palette) free(decoder->infoPng.color.palette); - decoder->infoPng.color.palettesize = chunkLength / 3; - decoder->infoPng.color.palette = (unsigned char*)malloc(4 * decoder->infoPng.color.palettesize); - if(!decoder->infoPng.color.palette && decoder->infoPng.color.palettesize) { decoder->error = 9937; break; } - if(!decoder->infoPng.color.palette) decoder->infoPng.color.palettesize = 0; /*malloc failed...*/ - if(decoder->infoPng.color.palettesize > 256) { decoder->error = 38; break; } /*error: palette too big*/ - for(i = 0; i < decoder->infoPng.color.palettesize; i++) - { - decoder->infoPng.color.palette[4 * i + 0] = data[pos++]; /*R*/ - decoder->infoPng.color.palette[4 * i + 1] = data[pos++]; /*G*/ - decoder->infoPng.color.palette[4 * i + 2] = data[pos++]; /*B*/ - decoder->infoPng.color.palette[4 * i + 3] = 255; /*alpha*/ - } - critical_pos = 2; - } - /*palette transparency chunk (tRNS)*/ - else if(LodePNG_chunk_type_equals(chunk, "tRNS")) - { - if(decoder->infoPng.color.colorType == 3) - { - if(chunkLength > decoder->infoPng.color.palettesize) { decoder->error = 39; break; } /*error: more alpha values given than there are palette entries*/ - for(i = 0; i < chunkLength; i++) decoder->infoPng.color.palette[4 * i + 3] = data[i]; - } - else if(decoder->infoPng.color.colorType == 0) - { - if(chunkLength != 2) { decoder->error = 40; break; } /*error: this chunk must be 2 bytes for greyscale image*/ - decoder->infoPng.color.key_defined = 1; - decoder->infoPng.color.key_r = decoder->infoPng.color.key_g = decoder->infoPng.color.key_b = 256 * data[0] + data[1]; - } - else if(decoder->infoPng.color.colorType == 2) - { - if(chunkLength != 6) { decoder->error = 41; break; } /*error: this chunk must be 6 bytes for RGB image*/ - decoder->infoPng.color.key_defined = 1; - decoder->infoPng.color.key_r = 256 * data[0] + data[1]; - decoder->infoPng.color.key_g = 256 * data[2] + data[3]; - decoder->infoPng.color.key_b = 256 * data[4] + data[5]; - } - else { decoder->error = 42; break; } /*error: tRNS chunk not allowed for other color models*/ - } -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /*background color chunk (bKGD)*/ - else if(LodePNG_chunk_type_equals(chunk, "bKGD")) - { - if(decoder->infoPng.color.colorType == 3) - { - if(chunkLength != 1) { decoder->error = 43; break; } /*error: this chunk must be 1 byte for indexed color image*/ - decoder->infoPng.background_defined = 1; - decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_g = data[0]; - } - else if(decoder->infoPng.color.colorType == 0 || decoder->infoPng.color.colorType == 4) - { - if(chunkLength != 2) { decoder->error = 44; break; } /*error: this chunk must be 2 bytes for greyscale image*/ - decoder->infoPng.background_defined = 1; - decoder->infoPng.background_r = decoder->infoPng.background_g = decoder->infoPng.background_b = 256 * data[0] + data[1]; - } - else if(decoder->infoPng.color.colorType == 2 || decoder->infoPng.color.colorType == 6) - { - if(chunkLength != 6) { decoder->error = 45; break; } /*error: this chunk must be 6 bytes for greyscale image*/ - decoder->infoPng.background_defined = 1; - decoder->infoPng.background_r = 256 * data[0] + data[1]; - decoder->infoPng.background_g = 256 * data[2] + data[3]; - decoder->infoPng.background_b = 256 * data[4] + data[5]; - } - } - /*text chunk (tEXt)*/ - else if(LodePNG_chunk_type_equals(chunk, "tEXt")) - { - if(decoder->settings.readTextChunks) - { - char *key = 0, *str = 0; - - while(!decoder->error) /*not really a while loop, only used to break on error*/ - { - unsigned length, string2_begin; - - for(length = 0; length < chunkLength && data[length] != 0; length++) ; - if(length + 1 >= chunkLength) { decoder->error = 75; break; } - key = (char*)malloc(length + 1); - if(!key) { decoder->error = 9938; break; } - key[length] = 0; - for(i = 0; i < length; i++) key[i] = data[i]; - - string2_begin = length + 1; - if(string2_begin > chunkLength) { decoder->error = 75; break; } - length = chunkLength - string2_begin; - str = (char*)malloc(length + 1); - if(!str) { decoder->error = 9939; break; } - str[length] = 0; - for(i = 0; i < length; i++) str[i] = data[string2_begin + i]; - - decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, str); - - break; - } - - free(key); - free(str); - } - } - /*compressed text chunk (zTXt)*/ - else if(LodePNG_chunk_type_equals(chunk, "zTXt")) - { - if(decoder->settings.readTextChunks) - { - unsigned length, string2_begin; - char *key = 0; - ucvector decoded; - - ucvector_init(&decoded); - - while(!decoder->error) /*not really a while loop, only used to break on error*/ - { - for(length = 0; length < chunkLength && data[length] != 0; length++) ; - if(length + 2 >= chunkLength) { decoder->error = 75; break; } - key = (char*)malloc(length + 1); - if(!key) { decoder->error = 9940; break; } - key[length] = 0; - for(i = 0; i < length; i++) key[i] = data[i]; - - if(data[length + 1] != 0) { decoder->error = 72; break; } /*the 0 byte indicating compression must be 0*/ - - string2_begin = length + 2; - if(string2_begin > chunkLength) { decoder->error = 75; break; } - length = chunkLength - string2_begin; - decoder->error = LodePNG_decompress(&decoded.data, &decoded.size, (unsigned char*)(&data[string2_begin]), length, &decoder->settings.zlibsettings); - if(decoder->error) break; - ucvector_push_back(&decoded, 0); - - decoder->error = LodePNG_Text_add(&decoder->infoPng.text, key, (char*)decoded.data); - - break; - } - - free(key); - ucvector_cleanup(&decoded); - if(decoder->error) break; - } - } - /*international text chunk (iTXt)*/ - else if(LodePNG_chunk_type_equals(chunk, "iTXt")) - { - if(decoder->settings.readTextChunks) - { - unsigned length, begin, compressed; - char *key = 0, *langtag = 0, *transkey = 0; - ucvector decoded; - ucvector_init(&decoded); - - while(!decoder->error) /*not really a while loop, only used to break on error*/ - { - if(chunkLength < 5) { decoder->error = 76; break; } - for(length = 0; length < chunkLength && data[length] != 0; length++) ; - if(length + 2 >= chunkLength) { decoder->error = 75; break; } - key = (char*)malloc(length + 1); - if(!key) { decoder->error = 9941; break; } - key[length] = 0; - for(i = 0; i < length; i++) key[i] = data[i]; - - compressed = data[length + 1]; - if(data[length + 2] != 0) { decoder->error = 72; break; } /*the 0 byte indicating compression must be 0*/ - - begin = length + 3; - length = 0; - for(i = begin; i < chunkLength && data[i] != 0; i++) length++; - if(begin + length + 1 >= chunkLength) { decoder->error = 75; break; } - langtag = (char*)malloc(length + 1); - if(!langtag) { decoder->error = 9942; break; } - langtag[length] = 0; - for(i = 0; i < length; i++) langtag[i] = data[begin + i]; - - begin += length + 1; - length = 0; - for(i = begin; i < chunkLength && data[i] != 0; i++) length++; - if(begin + length + 1 >= chunkLength) { decoder->error = 75; break; } - transkey = (char*)malloc(length + 1); - if(!transkey) { decoder->error = 9943; break; } - transkey[length] = 0; - for(i = 0; i < length; i++) transkey[i] = data[begin + i]; - - begin += length + 1; - if(begin > chunkLength) { decoder->error = 75; break; } - length = chunkLength - begin; - - if(compressed) - { - decoder->error = LodePNG_decompress(&decoded.data, &decoded.size, (unsigned char*)(&data[begin]), length, &decoder->settings.zlibsettings); - if(decoder->error) break; - ucvector_push_back(&decoded, 0); - } - else - { - if(!ucvector_resize(&decoded, length + 1)) { decoder->error = 9944; break; } - decoded.data[length] = 0; - for(i = 0; i < length; i++) decoded.data[i] = data[begin + i]; - } - - decoder->error = LodePNG_IText_add(&decoder->infoPng.itext, key, langtag, transkey, (char*)decoded.data); - - break; - } - - free(key); - free(langtag); - free(transkey); - ucvector_cleanup(&decoded); - if(decoder->error) break; - } - } - else if(LodePNG_chunk_type_equals(chunk, "tIME")) - { - if(chunkLength != 7) { decoder->error = 73; break; } - decoder->infoPng.time_defined = 1; - decoder->infoPng.time.year = 256 * data[0] + data[+ 1]; - decoder->infoPng.time.month = data[2]; - decoder->infoPng.time.day = data[3]; - decoder->infoPng.time.hour = data[4]; - decoder->infoPng.time.minute = data[5]; - decoder->infoPng.time.second = data[6]; - } - else if(LodePNG_chunk_type_equals(chunk, "pHYs")) - { - if(chunkLength != 9) { decoder->error = 74; break; } - decoder->infoPng.phys_defined = 1; - decoder->infoPng.phys_x = 16777216 * data[0] + 65536 * data[1] + 256 * data[2] + data[3]; - decoder->infoPng.phys_y = 16777216 * data[4] + 65536 * data[5] + 256 * data[6] + data[7]; - decoder->infoPng.phys_unit = data[8]; - } -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - else /*it's not an implemented chunk type, so ignore it: skip over the data*/ - { - if(LodePNG_chunk_critical(chunk)) { decoder->error = 69; break; } /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/ - unknown = 1; -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - if(decoder->settings.rememberUnknownChunks) - { - LodePNG_UnknownChunks* unknown = &decoder->infoPng.unknown_chunks; - decoder->error = LodePNG_append_chunk(&unknown->data[critical_pos - 1], &unknown->datasize[critical_pos - 1], chunk); - if(decoder->error) break; - } -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ - } - - if(!decoder->settings.ignoreCrc && !unknown) /*check CRC if wanted, only on known chunk types*/ - { - if(LodePNG_chunk_check_crc(chunk)) { decoder->error = 57; break; } - } - - if(!IEND) chunk = LodePNG_chunk_next_const(chunk); - } - - if(!decoder->error) - { - ucvector scanlines; - ucvector_init(&scanlines); - if(!ucvector_resize(&scanlines, ((decoder->infoPng.width * (decoder->infoPng.height * LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7)) / 8) + decoder->infoPng.height)) decoder->error = 9945; /*maximum final image length is already reserved in the vector's length - this is not really necessary*/ - if(!decoder->error) decoder->error = LodePNG_decompress(&scanlines.data, &scanlines.size, idat.data, idat.size, &decoder->settings.zlibsettings); /*decompress with the Zlib decompressor*/ - - if(!decoder->error) - { - ucvector outv; - ucvector_init(&outv); - if(!ucvector_resizev(&outv, (decoder->infoPng.height * decoder->infoPng.width * LodePNG_InfoColor_getBpp(&decoder->infoPng.color) + 7) / 8, 0)) decoder->error = 9946; - if(!decoder->error) decoder->error = postProcessScanlines(outv.data, scanlines.data, &decoder->infoPng); - *out = outv.data; - *outsize = outv.size; - } - ucvector_cleanup(&scanlines); - } - - ucvector_cleanup(&idat); -} - -void LodePNG_decode(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize) -{ - *out = 0; - *outsize = 0; - decodeGeneric(decoder, out, outsize, in, insize); - if(decoder->error) return; - if(!decoder->settings.color_convert || LodePNG_InfoColor_equal(&decoder->infoRaw.color, &decoder->infoPng.color)) - { - /*same color type, no copying or converting of data needed*/ - /*store the infoPng color settings on the infoRaw so that the infoRaw still reflects what colorType - the raw image has to the end user*/ - if(!decoder->settings.color_convert) - { - decoder->error = LodePNG_InfoColor_copy(&decoder->infoRaw.color, &decoder->infoPng.color); - if(decoder->error) return; - } - } - else - { - /*color conversion needed; sort of copy of the data*/ - unsigned char* data = *out; - - /*TODO: check if this works according to the statement in the documentation: "The converter can convert from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/ - if(!(decoder->infoRaw.color.colorType == 2 || decoder->infoRaw.color.colorType == 6) && !(decoder->infoRaw.color.bitDepth == 8)) { decoder->error = 56; return; } - - *outsize = (decoder->infoPng.width * decoder->infoPng.height * LodePNG_InfoColor_getBpp(&decoder->infoRaw.color) + 7) / 8; - *out = (unsigned char*)malloc(*outsize); - if(!(*out)) - { - decoder->error = 9947; - *outsize = 0; - } - else decoder->error = LodePNG_convert(*out, data, &decoder->infoRaw.color, &decoder->infoPng.color, decoder->infoPng.width, decoder->infoPng.height); - free(data); - } -} - -unsigned LodePNG_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) -{ - unsigned error; - size_t dummy_size; - LodePNG_Decoder decoder; - LodePNG_Decoder_init(&decoder); - LodePNG_decode(&decoder, out, &dummy_size, in, insize); - error = decoder.error; - *w = decoder.infoPng.width; - *h = decoder.infoPng.height; - LodePNG_Decoder_cleanup(&decoder); - return error; -} - -#ifdef LODEPNG_COMPILE_DISK -unsigned LodePNG_decode32f(unsigned char** out, unsigned* w, unsigned* h, const char* filename) -{ - unsigned char* buffer; - size_t buffersize; - unsigned error; - error = LodePNG_loadFile(&buffer, &buffersize, filename); - if(!error) error = LodePNG_decode32(out, w, h, buffer, buffersize); - free(buffer); - return error; -} -#endif /*LODEPNG_COMPILE_DISK*/ - -void LodePNG_DecodeSettings_init(LodePNG_DecodeSettings* settings) -{ - settings->color_convert = 1; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - settings->readTextChunks = 1; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - settings->ignoreCrc = 0; -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - settings->rememberUnknownChunks = 0; -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ - LodeZlib_DecompressSettings_init(&settings->zlibsettings); -} - -void LodePNG_Decoder_init(LodePNG_Decoder* decoder) -{ - LodePNG_DecodeSettings_init(&decoder->settings); - LodePNG_InfoRaw_init(&decoder->infoRaw); - LodePNG_InfoPng_init(&decoder->infoPng); - decoder->error = 1; -} - -void LodePNG_Decoder_cleanup(LodePNG_Decoder* decoder) -{ - LodePNG_InfoRaw_cleanup(&decoder->infoRaw); - LodePNG_InfoPng_cleanup(&decoder->infoPng); -} - -void LodePNG_Decoder_copy(LodePNG_Decoder* dest, const LodePNG_Decoder* source) -{ - LodePNG_Decoder_cleanup(dest); - *dest = *source; - LodePNG_InfoRaw_init(&dest->infoRaw); - LodePNG_InfoPng_init(&dest->infoPng); - dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw); if(dest->error) return; - dest->error = LodePNG_InfoPng_copy(&dest->infoPng, &source->infoPng); if(dest->error) return; -} - -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER /* ////////////////////////////////////////////////////////////////////////// */ /* / PNG Encoder / */ @@ -3300,7 +2034,7 @@ static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h, unsigned bi 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*/ @@ -3308,10 +2042,10 @@ static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h, unsigned bi ucvector_push_back(&header, 0); /*compression method*/ ucvector_push_back(&header, 0); /*filter method*/ ucvector_push_back(&header, interlaceMethod); /*interlace method*/ - + error = addChunk(out, "IHDR", header.data, header.size); ucvector_cleanup(&header); - + return error; } @@ -3324,7 +2058,7 @@ static unsigned addChunk_PLTE(ucvector* out, const LodePNG_InfoColor* info) for(i = 0; i < info->palettesize * 4; i++) if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]); /*add all channels except alpha channel*/ error = addChunk(out, "PLTE", PLTE.data, PLTE.size); ucvector_cleanup(&PLTE); - + return error; } @@ -3358,10 +2092,10 @@ static unsigned addChunk_tRNS(ucvector* out, const LodePNG_InfoColor* info) ucvector_push_back(&tRNS, (unsigned char)(info->key_b % 256)); } } - + error = addChunk(out, "tRNS", tRNS.data, tRNS.size); ucvector_cleanup(&tRNS); - + return error; } @@ -3369,13 +2103,13 @@ static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t d { ucvector zlibdata; unsigned error = 0; - + /*compress with the Zlib compressor*/ ucvector_init(&zlibdata); error = LodePNG_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings); if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size); ucvector_cleanup(&zlibdata); - + return error; } @@ -3386,149 +2120,6 @@ static unsigned addChunk_IEND(ucvector* out) return error; } -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - -static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring) /*add text chunk*/ -{ - unsigned error = 0; - size_t i; - ucvector text; - ucvector_init(&text); - for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&text, (unsigned char)keyword[i]); - ucvector_push_back(&text, 0); - for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&text, (unsigned char)textstring[i]); - error = addChunk(out, "tEXt", text.data, text.size); - ucvector_cleanup(&text); - - return error; -} - -static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring, LodeZlib_DeflateSettings* zlibsettings) -{ - unsigned error = 0; - ucvector data, compressed; - size_t i, textsize = strlen(textstring); - - ucvector_init(&data); - ucvector_init(&compressed); - for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]); - ucvector_push_back(&data, 0); /* 0 termination char*/ - ucvector_push_back(&data, 0); /*compression method: 0*/ - - error = LodePNG_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, LodeZlib_DeflateSettings* zlibsettings) -{ - unsigned error = 0; - ucvector data, compressed_data; - size_t i, textsize = strlen(textstring); - - ucvector_init(&data); - - for(i = 0; keyword[i] != 0; i++) ucvector_push_back(&data, (unsigned char)keyword[i]); - ucvector_push_back(&data, 0); /*null termination char*/ - ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/ - ucvector_push_back(&data, 0); /*compression method*/ - for(i = 0; langtag[i] != 0; i++) ucvector_push_back(&data, (unsigned char)langtag[i]); - ucvector_push_back(&data, 0); /*null termination char*/ - for(i = 0; transkey[i] != 0; i++) ucvector_push_back(&data, (unsigned char)transkey[i]); - ucvector_push_back(&data, 0); /*null termination char*/ - - if(compressed) - { - ucvector_init(&compressed_data); - error = LodePNG_compress(&compressed_data.data, &compressed_data.size, (unsigned char*)textstring, textsize, zlibsettings); - if(!error) - { - for(i = 0; i < compressed_data.size; i++) ucvector_push_back(&data, compressed_data.data[i]); - for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]); - } - } - else /*not compressed*/ - { - for(i = 0; textstring[i] != 0; i++) ucvector_push_back(&data, (unsigned char)textstring[i]); - } - - if(!error) error = addChunk(out, "iTXt", data.data, data.size); - ucvector_cleanup(&data); - return error; -} - -static unsigned addChunk_bKGD(ucvector* out, const LodePNG_InfoPng* info) -{ - unsigned error = 0; - ucvector bKGD; - ucvector_init(&bKGD); - if(info->color.colorType == 0 || info->color.colorType == 4) - { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); - } - else if(info->color.colorType == 2 || info->color.colorType == 6) - { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r / 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_g / 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_g % 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_b / 256)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_b % 256)); - } - else if(info->color.colorType == 3) - { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r % 256)); /*palette index*/ - } - - error = addChunk(out, "bKGD", bKGD.data, bKGD.size); - ucvector_cleanup(&bKGD); - - return error; -} - -static unsigned addChunk_tIME(ucvector* out, const LodePNG_Time* time) -{ - unsigned error = 0; - unsigned char* data = (unsigned char*)malloc(7); - if(!data) return 9948; - data[0] = (unsigned char)(time->year / 256); - data[1] = (unsigned char)(time->year % 256); - data[2] = time->month; - data[3] = time->day; - data[4] = time->hour; - data[5] = time->minute; - data[6] = time->second; - error = addChunk(out, "tIME", data, 7); - free(data); - return error; -} - -static unsigned addChunk_pHYs(ucvector* out, const LodePNG_InfoPng* info) -{ - unsigned error = 0; - ucvector data; - ucvector_init(&data); - - LodePNG_add32bitInt(&data, info->phys_x); - LodePNG_add32bitInt(&data, info->phys_y); - ucvector_push_back(&data, info->phys_unit); - - error = addChunk(out, "pHYs", data.data, data.size); - ucvector_cleanup(&data); - - return error; -} - -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline, size_t length, size_t bytewidth, unsigned char filterType) { size_t i; @@ -3578,14 +2169,14 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, /* 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 - + There is a nice heuristic described here: http://www.cs.toronto.edu/~cosmin/pngtech/optipng.html. It says: * 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. - + Here the above method is used mostly. Note though that it appears to be better to use the adaptive filtering on the plasma 8-bit palette example, but that image isn't the best reference for palette images in general. */ - + unsigned bpp = LodePNG_InfoColor_getBpp(info); size_t linebytes = (w * bpp + 7) / 8; /*the width of a scanline in bytes, not including the filter type*/ size_t bytewidth = (bpp + 7) / 8; /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ @@ -3593,13 +2184,13 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned x, y; unsigned heuristic; unsigned error = 0; - + if(bpp == 0) return 31; /*invalid color type*/ - + /*choose heuristic as described above*/ if(info->colorType == 3 || info->bitDepth < 8) heuristic = 0; else heuristic = 1; - + if(heuristic == 0) /*None filtertype for everything*/ { for(y = 0; y < h; y++) @@ -3618,13 +2209,13 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, ucvector attempt[5]; /*five filtering attempts, one for each filter type*/ size_t smallest = 0; unsigned type, bestType = 0; - + for(type = 0; type < 5; type++) ucvector_init(&attempt[type]); for(type = 0; type < 5; type++) { if(!ucvector_resize(&attempt[type], linebytes)) { error = 9949; break; } } - + if(!error) { for(y = 0; y < h; y++) @@ -3633,11 +2224,11 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, 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; for(x = 0; x < attempt[type].size; x+=3) sum[type] += attempt[type].data[x]; /*note that not all pixels are checked to speed this up while still having probably the best choice*/ - + /*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) { @@ -3645,47 +2236,18 @@ static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, 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]); - } - #if 0 /*deflate the scanline with a fixed tree after every filter attempt to see which one deflates best. This is slow, and _does not work as expected_: the heuristic gives smaller result!*/ - else if(heuristic == 2) /*adaptive filtering by using deflate*/ - { - size_t size[5]; - ucvector attempt[5]; /*five filtering attempts, one for each filter type*/ - size_t smallest; - unsigned type = 0, bestType = 0; - unsigned char* dummy; - LodeZlib_DeflateSettings deflatesettings = LodeZlib_defaultDeflateSettings; - deflatesettings.btype = 1; /*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*/ - for(type = 0; type < 5; type++) { ucvector_init(&attempt[type]); ucvector_resize(&attempt[type], linebytes); } - 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); - size[type] = 0; dummy = 0; - LodePNG_compress(&dummy, &size[type], attempt[type].data, attempt[type].size, &deflatesettings); - 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]); } - #endif - + return error; } @@ -3716,7 +2278,7 @@ static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigne unsigned i; Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); - + if(bpp >= 8) { for(i = 0; i < 7; i++) @@ -3770,7 +2332,7 @@ static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned w = infoPng->width; unsigned h = infoPng->height; unsigned error = 0; - + if(infoPng->interlaceMethod == 0) { *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/ @@ -3798,20 +2360,20 @@ static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const { unsigned char* adam7 = (unsigned char*)malloc((h * w * bpp + 7) / 8); if(!adam7 && ((h * w * bpp + 7) / 8)) error = 9952; /*malloc failed*/ - + while(!error) /*not a real while loop, used to break out to cleanup to avoid a goto*/ { unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; unsigned i; - + Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); - + *outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/ *out = (unsigned char*)malloc(*outsize); if(!(*out) && (*outsize)) { error = 9953; break; } - + Adam7_interlace(adam7, in, w, h, bpp); - + for(i = 0; i < 7; i++) { if(bpp < 8) @@ -3824,7 +2386,7 @@ static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const addPaddingBits(&padded.data[padded_passstart[i]], &adam7[passstart[i]], ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]); error = filter(&(*out)[filter_passstart[i]], &padded.data[padded_passstart[i]], passw[i], passh[i], &infoPng->color); } - + ucvector_cleanup(&padded); } else @@ -3832,13 +2394,13 @@ static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]], passw[i], passh[i], &infoPng->color); } } - + break; } free(adam7); } - + return error; } @@ -3892,55 +2454,40 @@ static unsigned isFullyOpaque(const unsigned char* image, unsigned w, unsigned h return 0; /*color type that isn't supported by this function yet, so assume there is transparency to be safe*/ } -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS -static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize) -{ - unsigned char* inchunk = data; - while((size_t)(inchunk - data) < datasize) - { - unsigned error = LodePNG_append_chunk(&out->data, &out->size, inchunk); - if(error) return error; /*error: not enough memory*/ - out->allocsize = out->size; /*fix the allocsize again*/ - inchunk = LodePNG_chunk_next(inchunk); - } - return 0; -} -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ - void LodePNG_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) { LodePNG_InfoPng info; ucvector outv; unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/ size_t datasize = 0; - + /*provide some proper output values if error will happen*/ *out = 0; *outsize = 0; encoder->error = 0; - + info = encoder->infoPng; /*UNSAFE copy to avoid having to cleanup! but we will only change primitive parameters, and not invoke the cleanup function nor touch the palette's buffer so we use it safely*/ info.width = w; info.height = h; - + if(encoder->settings.autoLeaveOutAlphaChannel && isFullyOpaque(image, w, h, &encoder->infoRaw.color)) { /*go to a color type without alpha channel*/ if(info.color.colorType == 6) info.color.colorType = 2; else if(info.color.colorType == 4) info.color.colorType = 0; } - + if(encoder->settings.zlibsettings.windowSize > 32768) { encoder->error = 60; return; } /*error: windowsize larger than allowed*/ if(encoder->settings.zlibsettings.btype > 2) { encoder->error = 61; return; } /*error: unexisting btype*/ if(encoder->infoPng.interlaceMethod > 1) { encoder->error = 71; return; } /*error: unexisting interlace mode*/ if((encoder->error = checkColorValidity(info.color.colorType, info.color.bitDepth))) return; /*error: unexisting color type given*/ if((encoder->error = checkColorValidity(encoder->infoRaw.color.colorType, encoder->infoRaw.color.bitDepth))) return; /*error: unexisting color type given*/ - + if(!LodePNG_InfoColor_equal(&encoder->infoRaw.color, &info.color)) { unsigned char* converted; size_t size = (w * h * LodePNG_InfoColor_getBpp(&info.color) + 7) / 8; - + if((info.color.colorType != 6 && info.color.colorType != 2) || (info.color.bitDepth != 8)) { encoder->error = 59; return; } /*for the output image, only these types are supported*/ converted = (unsigned char*)malloc(size); if(!converted && size) encoder->error = 9955; /*error: malloc failed*/ @@ -3949,21 +2496,14 @@ void LodePNG_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsi free(converted); } else preProcessScanlines(&data, &datasize, image, &info);/*filter(data.data, image, w, h, LodePNG_InfoColor_getBpp(&info.color));*/ - + ucvector_init(&outv); while(!encoder->error) /*not really a while loop, this is only used to break out if an error happens to avoid goto's to do the ucvector cleanup*/ { -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - size_t i; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ /*write signature and chunks*/ writeSignature(&outv); /*IHDR*/ addChunk_IHDR(&outv, w, h, info.color.bitDepth, info.color.colorType, info.interlaceMethod); -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - /*unknown chunks between IHDR and PLTE*/ - if(info.unknown_chunks.data[0]) { encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[0], info.unknown_chunks.datasize[0]); if(encoder->error) break; } -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ /*PLTE*/ if(info.color.colorType == 3) { @@ -3978,99 +2518,26 @@ void LodePNG_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsi /*tRNS*/ if(info.color.colorType == 3 && !isPaletteFullyOpaque(info.color.palette, info.color.palettesize)) addChunk_tRNS(&outv, &info.color); if((info.color.colorType == 0 || info.color.colorType == 2) && info.color.key_defined) addChunk_tRNS(&outv, &info.color); -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /*bKGD (must come between PLTE and the IDAt chunks*/ - if(info.background_defined) addChunk_bKGD(&outv, &info); - /*pHYs (must come before the IDAT chunks)*/ - if(info.phys_defined) addChunk_pHYs(&outv, &info); -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - /*unknown chunks between PLTE and IDAT*/ - if(info.unknown_chunks.data[1]) { encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[1], info.unknown_chunks.datasize[1]); if(encoder->error) break; } -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ /*IDAT (multiple IDAT chunks must be consecutive)*/ encoder->error = addChunk_IDAT(&outv, data, datasize, &encoder->settings.zlibsettings); if(encoder->error) break; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /*tIME*/ - if(info.time_defined) addChunk_tIME(&outv, &info.time); - /*tEXt and/or zTXt*/ - for(i = 0; i < info.text.num; i++) - { - if(strlen(info.text.keys[i]) > 79) { encoder->error = 66; break; } - if(strlen(info.text.keys[i]) < 1) { encoder->error = 67; break; } - if(encoder->settings.text_compression) - addChunk_zTXt(&outv, info.text.keys[i], info.text.strings[i], &encoder->settings.zlibsettings); - else - addChunk_tEXt(&outv, info.text.keys[i], info.text.strings[i]); - } - /*LodePNG version id in text chunk*/ - if(encoder->settings.add_id) - { - unsigned alread_added_id_text = 0; - for(i = 0; i < info.text.num; i++) - if(!strcmp(info.text.keys[i], "LodePNG")) { alread_added_id_text = 1; break; } - if(alread_added_id_text == 0) - addChunk_tEXt(&outv, "LodePNG", VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/ - } - /*iTXt*/ - for(i = 0; i < info.itext.num; i++) - { - if(strlen(info.itext.keys[i]) > 79) { encoder->error = 66; break; } - if(strlen(info.itext.keys[i]) < 1) { encoder->error = 67; break; } - addChunk_iTXt(&outv, encoder->settings.text_compression, - info.itext.keys[i], info.itext.langtags[i], info.itext.transkeys[i], info.itext.strings[i], - &encoder->settings.zlibsettings); - } -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - /*unknown chunks between IDAT and IEND*/ - if(info.unknown_chunks.data[2]) { encoder->error = addUnknownChunks(&outv, info.unknown_chunks.data[2], info.unknown_chunks.datasize[2]); if(encoder->error) break; } -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ /*IEND*/ addChunk_IEND(&outv); - + break; /*this isn't really a while loop; no error happened so break out now!*/ } - + free(data); /*instead of cleaning the vector up, give it to the output*/ *out = outv.data; *outsize = outv.size; } -unsigned LodePNG_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) -{ - unsigned error; - LodePNG_Encoder encoder; - LodePNG_Encoder_init(&encoder); - LodePNG_encode(&encoder, out, outsize, image, w, h); - error = encoder.error; - LodePNG_Encoder_cleanup(&encoder); - return error; -} - -#ifdef LODEPNG_COMPILE_DISK -unsigned LodePNG_encode32f(const char* filename, const unsigned char* image, unsigned w, unsigned h) -{ - unsigned char* buffer; - size_t buffersize; - unsigned error = LodePNG_encode32(&buffer, &buffersize, image, w, h); - LodePNG_saveFile(buffer, buffersize, filename); - free(buffer); - return error; -} -#endif /*LODEPNG_COMPILE_DISK*/ - void LodePNG_EncodeSettings_init(LodePNG_EncodeSettings* settings) { LodeZlib_DeflateSettings_init(&settings->zlibsettings); settings->autoLeaveOutAlphaChannel = 1; settings->force_palette = 0; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - settings->add_id = 1; - settings->text_compression = 0; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ } void LodePNG_Encoder_init(LodePNG_Encoder* encoder) @@ -4097,46 +2564,10 @@ void LodePNG_Encoder_copy(LodePNG_Encoder* dest, const LodePNG_Encoder* source) dest->error = LodePNG_InfoRaw_copy(&dest->infoRaw, &source->infoRaw); if(dest->error) return; } -#endif /*LODEPNG_COMPILE_ENCODER*/ - -#endif /*LODEPNG_COMPILE_PNG*/ - /* ////////////////////////////////////////////////////////////////////////// */ /* / File IO / */ /* ////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_DISK - -unsigned LodePNG_loadFile(unsigned char** out, size_t* outsize, const char* filename) /*designed for loading files from hard disk in a dynamically allocated buffer*/ -{ - FILE* file; - long size; - - /*provide some proper output values if error will happen*/ - *out = 0; - *outsize = 0; - - file = portable_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*/ - if (size>0) - { - *outsize = 0; - *out = (unsigned char*)malloc((size_t)size); - if(size && (*out)) (*outsize) = fread(*out, 1, (size_t)size, file); - } - - fclose(file); - if(!(*out) && size) return 80; /*the above malloc failed*/ - return 0; -} - /*write given buffer to the file, overwriting the file, it doesn't append to it.*/ unsigned LodePNG_saveFile(const unsigned char* buffer, size_t buffersize, const char* filename) { @@ -4148,5 +2579,3 @@ unsigned LodePNG_saveFile(const unsigned char* buffer, size_t buffersize, const return 0; } -#endif /*LODEPNG_COMPILE_DISK*/ - diff --git a/src/lodepng.h b/src/lodepng.h index bbf40dc0025..b6b255958b8 100644 --- a/src/lodepng.h +++ b/src/lodepng.h @@ -23,6 +23,8 @@ freely, subject to the following restrictions: distribution. */ +/** Minified version of LodePNG, with only the encoder code */ + #ifndef LODEPNG_H #define LODEPNG_H @@ -30,35 +32,11 @@ freely, subject to the following restrictions: #include #include -/* ////////////////////////////////////////////////////////////////////////// */ -/* Code Sections */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/*The following defines can be commented disable code sections. Gives potential faster compile and smaller binary.*/ - -#define LODEPNG_COMPILE_ZLIB /*deflate&zlib encoder and deflate&zlib decoder*/ -#define LODEPNG_COMPILE_PNG /*png encoder and png decoder*/ -//#define LODEPNG_COMPILE_DECODER /*deflate&zlib decoder and png decoder*/ -#define LODEPNG_COMPILE_ENCODER /*deflate&zlib encoder and png encoder*/ -#define LODEPNG_COMPILE_DISK /*the optional built in harddisk file loading and saving functions*/ -//#define LODEPNG_COMPILE_ANCILLARY_CHUNKS /*any code or struct datamember related to chunks other than IHDR, IDAT, PLTE, tRNS, IEND*/ -//#define LODEPNG_COMPILE_UNKNOWN_CHUNKS /*handling of unknown chunks*/ - /* ////////////////////////////////////////////////////////////////////////// */ /* LodeFlate & LodeZlib Setting structs */ /* ////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_DECODER -typedef struct LodeZlib_DecompressSettings -{ - unsigned ignoreAdler32; -} LodeZlib_DecompressSettings; - -extern const LodeZlib_DecompressSettings LodeZlib_defaultDecompressSettings; -void LodeZlib_DecompressSettings_init(LodeZlib_DecompressSettings* settings); -#endif /*LODEPNG_COMPILE_DECODER*/ -#ifdef LODEPNG_COMPILE_ENCODER typedef struct LodeZlib_DeflateSettings /*deflate = compress*/ { /*LZ77 related settings*/ @@ -69,58 +47,19 @@ typedef struct LodeZlib_DeflateSettings /*deflate = compress*/ extern const LodeZlib_DeflateSettings LodeZlib_defaultDeflateSettings; void LodeZlib_DeflateSettings_init(LodeZlib_DeflateSettings* settings); -#endif /*LODEPNG_COMPILE_ENCODER*/ -#ifdef LODEPNG_COMPILE_ZLIB /* ////////////////////////////////////////////////////////////////////////// */ /* LodeFlate & LodeZlib */ /* ////////////////////////////////////////////////////////////////////////// */ -#ifdef LODEPNG_COMPILE_DECODER -/*This function reallocates the out buffer and appends the data. -Either, *out must be NULL and *outsize must be 0, or, *out must be a valid buffer and *outsize its size in bytes.*/ -unsigned LodeZlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DecompressSettings* settings); -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER /*This function reallocates the out buffer and appends the data. Either, *out must be NULL and *outsize must be 0, or, *out must be a valid buffer and *outsize its size in bytes.*/ unsigned LodeZlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize, const LodeZlib_DeflateSettings* settings); -#endif /*LODEPNG_COMPILE_ENCODER*/ -#endif /*LODEPNG_COMPILE_ZLIB*/ - -#ifdef LODEPNG_COMPILE_PNG /* ////////////////////////////////////////////////////////////////////////// */ /* LodePNG */ /* ////////////////////////////////////////////////////////////////////////// */ -/*LodePNG_chunk functions: These functions need as input a large enough amount of allocated memory.*/ - -unsigned LodePNG_chunk_length(const unsigned char* chunk); /*get the length of the data of the chunk. Total chunk length has 12 bytes more.*/ - -void LodePNG_chunk_type(char type[5], const unsigned char* chunk); /*puts the 4-byte type in null terminated string*/ -unsigned char LodePNG_chunk_type_equals(const unsigned char* chunk, const char* type); /*check if the type is the given type*/ - -/*properties of PNG chunks gotten from capitalization of chunk type name, as defined by the standard*/ -unsigned char LodePNG_chunk_critical(const unsigned char* chunk); /*0: ancillary chunk, 1: it's one of the critical chunk types*/ -unsigned char LodePNG_chunk_private(const unsigned char* chunk); /*0: public, 1: private*/ -unsigned char LodePNG_chunk_safetocopy(const unsigned char* chunk); /*0: the chunk is unsafe to copy, 1: the chunk is safe to copy*/ - -unsigned char* LodePNG_chunk_data(unsigned char* chunk); /*get pointer to the data of the chunk*/ -const unsigned char* LodePNG_chunk_data_const(const unsigned char* chunk); /*get pointer to the data of the chunk*/ - -unsigned LodePNG_chunk_check_crc(const unsigned char* chunk); /*returns 0 if the crc is correct, 1 if it's incorrect*/ -void LodePNG_chunk_generate_crc(unsigned char* chunk); /*generates the correct CRC from the data and puts it in the last 4 bytes of the chunk*/ - -/*iterate to next chunks.*/ -unsigned char* LodePNG_chunk_next(unsigned char* chunk); -const unsigned char* LodePNG_chunk_next_const(const unsigned char* chunk); - -/*add chunks to out buffer. It reallocs the buffer to append the data. returns error code*/ -unsigned LodePNG_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk); /*appends chunk that was already created, to the data. Returns pointer to start of appended chunk, or NULL if error happened*/ -unsigned LodePNG_create_chunk(unsigned char** out, size_t* outlength, unsigned length, const char* type, const unsigned char* data); /*appends new chunk to out. Returns pointer to start of appended chunk, or NULL if error happened; may change memory address of out buffer*/ - typedef struct LodePNG_InfoColor /*info about the color type of an image*/ { /*header (IHDR)*/ @@ -130,7 +69,7 @@ typedef struct LodePNG_InfoColor /*info about the color type of an image*/ /*palette (PLTE)*/ unsigned char* palette; /*palette in RGBARGBA... order*/ size_t palettesize; /*palette size in number of colors (amount of bytes is 4 * palettesize)*/ - + /*transparent color key (tRNS)*/ unsigned key_defined; /*is a transparent color key given?*/ unsigned key_r; /*red component of color key*/ @@ -138,82 +77,6 @@ typedef struct LodePNG_InfoColor /*info about the color type of an image*/ unsigned key_b; /*blue component of color key*/ } LodePNG_InfoColor; -void LodePNG_InfoColor_init(LodePNG_InfoColor* info); -void LodePNG_InfoColor_cleanup(LodePNG_InfoColor* info); -unsigned LodePNG_InfoColor_copy(LodePNG_InfoColor* dest, const LodePNG_InfoColor* source); - -/*Use these functions instead of allocating palette manually*/ -void LodePNG_InfoColor_clearPalette(LodePNG_InfoColor* info); -unsigned LodePNG_InfoColor_addPalette(LodePNG_InfoColor* info, unsigned char r, unsigned char g, unsigned char b, unsigned char a); /*add 1 color to the palette*/ - -/*additional color info*/ -unsigned LodePNG_InfoColor_getBpp(const LodePNG_InfoColor* info); /*bits per pixel*/ -unsigned LodePNG_InfoColor_getChannels(const LodePNG_InfoColor* info); /*amount of channels*/ -unsigned LodePNG_InfoColor_isGreyscaleType(const LodePNG_InfoColor* info); /*is it a greyscale type? (colorType 0 or 4)*/ -unsigned LodePNG_InfoColor_isAlphaType(const LodePNG_InfoColor* info); /*has it an alpha channel? (colorType 2 or 6)*/ - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -typedef struct LodePNG_Time /*LodePNG's encoder does not generate the current time. To make it add a time chunk the correct time has to be provided*/ -{ - unsigned year; /*2 bytes*/ - unsigned char month; /*1-12*/ - unsigned char day; /*1-31*/ - unsigned char hour; /*0-23*/ - unsigned char minute; /*0-59*/ - unsigned char second; /*0-60 (to allow for leap seconds)*/ -} LodePNG_Time; - -typedef struct LodePNG_Text /*non-international text*/ -{ - size_t num; - char** keys; /*the keyword of a text chunk (e.g. "Comment")*/ - char** strings; /*the actual text*/ -} LodePNG_Text; - -void LodePNG_Text_init(LodePNG_Text* text); -void LodePNG_Text_cleanup(LodePNG_Text* text); -unsigned LodePNG_Text_copy(LodePNG_Text* dest, const LodePNG_Text* source); - -/*Use these functions instead of allocating the char**s manually*/ -void LodePNG_Text_clear(LodePNG_Text* text); -unsigned LodePNG_Text_add(LodePNG_Text* text, const char* key, const char* str); /*push back both texts at once*/ - - -typedef struct LodePNG_IText /*international text*/ -{ - size_t num; - char** keys; /*the English keyword of the text chunk (e.g. "Comment")*/ - char** langtags; /*the language tag for this text's international language, ISO/IEC 646 string, e.g. ISO 639 language tag*/ - char** transkeys; /*keyword translated to the international language - UTF-8 string*/ - char** strings; /*the actual international text - UTF-8 string*/ -} LodePNG_IText; - -void LodePNG_IText_init(LodePNG_IText* text); -void LodePNG_IText_cleanup(LodePNG_IText* text); -unsigned LodePNG_IText_copy(LodePNG_IText* dest, const LodePNG_IText* source); - -/*Use these functions instead of allocating the char**s manually*/ -void LodePNG_IText_clear(LodePNG_IText* text); -unsigned LodePNG_IText_add(LodePNG_IText* text, 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*/ - -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS -typedef struct LodePNG_UnknownChunks /*unknown chunks read from the PNG, or extra chunks the user wants to have added in the encoded PNG*/ -{ - /*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*/ - unsigned char* data[3]; - size_t datasize[3]; /*size in bytes of the unknown chunks, given for protection*/ - -} LodePNG_UnknownChunks; - -void LodePNG_UnknownChunks_init(LodePNG_UnknownChunks* chunks); -void LodePNG_UnknownChunks_cleanup(LodePNG_UnknownChunks* chunks); -unsigned LodePNG_UnknownChunks_copy(LodePNG_UnknownChunks* dest, const LodePNG_UnknownChunks* src); -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ - typedef struct LodePNG_InfoPng /*information about the PNG image, except pixels and sometimes except width and height*/ { /*header (IHDR), palette (PLTE) and transparency (tRNS)*/ @@ -223,114 +86,21 @@ typedef struct LodePNG_InfoPng /*information about the PNG image, except pixels unsigned filterMethod; /*filter method of the original file*/ unsigned interlaceMethod; /*interlace method of the original file*/ LodePNG_InfoColor color; /*color type and bits, palette, transparency*/ - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - - /*suggested background color (bKGD)*/ - 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)*/ - LodePNG_Text text; - - /*international text chunks (iTXt)*/ - LodePNG_IText itext; - - /*time chunk (tIME)*/ - unsigned char time_defined; /*if 0, no tIME chunk was or will be generated in the PNG image*/ - LodePNG_Time time; - - /*phys chunk (pHYs)*/ - unsigned phys_defined; /*is pHYs chunk defined?*/ - unsigned phys_x; - unsigned phys_y; - unsigned char phys_unit; /*may be 0 (unknown unit) or 1 (metre)*/ - -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - /*unknown chunks*/ - LodePNG_UnknownChunks unknown_chunks; -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ - } LodePNG_InfoPng; -void LodePNG_InfoPng_init(LodePNG_InfoPng* info); -void LodePNG_InfoPng_cleanup(LodePNG_InfoPng* info); -unsigned LodePNG_InfoPng_copy(LodePNG_InfoPng* dest, const LodePNG_InfoPng* source); - typedef struct LodePNG_InfoRaw /*contains user-chosen information about the raw image data, which is independent of the PNG image*/ { LodePNG_InfoColor color; } LodePNG_InfoRaw; -void LodePNG_InfoRaw_init(LodePNG_InfoRaw* info); -void LodePNG_InfoRaw_cleanup(LodePNG_InfoRaw* info); -unsigned LodePNG_InfoRaw_copy(LodePNG_InfoRaw* dest, const LodePNG_InfoRaw* source); - -/* -LodePNG_convert: 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, where bpp is the bits per pixel of the output color type (LodePNG_InfoColor_getBpp) -*/ -unsigned LodePNG_convert(unsigned char* out, const unsigned char* in, LodePNG_InfoColor* infoOut, LodePNG_InfoColor* infoIn, unsigned w, unsigned h); - -#ifdef LODEPNG_COMPILE_DECODER - -typedef struct LodePNG_DecodeSettings -{ - LodeZlib_DecompressSettings zlibsettings; /*in here is the setting to ignore Adler32 checksums*/ - - unsigned ignoreCrc; /*ignore CRC checksums*/ - unsigned color_convert; /*whether to convert the PNG to the color type you want. Default: yes*/ - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - unsigned readTextChunks; /*if false but rememberUnknownChunks is true, they're stored in the unknown chunks*/ -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -#ifdef LODEPNG_COMPILE_UNKNOWN_CHUNKS - unsigned rememberUnknownChunks; /*store all bytes from unknown chunks in the InfoPng (off by default, useful for a png editor)*/ -#endif /*LODEPNG_COMPILE_UNKNOWN_CHUNKS*/ -} LodePNG_DecodeSettings; - -void LodePNG_DecodeSettings_init(LodePNG_DecodeSettings* settings); - -typedef struct LodePNG_Decoder -{ - LodePNG_DecodeSettings settings; - LodePNG_InfoRaw infoRaw; - LodePNG_InfoPng infoPng; /*info of the PNG image obtained after decoding*/ - unsigned error; -} LodePNG_Decoder; - -void LodePNG_Decoder_init(LodePNG_Decoder* decoder); -void LodePNG_Decoder_cleanup(LodePNG_Decoder* decoder); -void LodePNG_Decoder_copy(LodePNG_Decoder* dest, const LodePNG_Decoder* source); - -/*decoding functions*/ -/*This function allocates the out buffer and stores the size in *outsize.*/ -void LodePNG_decode(LodePNG_Decoder* decoder, unsigned char** out, size_t* outsize, const unsigned char* in, size_t insize); -unsigned LodePNG_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize); /*return value is error*/ -#ifdef LODEPNG_COMPILE_DISK -unsigned LodePNG_decode32f(unsigned char** out, unsigned* w, unsigned* h, const char* filename); -#endif /*LODEPNG_COMPILE_DISK*/ -void LodePNG_inspect(LodePNG_Decoder* decoder, const unsigned char* in, size_t size); /*read the png header*/ - -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER +unsigned LodePNG_InfoColor_addPalette(LodePNG_InfoColor* info, unsigned char r, unsigned char g, unsigned char b, unsigned char a); /*add 1 color to the palette*/ typedef struct LodePNG_EncodeSettings { LodeZlib_DeflateSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/ - + unsigned autoLeaveOutAlphaChannel; /*automatically use color type without alpha instead of given one, if given image is opaque*/ unsigned force_palette; /*force creating a PLTE chunk if colortype is 2 or 6 (= a suggested palette). If colortype is 3, PLTE is _always_ created.*/ -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - unsigned add_id; /*add LodePNG version as text chunk*/ - unsigned text_compression; /*encode text chunks as zTXt chunks instead of tEXt chunks, and use compression in iTXt chunks*/ -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ } LodePNG_EncodeSettings; void LodePNG_EncodeSettings_init(LodePNG_EncodeSettings* settings); @@ -349,1227 +119,11 @@ void LodePNG_Encoder_copy(LodePNG_Encoder* dest, const LodePNG_Encoder* source); /*This function allocates the out buffer and stores the size in *outsize.*/ void LodePNG_encode(LodePNG_Encoder* encoder, unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h); -unsigned LodePNG_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h); /*return value is error*/ -#ifdef LODEPNG_COMPILE_DISK -unsigned LodePNG_encode32f(const char* filename, const unsigned char* image, unsigned w, unsigned h); -#endif /*LODEPNG_COMPILE_DISK*/ -#endif /*LODEPNG_COMPILE_ENCODER*/ -#endif /*LODEPNG_COMPILE_PNG*/ -#ifdef LODEPNG_COMPILE_DISK /*free functions allowing to load and save a file from/to harddisk*/ /*This function allocates the out buffer and stores the size in *outsize.*/ -unsigned LodePNG_loadFile(unsigned char** out, size_t* outsize, const char* filename); +//unsigned LodePNG_loadFile(unsigned char** out, size_t* outsize, const char* filename); unsigned LodePNG_saveFile(const unsigned char* buffer, size_t buffersize, const char* filename); -#endif /*LODEPNG_COMPILE_DISK*/ - - -/* -TODO: -[ ] test if there are no memory leaks or security exploits - done a lot but needs to be checked often -[ ] LZ77 encoder more like the one described in zlib - to make sure it's patentfree -[ ] converting color to 16-bit types -[ ] read all public PNG chunk types (but never let the color profile and gamma ones ever touch RGB values, that is very annoying for textures as well as images in a browser) -[ ] make sure encoder generates no chunks with size > (2^31)-1 -[ ] partial decoding (stream processing) -[ ] let the "isFullyOpaque" function check color keys and transparent palettes too -[ ] better name for the variables "codes", "codesD", "codelengthcodes", "clcl" and "lldl" -[ ] check compatibility with vareous compilers - done but needs to be redone for every newer version -[ ] don't stop decoding on errors like 69, 57, 58 (make warnings that the decoder stores in the error at the very end? and make some errors just let it stop with this one chunk but still do the next ones) -[ ] make option to choose if the raw image with non multiple of 8 bits per scanline should have padding bits or not, if people like storing raw images that way -*/ #endif -/* -LodePNG Documentation ---------------------- - -0. table of contents --------------------- - - 1. about - 1.1. supported features - 1.2. features not supported - 2. C and C++ version - 3. A note about security! - 4. simple functions - 4.1 C Simple Functions - 4.2 C++ Simple Functions - 5. decoder - 6. encoder - 7. color conversions - 8. info values - 9. error values - 10. file IO - 11. chunks and PNG editing - 12. compiler support - 13. examples - 13.1. decoder example - 13.2. encoder example - 14. LodeZlib - 15. changes - 16. contact information - - -1. about --------- - -PNG is a file format to store raster images losslessly with good compression, -supporting different color types. It can be implemented in a patent-free way. - -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://members.gamedev.net/lode/projects/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 depending on your usage - -If you want to start using LodePNG right away without reading this doc, get the -files lodepng_examples.c or lodepng_examples.cpp 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. To decode PNGs, there's a Decoder struct or class that -can convert any PNG file data into an RGBA image buffer with a single function -call. To encode PNGs, there's an Encoder struct or class that can convert image -data into PNG file data with a single function call. 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, demoscene -productions, saving a screenshot, images in programs that require them for simple -usage, ... 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, ... -LodePNG has a standards conformant decoder and encoder, and supports the ability -to make a somewhat conformant editor. - -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 - - -2. C and C++ version --------------------- - -The C version uses buffers allocated with alloc instead that you need to free() -yourself. On top of that, 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 constructors and destructors that take care of these things, -and uses std::vectors in the interface for storing data. - -Both the C and the C++ version are contained in this file! The C++ code depends on -the C code, the C code works on its own. - -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. A note about security! -------------------------- - -Despite being used already and having received bug fixes whenever bugs were reported, -LodePNG may still contain possible exploits. - -If you discover a possible exploit, please let me know, and it will be eliminated. - -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, to avoid exploits --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 be inited already! - - -4. "Simple" Functions ---------------------- - -For the most simple usage cases of loading and saving a PNG image, there -are some simple functions that do everything in 1 call (instead of you -having to instantiate a struct or class). - -The simple versions always use 32-bit RGBA color for the raw image, but -still support loading arbitrary-colortype PNG images. - -The later sections of this manual are devoted to the complex versions, where -you can use other color types and conversions. - -4.1 C Simple Functions ----------------------- - -The C simple functions have a "32" or "32f" in their name, and don't take a struct as -parameter, unlike the non-simple ones (see more down in the documentation). - -unsigned LodePNG_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize); - -Load PNG from given buffer. -As input, give an unsigned char* buffer gotten by loading the .png file and its size. -As output, you get a dynamically allocated buffer of large enough size, and the width and height of the image. -The buffer's size is w * h * 4. The image is in RGBA format. -The return value is the error (0 if ok). -You need to do free(out) after usage to clean up the memory. - -unsigned LodePNG_decode32f(unsigned char** out, unsigned* w, unsigned* h, const char* filename); - -Load PNG from disk, from file with given name. -Same as decode32, except you give a filename instead of an input buffer. - -unsigned LodePNG_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h); - -Encode PNG into buffer. -As input, give a image buffer of size w * h * 4, in RGBA format. -As output, you get a dynamically allocated buffer and its size, which is a PNG file that can -directly be saved in this form to the harddisk. -The return value is the error (0 if ok). -You need to do free(out) after usage to clean up the memory. - -unsigned LodePNG_encode32f(const char* filename, const unsigned char* image, unsigned w, unsigned h); - -Encode PNG into file on disk with given name. -If the file exists, it's overwritten without warning! -Same parameters as encode2, except the result is stored in a file instead of a dynamic buffer. - -4.2 C++ Simple Functions ------------------------- - -For decoding a PNG there are: - -unsigned LodePNG::decode(std::vector& out, unsigned& w, unsigned& h, const unsigned char* in, unsigned size); -unsigned LodePNG::decode(std::vector& out, unsigned& w, unsigned& h, const std::vector& in); -unsigned LodePNG::decode(std::vector& out, unsigned& w, unsigned& h, const std::string& filename); - -These store the pixel data as 32-bit RGBA color in the out vector, and the width -and height of the image in w and h. -The 3 functions each have a different input type: The first as unsigned char -buffer, the second as std::vector buffer, and the third allows you to give the -filename in case you want to load the PNG from disk instead of from a buffer. -The return value is the error (0 if ok). - -For encoding a PNG there are: - -unsigned LodePNG::encode(std::vector& out, const unsigned char* in, unsigned w, unsigned h); -unsigned LodePNG::encode(std::vector& out, const std::vector& in, unsigned w, unsigned h); -unsigned LodePNG::encode(const std::string& filename, const std::vector& in, unsigned w, unsigned h); -unsigned LodePNG::encode(const std::string& filename, const unsigned char* in, unsigned w, unsigned h); - -Specify the width and height of the input image with w and h. -You can choose to get the output in an std::vector or stored in a file, and -the input can come from an std::vector or an unsigned char* buffer. The input -buffer must be in RGBA format and the size must be w * h * 4 bytes. - -The first two functions append to the out buffer, they don't clear it, clear it -first before encoding into a buffer that you expect to only contain this result. - -On the other hand, the functions that encode to a file will completely overwrite -the original file without warning if it exists. - -The return value is the error (0 if ok). - -5. Decoder ----------- - -This is about the LodePNG_Decoder struct in the C version, and the -LodePNG::Decoder class in the C++ version. The C++ version inherits -from the C struct and adds functions in the interface. - -The Decoder class can be used to convert a PNG image to a raw image. - -Usage: - --in C++: - declare a LodePNG::Decoder - call its decode member function with the parameters described below - --in C more needs to be done due to the lack of constructors and destructors: - declare a LodePNG_Decoder struct - call LodePNG_Decoder_init with the struct as parameter - call LodePNG_Decode with the parameters described below - after usage, call LodePNG_Decoder_cleanup with the struct as parameter - after usage, free() the out buffer with image data that was created by the decode function - -The other parameters of the decode function are: -*) out: this buffer will be filled with the raw image pixels -*) in: pointer to the PNG image data or std::vector with the data -*) size: the size of the PNG image data (not needed for std::vector version) - -After decoding you need to read the width and height of the image from the -decoder, see further down in this manual to see how. - -There's also an optional function "inspect". It has the same parameters as decode except -the "out" parameter. This function will read only the header chunk of the PNG -image, and store the information from it in the LodePNG_InfoPng (see below). -This allows knowing information about the image without decoding it. Only the -header (IHDR) information is read by this, not text chunks, not the palette, ... - -During the decoding it's possible that an error can happen, for example if the -PNG image was corrupted. To check if an error happened during the last decoding, -check the value error, which is a member of the decoder struct. -In the C++ version, use hasError() and getError() of the Decoder. -The error codes are explained in another section. - -Now about colors and settings... - -The Decoder contains 3 components: -*) LodePNG_InfoPng: it stores information about the PNG (the input) in an LodePNG_InfoPng struct, don't modify this one yourself -*) Settings: you can specify a few other settings for the decoder to use -*) LodePNG_InfoRaw: here you can say what type of raw image (the output) you want to get - -Some of the parameters described below may be inside the sub-struct "LodePNG_InfoColor color". -In the C and C++ version, when using Info structs outside of the decoder or encoder, you need to use their -init and cleanup functions, but normally you use the ones in the decoder that are already handled -in the init and cleanup functions of the decoder itself. - -=LodePNG_InfoPng= - -This contains information such as the original color type of the PNG image, text -comments, suggested background color, etc... More details about the LodePNG_InfoPng struct -are in another section. - -Because the dimensions of the image are important, there are shortcuts to get them in the -C++ version: use decoder.getWidth() and decoder.getHeight(). -In the C version, use decoder.infoPng.width and decoder.infoPng.height. - -=LodePNG_InfoRaw= - -In the LodePNG_InfoRaw struct of the Decoder, 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 to your LodePNG_InfoRaw -settings. Currently the following options are supported to convert to: --colorType 6, bitDepth 8: 32-bit RGBA --colorType 2, bitDepth 8: 24-bit RGB --other color types if it's exactly the same as that in the PNG image - -Palette of LodePNG_InfoRaw isn't used by the Decoder, when converting from palette color -to palette color, the values of the pixels are left untouched so that the colors -will change if the palette is different. Color key of LodePNG_InfoRaw is not used by the -Decoder. If setting color_convert is false then LodePNG_InfoRaw is completely ignored, -but it will be modified to match the color type of the PNG so will be overwritten. - -By default, 32-bit color is used for the result. - -=Settings= - -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 LodePNG_InfoPng. - - -6. Encoder ----------- - -This is about the LodePNG_Encoder struct in the C version, and the -LodePNG::Encoder class in the C++ version. - -The Encoder class can be used to convert raw image data into a PNG image. - -The PNG part of the encoder is working good, the zlib compression part is -becoming quite fine but not as good as the official zlib yet, because it's not -as fast and doesn't provide an as high compression ratio. - -Usage: - --in C++: - declare a LodePNG::Encoder - call its encode member function with the parameters described below - --in C more needs to be done due to the lack of constructors and destructors: - declare a LodePNG_Encoder struct - call LodePNG_Encoder_init with the struct as parameter - call LodePNG_Encode with the parameters described below - after usage, call LodePNG_Encoder_cleanup with the struct as parameter - after usage, free() the out buffer with PNG data that was created by the encode function - -The raw image given to the encoder is an unsigned char* buffer. You also have to -specify the width and height of the raw image. The result is stored in a given -buffer. These buffers can be unsigned char* pointers, std::vectors or dynamically -allocated unsigned char* buffers that you have to free() yourself, depending on -which you use. - -The parameters of the encode function are: -*) out: in this buffer the PNG file data will be stored (it will be appended) -*) in: vector of or pointer to a buffer containing the raw image -*) w and h: the width and height of the raw image in pixels - -Make sure that the in buffer you provide, is big enough to contain w * h pixels -of the color type specified by the LodePNG_InfoRaw. - -In the C version, you need to free() the out buffer after usage to avoid memory leaks. -In the C version, you need to use the LodePNG_Encoder_init function before using the decoder, -and the LodePNG_Encoder_cleanup function after using it. -In the C++ version, you don't need to do this since RAII takes care of it. - -The encoder generates some errors but not for everything, because, unlike when -decoding a PNG, when encoding one there aren't so much parameters of the input -that can be corrupted. It's the responsibility of the user to make sure that all -preconditions are satesfied, such as giving a correct window size, giving an -existing btype, making sure the given buffer is large enough to contain an image -with the given width and height and colortype, ... The encoder can generate -some errors, see the section with the explanations of errors for those. - -Like the Decoder, the Encoder has 3 components: -*) LodePNG_InfoRaw: here you say what color type of the raw image (the input) has -*) Settings: you can specify a few settings for the encoder to use -*) LodePNG_InfoPng: the same LodePNG_InfoPng struct as created by the Decoder. For the encoder, -with this you specify how you want the PNG (the output) to be. - -Some of the parameters described below may be inside the sub-struct "LodePNG_InfoColor color". -In the C and C++ version, when using Info structs outside of the decoder or encoder, you need to use their -init and cleanup functions, but normally you use the ones in the encoder that are already handled -in the init and cleanup functions of the decoder itself. - -=LodePNG_InfoPng= - -The Decoder class stores information about the PNG image in an LodePNG_InfoPng object. With -the Encoder you can do the opposite: you give it an LodePNG_InfoPng object, and it'll try -to match the LodePNG_InfoPng you give as close as possible in the PNG it encodes. For -example in the LodePNG_InfoPng you can specify the color type you want to use, possible -tEXt chunks you want the PNG to contain, etc... For an explanation of all the -values in LodePNG_InfoPng see a further section. Not all PNG color types are supported -by the Encoder. - -Note that the encoder will only TRY to match the LodePNG_InfoPng struct you give. -Some things are ignored by the encoder. The width and height of LodePNG_InfoPng are -ignored as well, because instead the width and height of the raw image you give -in the input are used. In fact the encoder currently uses only the following -settings from it: --colorType: the ones it supports --text chunks, that you can add to the LodePNG_InfoPng with "addText" --the color key, if applicable for the given color type --the palette, if you encode to a PNG with colorType 3 --the background color: it'll add a bKGD chunk to the PNG if one is given --the interlaceMethod: None (0) or Adam7 (1) - -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. - -=LodePNG_InfoRaw= - -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. - -=Settings= - -The following settings are supported (some are in sub-structs): -*) autoLeaveOutAlphaChannel: when this option is enabled, when you specify a PNG -color type with alpha channel (not to be confused with the color type of the raw -image you specify!!), but the encoder detects that all pixels of the given image -are opaque, then it'll automatically use the corresponding type without alpha -channel, resulting in a smaller PNG image. -*) btype: the block type for LZ77. 0 = uncompressed, 1 = fixed huffman tree, 2 = dynamic huffman tree (best compression) -*) useLZ77: whether or not to use LZ77 for compressed block types -*) windowSize: the window size used by the LZ77 encoder (1 - 32768) -*) 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 " to the image. -*) text_compression: default 0. 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. - - -7. color conversions --------------------- - -For trickier usage of LodePNG, you need to understand about PNG color types and -about how and when LodePNG uses the settings in LodePNG_InfoPng, LodePNG_InfoRaw and Settings. - -=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 mentions 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 color channel. - -=Default Behaviour of LodePNG= - -By default, the Decoder will convert the data from the PNG to 32-bit RGBA color, -no matter what color type the PNG has, so that the result can be used directly -as a texture in OpenGL etc... without worries about what color type the original -image has. - -The Encoder assumes by default that the raw input you give it is a 32-bit RGBA -buffer and will store the PNG as either 32 bit or 24 bit depending on whether -or not any translucent pixels were detected in it. - -To get the default behaviour, don't change the values of LodePNG_InfoRaw and LodePNG_InfoPng of -the encoder, and don't change the values of LodePNG_InfoRaw of the decoder. - -=Color Conversions= - -As explained in the sections about the Encoder and Decoder, you can specify -color types and bit depths in LodePNG_InfoPng and LodePNG_InfoRaw, to change the default behaviour -explained above. (for the Decoder you can only specify the LodePNG_InfoRaw, because the -LodePNG_InfoPng contains what the PNG file has). - -To avoid some confusion: --the Decoder converts from PNG to raw image --the Encoder converts from raw image to PNG --the color type and bit depth in LodePNG_InfoRaw, are those of the raw image --the color type and bit depth in LodePNG_InfoPng, are those of the PNG --if the color type of the LodePNG_InfoRaw and PNG image aren't the same, a conversion -between the color types is done if the color types are supported - -Supported color types: --It's possible to load PNGs from any colortype and to save PNGs of any colorType. --Both encoder and decoder use the same converter. So both encoder and decoder -suport the same color types at the input and the output. So the decoder supports -any type of PNG image and can convert it to certain types of raw image, while the -encoder supports any type of raw data but only certain color types for the output PNG. --The converter can convert from _any_ input color type, to 24-bit RGB or 32-bit RGBA --The converter can convert from greyscale input color type, to 8-bit greyscale or greyscale with alpha --If both color types are the same, conversion from anything to anything is possible --Color types that are invalid according to the PNG specification are not allowed --When converting from a type with alpha channel to one without, the alpha channel information is discarded --When converting from a type without alpha channel to one with, the result will be opaque except pixels that have the same color as the color key of the input if one was given --When converting from 16-bit bitDepth to 8-bit bitDepth, the 16-bit precision information is lost, only the most significant byte is kept --Converting from color to greyscale is not supported on purpose: choosing what kind of color to greyscale conversion to do is not a decision a PNG codec should make --Converting from/to a palette type, only keeps the indices, it ignores the colors defined in the palette - -No conversion needed...: --If the color type of the PNG image and raw image are the same, then no -conversion is done, and all color types are supported. --In the encoder, you can make it save a PNG with any color by giving the -LodePNG_InfoRaw and LodePNG_InfoPng the same color type. --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 -infoRaw are then ignored. - -The function LodePNG_convert does this, which is available in the interface but -normally isn't needed since the encoder and decoder already call it. - -=More Notes= - -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. -However: The input image you give to the encoder, and the output image you get from the decoder -will NOT have these padding bits in that case, 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. - -8. info values --------------- - -Both the encoder and decoder use a variable of type LodePNG_InfoPng and LodePNG_InfoRaw, which -both also contain a LodePNG_InfoColor. Here's a list of each of the values stored in them: - -*) info from the PNG header (IHDR chunk): - -width: width of the image in pixels -height: height of the image in pixels -colorType: color type of the original PNG file -bitDepth: bits per sample -compressionMethod: compression method of the original file. Always 0. -filterMethod: filter method of the original file. Always 0. -interlaceMethod: interlace method of the original file. 0 is no interlace, 1 is adam7 interlace. - -Note: width and height are only used as information of a decoded PNG image. When encoding one, you don't have -to specify width and height in an LodePNG_Info struct, but you give them as parameters of the encode function. -The rest of the LodePNG_Info struct IS used by the encoder though! - -*) palette: - -This is a dynamically allocated unsigned char array with the colors of the palette. The value palettesize -indicates the amount of colors in the palette. The allocated size of the buffer is 4 * palettesize bytes, -because there are 4 values per color: R, G, B and A. Even if less color channels are used, the palette -is always in RGBA format, in the order RGBARGBARGBA..... - -When encoding a PNG, to store your colors in the palette of the LodePNG_InfoRaw, first use -LodePNG_InfoColor_clearPalette, then for each color use LodePNG_InfoColor_addPalette. -In the C++ version the Encoder class also has the above functions available directly in its interface. - -Note that the palette information from the tRNS chunk is also already included in this palette vector. - -If you encode an image with palette, don't forget that you have to set the alpha channels (A) of the palette -too, set them to 255 for an opaque palette. If you leave them at zero, the image will be encoded as -fully invisible. This both for the palette in the infoRaw and the infoPng if the png is to have a palette. - -*) transparent color key - -key_defined: is a transparent color key given? -key_r: red/greyscale component of color key -key_g: green component of color key -key_b: blue component of color key - -For greyscale PNGs, r, g and b will all 3 be set to the same. - -This color is 8-bit for 8-bit PNGs, 16-bit for 16-bit per channel PNGs. - -*) suggested background color - -background_defined: is a suggested background color given? -background_r: red component of sugg. background color -background_g: green component of sugg. background color -background_b: blue component of sugg. background color - -This color is 8-bit for 8-bit PNGs, 16-bit for 16-bit PNGs - -For greyscale PNGs, r, g and b will all 3 be set to the same. When encoding -the encoder writes the red one away. -For palette PNGs: When decoding, the RGB value will be stored, no a palette -index. But when encoding, specify the index of the palette in background_r, -the other two are then ignored. - -The decoder pretty much ignores this background color, after all if you make a -PNG translucent normally you intend it to be used against any background, on -websites, as translucent textures in games, ... But you can get the color this -way if needed. - -*) text and itext - -Non-international text: - --text.keys: a char** buffer containing the keywords (see below) --text.strings: a char** buffer containing the texts (see below) --text.num: the amount of texts in the above char** buffers (there may be more texts in itext) --LodePNG_InfoText_clearText: use this to clear the texts again after you filled them in --LodePNG_InfoText_addText: this function is used to push back a keyword and text - -International text: This is stored in separate arrays! The sum text.num and itext.num is the real amount of texts. - --itext.keys: keyword in English --itext.langtags: ISO 639 letter code for the language --itext.transkeys: keyword in this language --itext.strings: the text in this language, in UTF-8 --itext.num: the amount of international texts in this PNG --LodePNG_InfoIText_clearText: use this to clear the itexts again after you filled them in --LodePNG_InfoIText_addText: this function is used to push back all 4 parts of an itext - -Don't allocate these text buffers yourself. Use the init/cleanup functions -correctly and use addText and clearText. - -In the C++ version the Encoder class also has the above functions available directly in its interface. -The char** buffers are used like the argv parameter of a main() function, and (i)text.num takes the role -of argc. - -In a text, there must be as much keys as strings because they always form pairs. In an itext, -there must always be as much keys, langtags, transkeys and strings. - -They keyword of text chunks gives a short description what the actual text -represents. There are a few standard standard keywords recognised -by many programs: Title, Author, Description, Copyright, Creation Time, -Software, Disclaimer, Warning, Source, Comment. It's allowed to use other keys. - -The 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. - -*) additional color info - -These functions are available with longer names in the C version, and directly -in the Decoder's interface in the C++ version. - -getBpp(): bits per pixel of the PNG image -getChannels(): amount of color channels of the PNG image -isGreyscaleType(): its color type 0 or 4 -isAlphaType(): its color type 2 or 6 - -These values are calculated out of color type and bit depth of InfoColor. - -The difference between bits per pixel and bit depth is that bit depth is the -number of bits per color channel, while a pixel can have multiple channels. - -*) pHYs chunk (image dimensions) - -phys_defined: if 0, there is no pHYs chunk and the values are undefined, if 1 else there is one -phys_x: pixels per unit in x direction -phys_y: pixels per unit in y direction -phys_unit: the unit, 0 is no unit (x and y only give the ratio), 1 is metre - -*) tIME chunk (modification time) - -time_defined: if 0, there is no tIME chunk and the values are undefined, if 1 there is one -time: this struct contains year as a 2-byte number (0-65535), month, day, hour, minute, -second as 1-byte numbers that must be in the correct range - -Note: to make the encoder add a time chunk, set time_defined to 1 and fill in -the correct values in all the time parameters, LodePNG will not fill the current -time in these values itself, all it does is copy them over into the chunk bytes. - - -9. error values ---------------- - -The meanings of the LodePNG error values: - -*) 0: no error, everything went ok -*) 1: the Encoder/Decoder has done nothing yet, so error checking makes no sense yet -*) 10: while huffman decoding: end of input memory reached without endcode -*) 11: while huffman decoding: error in code tree made it jump outside of tree -*) 13: problem while processing dynamic deflate block -*) 14: problem while processing dynamic deflate block -*) 15: problem while processing dynamic deflate block -*) 16: unexisting code while processing dynamic deflate block -*) 17: while inflating: end of out buffer memory reached -*) 18: while inflating: invalid distance code -*) 19: while inflating: end of out buffer memory reached -*) 20: invalid deflate block BTYPE encountered while decoding -*) 21: NLEN is not ones complement of LEN in a deflate block -*) 22: while inflating: end of out buffer memory reached. - 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. -*) 23: while inflating: end of in buffer memory reached -*) 24: invalid FCHECK in zlib header -*) 25: invalid compression method in zlib header -*) 26: FDICT encountered in zlib header while it's not used for PNG -*) 27: PNG file is smaller than a PNG header -*) 28: incorrect PNG signature (the first 8 bytes of the PNG file) - Maybe it's not a PNG, or a PNG file that got corrupted so that the header indicates the corruption. -*) 29: first chunk is not the header chunk -*) 30: chunk length too large, chunk broken off at end of file -*) 31: illegal PNG color type or bpp -*) 32: illegal PNG compression method -*) 33: illegal PNG filter method -*) 34: illegal PNG interlace method -*) 35: chunk length of a chunk is too large or the chunk too small -*) 36: illegal PNG filter type encountered -*) 37: illegal bit depth for this color type given -*) 38: the palette is too big (more than 256 colors) -*) 39: more palette alpha values given in tRNS, than there are colors in the palette -*) 40: tRNS chunk has wrong size for greyscale image -*) 41: tRNS chunk has wrong size for RGB image -*) 42: tRNS chunk appeared while it was not allowed for this color type -*) 43: bKGD chunk has wrong size for palette image -*) 44: bKGD chunk has wrong size for greyscale image -*) 45: bKGD chunk has wrong size for RGB image -*) 46: value encountered in indexed image is larger than the palette size (bitdepth == 8). Is the palette too small? -*) 47: value encountered in indexed image is larger than the palette size (bitdepth < 8). Is the palette too small? -*) 48: the input data is empty. Maybe a PNG file you tried to load doesn't exist or is in the wrong path. -*) 49: jumped past memory while generating dynamic huffman tree -*) 50: jumped past memory while generating dynamic huffman tree -*) 51: jumped past memory while inflating huffman block -*) 52: jumped past memory while inflating -*) 53: size of zlib data too small -*) 55: 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 lengths. They call this an oversubscribed dynamic bit lengths tree in zlib. -*) 56: given output image colorType or bitDepth not supported for color conversion -*) 57: invalid CRC encountered (checking CRC can be disabled) -*) 58: invalid ADLER32 encountered (checking ADLER32 can be disabled) -*) 59: conversion to unexisting or unsupported color type or bit depth requested by encoder or decoder -*) 60: invalid window size given in the settings of the encoder (must be 0-32768) -*) 61: invalid BTYPE given in the settings of the encoder (only 0, 1 and 2 are allowed) -*) 62: conversion from non-greyscale color to greyscale color requested by encoder or decoder. LodePNG - leaves the choice of RGB to greyscale conversion formula to the user. -*) 63: length of a chunk too long, max allowed for PNG is 2147483647 bytes per chunk (2^31-1) -*) 64: the length of the "end" symbol 256 in the Huffman tree is 0, resulting in the inability of a deflated - block to ever contain an end code. It must be at least 1. -*) 66: the length of a text chunk keyword given to the encoder is longer than the maximum 79 bytes. -*) 67: the length of a text chunk keyword given to the encoder is smaller than the minimum 1 byte. -*) 68: tried to encode a PLTE chunk with a palette that has less than 1 or more than 256 colors -*) 69: unknown chunk type with "critical" flag encountered by the decoder -*) 71: unexisting interlace mode given to encoder (must be 0 or 1) -*) 72: while decoding, unexisting compression method encountering in zTXt or iTXt chunk (it must be 0) -*) 73: invalid tIME chunk size -*) 74: invalid pHYs chunk size -*) 75: no null termination char found while decoding any kind of text chunk, or wrong length -*) 76: iTXt chunk too short to contain required bytes -*) 77: integer overflow in buffer size happened somewhere -*) 78: file doesn't exist or couldn't be opened for reading -*) 79: file couldn't be opened for writing -*) 80: tried creating a tree for 0 symbols -*) 9900-9999: out of memory while allocating chunk of memory somewhere - - -10. file IO ------------ - -For cases where you want to load the PNG image from a file, you can use your own -file loading code, or the file loading and saving functions provided with -LodePNG. These use the same unsigned char format used by the Decoder and Encoder. - -The loadFile function fills the given buffer up with the file from harddisk -with the given name. - -The saveFile function saves the contents of the given buffer to the file -with given name. Warning: this overwrites the contents that were previously in -the file if it already existed, without warning. - -Note that you don't have to decode a PNG image from a file, you can as well -retrieve the buffer another way in your code, because the decode function takes -a buffer as parameter, not a filename. - -Both C and C++ versions of the loadFile and saveFile functions are available. -For the C version of loadFile, you need to free() the buffer after use. The -C++ versions use std::vectors so they clean themselves automatically. - - -11. 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 you -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 - - -11.1 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_append_chunk(unsigned char** out, size_t* outlength, const unsigned char* chunk): -unsigned LodePNG_create_chunk(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. - - -11.2 chunks in infoPng ----------------------- - -The LodePNG_InfoPng struct contains a struct LodePNG_UnknownChunks in it. This -struct 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. - -infoPng.unknown_chunks.data[0] is the chunks before PLTE -infoPng.unknown_chunks.data[1] is the chunks after PLTE, before IDAT -infoPng.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.rememberUnknownChunks to 1. By default, this option -is off and is 0. - -The encoder will always encode unknown chunks that are stored in the infoPng. If -you need it to add a particular chunk that isn't known by LodePNG, you can use -LodePNG_append_chunk or LodePNG_create_chunk to the chunk data in -infoPng.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 and LodePNG will generate the chunk. - - -12. 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. - -Use optimization! For both the encoder and decoder, compiling with the best -optimizations 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 resulting in bad things. - -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 4.2.2 on Linux. - -*) Mingw and Bloodshed DevC++ - -The Mingw compiler (a port of gcc) used by Bloodshed DevC++ for Windows is fully -supported by LodePNG. - -*) Visual Studio 2005 and Visual C++ 2005 Express Edition - -Versions 20070604 up to 20080107 have been tested on VS2005 and work. There are no -warnings, except two warnings about 'fopen' being deprecated. 'fopen' is a function -required by the C standard, so this warning is the fault of VS2005, it's nice of -them to enforce secure code, however the multiplatform LodePNG can't follow their -non-standard extensions. LodePNG is fully ISO C90 compliant. - -If you're using LodePNG in VS2005 and don't want to see the deprecated warnings, -put this on top of lodepng.h before the inclusions: #define _CRT_SECURE_NO_DEPRECATE - -*) Visual Studio 6.0 - -The C++ version of LodePNG was not supported by Visual Studio 6.0 because Visual -Studio 6.0 doesn't follow the C++ standard and implements it incorrectly. -The current C version of LodePNG has not been tested in VS6 but may work now. - -*) 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 - -I'd love to support Macintosh but don't have one available to test it on. -If it doesn't work with your compiler, maybe it can be gotten to work with the -gcc compiler for Macintosh. Someone reported that it doesn't work well at all -for Macintosh. All information on attempts to get it to work on Mac is welcome. - -*) Other Compilers - -If you encounter problems on other compilers, I'm happy to help out make LodePNG -support the compiler if it supports the ISO C90 and C++ standard well enough. If -the required modification to support the compiler requires using non standard or -lesser C/C++ code or headers, I won't support it. - - -13. examples ------------- - -This decoder and encoder example show the most basic usage of LodePNG (using the -classes, not the simple functions, which would be trivial) - -More complex examples can be found in: --lodepng_examples.c: 9 different examples in C, such as showing the image with SDL, ... --lodepng_examples.cpp: the exact same examples in C++ using the C++ wrapper of LodePNG - - -13.1. decoder C++ example -------------------------- - -//////////////////////////////////////////////////////////////////////////////// -#include "lodepng.h" -#include - -int main(int argc, char *argv[]) -{ - const char* filename = argc > 1 ? argv[1] : "test.png"; - - //load and decode - std::vector buffer, image; - LodePNG::loadFile(buffer, filename); //load the image file with given filename - LodePNG::Decoder decoder; - decoder.decode(image, buffer.size() ? &buffer[0] : 0, (unsigned)buffer.size()); //decode the png - - //if there's an error, display it - if(decoder.hasError()) std::cout << "error: " << decoder.getError() << std::endl; - - //the pixels are now in the vector "image", use it as texture, draw it, ... -} - -//alternative version using the "simple" function -int main(int argc, char *argv[]) -{ - const char* filename = argc > 1 ? argv[1] : "test.png"; - - //load and decode - std::vector image; - unsigned w, h; - unsigned error = LodePNG::decode(image, w, h, filename); - - //if there's an error, display it - if(error != 0) std::cout << "error: " << error << std::endl; - - //the pixels are now in the vector "image", use it as texture, draw it, ... -} -//////////////////////////////////////////////////////////////////////////////// - - -13.2 encoder C++ example ------------------------- - -//////////////////////////////////////////////////////////////////////////////// -#include "lodepng.h" -#include - -int main(int argc, char *argv[]) -{ - //check if user gave a filename - if(argc <= 1) - { - std::cout << "please provide a filename to save to\n"; - return 0; - } - - //generate some image - std::vector image; - image.resize(512 * 512 * 4); - for(unsigned y = 0; y < 512; y++) - for(unsigned x = 0; x < 512; x++) - { - image[4 * 512 * y + 4 * x + 0] = 255 * !(x & y); - image[4 * 512 * y + 4 * x + 1] = x ^ y; - image[4 * 512 * y + 4 * x + 2] = x | y; - image[4 * 512 * y + 4 * x + 3] = 255; - } - - //encode and save - std::vector buffer; - LodePNG::Encoder encoder; - encoder.encode(buffer, image, 512, 512); - LodePNG::saveFile(buffer, argv[1]); - - //the same as the 4 lines of code above, but in 1 call: - //LodePNG::encode(argv[1], image, 512, 512); -} -//////////////////////////////////////////////////////////////////////////////// - - -13.3 Decoder C example ----------------------- - -This example loads the PNG in 1 function call - -#include "lodepng.h" - -int main(int argc, char *argv[]) -{ - unsigned error; - unsigned char* image; - size_t w, h; - - if(argc <= 1) return 0; - - error = LodePNG_decode3(&image, &w, &h, filename); - - free(image); -} - - -14. LodeZlib ------------- - -Also available in the interface is LodeZlib. Both C and C++ versions of these -functions are available. The interface is similar to that of the "simple" PNG -encoding and decoding functions. - -LodeZlib can be used to zlib compress and decompress a buffer. It cannot be -used to create gzip files however. Also, it only supports the part of zlib -that is required for PNG, it does not support compression and decompression -with dictionaries. - - -15. 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. - -*) 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 - - -16. 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) 2005-2008 Lode Vandevenne -*/