From: Daniel Maslowski info@orangecms.org
* adjust header imports * remove ancillary chunks, encoder code, and CPP wrapper * ignore adler32 check * reimplement realloc and pass old size * implement abs
Signed-off-by: Daniel Maslowski info@orangecms.org --- src/lodepng.c | 6091 +++++++++++-------------------------------------- src/lodepng.h | 2 +- 2 files changed, 1364 insertions(+), 4729 deletions(-)
diff --git a/src/lodepng.c b/src/lodepng.c index 9128a9b..d9c8443 100644 --- a/src/lodepng.c +++ b/src/lodepng.c @@ -30,9 +30,9 @@ Rename this file to lodepng.cpp to use it for C++, or to lodepng.c to use it for
#include "lodepng.h"
-#include <limits.h> -#include <stdio.h> -#include <stdlib.h> +#include "malloc.h" +#include "string.h" +#include "util.h"
#if defined(_MSC_VER) && (_MSC_VER >= 1310) /*Visual Studio: A few warning types are not desired here.*/ #pragma warning( disable : 4244 ) /*implicit conversions: not warned by gcc -Wall -Wextra and requires too much casts*/ @@ -47,41 +47,39 @@ with the "LODEPNG_COMPILE_" #defines divide this up further in an intermixed way -Tools for C and common code for PNG and Zlib -C Code for Zlib (huffman, deflate, ...) -C Code for PNG (file format chunks, adam7, PNG filters, color conversions, ...) --The C++ wrapper around all of the above */
-/*The malloc, realloc and free functions defined here with "lodepng_" in front -of the name, so that you can easily change them to others related to your -platform if needed. Everything else in the code calls these. Pass --DLODEPNG_NO_COMPILE_ALLOCATORS to the compiler, or comment out -#define LODEPNG_COMPILE_ALLOCATORS in the header, to disable the ones here and -define them in your own project's source files without needing to change -lodepng source code. Don't forget to remove "static" if you copypaste them -from here.*/ - -#ifdef LODEPNG_COMPILE_ALLOCATORS static void* lodepng_malloc(size_t size) { #ifdef LODEPNG_MAX_ALLOC if(size > LODEPNG_MAX_ALLOC) return 0; #endif - return malloc(size); + return malloc_tmphigh(size); }
-static void* lodepng_realloc(void* ptr, size_t new_size) { +static void* lodepng_realloc(void* ptr, size_t old_size, size_t new_size) { #ifdef LODEPNG_MAX_ALLOC if(new_size > LODEPNG_MAX_ALLOC) return 0; #endif - return realloc(ptr, new_size); + if (new_size == 0) { + free(ptr); + return 0; + } else if (!ptr) { + return lodepng_malloc(new_size); + } else if (new_size <= old_size) { + return ptr; + } else { + void *ptr_new = lodepng_malloc(new_size); + if (ptr_new) { + memcpy(ptr_new, ptr, old_size); + free(ptr); + } + return ptr_new; + } }
static void lodepng_free(void* ptr) { free(ptr); } -#else /*LODEPNG_COMPILE_ALLOCATORS*/ -void* lodepng_malloc(size_t size); -void* lodepng_realloc(void* ptr, size_t new_size); -void lodepng_free(void* ptr); -#endif /*LODEPNG_COMPILE_ALLOCATORS*/
/* ////////////////////////////////////////////////////////////////////////// */ /* ////////////////////////////////////////////////////////////////////////// */ @@ -152,7 +150,7 @@ static void uivector_cleanup(void* p) { static unsigned uivector_reserve(uivector* p, size_t allocsize) { if(allocsize > p->allocsize) { size_t newsize = (allocsize > p->allocsize * 2) ? allocsize : (allocsize * 3 / 2); - void* data = lodepng_realloc(p->data, newsize); + void* data = lodepng_realloc(p->data, p->allocsize, newsize); if(data) { p->allocsize = newsize; p->data = (unsigned*)data; @@ -182,14 +180,6 @@ static void uivector_init(uivector* p) { p->size = p->allocsize = 0; }
-#ifdef LODEPNG_COMPILE_ENCODER -/*returns 1 if success, 0 if failure ==> nothing done*/ -static unsigned uivector_push_back(uivector* p, unsigned c) { - if(!uivector_resize(p, p->size + 1)) return 0; - p->data[p->size - 1] = c; - return 1; -} -#endif /*LODEPNG_COMPILE_ENCODER*/ #endif /*LODEPNG_COMPILE_ZLIB*/
/* /////////////////////////////////////////////////////////////////////////// */ @@ -205,7 +195,7 @@ typedef struct ucvector { static unsigned ucvector_reserve(ucvector* p, size_t allocsize) { if(allocsize > p->allocsize) { size_t newsize = (allocsize > p->allocsize * 2) ? allocsize : (allocsize * 3 / 2); - void* data = lodepng_realloc(p->data, newsize); + void* data = lodepng_realloc(p->data, p->allocsize, newsize); if(data) { p->allocsize = newsize; p->data = (unsigned char*)data; @@ -245,41 +235,9 @@ static void ucvector_init_buffer(ucvector* p, unsigned char* buffer, size_t size } #endif /*LODEPNG_COMPILE_ZLIB*/
-#if (defined(LODEPNG_COMPILE_PNG) && defined(LODEPNG_COMPILE_ANCILLARY_CHUNKS)) || defined(LODEPNG_COMPILE_ENCODER) -/*returns 1 if success, 0 if failure ==> nothing done*/ -static unsigned ucvector_push_back(ucvector* p, unsigned char c) { - if(!ucvector_resize(p, p->size + 1)) return 0; - p->data[p->size - 1] = c; - return 1; -} -#endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/ - - /* ////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_PNG -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - -/*free string pointer and set it to NULL*/ -static void string_cleanup(char** out) { - lodepng_free(*out); - *out = NULL; -} - -/* dynamically allocates a new string with a copy of the null terminated input text */ -static char* alloc_string(const char* in) { - size_t insize = strlen(in); - char* out = (char*)lodepng_malloc(insize + 1); - if(out) { - size_t i; - for(i = 0; i != insize; ++i) { - out[i] = in[i]; - } - out[i] = 0; - } - return out; -} -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ #endif /*LODEPNG_COMPILE_PNG*/
/* ////////////////////////////////////////////////////////////////////////// */ @@ -297,104 +255,12 @@ static void lodepng_set32bitInt(unsigned char* buffer, unsigned value) { buffer[3] = (unsigned char)((value ) & 0xff); } #endif /*defined(LODEPNG_COMPILE_PNG) || defined(LODEPNG_COMPILE_ENCODER)*/ - -#ifdef LODEPNG_COMPILE_ENCODER -static void lodepng_add32bitInt(ucvector* buffer, unsigned value) { - ucvector_resize(buffer, buffer->size + 4); /*todo: give error if resize failed*/ - lodepng_set32bitInt(&buffer->data[buffer->size - 4], value); -} -#endif /*LODEPNG_COMPILE_ENCODER*/ - -/* ////////////////////////////////////////////////////////////////////////// */ -/* / File IO / */ -/* ////////////////////////////////////////////////////////////////////////// */ - -#ifdef LODEPNG_COMPILE_DISK - -/* returns negative value on error. This should be pure C compatible, so no fstat. */ -static long lodepng_filesize(const char* filename) { - FILE* file; - long size; - file = fopen(filename, "rb"); - if(!file) return -1; - - if(fseek(file, 0, SEEK_END) != 0) { - fclose(file); - return -1; - } - - size = ftell(file); - /* It may give LONG_MAX as directory size, this is invalid for us. */ - if(size == LONG_MAX) size = -1; - - fclose(file); - return size; -} - -/* load file into buffer that already has the correct allocated size. Returns error code.*/ -static unsigned lodepng_buffer_file(unsigned char* out, size_t size, const char* filename) { - FILE* file; - size_t readsize; - file = fopen(filename, "rb"); - if(!file) return 78; - - readsize = fread(out, 1, size, file); - fclose(file); - - if (readsize != size) return 78; - return 0; -} - -unsigned lodepng_load_file(unsigned char** out, size_t* outsize, const char* filename) { - long size = lodepng_filesize(filename); - if (size < 0) return 78; - *outsize = (size_t)size; - - *out = (unsigned char*)lodepng_malloc((size_t)size); - if(!(*out) && size > 0) return 83; /*the above malloc failed*/ - - return lodepng_buffer_file(*out, (size_t)size, filename); -} - -/*write given buffer to the file, overwriting the file, it doesn't append to it.*/ -unsigned lodepng_save_file(const unsigned char* buffer, size_t buffersize, const char* filename) { - FILE* file; - file = fopen(filename, "wb" ); - if(!file) return 79; - fwrite(buffer, 1, buffersize, file); - fclose(file); - return 0; -} - -#endif /*LODEPNG_COMPILE_DISK*/ - -/* ////////////////////////////////////////////////////////////////////////// */ /* ////////////////////////////////////////////////////////////////////////// */ /* // End of common code and tools. Begin of Zlib related code. // */ /* ////////////////////////////////////////////////////////////////////////// */ /* ////////////////////////////////////////////////////////////////////////// */
#ifdef LODEPNG_COMPILE_ZLIB -#ifdef LODEPNG_COMPILE_ENCODER -/*TODO: this ignores potential out of memory errors*/ -#define addBitToStream(/*size_t**/ bitpointer, /*ucvector**/ bitstream, /*unsigned char*/ bit){\ - /*add a new byte at the end*/\ - if(((*bitpointer) & 7) == 0) ucvector_push_back(bitstream, (unsigned char)0);\ - /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/\ - (bitstream->data[bitstream->size - 1]) |= (bit << ((*bitpointer) & 0x7));\ - ++(*bitpointer);\ -} - -static void addBitsToStream(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits) { - size_t i; - for(i = 0; i != nbits; ++i) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> i) & 1)); -} - -static void addBitsToStreamReversed(size_t* bitpointer, ucvector* bitstream, unsigned value, size_t nbits) { - size_t i; - for(i = 0; i != nbits; ++i) addBitToStream(bitpointer, bitstream, (unsigned char)((value >> (nbits - 1 - i)) & 1)); -} -#endif /*LODEPNG_COMPILE_ENCODER*/
#ifdef LODEPNG_COMPILE_DECODER
@@ -599,215 +465,6 @@ static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* b return HuffmanTree_makeFromLengths2(tree); }
-#ifdef LODEPNG_COMPILE_ENCODER - -/*BPM: Boundary Package Merge, see "A Fast and Space-Economical Algorithm for Length-Limited Coding", -Jyrki Katajainen, Alistair Moffat, Andrew Turpin, 1995.*/ - -/*chain node for boundary package merge*/ -typedef struct BPMNode { - int weight; /*the sum of all weights in this chain*/ - unsigned index; /*index of this leaf node (called "count" in the paper)*/ - struct BPMNode* tail; /*the next nodes in this chain (null if last)*/ - int in_use; -} BPMNode; - -/*lists of chains*/ -typedef struct BPMLists { - /*memory pool*/ - unsigned memsize; - BPMNode* memory; - unsigned numfree; - unsigned nextfree; - BPMNode** freelist; - /*two heads of lookahead chains per list*/ - unsigned listsize; - BPMNode** chains0; - BPMNode** chains1; -} BPMLists; - -/*creates a new chain node with the given parameters, from the memory in the lists */ -static BPMNode* bpmnode_create(BPMLists* lists, int weight, unsigned index, BPMNode* tail) { - unsigned i; - BPMNode* result; - - /*memory full, so garbage collect*/ - if(lists->nextfree >= lists->numfree) { - /*mark only those that are in use*/ - for(i = 0; i != lists->memsize; ++i) lists->memory[i].in_use = 0; - for(i = 0; i != lists->listsize; ++i) { - BPMNode* node; - for(node = lists->chains0[i]; node != 0; node = node->tail) node->in_use = 1; - for(node = lists->chains1[i]; node != 0; node = node->tail) node->in_use = 1; - } - /*collect those that are free*/ - lists->numfree = 0; - for(i = 0; i != lists->memsize; ++i) { - if(!lists->memory[i].in_use) lists->freelist[lists->numfree++] = &lists->memory[i]; - } - lists->nextfree = 0; - } - - result = lists->freelist[lists->nextfree++]; - result->weight = weight; - result->index = index; - result->tail = tail; - return result; -} - -/*sort the leaves with stable mergesort*/ -static void bpmnode_sort(BPMNode* leaves, size_t num) { - BPMNode* mem = (BPMNode*)lodepng_malloc(sizeof(*leaves) * num); - size_t width, counter = 0; - for(width = 1; width < num; width *= 2) { - BPMNode* a = (counter & 1) ? mem : leaves; - BPMNode* b = (counter & 1) ? leaves : mem; - size_t p; - for(p = 0; p < num; p += 2 * width) { - size_t q = (p + width > num) ? num : (p + width); - size_t r = (p + 2 * width > num) ? num : (p + 2 * width); - size_t i = p, j = q, k; - for(k = p; k < r; k++) { - if(i < q && (j >= r || a[i].weight <= a[j].weight)) b[k] = a[i++]; - else b[k] = a[j++]; - } - } - counter++; - } - if(counter & 1) memcpy(leaves, mem, sizeof(*leaves) * num); - lodepng_free(mem); -} - -/*Boundary Package Merge step, numpresent is the amount of leaves, and c is the current chain.*/ -static void boundaryPM(BPMLists* lists, BPMNode* leaves, size_t numpresent, int c, int num) { - unsigned lastindex = lists->chains1[c]->index; - - if(c == 0) { - if(lastindex >= numpresent) return; - lists->chains0[c] = lists->chains1[c]; - lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, 0); - } else { - /*sum of the weights of the head nodes of the previous lookahead chains.*/ - int sum = lists->chains0[c - 1]->weight + lists->chains1[c - 1]->weight; - lists->chains0[c] = lists->chains1[c]; - if(lastindex < numpresent && sum > leaves[lastindex].weight) { - lists->chains1[c] = bpmnode_create(lists, leaves[lastindex].weight, lastindex + 1, lists->chains1[c]->tail); - return; - } - lists->chains1[c] = bpmnode_create(lists, sum, lastindex, lists->chains1[c - 1]); - /*in the end we are only interested in the chain of the last list, so no - need to recurse if we're at the last one (this gives measurable speedup)*/ - if(num + 1 < (int)(2 * numpresent - 2)) { - boundaryPM(lists, leaves, numpresent, c - 1, num); - boundaryPM(lists, leaves, numpresent, c - 1, num); - } - } -} - -unsigned lodepng_huffman_code_lengths(unsigned* lengths, const unsigned* frequencies, - size_t numcodes, unsigned maxbitlen) { - unsigned error = 0; - unsigned i; - size_t numpresent = 0; /*number of symbols with non-zero frequency*/ - BPMNode* leaves; /*the symbols, only those with > 0 frequency*/ - - if(numcodes == 0) return 80; /*error: a tree of 0 symbols is not supposed to be made*/ - if((1u << maxbitlen) < (unsigned)numcodes) return 80; /*error: represent all symbols*/ - - leaves = (BPMNode*)lodepng_malloc(numcodes * sizeof(*leaves)); - if(!leaves) return 83; /*alloc fail*/ - - for(i = 0; i != numcodes; ++i) { - if(frequencies[i] > 0) { - leaves[numpresent].weight = (int)frequencies[i]; - leaves[numpresent].index = i; - ++numpresent; - } - } - - for(i = 0; i != numcodes; ++i) lengths[i] = 0; - - /*ensure at least two present symbols. There should be at least one symbol - according to RFC 1951 section 3.2.7. Some decoders incorrectly require two. To - make these work as well ensure there are at least two symbols. The - Package-Merge code below also doesn't work correctly if there's only one - symbol, it'd give it the theoritical 0 bits but in practice zlib wants 1 bit*/ - if(numpresent == 0) { - lengths[0] = lengths[1] = 1; /*note that for RFC 1951 section 3.2.7, only lengths[0] = 1 is needed*/ - } else if(numpresent == 1) { - lengths[leaves[0].index] = 1; - lengths[leaves[0].index == 0 ? 1 : 0] = 1; - } else { - BPMLists lists; - BPMNode* node; - - bpmnode_sort(leaves, numpresent); - - lists.listsize = maxbitlen; - lists.memsize = 2 * maxbitlen * (maxbitlen + 1); - lists.nextfree = 0; - lists.numfree = lists.memsize; - lists.memory = (BPMNode*)lodepng_malloc(lists.memsize * sizeof(*lists.memory)); - lists.freelist = (BPMNode**)lodepng_malloc(lists.memsize * sizeof(BPMNode*)); - lists.chains0 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*)); - lists.chains1 = (BPMNode**)lodepng_malloc(lists.listsize * sizeof(BPMNode*)); - if(!lists.memory || !lists.freelist || !lists.chains0 || !lists.chains1) error = 83; /*alloc fail*/ - - if(!error) { - for(i = 0; i != lists.memsize; ++i) lists.freelist[i] = &lists.memory[i]; - - bpmnode_create(&lists, leaves[0].weight, 1, 0); - bpmnode_create(&lists, leaves[1].weight, 2, 0); - - for(i = 0; i != lists.listsize; ++i) { - lists.chains0[i] = &lists.memory[0]; - lists.chains1[i] = &lists.memory[1]; - } - - /*each boundaryPM call adds one chain to the last list, and we need 2 * numpresent - 2 chains.*/ - for(i = 2; i != 2 * numpresent - 2; ++i) boundaryPM(&lists, leaves, numpresent, (int)maxbitlen - 1, (int)i); - - for(node = lists.chains1[maxbitlen - 1]; node; node = node->tail) { - for(i = 0; i != node->index; ++i) ++lengths[leaves[i].index]; - } - } - - lodepng_free(lists.memory); - lodepng_free(lists.freelist); - lodepng_free(lists.chains0); - lodepng_free(lists.chains1); - } - - lodepng_free(leaves); - return error; -} - -/*Create the Huffman tree given the symbol frequencies*/ -static unsigned HuffmanTree_makeFromFrequencies(HuffmanTree* tree, const unsigned* frequencies, - size_t mincodes, size_t numcodes, unsigned maxbitlen) { - unsigned error = 0; - while(!frequencies[numcodes - 1] && numcodes > mincodes) --numcodes; /*trim zeroes*/ - tree->maxbitlen = maxbitlen; - tree->numcodes = (unsigned)numcodes; /*number of symbols*/ - tree->lengths = (unsigned*)lodepng_realloc(tree->lengths, numcodes * sizeof(unsigned)); - if(!tree->lengths) return 83; /*alloc fail*/ - /*initialize all lengths to 0*/ - memset(tree->lengths, 0, numcodes * sizeof(unsigned)); - - error = lodepng_huffman_code_lengths(tree->lengths, frequencies, numcodes, maxbitlen); - if(!error) error = HuffmanTree_makeFromLengths2(tree); - return error; -} - -static unsigned HuffmanTree_getCode(const HuffmanTree* tree, unsigned index) { - return tree->tree1d[index]; -} - -static unsigned HuffmanTree_getLength(const HuffmanTree* tree, unsigned index) { - return tree->lengths[index]; -} -#endif /*LODEPNG_COMPILE_ENCODER*/ - /*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/ static unsigned generateFixedLitLenTree(HuffmanTree* tree) { unsigned i, error = 0; @@ -863,9 +520,6 @@ static unsigned huffmanDecodeSymbol(const unsigned char* in, size_t* bp, if(treepos >= codetree->numcodes) return (unsigned)(-1); /*error: it appeared outside the codetree*/ } } -#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_DECODER
/* ////////////////////////////////////////////////////////////////////////// */ /* / Inflator (Decompressor) / */ @@ -1171,4042 +825,1268 @@ static unsigned inflate(unsigned char** out, size_t* outsize,
#endif /*LODEPNG_COMPILE_DECODER*/
-#ifdef LODEPNG_COMPILE_ENCODER - /* ////////////////////////////////////////////////////////////////////////// */ -/* / Deflator (Compressor) / */ +/* / Adler32 */ /* ////////////////////////////////////////////////////////////////////////// */
-static const size_t MAX_SUPPORTED_DEFLATE_LENGTH = 258; - -/*bitlen is the size in bits of the code*/ -static void addHuffmanSymbol(size_t* bp, ucvector* compressed, unsigned code, unsigned bitlen) { - addBitsToStreamReversed(bp, compressed, code, bitlen); -} +static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len) { + unsigned s1 = adler & 0xffff; + unsigned s2 = (adler >> 16) & 0xffff;
-/*search the index in the array, that has the largest value smaller than or equal to the given value, -given array must be sorted (if no value is smaller, it returns the size of the given array)*/ -static size_t searchCodeIndex(const unsigned* array, size_t array_size, size_t value) { - /*binary search (only small gain over linear). TODO: use CPU log2 instruction for getting symbols instead*/ - size_t left = 1; - size_t right = array_size - 1; - - while(left <= right) { - size_t mid = (left + right) >> 1; - if (array[mid] >= value) right = mid - 1; - else left = mid + 1; + while(len > 0) { + /*at least 5552 sums can be done before the sums overflow, saving a lot of module divisions*/ + unsigned amount = len > 5552 ? 5552 : len; + len -= amount; + while(amount > 0) { + s1 += (*data++); + s2 += s1; + --amount; + } + s1 %= 65521; + s2 %= 65521; } - if(left >= array_size || array[left] > value) left--; - return left; + + return (s2 << 16) | s1; }
-static void addLengthDistance(uivector* values, size_t length, size_t distance) { - /*values in encoded vector are those used by deflate: - 0-255: literal bytes - 256: end - 257-285: length/distance pair (length code, followed by extra length bits, distance code, extra distance bits) - 286-287: invalid*/ - - unsigned length_code = (unsigned)searchCodeIndex(LENGTHBASE, 29, length); - unsigned extra_length = (unsigned)(length - LENGTHBASE[length_code]); - unsigned dist_code = (unsigned)searchCodeIndex(DISTANCEBASE, 30, distance); - unsigned extra_distance = (unsigned)(distance - DISTANCEBASE[dist_code]); - - uivector_push_back(values, length_code + FIRST_LENGTH_CODE_INDEX); - uivector_push_back(values, extra_length); - uivector_push_back(values, dist_code); - uivector_push_back(values, extra_distance); +/*Return the adler32 of the bytes data[0..len-1]*/ +static unsigned adler32(const unsigned char* data, unsigned len) { + return update_adler32(1L, data, len); }
-/*3 bytes of data get encoded into two bytes. The hash cannot use more than 3 -bytes as input because 3 is the minimum match length for deflate*/ -static const unsigned HASH_NUM_VALUES = 65536; -static const unsigned HASH_BIT_MASK = 65535; /*HASH_NUM_VALUES - 1, but C90 does not like that as initializer*/ - -typedef struct Hash { - int* head; /*hash value to head circular pos - can be outdated if went around window*/ - /*circular pos to prev circular pos*/ - unsigned short* chain; - int* val; /*circular pos to hash value*/ - - /*TODO: do this not only for zeros but for any repeated byte. However for PNG - it's always going to be the zeros that dominate, so not important for PNG*/ - int* headz; /*similar to head, but for chainz*/ - unsigned short* chainz; /*those with same amount of zeros*/ - unsigned short* zeros; /*length of zeros streak, used as a second hash chain*/ -} Hash; - -static unsigned hash_init(Hash* hash, unsigned windowsize) { - unsigned i; - hash->head = (int*)lodepng_malloc(sizeof(int) * HASH_NUM_VALUES); - hash->val = (int*)lodepng_malloc(sizeof(int) * windowsize); - hash->chain = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize); +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Zlib / */ +/* ////////////////////////////////////////////////////////////////////////// */
- hash->zeros = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize); - hash->headz = (int*)lodepng_malloc(sizeof(int) * (MAX_SUPPORTED_DEFLATE_LENGTH + 1)); - hash->chainz = (unsigned short*)lodepng_malloc(sizeof(unsigned short) * windowsize); +#ifdef LODEPNG_COMPILE_DECODER
- if(!hash->head || !hash->chain || !hash->val || !hash->headz|| !hash->chainz || !hash->zeros) { - return 83; /*alloc fail*/ +unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNGDecompressSettings* settings) { + unsigned error = 0; + unsigned CM, CINFO, FDICT; + + if(insize < 2) return 53; /*error, size of zlib data too small*/ + /*read information from zlib header*/ + if((in[0] * 256 + in[1]) % 31 != 0) { + /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/ + return 24; }
- /*initialize hash table*/ - for(i = 0; i != HASH_NUM_VALUES; ++i) hash->head[i] = -1; - for(i = 0; i != windowsize; ++i) hash->val[i] = -1; - for(i = 0; i != windowsize; ++i) hash->chain[i] = i; /*same value as index indicates uninitialized*/ + CM = in[0] & 15; + CINFO = (in[0] >> 4) & 15; + /*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/ + FDICT = (in[1] >> 5) & 1; + /*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/
- for(i = 0; i <= MAX_SUPPORTED_DEFLATE_LENGTH; ++i) hash->headz[i] = -1; - for(i = 0; i != windowsize; ++i) hash->chainz[i] = i; /*same value as index indicates uninitialized*/ + if(CM != 8 || CINFO > 7) { + /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/ + return 25; + } + if(FDICT != 0) { + /*error: the specification of PNG says about the zlib stream: + "The additional flags shall not specify a preset dictionary."*/ + return 26; + }
- return 0; -} + error = inflate(out, outsize, in + 2, insize - 2, settings); + if(error) return error;
-static void hash_cleanup(Hash* hash) { - lodepng_free(hash->head); - lodepng_free(hash->val); - lodepng_free(hash->chain); + if(!settings->ignore_adler32) { + unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]); + unsigned checksum = adler32(*out, (unsigned)(*outsize)); + if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/ + }
- lodepng_free(hash->zeros); - lodepng_free(hash->headz); - lodepng_free(hash->chainz); + return 0; /*no error*/ }
- - -static unsigned getHash(const unsigned char* data, size_t size, size_t pos) { - unsigned result = 0; - if(pos + 2 < size) { - /*A simple shift and xor hash is used. Since the data of PNGs is dominated - by zeroes due to the filters, a better hash does not have a significant - effect on speed in traversing the chain, and causes more time spend on - calculating the hash.*/ - result ^= (unsigned)(data[pos + 0] << 0u); - result ^= (unsigned)(data[pos + 1] << 4u); - result ^= (unsigned)(data[pos + 2] << 8u); +static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNGDecompressSettings* settings) { + if(settings->custom_zlib) { + return settings->custom_zlib(out, outsize, in, insize, settings); } else { - size_t amount, i; - if(pos >= size) return 0; - amount = size - pos; - for(i = 0; i != amount; ++i) result ^= (unsigned)(data[pos + i] << (i * 8u)); + return lodepng_zlib_decompress(out, outsize, in, insize, settings); } - return result & HASH_BIT_MASK; }
-static unsigned countZeros(const unsigned char* data, size_t size, size_t pos) { - const unsigned char* start = data + pos; - const unsigned char* end = start + MAX_SUPPORTED_DEFLATE_LENGTH; - if(end > data + size) end = data + size; - data = start; - while(data != end && *data == 0) ++data; - /*subtracting two addresses returned as 32-bit number (max value is MAX_SUPPORTED_DEFLATE_LENGTH)*/ - return (unsigned)(data - start); -} +#endif /*LODEPNG_COMPILE_DECODER*/
-/*wpos = pos & (windowsize - 1)*/ -static void updateHashChain(Hash* hash, size_t wpos, unsigned hashval, unsigned short numzeros) { - hash->val[wpos] = (int)hashval; - if(hash->head[hashval] != -1) hash->chain[wpos] = hash->head[hashval]; - hash->head[hashval] = (int)wpos; +#else /*no LODEPNG_COMPILE_ZLIB*/
- hash->zeros[wpos] = numzeros; - if(hash->headz[numzeros] != -1) hash->chainz[wpos] = hash->headz[numzeros]; - hash->headz[numzeros] = (int)wpos; +#ifdef LODEPNG_COMPILE_DECODER +static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, + size_t insize, const LodePNGDecompressSettings* settings) { + if(!settings->custom_zlib) return 87; /*no custom zlib function provided */ + return settings->custom_zlib(out, outsize, in, insize, settings); } +#endif /*LODEPNG_COMPILE_DECODER*/
-/* -LZ77-encode the data. Return value is error code. The input are raw bytes, the output -is in the form of unsigned integers with codes representing for example literal bytes, or -length/distance pairs. -It uses a hash table technique to let it encode faster. When doing LZ77 encoding, a -sliding window (of windowsize) is used, and all past bytes in that window can be used as -the "dictionary". A brute force search through all possible distances would be slow, and -this hash technique is one out of several ways to speed this up. -*/ -static unsigned encodeLZ77(uivector* out, Hash* hash, - const unsigned char* in, size_t inpos, size_t insize, unsigned windowsize, - unsigned minmatch, unsigned nicematch, unsigned lazymatching) { - size_t pos; - unsigned i, error = 0; - /*for large window lengths, assume the user wants no compression loss. Otherwise, max hash chain length speedup.*/ - unsigned maxchainlength = windowsize >= 8192 ? windowsize : windowsize / 8; - unsigned maxlazymatch = windowsize >= 8192 ? MAX_SUPPORTED_DEFLATE_LENGTH : 64; - - unsigned usezeros = 1; /*not sure if setting it to false for windowsize < 8192 is better or worse*/ - unsigned numzeros = 0; - - unsigned offset; /*the offset represents the distance in LZ77 terminology*/ - unsigned length; - unsigned lazy = 0; - unsigned lazylength = 0, lazyoffset = 0; - unsigned hashval; - unsigned current_offset, current_length; - unsigned prev_offset; - const unsigned char *lastptr, *foreptr, *backptr; - unsigned hashpos; - - if(windowsize == 0 || windowsize > 32768) return 60; /*error: windowsize smaller/larger than allowed*/ - if((windowsize & (windowsize - 1)) != 0) return 90; /*error: must be power of two*/ - - if(nicematch > MAX_SUPPORTED_DEFLATE_LENGTH) nicematch = MAX_SUPPORTED_DEFLATE_LENGTH; - - for(pos = inpos; pos < insize; ++pos) { - size_t wpos = pos & (windowsize - 1); /*position for in 'circular' hash buffers*/ - unsigned chainlength = 0; - - hashval = getHash(in, insize, pos); - - if(usezeros && hashval == 0) { - if(numzeros == 0) numzeros = countZeros(in, insize, pos); - else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros; - } else { - numzeros = 0; - } - - updateHashChain(hash, wpos, hashval, numzeros); - - /*the length and offset found for the current position*/ - length = 0; - offset = 0; - - hashpos = hash->chain[wpos]; - - lastptr = &in[insize < pos + MAX_SUPPORTED_DEFLATE_LENGTH ? insize : pos + MAX_SUPPORTED_DEFLATE_LENGTH]; - - /*search for the longest string*/ - prev_offset = 0; - for(;;) { - if(chainlength++ >= maxchainlength) break; - current_offset = (unsigned)(hashpos <= wpos ? wpos - hashpos : wpos - hashpos + windowsize); - - if(current_offset < prev_offset) break; /*stop when went completely around the circular buffer*/ - prev_offset = current_offset; - if(current_offset > 0) { - /*test the next characters*/ - foreptr = &in[pos]; - backptr = &in[pos - current_offset]; - - /*common case in PNGs is lots of zeros. Quickly skip over them as a speedup*/ - if(numzeros >= 3) { - unsigned skip = hash->zeros[hashpos]; - if(skip > numzeros) skip = numzeros; - backptr += skip; - foreptr += skip; - } - - while(foreptr != lastptr && *backptr == *foreptr) /*maximum supported length by deflate is max length*/ { - ++backptr; - ++foreptr; - } - current_length = (unsigned)(foreptr - &in[pos]); - - if(current_length > length) { - length = current_length; /*the longest length*/ - offset = current_offset; /*the offset that is related to this longest length*/ - /*jump out once a length of max length is found (speed gain). This also jumps - out if length is MAX_SUPPORTED_DEFLATE_LENGTH*/ - if(current_length >= nicematch) break; - } - } +#endif /*LODEPNG_COMPILE_ZLIB*/
- if(hashpos == hash->chain[hashpos]) break; +/* ////////////////////////////////////////////////////////////////////////// */
- if(numzeros >= 3 && length > numzeros) { - hashpos = hash->chainz[hashpos]; - if(hash->zeros[hashpos] != numzeros) break; - } else { - hashpos = hash->chain[hashpos]; - /*outdated hash value, happens if particular value was not encountered in whole last window*/ - if(hash->val[hashpos] != (int)hashval) break; - } - } +#ifdef LODEPNG_COMPILE_DECODER
- if(lazymatching) { - if(!lazy && length >= 3 && length <= maxlazymatch && length < MAX_SUPPORTED_DEFLATE_LENGTH) { - lazy = 1; - lazylength = length; - lazyoffset = offset; - continue; /*try the next byte*/ - } - if(lazy) { - lazy = 0; - if(pos == 0) ERROR_BREAK(81); - if(length > lazylength + 1) { - /*push the previous character as literal*/ - if(!uivector_push_back(out, in[pos - 1])) ERROR_BREAK(83 /*alloc fail*/); - } else { - length = lazylength; - offset = lazyoffset; - hash->head[hashval] = -1; /*the same hashchain update will be done, this ensures no wrong alteration*/ - hash->headz[numzeros] = -1; /*idem*/ - --pos; - } - } - } - if(length >= 3 && offset > windowsize) ERROR_BREAK(86 /*too big (or overflown negative) offset*/); - - /*encode it as length/distance pair or literal value*/ - if(length < 3) /*only lengths of 3 or higher are supported as length/distance pair*/ { - if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/); - } else if(length < minmatch || (length == 3 && offset > 4096)) { - /*compensate for the fact that longer offsets have more extra bits, a - length of only 3 may be not worth it then*/ - if(!uivector_push_back(out, in[pos])) ERROR_BREAK(83 /*alloc fail*/); - } else { - addLengthDistance(out, length, offset); - for(i = 1; i < length; ++i) { - ++pos; - wpos = pos & (windowsize - 1); - hashval = getHash(in, insize, pos); - if(usezeros && hashval == 0) { - if(numzeros == 0) numzeros = countZeros(in, insize, pos); - else if(pos + numzeros > insize || in[pos + numzeros - 1] != 0) --numzeros; - } else { - numzeros = 0; - } - updateHashChain(hash, wpos, hashval, numzeros); - } - } - } /*end of the loop through each character of input*/ +void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings) { + settings->ignore_adler32 = 1;
- return error; + settings->custom_zlib = 0; + settings->custom_inflate = 0; + settings->custom_context = 0; }
-/* /////////////////////////////////////////////////////////////////////////// */ - -static unsigned deflateNoCompression(ucvector* out, const unsigned char* data, size_t datasize) { - /*non compressed deflate block data: 1 bit BFINAL,2 bits BTYPE,(5 bits): it jumps to start of next byte, - 2 bytes LEN, 2 bytes NLEN, LEN bytes literal DATA*/ - - size_t i, j, numdeflateblocks = (datasize + 65534) / 65535; - unsigned datapos = 0; - for(i = 0; i != numdeflateblocks; ++i) { - unsigned BFINAL, BTYPE, LEN, NLEN; - unsigned char firstbyte; - - BFINAL = (i == numdeflateblocks - 1); - BTYPE = 0; +const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0};
- firstbyte = (unsigned char)(BFINAL + ((BTYPE & 1) << 1) + ((BTYPE & 2) << 1)); - ucvector_push_back(out, firstbyte); +#endif /*LODEPNG_COMPILE_DECODER*/
- LEN = 65535; - if(datasize - datapos < 65535) LEN = (unsigned)datasize - datapos; - NLEN = 65535 - LEN; +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* // End of Zlib related code. Begin of PNG related code. // */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* ////////////////////////////////////////////////////////////////////////// */
- ucvector_push_back(out, (unsigned char)(LEN & 255)); - ucvector_push_back(out, (unsigned char)(LEN >> 8)); - ucvector_push_back(out, (unsigned char)(NLEN & 255)); - ucvector_push_back(out, (unsigned char)(NLEN >> 8)); +#ifdef LODEPNG_COMPILE_PNG
- /*Decompressed data*/ - for(j = 0; j < 65535 && datapos < datasize; ++j) { - ucvector_push_back(out, data[datapos++]); - } - } +/* ////////////////////////////////////////////////////////////////////////// */ +/* / CRC32 / */ +/* ////////////////////////////////////////////////////////////////////////// */
- return 0; -}
-/* -write the lz77-encoded data, which has lit, len and dist codes, to compressed stream using huffman trees. -tree_ll: the tree for lit and len codes. -tree_d: the tree for distance codes. -*/ -static void writeLZ77data(size_t* bp, ucvector* out, const uivector* lz77_encoded, - const HuffmanTree* tree_ll, const HuffmanTree* tree_d) { - size_t i = 0; - for(i = 0; i != lz77_encoded->size; ++i) { - unsigned val = lz77_encoded->data[i]; - addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_ll, val), HuffmanTree_getLength(tree_ll, val)); - if(val > 256) /*for a length code, 3 more things have to be added*/ { - unsigned length_index = val - FIRST_LENGTH_CODE_INDEX; - unsigned n_length_extra_bits = LENGTHEXTRA[length_index]; - unsigned length_extra_bits = lz77_encoded->data[++i]; - - unsigned distance_code = lz77_encoded->data[++i]; - - unsigned distance_index = distance_code; - unsigned n_distance_extra_bits = DISTANCEEXTRA[distance_index]; - unsigned distance_extra_bits = lz77_encoded->data[++i]; - - addBitsToStream(bp, out, length_extra_bits, n_length_extra_bits); - addHuffmanSymbol(bp, out, HuffmanTree_getCode(tree_d, distance_code), - HuffmanTree_getLength(tree_d, distance_code)); - addBitsToStream(bp, out, distance_extra_bits, n_distance_extra_bits); - } +#ifndef LODEPNG_NO_COMPILE_CRC +/* CRC polynomial: 0xedb88320 */ +static unsigned lodepng_crc32_table[256] = { + 0u, 1996959894u, 3993919788u, 2567524794u, 124634137u, 1886057615u, 3915621685u, 2657392035u, + 249268274u, 2044508324u, 3772115230u, 2547177864u, 162941995u, 2125561021u, 3887607047u, 2428444049u, + 498536548u, 1789927666u, 4089016648u, 2227061214u, 450548861u, 1843258603u, 4107580753u, 2211677639u, + 325883990u, 1684777152u, 4251122042u, 2321926636u, 335633487u, 1661365465u, 4195302755u, 2366115317u, + 997073096u, 1281953886u, 3579855332u, 2724688242u, 1006888145u, 1258607687u, 3524101629u, 2768942443u, + 901097722u, 1119000684u, 3686517206u, 2898065728u, 853044451u, 1172266101u, 3705015759u, 2882616665u, + 651767980u, 1373503546u, 3369554304u, 3218104598u, 565507253u, 1454621731u, 3485111705u, 3099436303u, + 671266974u, 1594198024u, 3322730930u, 2970347812u, 795835527u, 1483230225u, 3244367275u, 3060149565u, + 1994146192u, 31158534u, 2563907772u, 4023717930u, 1907459465u, 112637215u, 2680153253u, 3904427059u, + 2013776290u, 251722036u, 2517215374u, 3775830040u, 2137656763u, 141376813u, 2439277719u, 3865271297u, + 1802195444u, 476864866u, 2238001368u, 4066508878u, 1812370925u, 453092731u, 2181625025u, 4111451223u, + 1706088902u, 314042704u, 2344532202u, 4240017532u, 1658658271u, 366619977u, 2362670323u, 4224994405u, + 1303535960u, 984961486u, 2747007092u, 3569037538u, 1256170817u, 1037604311u, 2765210733u, 3554079995u, + 1131014506u, 879679996u, 2909243462u, 3663771856u, 1141124467u, 855842277u, 2852801631u, 3708648649u, + 1342533948u, 654459306u, 3188396048u, 3373015174u, 1466479909u, 544179635u, 3110523913u, 3462522015u, + 1591671054u, 702138776u, 2966460450u, 3352799412u, 1504918807u, 783551873u, 3082640443u, 3233442989u, + 3988292384u, 2596254646u, 62317068u, 1957810842u, 3939845945u, 2647816111u, 81470997u, 1943803523u, + 3814918930u, 2489596804u, 225274430u, 2053790376u, 3826175755u, 2466906013u, 167816743u, 2097651377u, + 4027552580u, 2265490386u, 503444072u, 1762050814u, 4150417245u, 2154129355u, 426522225u, 1852507879u, + 4275313526u, 2312317920u, 282753626u, 1742555852u, 4189708143u, 2394877945u, 397917763u, 1622183637u, + 3604390888u, 2714866558u, 953729732u, 1340076626u, 3518719985u, 2797360999u, 1068828381u, 1219638859u, + 3624741850u, 2936675148u, 906185462u, 1090812512u, 3747672003u, 2825379669u, 829329135u, 1181335161u, + 3412177804u, 3160834842u, 628085408u, 1382605366u, 3423369109u, 3138078467u, 570562233u, 1426400815u, + 3317316542u, 2998733608u, 733239954u, 1555261956u, 3268935591u, 3050360625u, 752459403u, 1541320221u, + 2607071920u, 3965973030u, 1969922972u, 40735498u, 2617837225u, 3943577151u, 1913087877u, 83908371u, + 2512341634u, 3803740692u, 2075208622u, 213261112u, 2463272603u, 3855990285u, 2094854071u, 198958881u, + 2262029012u, 4057260610u, 1759359992u, 534414190u, 2176718541u, 4139329115u, 1873836001u, 414664567u, + 2282248934u, 4279200368u, 1711684554u, 285281116u, 2405801727u, 4167216745u, 1634467795u, 376229701u, + 2685067896u, 3608007406u, 1308918612u, 956543938u, 2808555105u, 3495958263u, 1231636301u, 1047427035u, + 2932959818u, 3654703836u, 1088359270u, 936918000u, 2847714899u, 3736837829u, 1202900863u, 817233897u, + 3183342108u, 3401237130u, 1404277552u, 615818150u, 3134207493u, 3453421203u, 1423857449u, 601450431u, + 3009837614u, 3294710456u, 1567103746u, 711928724u, 3020668471u, 3272380065u, 1510334235u, 755167117u +}; + +/*Return the CRC of the bytes buf[0..len-1].*/ +unsigned lodepng_crc32(const unsigned char* data, size_t length) { + unsigned r = 0xffffffffu; + size_t i; + for(i = 0; i < length; ++i) { + r = lodepng_crc32_table[(r ^ data[i]) & 0xff] ^ (r >> 8); } + return r ^ 0xffffffffu; } +#else /* !LODEPNG_NO_COMPILE_CRC */ +unsigned lodepng_crc32(const unsigned char* data, size_t length); +#endif /* !LODEPNG_NO_COMPILE_CRC */
-/*Deflate for a block of type "dynamic", that is, with freely, optimally, created huffman trees*/ -static unsigned deflateDynamic(ucvector* out, size_t* bp, Hash* hash, - const unsigned char* data, size_t datapos, size_t dataend, - const LodePNGCompressSettings* settings, unsigned final) { - unsigned error = 0; - - /* - A block is compressed as follows: The PNG data is lz77 encoded, resulting in - literal bytes and length/distance pairs. This is then huffman compressed with - two huffman trees. One huffman tree is used for the lit and len values ("ll"), - another huffman tree is used for the dist values ("d"). These two trees are - stored using their code lengths, and to compress even more these code lengths - are also run-length encoded and huffman compressed. This gives a huffman tree - of code lengths "cl". The code lenghts used to describe this third tree are - the code length code lengths ("clcl"). - */ +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Reading and writing single bits and bytes from/to stream for LodePNG / */ +/* ////////////////////////////////////////////////////////////////////////// */
- /*The lz77 encoded data, represented with integers since there will also be length and distance codes in it*/ - uivector lz77_encoded; - HuffmanTree tree_ll; /*tree for lit,len values*/ - HuffmanTree tree_d; /*tree for distance codes*/ - HuffmanTree tree_cl; /*tree for encoding the code lengths representing tree_ll and tree_d*/ - uivector frequencies_ll; /*frequency of lit,len codes*/ - uivector frequencies_d; /*frequency of dist codes*/ - uivector frequencies_cl; /*frequency of code length codes*/ - uivector bitlen_lld; /*lit,len,dist code lenghts (int bits), literally (without repeat codes).*/ - uivector bitlen_lld_e; /*bitlen_lld encoded with repeat codes (this is a rudemtary run length compression)*/ - /*bitlen_cl is the code length code lengths ("clcl"). The bit lengths of codes to represent tree_cl - (these are written as is in the file, it would be crazy to compress these using yet another huffman - tree that needs to be represented by yet another set of code lengths)*/ - uivector bitlen_cl; - size_t datasize = dataend - datapos; +static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream) { + unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1); + ++(*bitpointer); + return result; +}
- /* - Due to the huffman compression of huffman tree representations ("two levels"), there are some anologies: - bitlen_lld is to tree_cl what data is to tree_ll and tree_d. - bitlen_lld_e is to bitlen_lld what lz77_encoded is to data. - bitlen_cl is to bitlen_lld_e what bitlen_lld is to lz77_encoded. - */ +static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits) { + unsigned result = 0; + size_t i; + for(i = 0 ; i < nbits; ++i) { + result <<= 1; + result |= (unsigned)readBitFromReversedStream(bitpointer, bitstream); + } + return result; +}
- unsigned BFINAL = final; - size_t numcodes_ll, numcodes_d, i; - unsigned HLIT, HDIST, HCLEN; +#ifdef LODEPNG_COMPILE_DECODER +static void setBitOfReversedStream0(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) { + /*the current bit in bitstream must be 0 for this to work*/ + if(bit) { + /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/ + bitstream[(*bitpointer) >> 3] |= (bit << (7 - ((*bitpointer) & 0x7))); + } + ++(*bitpointer); +} +#endif /*LODEPNG_COMPILE_DECODER*/
- uivector_init(&lz77_encoded); - HuffmanTree_init(&tree_ll); - HuffmanTree_init(&tree_d); - HuffmanTree_init(&tree_cl); - uivector_init(&frequencies_ll); - uivector_init(&frequencies_d); - uivector_init(&frequencies_cl); - uivector_init(&bitlen_lld); - uivector_init(&bitlen_lld_e); - uivector_init(&bitlen_cl); - - /*This while loop never loops due to a break at the end, it is here to - allow breaking out of it to the cleanup phase on error conditions.*/ - while(!error) { - if(settings->use_lz77) { - error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize, - settings->minmatch, settings->nicematch, settings->lazymatching); - if(error) break; - } else { - if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83 /*alloc fail*/); - for(i = datapos; i < dataend; ++i) lz77_encoded.data[i - datapos] = data[i]; /*no LZ77, but still will be Huffman compressed*/ - } +static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) { + /*the current bit in bitstream may be 0 or 1 for this to work*/ + if(bit == 0) bitstream[(*bitpointer) >> 3] &= (unsigned char)(~(1 << (7 - ((*bitpointer) & 0x7)))); + else bitstream[(*bitpointer) >> 3] |= (1 << (7 - ((*bitpointer) & 0x7))); + ++(*bitpointer); +}
- if(!uivector_resizev(&frequencies_ll, 286, 0)) ERROR_BREAK(83 /*alloc fail*/); - if(!uivector_resizev(&frequencies_d, 30, 0)) ERROR_BREAK(83 /*alloc fail*/); - - /*Count the frequencies of lit, len and dist codes*/ - for(i = 0; i != lz77_encoded.size; ++i) { - unsigned symbol = lz77_encoded.data[i]; - ++frequencies_ll.data[symbol]; - if(symbol > 256) { - unsigned dist = lz77_encoded.data[i + 2]; - ++frequencies_d.data[dist]; - i += 3; - } - } - frequencies_ll.data[256] = 1; /*there will be exactly 1 end code, at the end of the block*/ +/* ////////////////////////////////////////////////////////////////////////// */ +/* / PNG chunks / */ +/* ////////////////////////////////////////////////////////////////////////// */
- /*Make both huffman trees, one for the lit and len codes, one for the dist codes*/ - error = HuffmanTree_makeFromFrequencies(&tree_ll, frequencies_ll.data, 257, frequencies_ll.size, 15); - if(error) break; - /*2, not 1, is chosen for mincodes: some buggy PNG decoders require at least 2 symbols in the dist tree*/ - error = HuffmanTree_makeFromFrequencies(&tree_d, frequencies_d.data, 2, frequencies_d.size, 15); - if(error) break; +unsigned lodepng_chunk_length(const unsigned char* chunk) { + return lodepng_read32bitInt(&chunk[0]); +}
- numcodes_ll = tree_ll.numcodes; if(numcodes_ll > 286) numcodes_ll = 286; - numcodes_d = tree_d.numcodes; if(numcodes_d > 30) numcodes_d = 30; - /*store the code lengths of both generated trees in bitlen_lld*/ - for(i = 0; i != numcodes_ll; ++i) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_ll, (unsigned)i)); - for(i = 0; i != numcodes_d; ++i) uivector_push_back(&bitlen_lld, HuffmanTree_getLength(&tree_d, (unsigned)i)); - - /*run-length compress bitlen_ldd into bitlen_lld_e by using repeat codes 16 (copy length 3-6 times), - 17 (3-10 zeroes), 18 (11-138 zeroes)*/ - for(i = 0; i != (unsigned)bitlen_lld.size; ++i) { - unsigned j = 0; /*amount of repititions*/ - while(i + j + 1 < (unsigned)bitlen_lld.size && bitlen_lld.data[i + j + 1] == bitlen_lld.data[i]) ++j; - - if(bitlen_lld.data[i] == 0 && j >= 2) /*repeat code for zeroes*/ { - ++j; /*include the first zero*/ - if(j <= 10) /*repeat code 17 supports max 10 zeroes*/ { - uivector_push_back(&bitlen_lld_e, 17); - uivector_push_back(&bitlen_lld_e, j - 3); - } else /*repeat code 18 supports max 138 zeroes*/ { - if(j > 138) j = 138; - uivector_push_back(&bitlen_lld_e, 18); - uivector_push_back(&bitlen_lld_e, j - 11); - } - i += (j - 1); - } else if(j >= 3) /*repeat code for value other than zero*/ { - size_t k; - unsigned num = j / 6, rest = j % 6; - uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]); - for(k = 0; k < num; ++k) { - uivector_push_back(&bitlen_lld_e, 16); - uivector_push_back(&bitlen_lld_e, 6 - 3); - } - if(rest >= 3) { - uivector_push_back(&bitlen_lld_e, 16); - uivector_push_back(&bitlen_lld_e, rest - 3); - } - else j -= rest; - i += j; - } else /*too short to benefit from repeat code*/ { - uivector_push_back(&bitlen_lld_e, bitlen_lld.data[i]); - } - } +void lodepng_chunk_type(char type[5], const unsigned char* chunk) { + unsigned i; + for(i = 0; i != 4; ++i) type[i] = (char)chunk[4 + i]; + type[4] = 0; /*null termination char*/ +}
- /*generate tree_cl, the huffmantree of huffmantrees*/ +unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type) { + if(strlen(type) != 4) return 0; + return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]); +}
- if(!uivector_resizev(&frequencies_cl, NUM_CODE_LENGTH_CODES, 0)) ERROR_BREAK(83 /*alloc fail*/); - for(i = 0; i != bitlen_lld_e.size; ++i) { - ++frequencies_cl.data[bitlen_lld_e.data[i]]; - /*after a repeat code come the bits that specify the number of repetitions, - those don't need to be in the frequencies_cl calculation*/ - if(bitlen_lld_e.data[i] >= 16) ++i; - } +unsigned char lodepng_chunk_ancillary(const unsigned char* chunk) { + return((chunk[4] & 32) != 0); +}
- error = HuffmanTree_makeFromFrequencies(&tree_cl, frequencies_cl.data, - frequencies_cl.size, frequencies_cl.size, 7); - if(error) break; +unsigned char lodepng_chunk_private(const unsigned char* chunk) { + return((chunk[6] & 32) != 0); +}
- if(!uivector_resize(&bitlen_cl, tree_cl.numcodes)) ERROR_BREAK(83 /*alloc fail*/); - for(i = 0; i != tree_cl.numcodes; ++i) { - /*lenghts of code length tree is in the order as specified by deflate*/ - bitlen_cl.data[i] = HuffmanTree_getLength(&tree_cl, CLCL_ORDER[i]); - } - while(bitlen_cl.data[bitlen_cl.size - 1] == 0 && bitlen_cl.size > 4) { - /*remove zeros at the end, but minimum size must be 4*/ - if(!uivector_resize(&bitlen_cl, bitlen_cl.size - 1)) ERROR_BREAK(83 /*alloc fail*/); - } - if(error) break; +unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk) { + return((chunk[7] & 32) != 0); +}
- /* - Write everything into the output - - After the BFINAL and BTYPE, the dynamic block consists out of the following: - - 5 bits HLIT, 5 bits HDIST, 4 bits HCLEN - - (HCLEN+4)*3 bits code lengths of code length alphabet - - HLIT + 257 code lenghts of lit/length alphabet (encoded using the code length - alphabet, + possible repetition codes 16, 17, 18) - - HDIST + 1 code lengths of distance alphabet (encoded using the code length - alphabet, + possible repetition codes 16, 17, 18) - - compressed data - - 256 (end code) - */ +unsigned char* lodepng_chunk_data(unsigned char* chunk) { + return &chunk[8]; +}
- /*Write block type*/ - addBitToStream(bp, out, BFINAL); - addBitToStream(bp, out, 0); /*first bit of BTYPE "dynamic"*/ - addBitToStream(bp, out, 1); /*second bit of BTYPE "dynamic"*/ - - /*write the HLIT, HDIST and HCLEN values*/ - HLIT = (unsigned)(numcodes_ll - 257); - HDIST = (unsigned)(numcodes_d - 1); - HCLEN = (unsigned)bitlen_cl.size - 4; - /*trim zeroes for HCLEN. HLIT and HDIST were already trimmed at tree creation*/ - while(!bitlen_cl.data[HCLEN + 4 - 1] && HCLEN > 0) --HCLEN; - addBitsToStream(bp, out, HLIT, 5); - addBitsToStream(bp, out, HDIST, 5); - addBitsToStream(bp, out, HCLEN, 4); - - /*write the code lenghts of the code length alphabet*/ - for(i = 0; i != HCLEN + 4; ++i) addBitsToStream(bp, out, bitlen_cl.data[i], 3); - - /*write the lenghts of the lit/len AND the dist alphabet*/ - for(i = 0; i != bitlen_lld_e.size; ++i) { - addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_cl, bitlen_lld_e.data[i]), - HuffmanTree_getLength(&tree_cl, bitlen_lld_e.data[i])); - /*extra bits of repeat codes*/ - if(bitlen_lld_e.data[i] == 16) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 2); - else if(bitlen_lld_e.data[i] == 17) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 3); - else if(bitlen_lld_e.data[i] == 18) addBitsToStream(bp, out, bitlen_lld_e.data[++i], 7); - } +const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk) { + return &chunk[8]; +}
- /*write the compressed data symbols*/ - writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d); - /*error: the length of the end code 256 must be larger than 0*/ - if(HuffmanTree_getLength(&tree_ll, 256) == 0) ERROR_BREAK(64); +unsigned lodepng_chunk_check_crc(const unsigned char* chunk) { + unsigned length = lodepng_chunk_length(chunk); + unsigned CRC = lodepng_read32bitInt(&chunk[length + 8]); + /*the CRC is taken of the data and the 4 chunk type letters, not the length*/ + unsigned checksum = lodepng_crc32(&chunk[4], length + 4); + if(CRC != checksum) return 1; + else return 0; +}
- /*write the end code*/ - addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256)); +void lodepng_chunk_generate_crc(unsigned char* chunk) { + unsigned length = lodepng_chunk_length(chunk); + unsigned CRC = lodepng_crc32(&chunk[4], length + 4); + lodepng_set32bitInt(chunk + 8 + length, CRC); +}
- break; /*end of error-while*/ +unsigned char* lodepng_chunk_next(unsigned char* chunk) { + if(chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47 + && chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) { + /* Is PNG magic header at start of PNG file. Jump to first actual chunk. */ + return chunk + 8; + } else { + unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; + return chunk + total_chunk_length; } - - /*cleanup*/ - uivector_cleanup(&lz77_encoded); - HuffmanTree_cleanup(&tree_ll); - HuffmanTree_cleanup(&tree_d); - HuffmanTree_cleanup(&tree_cl); - uivector_cleanup(&frequencies_ll); - uivector_cleanup(&frequencies_d); - uivector_cleanup(&frequencies_cl); - uivector_cleanup(&bitlen_lld_e); - uivector_cleanup(&bitlen_lld); - uivector_cleanup(&bitlen_cl); - - return error; }
-static unsigned deflateFixed(ucvector* out, size_t* bp, Hash* hash, - const unsigned char* data, - size_t datapos, size_t dataend, - const LodePNGCompressSettings* settings, unsigned final) { - HuffmanTree tree_ll; /*tree for literal values and length codes*/ - HuffmanTree tree_d; /*tree for distance codes*/ - - unsigned BFINAL = final; - unsigned error = 0; - size_t i; - - HuffmanTree_init(&tree_ll); - HuffmanTree_init(&tree_d); - - generateFixedLitLenTree(&tree_ll); - generateFixedDistanceTree(&tree_d); - - addBitToStream(bp, out, BFINAL); - addBitToStream(bp, out, 1); /*first bit of BTYPE*/ - addBitToStream(bp, out, 0); /*second bit of BTYPE*/ - - if(settings->use_lz77) /*LZ77 encoded*/ { - uivector lz77_encoded; - uivector_init(&lz77_encoded); - error = encodeLZ77(&lz77_encoded, hash, data, datapos, dataend, settings->windowsize, - settings->minmatch, settings->nicematch, settings->lazymatching); - if(!error) writeLZ77data(bp, out, &lz77_encoded, &tree_ll, &tree_d); - uivector_cleanup(&lz77_encoded); - } else /*no LZ77, but still will be Huffman compressed*/ { - for(i = datapos; i < dataend; ++i) { - addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, data[i]), HuffmanTree_getLength(&tree_ll, data[i])); - } +const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk) { + if(chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47 + && chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) { + /* Is PNG magic header at start of PNG file. Jump to first actual chunk. */ + return chunk + 8; + } else { + unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; + return chunk + total_chunk_length; } - /*add END code*/ - if(!error) addHuffmanSymbol(bp, out, HuffmanTree_getCode(&tree_ll, 256), HuffmanTree_getLength(&tree_ll, 256)); - - /*cleanup*/ - HuffmanTree_cleanup(&tree_ll); - HuffmanTree_cleanup(&tree_d); - - return error; }
-static unsigned lodepng_deflatev(ucvector* out, const unsigned char* in, size_t insize, - const LodePNGCompressSettings* settings) { - unsigned error = 0; - size_t i, blocksize, numdeflateblocks; - size_t bp = 0; /*the bit pointer*/ - Hash hash; - - if(settings->btype > 2) return 61; - else if(settings->btype == 0) return deflateNoCompression(out, in, insize); - else if(settings->btype == 1) blocksize = insize; - else /*if(settings->btype == 2)*/ { - /*on PNGs, deflate blocks of 65-262k seem to give most dense encoding*/ - blocksize = insize / 8 + 8; - if(blocksize < 65536) blocksize = 65536; - if(blocksize > 262144) blocksize = 262144; +unsigned char* lodepng_chunk_find(unsigned char* chunk, const unsigned char* end, const char type[5]) { + for(;;) { + if(chunk + 12 >= end) return 0; + if(lodepng_chunk_type_equals(chunk, type)) return chunk; + chunk = lodepng_chunk_next(chunk); } +}
- numdeflateblocks = (insize + blocksize - 1) / blocksize; - if(numdeflateblocks == 0) numdeflateblocks = 1; - - error = hash_init(&hash, settings->windowsize); - if(error) return error; - - for(i = 0; i != numdeflateblocks && !error; ++i) { - unsigned final = (i == numdeflateblocks - 1); - size_t start = i * blocksize; - size_t end = start + blocksize; - if(end > insize) end = insize; - - if(settings->btype == 1) error = deflateFixed(out, &bp, &hash, in, start, end, settings, final); - else if(settings->btype == 2) error = deflateDynamic(out, &bp, &hash, in, start, end, settings, final); +const unsigned char* lodepng_chunk_find_const(const unsigned char* chunk, const unsigned char* end, const char type[5]) { + for(;;) { + if(chunk + 12 >= end) return 0; + if(lodepng_chunk_type_equals(chunk, type)) return chunk; + chunk = lodepng_chunk_next_const(chunk); } - - hash_cleanup(&hash); - - return error; }
-unsigned lodepng_deflate(unsigned char** out, size_t* outsize, - const unsigned char* in, size_t insize, - const LodePNGCompressSettings* settings) { - unsigned error; - ucvector v; - ucvector_init_buffer(&v, *out, *outsize); - error = lodepng_deflatev(&v, in, insize, settings); - *out = v.data; - *outsize = v.size; - return error; +/* ////////////////////////////////////////////////////////////////////////// */ +/* / Color types and such / */ +/* ////////////////////////////////////////////////////////////////////////// */ + +/*return type is a LodePNG error code*/ +static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) /*bd = bitdepth*/ { + switch(colortype) { + case 0: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/ + case 2: if(!( bd == 8 || bd == 16)) return 37; break; /*RGB*/ + case 3: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 )) return 37; break; /*palette*/ + case 4: if(!( bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/ + case 6: if(!( bd == 8 || bd == 16)) return 37; break; /*RGBA*/ + default: return 31; + } + return 0; /*allowed color type / bits combination*/ }
-static unsigned deflate(unsigned char** out, size_t* outsize, - const unsigned char* in, size_t insize, - const LodePNGCompressSettings* settings) { - if(settings->custom_deflate) { - return settings->custom_deflate(out, outsize, in, insize, settings); - } else { - return lodepng_deflate(out, outsize, in, insize, settings); +static unsigned getNumColorChannels(LodePNGColorType colortype) { + switch(colortype) { + case 0: return 1; /*grey*/ + case 2: return 3; /*RGB*/ + case 3: return 1; /*palette*/ + case 4: return 2; /*grey + alpha*/ + case 6: return 4; /*RGBA*/ } + return 0; /*unexisting color type*/ }
-#endif /*LODEPNG_COMPILE_DECODER*/ +static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth) { + /*bits per pixel is amount of channels * bits per channel*/ + return getNumColorChannels(colortype) * bitdepth; +}
/* ////////////////////////////////////////////////////////////////////////// */ -/* / Adler32 */ -/* ////////////////////////////////////////////////////////////////////////// */ - -static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len) { - unsigned s1 = adler & 0xffff; - unsigned s2 = (adler >> 16) & 0xffff;
- while(len > 0) { - /*at least 5552 sums can be done before the sums overflow, saving a lot of module divisions*/ - unsigned amount = len > 5552 ? 5552 : len; - len -= amount; - while(amount > 0) { - s1 += (*data++); - s2 += s1; - --amount; - } - s1 %= 65521; - s2 %= 65521; - } - - return (s2 << 16) | s1; +void lodepng_color_mode_init(LodePNGColorMode* info) { + info->key_defined = 0; + info->key_r = info->key_g = info->key_b = 0; + info->colortype = LCT_RGBA; + info->bitdepth = 8; + info->palette = 0; + info->palettesize = 0; }
-/*Return the adler32 of the bytes data[0..len-1]*/ -static unsigned adler32(const unsigned char* data, unsigned len) { - return update_adler32(1L, data, len); +void lodepng_color_mode_cleanup(LodePNGColorMode* info) { + lodepng_palette_clear(info); }
-/* ////////////////////////////////////////////////////////////////////////// */ -/* / Zlib / */ -/* ////////////////////////////////////////////////////////////////////////// */ - -#ifdef LODEPNG_COMPILE_DECODER - -unsigned lodepng_zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGDecompressSettings* settings) { - unsigned error = 0; - unsigned CM, CINFO, FDICT; - - if(insize < 2) return 53; /*error, size of zlib data too small*/ - /*read information from zlib header*/ - if((in[0] * 256 + in[1]) % 31 != 0) { - /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/ - return 24; +unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source) { + size_t i; + lodepng_color_mode_cleanup(dest); + *dest = *source; + if(source->palette) { + dest->palette = (unsigned char*)lodepng_malloc(1024); + if(!dest->palette && source->palettesize) return 83; /*alloc fail*/ + for(i = 0; i != source->palettesize * 4; ++i) dest->palette[i] = source->palette[i]; } + return 0; +}
- CM = in[0] & 15; - CINFO = (in[0] >> 4) & 15; - /*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/ - FDICT = (in[1] >> 5) & 1; - /*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/ +LodePNGColorMode lodepng_color_mode_make(LodePNGColorType colortype, unsigned bitdepth) { + LodePNGColorMode result; + lodepng_color_mode_init(&result); + result.colortype = colortype; + result.bitdepth = bitdepth; + return result; +}
- if(CM != 8 || CINFO > 7) { - /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/ - return 25; - } - if(FDICT != 0) { - /*error: the specification of PNG says about the zlib stream: - "The additional flags shall not specify a preset dictionary."*/ - return 26; +static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b) { + size_t i; + if(a->colortype != b->colortype) return 0; + if(a->bitdepth != b->bitdepth) return 0; + if(a->key_defined != b->key_defined) return 0; + if(a->key_defined) { + if(a->key_r != b->key_r) return 0; + if(a->key_g != b->key_g) return 0; + if(a->key_b != b->key_b) return 0; } - - error = inflate(out, outsize, in + 2, insize - 2, settings); - if(error) return error; - - if(!settings->ignore_adler32) { - unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]); - unsigned checksum = adler32(*out, (unsigned)(*outsize)); - if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/ + if(a->palettesize != b->palettesize) return 0; + for(i = 0; i != a->palettesize * 4; ++i) { + if(a->palette[i] != b->palette[i]) return 0; } + return 1; +}
- return 0; /*no error*/ +void lodepng_palette_clear(LodePNGColorMode* info) { + if(info->palette) lodepng_free(info->palette); + info->palette = 0; + info->palettesize = 0; }
-static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGDecompressSettings* settings) { - if(settings->custom_zlib) { - return settings->custom_zlib(out, outsize, in, insize, settings); - } else { - return lodepng_zlib_decompress(out, outsize, in, insize, settings); +unsigned lodepng_palette_add(LodePNGColorMode* info, + unsigned char r, unsigned char g, unsigned char b, unsigned char a) { + unsigned char* data; + /*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with + the max of 256 colors, it'll have the exact alloc size*/ + if(!info->palette) /*allocate palette if empty*/ { + /*room for 256 colors with 4 bytes each*/ + data = (unsigned char*)lodepng_malloc(1024); + if(!data) return 83; /*alloc fail*/ + else info->palette = data; } + info->palette[4 * info->palettesize + 0] = r; + info->palette[4 * info->palettesize + 1] = g; + info->palette[4 * info->palettesize + 2] = b; + info->palette[4 * info->palettesize + 3] = a; + ++info->palettesize; + return 0; }
-#endif /*LODEPNG_COMPILE_DECODER*/ - -#ifdef LODEPNG_COMPILE_ENCODER - -unsigned lodepng_zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGCompressSettings* settings) { - /*initially, *out must be NULL and outsize 0, if you just give some random *out - that's pointing to a non allocated buffer, this'll crash*/ - ucvector outv; - size_t i; - unsigned error; - unsigned char* deflatedata = 0; - size_t deflatesize = 0; +/*calculate bits per pixel out of colortype and bitdepth*/ +unsigned lodepng_get_bpp(const LodePNGColorMode* info) { + return lodepng_get_bpp_lct(info->colortype, info->bitdepth); +}
- /*zlib data: 1 byte CMF (CM+CINFO), 1 byte FLG, deflate data, 4 byte ADLER32 checksum of the Decompressed data*/ - unsigned CMF = 120; /*0b01111000: CM 8, CINFO 7. With CINFO 7, any window size up to 32768 can be used.*/ - unsigned FLEVEL = 0; - unsigned FDICT = 0; - unsigned CMFFLG = 256 * CMF + FDICT * 32 + FLEVEL * 64; - unsigned FCHECK = 31 - CMFFLG % 31; - CMFFLG += FCHECK; +unsigned lodepng_get_channels(const LodePNGColorMode* info) { + return getNumColorChannels(info->colortype); +}
- /*ucvector-controlled version of the output buffer, for dynamic array*/ - ucvector_init_buffer(&outv, *out, *outsize); +unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info) { + return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA; +}
- ucvector_push_back(&outv, (unsigned char)(CMFFLG >> 8)); - ucvector_push_back(&outv, (unsigned char)(CMFFLG & 255)); +unsigned lodepng_is_alpha_type(const LodePNGColorMode* info) { + return (info->colortype & 4) != 0; /*4 or 6*/ +}
- error = deflate(&deflatedata, &deflatesize, in, insize, settings); +unsigned lodepng_is_palette_type(const LodePNGColorMode* info) { + return info->colortype == LCT_PALETTE; +}
- if(!error) { - unsigned ADLER32 = adler32(in, (unsigned)insize); - for(i = 0; i != deflatesize; ++i) ucvector_push_back(&outv, deflatedata[i]); - lodepng_free(deflatedata); - lodepng_add32bitInt(&outv, ADLER32); +unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info) { + size_t i; + for(i = 0; i != info->palettesize; ++i) { + if(info->palette[i * 4 + 3] < 255) return 1; } + return 0; +}
- *out = outv.data; - *outsize = outv.size; - - return error; +unsigned lodepng_can_have_alpha(const LodePNGColorMode* info) { + return info->key_defined + || lodepng_is_alpha_type(info) + || lodepng_has_palette_alpha(info); }
-/* compress using the default or custom zlib function */ -static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGCompressSettings* settings) { - if(settings->custom_zlib) { - return settings->custom_zlib(out, outsize, in, insize, settings); - } else { - return lodepng_zlib_compress(out, outsize, in, insize, settings); - } +size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) { + size_t bpp = lodepng_get_bpp_lct(colortype, bitdepth); + size_t n = (size_t)w * (size_t)h; + return ((n / 8) * bpp) + ((n & 7) * bpp + 7) / 8; }
-#endif /*LODEPNG_COMPILE_ENCODER*/ +size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color) { + return lodepng_get_raw_size_lct(w, h, color->colortype, color->bitdepth); +}
-#else /*no LODEPNG_COMPILE_ZLIB*/
+#ifdef LODEPNG_COMPILE_PNG #ifdef LODEPNG_COMPILE_DECODER -static unsigned zlib_decompress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGDecompressSettings* settings) { - if(!settings->custom_zlib) return 87; /*no custom zlib function provided */ - return settings->custom_zlib(out, outsize, in, insize, settings); + +/*in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer, +and in addition has one extra byte per line: the filter byte. So this gives a larger +result than lodepng_get_raw_size. */ +static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, const LodePNGColorMode* color) { + size_t bpp = lodepng_get_bpp(color); + /* + 1 for the filter byte, and possibly plus padding bits per line */ + size_t line = ((size_t)(w / 8) * bpp) + 1 + ((w & 7) * bpp + 7) / 8; + return (size_t)h * line; } -#endif /*LODEPNG_COMPILE_DECODER*/ -#ifdef LODEPNG_COMPILE_ENCODER -static unsigned zlib_compress(unsigned char** out, size_t* outsize, const unsigned char* in, - size_t insize, const LodePNGCompressSettings* settings) { - if(!settings->custom_zlib) return 87; /*no custom zlib function provided */ - return settings->custom_zlib(out, outsize, in, insize, settings); + +/* Safely check if multiplying two integers will overflow (no undefined +behavior, compiler removing the code, etc...) and output result. */ +static int lodepng_mulofl(size_t a, size_t b, size_t* result) { + *result = a * b; /* Unsigned multiplication is well defined and safe in C90 */ + return (a != 0 && *result / a != b); } -#endif /*LODEPNG_COMPILE_ENCODER*/
-#endif /*LODEPNG_COMPILE_ZLIB*/ +/* Safely check if adding two integers will overflow (no undefined +behavior, compiler removing the code, etc...) and output result. */ +static int lodepng_addofl(size_t a, size_t b, size_t* result) { + *result = a + b; /* Unsigned addition is well defined and safe in C90 */ + return *result < a; +}
-/* ////////////////////////////////////////////////////////////////////////// */ +/*Safely checks whether size_t overflow can be caused due to amount of pixels. +This check is overcautious rather than precise. If this check indicates no overflow, +you can safely compute in a size_t (but not an unsigned): +-(size_t)w * (size_t)h * 8 +-amount of bytes in IDAT (including filter, padding and Adam7 bytes) +-amount of bytes in raw color model +Returns 1 if overflow possible, 0 if not. +*/ +static int lodepng_pixel_overflow(unsigned w, unsigned h, + const LodePNGColorMode* pngcolor, const LodePNGColorMode* rawcolor) { + size_t bpp = LODEPNG_MAX(lodepng_get_bpp(pngcolor), lodepng_get_bpp(rawcolor)); + size_t numpixels, total; + size_t line; /* bytes per line in worst case */
-#ifdef LODEPNG_COMPILE_ENCODER + if(lodepng_mulofl((size_t)w, (size_t)h, &numpixels)) return 1; + if(lodepng_mulofl(numpixels, 8, &total)) return 1; /* bit pointer with 8-bit color, or 8 bytes per channel color */
-/*this is a good tradeoff between speed and compression ratio*/ -#define DEFAULT_WINDOWSIZE 2048 + /* Bytes per scanline with the expression "(w / 8) * bpp) + ((w & 7) * bpp + 7) / 8" */ + if(lodepng_mulofl((size_t)(w / 8), bpp, &line)) return 1; + if(lodepng_addofl(line, ((w & 7) * bpp + 7) / 8, &line)) return 1;
-void lodepng_compress_settings_init(LodePNGCompressSettings* settings) { - /*compress with dynamic huffman tree (not in the mathematical sense, just not the predefined one)*/ - settings->btype = 2; - settings->use_lz77 = 1; - settings->windowsize = DEFAULT_WINDOWSIZE; - settings->minmatch = 3; - settings->nicematch = 128; - settings->lazymatching = 1; + if(lodepng_addofl(line, 5, &line)) return 1; /* 5 bytes overhead per line: 1 filterbyte, 4 for Adam7 worst case */ + if(lodepng_mulofl(line, h, &total)) return 1; /* Total bytes in worst case */
- settings->custom_zlib = 0; - settings->custom_deflate = 0; - settings->custom_context = 0; + return 0; /* no overflow */ } +#endif /*LODEPNG_COMPILE_DECODER*/ +#endif /*LODEPNG_COMPILE_PNG*/
-const LodePNGCompressSettings lodepng_default_compress_settings = {2, 1, DEFAULT_WINDOWSIZE, 3, 128, 1, 0, 0, 0}; +void lodepng_info_init(LodePNGInfo* info) { + lodepng_color_mode_init(&info->color); + info->interlace_method = 0; + info->compression_method = 0; + info->filter_method = 0; +}
+void lodepng_info_cleanup(LodePNGInfo* info) { + lodepng_color_mode_cleanup(&info->color); +}
-#endif /*LODEPNG_COMPILE_ENCODER*/ +unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) { + lodepng_info_cleanup(dest); + *dest = *source; + lodepng_color_mode_init(&dest->color); + CERROR_TRY_RETURN(lodepng_color_mode_copy(&dest->color, &source->color));
-#ifdef LODEPNG_COMPILE_DECODER + return 0; +}
-void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings) { - settings->ignore_adler32 = 0; +/* ////////////////////////////////////////////////////////////////////////// */
- settings->custom_zlib = 0; - settings->custom_inflate = 0; - settings->custom_context = 0; +/*index: bitgroup index, bits: bitgroup size(1, 2 or 4), in: bitgroup value, out: octet array to add bits to*/ +static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in) { + unsigned m = bits == 1 ? 7 : bits == 2 ? 3 : 1; /*8 / bits - 1*/ + /*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/ + unsigned p = index & m; + in &= (1u << bits) - 1u; /*filter out any other bits of the input value*/ + in = in << (bits * (m - p)); + if(p == 0) out[index * bits / 8] = in; + else out[index * bits / 8] |= in; }
-const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0}; - -#endif /*LODEPNG_COMPILE_DECODER*/ +typedef struct ColorTree ColorTree;
-/* ////////////////////////////////////////////////////////////////////////// */ -/* ////////////////////////////////////////////////////////////////////////// */ -/* // End of Zlib related code. Begin of PNG related code. // */ -/* ////////////////////////////////////////////////////////////////////////// */ -/* ////////////////////////////////////////////////////////////////////////// */ - -#ifdef LODEPNG_COMPILE_PNG - -/* ////////////////////////////////////////////////////////////////////////// */ -/* / CRC32 / */ -/* ////////////////////////////////////////////////////////////////////////// */ - - -#ifndef LODEPNG_NO_COMPILE_CRC -/* CRC polynomial: 0xedb88320 */ -static unsigned lodepng_crc32_table[256] = { - 0u, 1996959894u, 3993919788u, 2567524794u, 124634137u, 1886057615u, 3915621685u, 2657392035u, - 249268274u, 2044508324u, 3772115230u, 2547177864u, 162941995u, 2125561021u, 3887607047u, 2428444049u, - 498536548u, 1789927666u, 4089016648u, 2227061214u, 450548861u, 1843258603u, 4107580753u, 2211677639u, - 325883990u, 1684777152u, 4251122042u, 2321926636u, 335633487u, 1661365465u, 4195302755u, 2366115317u, - 997073096u, 1281953886u, 3579855332u, 2724688242u, 1006888145u, 1258607687u, 3524101629u, 2768942443u, - 901097722u, 1119000684u, 3686517206u, 2898065728u, 853044451u, 1172266101u, 3705015759u, 2882616665u, - 651767980u, 1373503546u, 3369554304u, 3218104598u, 565507253u, 1454621731u, 3485111705u, 3099436303u, - 671266974u, 1594198024u, 3322730930u, 2970347812u, 795835527u, 1483230225u, 3244367275u, 3060149565u, - 1994146192u, 31158534u, 2563907772u, 4023717930u, 1907459465u, 112637215u, 2680153253u, 3904427059u, - 2013776290u, 251722036u, 2517215374u, 3775830040u, 2137656763u, 141376813u, 2439277719u, 3865271297u, - 1802195444u, 476864866u, 2238001368u, 4066508878u, 1812370925u, 453092731u, 2181625025u, 4111451223u, - 1706088902u, 314042704u, 2344532202u, 4240017532u, 1658658271u, 366619977u, 2362670323u, 4224994405u, - 1303535960u, 984961486u, 2747007092u, 3569037538u, 1256170817u, 1037604311u, 2765210733u, 3554079995u, - 1131014506u, 879679996u, 2909243462u, 3663771856u, 1141124467u, 855842277u, 2852801631u, 3708648649u, - 1342533948u, 654459306u, 3188396048u, 3373015174u, 1466479909u, 544179635u, 3110523913u, 3462522015u, - 1591671054u, 702138776u, 2966460450u, 3352799412u, 1504918807u, 783551873u, 3082640443u, 3233442989u, - 3988292384u, 2596254646u, 62317068u, 1957810842u, 3939845945u, 2647816111u, 81470997u, 1943803523u, - 3814918930u, 2489596804u, 225274430u, 2053790376u, 3826175755u, 2466906013u, 167816743u, 2097651377u, - 4027552580u, 2265490386u, 503444072u, 1762050814u, 4150417245u, 2154129355u, 426522225u, 1852507879u, - 4275313526u, 2312317920u, 282753626u, 1742555852u, 4189708143u, 2394877945u, 397917763u, 1622183637u, - 3604390888u, 2714866558u, 953729732u, 1340076626u, 3518719985u, 2797360999u, 1068828381u, 1219638859u, - 3624741850u, 2936675148u, 906185462u, 1090812512u, 3747672003u, 2825379669u, 829329135u, 1181335161u, - 3412177804u, 3160834842u, 628085408u, 1382605366u, 3423369109u, 3138078467u, 570562233u, 1426400815u, - 3317316542u, 2998733608u, 733239954u, 1555261956u, 3268935591u, 3050360625u, 752459403u, 1541320221u, - 2607071920u, 3965973030u, 1969922972u, 40735498u, 2617837225u, 3943577151u, 1913087877u, 83908371u, - 2512341634u, 3803740692u, 2075208622u, 213261112u, 2463272603u, 3855990285u, 2094854071u, 198958881u, - 2262029012u, 4057260610u, 1759359992u, 534414190u, 2176718541u, 4139329115u, 1873836001u, 414664567u, - 2282248934u, 4279200368u, 1711684554u, 285281116u, 2405801727u, 4167216745u, 1634467795u, 376229701u, - 2685067896u, 3608007406u, 1308918612u, 956543938u, 2808555105u, 3495958263u, 1231636301u, 1047427035u, - 2932959818u, 3654703836u, 1088359270u, 936918000u, 2847714899u, 3736837829u, 1202900863u, 817233897u, - 3183342108u, 3401237130u, 1404277552u, 615818150u, 3134207493u, 3453421203u, 1423857449u, 601450431u, - 3009837614u, 3294710456u, 1567103746u, 711928724u, 3020668471u, 3272380065u, 1510334235u, 755167117u +/* +One node of a color tree +This is the data structure used to count the number of unique colors and to get a palette +index for a color. It's like an octree, but because the alpha channel is used too, each +node has 16 instead of 8 children. +*/ +struct ColorTree { + ColorTree* children[16]; /*up to 16 pointers to ColorTree of next level*/ + int index; /*the payload. Only has a meaningful value if this is in the last level*/ };
-/*Return the CRC of the bytes buf[0..len-1].*/ -unsigned lodepng_crc32(const unsigned char* data, size_t length) { - unsigned r = 0xffffffffu; - size_t i; - for(i = 0; i < length; ++i) { - r = lodepng_crc32_table[(r ^ data[i]) & 0xff] ^ (r >> 8); - } - return r ^ 0xffffffffu; -} -#else /* !LODEPNG_NO_COMPILE_CRC */ -unsigned lodepng_crc32(const unsigned char* data, size_t length); -#endif /* !LODEPNG_NO_COMPILE_CRC */ - -/* ////////////////////////////////////////////////////////////////////////// */ -/* / Reading and writing single bits and bytes from/to stream for LodePNG / */ -/* ////////////////////////////////////////////////////////////////////////// */ - -static unsigned char readBitFromReversedStream(size_t* bitpointer, const unsigned char* bitstream) { - unsigned char result = (unsigned char)((bitstream[(*bitpointer) >> 3] >> (7 - ((*bitpointer) & 0x7))) & 1); - ++(*bitpointer); - return result; +static void color_tree_init(ColorTree* tree) { + int i; + for(i = 0; i != 16; ++i) tree->children[i] = 0; + tree->index = -1; }
-static unsigned readBitsFromReversedStream(size_t* bitpointer, const unsigned char* bitstream, size_t nbits) { - unsigned result = 0; - size_t i; - for(i = 0 ; i < nbits; ++i) { - result <<= 1; - result |= (unsigned)readBitFromReversedStream(bitpointer, bitstream); +static void color_tree_cleanup(ColorTree* tree) { + int i; + for(i = 0; i != 16; ++i) { + if(tree->children[i]) { + color_tree_cleanup(tree->children[i]); + lodepng_free(tree->children[i]); + } } - return result; }
-#ifdef LODEPNG_COMPILE_DECODER -static void setBitOfReversedStream0(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) { - /*the current bit in bitstream must be 0 for this to work*/ - if(bit) { - /*earlier bit of huffman code is in a lesser significant bit of an earlier byte*/ - bitstream[(*bitpointer) >> 3] |= (bit << (7 - ((*bitpointer) & 0x7))); +/*returns -1 if color not present, its index otherwise*/ +static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) { + int bit = 0; + for(bit = 0; bit < 8; ++bit) { + int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1); + if(!tree->children[i]) return -1; + else tree = tree->children[i]; } - ++(*bitpointer); -} -#endif /*LODEPNG_COMPILE_DECODER*/ - -static void setBitOfReversedStream(size_t* bitpointer, unsigned char* bitstream, unsigned char bit) { - /*the current bit in bitstream may be 0 or 1 for this to work*/ - if(bit == 0) bitstream[(*bitpointer) >> 3] &= (unsigned char)(~(1 << (7 - ((*bitpointer) & 0x7)))); - else bitstream[(*bitpointer) >> 3] |= (1 << (7 - ((*bitpointer) & 0x7))); - ++(*bitpointer); -} - -/* ////////////////////////////////////////////////////////////////////////// */ -/* / PNG chunks / */ -/* ////////////////////////////////////////////////////////////////////////// */ - -unsigned lodepng_chunk_length(const unsigned char* chunk) { - return lodepng_read32bitInt(&chunk[0]); -} - -void lodepng_chunk_type(char type[5], const unsigned char* chunk) { - unsigned i; - for(i = 0; i != 4; ++i) type[i] = (char)chunk[4 + i]; - type[4] = 0; /*null termination char*/ -} - -unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type) { - if(strlen(type) != 4) return 0; - return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]); -} - -unsigned char lodepng_chunk_ancillary(const unsigned char* chunk) { - return((chunk[4] & 32) != 0); -} - -unsigned char lodepng_chunk_private(const unsigned char* chunk) { - return((chunk[6] & 32) != 0); -} - -unsigned char lodepng_chunk_safetocopy(const unsigned char* chunk) { - return((chunk[7] & 32) != 0); -} - -unsigned char* lodepng_chunk_data(unsigned char* chunk) { - return &chunk[8]; -} - -const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk) { - return &chunk[8]; -} - -unsigned lodepng_chunk_check_crc(const unsigned char* chunk) { - unsigned length = lodepng_chunk_length(chunk); - unsigned CRC = lodepng_read32bitInt(&chunk[length + 8]); - /*the CRC is taken of the data and the 4 chunk type letters, not the length*/ - unsigned checksum = lodepng_crc32(&chunk[4], length + 4); - if(CRC != checksum) return 1; - else return 0; -} - -void lodepng_chunk_generate_crc(unsigned char* chunk) { - unsigned length = lodepng_chunk_length(chunk); - unsigned CRC = lodepng_crc32(&chunk[4], length + 4); - lodepng_set32bitInt(chunk + 8 + length, CRC); + return tree ? tree->index : -1; }
-unsigned char* lodepng_chunk_next(unsigned char* chunk) { - if(chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47 - && chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) { - /* Is PNG magic header at start of PNG file. Jump to first actual chunk. */ - return chunk + 8; - } else { - unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; - return chunk + total_chunk_length; +/*color is not allowed to already exist. +Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")*/ +static void color_tree_add(ColorTree* tree, + unsigned char r, unsigned char g, unsigned char b, unsigned char a, unsigned index) { + int bit; + for(bit = 0; bit < 8; ++bit) { + int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1); + if(!tree->children[i]) { + tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree)); + color_tree_init(tree->children[i]); + } + tree = tree->children[i]; } + tree->index = (int)index; }
-const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk) { - if(chunk[0] == 0x89 && chunk[1] == 0x50 && chunk[2] == 0x4e && chunk[3] == 0x47 - && chunk[4] == 0x0d && chunk[5] == 0x0a && chunk[6] == 0x1a && chunk[7] == 0x0a) { - /* Is PNG magic header at start of PNG file. Jump to first actual chunk. */ - return chunk + 8; - } else { - unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; - return chunk + total_chunk_length; +/*put a pixel, given its RGBA color, into image of any color type*/ +static unsigned rgba8ToPixel(unsigned char* out, size_t i, + const LodePNGColorMode* mode, ColorTree* tree /*for palette*/, + unsigned char r, unsigned char g, unsigned char b, unsigned char a) { + if(mode->colortype == LCT_GREY) { + unsigned char grey = r; /*((unsigned short)r + g + b) / 3;*/ + if(mode->bitdepth == 8) out[i] = grey; + else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = grey; + else { + /*take the most significant bits of grey*/ + grey = (grey >> (8 - mode->bitdepth)) & ((1 << mode->bitdepth) - 1); + addColorBits(out, i, mode->bitdepth, grey); + } + } else if(mode->colortype == LCT_RGB) { + if(mode->bitdepth == 8) { + out[i * 3 + 0] = r; + out[i * 3 + 1] = g; + out[i * 3 + 2] = b; + } else { + out[i * 6 + 0] = out[i * 6 + 1] = r; + out[i * 6 + 2] = out[i * 6 + 3] = g; + out[i * 6 + 4] = out[i * 6 + 5] = b; + } + } else if(mode->colortype == LCT_PALETTE) { + int index = color_tree_get(tree, r, g, b, a); + if(index < 0) return 82; /*color not in palette*/ + if(mode->bitdepth == 8) out[i] = index; + else addColorBits(out, i, mode->bitdepth, (unsigned)index); + } else if(mode->colortype == LCT_GREY_ALPHA) { + unsigned char grey = r; /*((unsigned short)r + g + b) / 3;*/ + if(mode->bitdepth == 8) { + out[i * 2 + 0] = grey; + out[i * 2 + 1] = a; + } else if(mode->bitdepth == 16) { + out[i * 4 + 0] = out[i * 4 + 1] = grey; + out[i * 4 + 2] = out[i * 4 + 3] = a; + } + } else if(mode->colortype == LCT_RGBA) { + if(mode->bitdepth == 8) { + out[i * 4 + 0] = r; + out[i * 4 + 1] = g; + out[i * 4 + 2] = b; + out[i * 4 + 3] = a; + } else { + out[i * 8 + 0] = out[i * 8 + 1] = r; + out[i * 8 + 2] = out[i * 8 + 3] = g; + out[i * 8 + 4] = out[i * 8 + 5] = b; + out[i * 8 + 6] = out[i * 8 + 7] = a; + } } -}
-unsigned char* lodepng_chunk_find(unsigned char* chunk, const unsigned char* end, const char type[5]) { - for(;;) { - if(chunk + 12 >= end) return 0; - if(lodepng_chunk_type_equals(chunk, type)) return chunk; - chunk = lodepng_chunk_next(chunk); - } + return 0; /*no error*/ }
-const unsigned char* lodepng_chunk_find_const(const unsigned char* chunk, const unsigned char* end, const char type[5]) { - for(;;) { - if(chunk + 12 >= end) return 0; - if(lodepng_chunk_type_equals(chunk, type)) return chunk; - chunk = lodepng_chunk_next_const(chunk); - } -} - -unsigned lodepng_chunk_append(unsigned char** out, size_t* outlength, const unsigned char* chunk) { - unsigned i; - unsigned total_chunk_length = lodepng_chunk_length(chunk) + 12; - unsigned char *chunk_start, *new_buffer; - size_t new_length = (*outlength) + total_chunk_length; - if(new_length < total_chunk_length || new_length < (*outlength)) return 77; /*integer overflow happened*/ - - new_buffer = (unsigned char*)lodepng_realloc(*out, new_length); - if(!new_buffer) return 83; /*alloc fail*/ - (*out) = new_buffer; - (*outlength) = new_length; - chunk_start = &(*out)[new_length - total_chunk_length]; - - for(i = 0; i != total_chunk_length; ++i) chunk_start[i] = chunk[i]; - - return 0; -} - -unsigned lodepng_chunk_create(unsigned char** out, size_t* outlength, unsigned length, - const char* type, const unsigned char* data) { - unsigned i; - unsigned char *chunk, *new_buffer; - size_t new_length = (*outlength) + length + 12; - if(new_length < length + 12 || new_length < (*outlength)) return 77; /*integer overflow happened*/ - new_buffer = (unsigned char*)lodepng_realloc(*out, new_length); - if(!new_buffer) return 83; /*alloc fail*/ - (*out) = new_buffer; - (*outlength) = new_length; - chunk = &(*out)[(*outlength) - length - 12]; - - /*1: length*/ - lodepng_set32bitInt(chunk, (unsigned)length); - - /*2: chunk name (4 letters)*/ - chunk[4] = (unsigned char)type[0]; - chunk[5] = (unsigned char)type[1]; - chunk[6] = (unsigned char)type[2]; - chunk[7] = (unsigned char)type[3]; - - /*3: the data*/ - for(i = 0; i != length; ++i) chunk[8 + i] = data[i]; - - /*4: CRC (of the chunkname characters and the data)*/ - lodepng_chunk_generate_crc(chunk); - - return 0; -} - -/* ////////////////////////////////////////////////////////////////////////// */ -/* / Color types and such / */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/*return type is a LodePNG error code*/ -static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd) /*bd = bitdepth*/ { - switch(colortype) { - case 0: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break; /*grey*/ - case 2: if(!( bd == 8 || bd == 16)) return 37; break; /*RGB*/ - case 3: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 )) return 37; break; /*palette*/ - case 4: if(!( bd == 8 || bd == 16)) return 37; break; /*grey + alpha*/ - case 6: if(!( bd == 8 || bd == 16)) return 37; break; /*RGBA*/ - default: return 31; - } - return 0; /*allowed color type / bits combination*/ -} - -static unsigned getNumColorChannels(LodePNGColorType colortype) { - switch(colortype) { - case 0: return 1; /*grey*/ - case 2: return 3; /*RGB*/ - case 3: return 1; /*palette*/ - case 4: return 2; /*grey + alpha*/ - case 6: return 4; /*RGBA*/ - } - return 0; /*unexisting color type*/ -} - -static unsigned lodepng_get_bpp_lct(LodePNGColorType colortype, unsigned bitdepth) { - /*bits per pixel is amount of channels * bits per channel*/ - return getNumColorChannels(colortype) * bitdepth; -} - -/* ////////////////////////////////////////////////////////////////////////// */ - -void lodepng_color_mode_init(LodePNGColorMode* info) { - info->key_defined = 0; - info->key_r = info->key_g = info->key_b = 0; - info->colortype = LCT_RGBA; - info->bitdepth = 8; - info->palette = 0; - info->palettesize = 0; -} - -void lodepng_color_mode_cleanup(LodePNGColorMode* info) { - lodepng_palette_clear(info); -} - -unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source) { - size_t i; - lodepng_color_mode_cleanup(dest); - *dest = *source; - if(source->palette) { - dest->palette = (unsigned char*)lodepng_malloc(1024); - if(!dest->palette && source->palettesize) return 83; /*alloc fail*/ - for(i = 0; i != source->palettesize * 4; ++i) dest->palette[i] = source->palette[i]; - } - return 0; -} - -LodePNGColorMode lodepng_color_mode_make(LodePNGColorType colortype, unsigned bitdepth) { - LodePNGColorMode result; - lodepng_color_mode_init(&result); - result.colortype = colortype; - result.bitdepth = bitdepth; - return result; -} - -static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b) { - size_t i; - if(a->colortype != b->colortype) return 0; - if(a->bitdepth != b->bitdepth) return 0; - if(a->key_defined != b->key_defined) return 0; - if(a->key_defined) { - if(a->key_r != b->key_r) return 0; - if(a->key_g != b->key_g) return 0; - if(a->key_b != b->key_b) return 0; - } - if(a->palettesize != b->palettesize) return 0; - for(i = 0; i != a->palettesize * 4; ++i) { - if(a->palette[i] != b->palette[i]) return 0; - } - return 1; -} - -void lodepng_palette_clear(LodePNGColorMode* info) { - if(info->palette) lodepng_free(info->palette); - info->palette = 0; - info->palettesize = 0; -} - -unsigned lodepng_palette_add(LodePNGColorMode* info, - unsigned char r, unsigned char g, unsigned char b, unsigned char a) { - unsigned char* data; - /*the same resize technique as C++ std::vectors is used, and here it's made so that for a palette with - the max of 256 colors, it'll have the exact alloc size*/ - if(!info->palette) /*allocate palette if empty*/ { - /*room for 256 colors with 4 bytes each*/ - data = (unsigned char*)lodepng_realloc(info->palette, 1024); - if(!data) return 83; /*alloc fail*/ - else info->palette = data; - } - info->palette[4 * info->palettesize + 0] = r; - info->palette[4 * info->palettesize + 1] = g; - info->palette[4 * info->palettesize + 2] = b; - info->palette[4 * info->palettesize + 3] = a; - ++info->palettesize; - return 0; -} - -/*calculate bits per pixel out of colortype and bitdepth*/ -unsigned lodepng_get_bpp(const LodePNGColorMode* info) { - return lodepng_get_bpp_lct(info->colortype, info->bitdepth); -} - -unsigned lodepng_get_channels(const LodePNGColorMode* info) { - return getNumColorChannels(info->colortype); -} - -unsigned lodepng_is_greyscale_type(const LodePNGColorMode* info) { - return info->colortype == LCT_GREY || info->colortype == LCT_GREY_ALPHA; -} - -unsigned lodepng_is_alpha_type(const LodePNGColorMode* info) { - return (info->colortype & 4) != 0; /*4 or 6*/ -} - -unsigned lodepng_is_palette_type(const LodePNGColorMode* info) { - return info->colortype == LCT_PALETTE; -} - -unsigned lodepng_has_palette_alpha(const LodePNGColorMode* info) { - size_t i; - for(i = 0; i != info->palettesize; ++i) { - if(info->palette[i * 4 + 3] < 255) return 1; - } - return 0; -} - -unsigned lodepng_can_have_alpha(const LodePNGColorMode* info) { - return info->key_defined - || lodepng_is_alpha_type(info) - || lodepng_has_palette_alpha(info); -} - -size_t lodepng_get_raw_size_lct(unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) { - size_t bpp = lodepng_get_bpp_lct(colortype, bitdepth); - size_t n = (size_t)w * (size_t)h; - return ((n / 8) * bpp) + ((n & 7) * bpp + 7) / 8; -} - -size_t lodepng_get_raw_size(unsigned w, unsigned h, const LodePNGColorMode* color) { - return lodepng_get_raw_size_lct(w, h, color->colortype, color->bitdepth); -} - - -#ifdef LODEPNG_COMPILE_PNG -#ifdef LODEPNG_COMPILE_DECODER - -/*in an idat chunk, each scanline is a multiple of 8 bits, unlike the lodepng output buffer, -and in addition has one extra byte per line: the filter byte. So this gives a larger -result than lodepng_get_raw_size. */ -static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, const LodePNGColorMode* color) { - size_t bpp = lodepng_get_bpp(color); - /* + 1 for the filter byte, and possibly plus padding bits per line */ - size_t line = ((size_t)(w / 8) * bpp) + 1 + ((w & 7) * bpp + 7) / 8; - return (size_t)h * line; -} - -/* Safely check if multiplying two integers will overflow (no undefined -behavior, compiler removing the code, etc...) and output result. */ -static int lodepng_mulofl(size_t a, size_t b, size_t* result) { - *result = a * b; /* Unsigned multiplication is well defined and safe in C90 */ - return (a != 0 && *result / a != b); -} - -/* Safely check if adding two integers will overflow (no undefined -behavior, compiler removing the code, etc...) and output result. */ -static int lodepng_addofl(size_t a, size_t b, size_t* result) { - *result = a + b; /* Unsigned addition is well defined and safe in C90 */ - return *result < a; -} - -/*Safely checks whether size_t overflow can be caused due to amount of pixels. -This check is overcautious rather than precise. If this check indicates no overflow, -you can safely compute in a size_t (but not an unsigned): --(size_t)w * (size_t)h * 8 --amount of bytes in IDAT (including filter, padding and Adam7 bytes) --amount of bytes in raw color model -Returns 1 if overflow possible, 0 if not. -*/ -static int lodepng_pixel_overflow(unsigned w, unsigned h, - const LodePNGColorMode* pngcolor, const LodePNGColorMode* rawcolor) { - size_t bpp = LODEPNG_MAX(lodepng_get_bpp(pngcolor), lodepng_get_bpp(rawcolor)); - size_t numpixels, total; - size_t line; /* bytes per line in worst case */ - - if(lodepng_mulofl((size_t)w, (size_t)h, &numpixels)) return 1; - if(lodepng_mulofl(numpixels, 8, &total)) return 1; /* bit pointer with 8-bit color, or 8 bytes per channel color */ - - /* Bytes per scanline with the expression "(w / 8) * bpp) + ((w & 7) * bpp + 7) / 8" */ - if(lodepng_mulofl((size_t)(w / 8), bpp, &line)) return 1; - if(lodepng_addofl(line, ((w & 7) * bpp + 7) / 8, &line)) return 1; - - if(lodepng_addofl(line, 5, &line)) return 1; /* 5 bytes overhead per line: 1 filterbyte, 4 for Adam7 worst case */ - if(lodepng_mulofl(line, h, &total)) return 1; /* Total bytes in worst case */ - - return 0; /* no overflow */ -} -#endif /*LODEPNG_COMPILE_DECODER*/ -#endif /*LODEPNG_COMPILE_PNG*/ - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - -static void LodePNGUnknownChunks_init(LodePNGInfo* info) { - unsigned i; - for(i = 0; i != 3; ++i) info->unknown_chunks_data[i] = 0; - for(i = 0; i != 3; ++i) info->unknown_chunks_size[i] = 0; -} - -static void LodePNGUnknownChunks_cleanup(LodePNGInfo* info) { - unsigned i; - for(i = 0; i != 3; ++i) lodepng_free(info->unknown_chunks_data[i]); -} - -static unsigned LodePNGUnknownChunks_copy(LodePNGInfo* dest, const LodePNGInfo* src) { - unsigned i; - - LodePNGUnknownChunks_cleanup(dest); - - for(i = 0; i != 3; ++i) { - size_t j; - dest->unknown_chunks_size[i] = src->unknown_chunks_size[i]; - dest->unknown_chunks_data[i] = (unsigned char*)lodepng_malloc(src->unknown_chunks_size[i]); - if(!dest->unknown_chunks_data[i] && dest->unknown_chunks_size[i]) return 83; /*alloc fail*/ - for(j = 0; j < src->unknown_chunks_size[i]; ++j) { - dest->unknown_chunks_data[i][j] = src->unknown_chunks_data[i][j]; - } - } - - return 0; -} - -/******************************************************************************/ - -static void LodePNGText_init(LodePNGInfo* info) { - info->text_num = 0; - info->text_keys = NULL; - info->text_strings = NULL; -} - -static void LodePNGText_cleanup(LodePNGInfo* info) { - size_t i; - for(i = 0; i != info->text_num; ++i) { - string_cleanup(&info->text_keys[i]); - string_cleanup(&info->text_strings[i]); - } - lodepng_free(info->text_keys); - lodepng_free(info->text_strings); -} - -static unsigned LodePNGText_copy(LodePNGInfo* dest, const LodePNGInfo* source) { - size_t i = 0; - dest->text_keys = 0; - dest->text_strings = 0; - dest->text_num = 0; - for(i = 0; i != source->text_num; ++i) { - CERROR_TRY_RETURN(lodepng_add_text(dest, source->text_keys[i], source->text_strings[i])); - } - return 0; -} - -void lodepng_clear_text(LodePNGInfo* info) { - LodePNGText_cleanup(info); -} - -unsigned lodepng_add_text(LodePNGInfo* info, const char* key, const char* str) { - char** new_keys = (char**)(lodepng_realloc(info->text_keys, sizeof(char*) * (info->text_num + 1))); - char** new_strings = (char**)(lodepng_realloc(info->text_strings, sizeof(char*) * (info->text_num + 1))); - if(!new_keys || !new_strings) { - lodepng_free(new_keys); - lodepng_free(new_strings); - return 83; /*alloc fail*/ - } - - ++info->text_num; - info->text_keys = new_keys; - info->text_strings = new_strings; - - info->text_keys[info->text_num - 1] = alloc_string(key); - info->text_strings[info->text_num - 1] = alloc_string(str); - - return 0; -} - -/******************************************************************************/ - -static void LodePNGIText_init(LodePNGInfo* info) { - info->itext_num = 0; - info->itext_keys = NULL; - info->itext_langtags = NULL; - info->itext_transkeys = NULL; - info->itext_strings = NULL; -} - -static void LodePNGIText_cleanup(LodePNGInfo* info) { - size_t i; - for(i = 0; i != info->itext_num; ++i) { - string_cleanup(&info->itext_keys[i]); - string_cleanup(&info->itext_langtags[i]); - string_cleanup(&info->itext_transkeys[i]); - string_cleanup(&info->itext_strings[i]); - } - lodepng_free(info->itext_keys); - lodepng_free(info->itext_langtags); - lodepng_free(info->itext_transkeys); - lodepng_free(info->itext_strings); -} - -static unsigned LodePNGIText_copy(LodePNGInfo* dest, const LodePNGInfo* source) { - size_t i = 0; - dest->itext_keys = 0; - dest->itext_langtags = 0; - dest->itext_transkeys = 0; - dest->itext_strings = 0; - dest->itext_num = 0; - for(i = 0; i != source->itext_num; ++i) { - CERROR_TRY_RETURN(lodepng_add_itext(dest, source->itext_keys[i], source->itext_langtags[i], - source->itext_transkeys[i], source->itext_strings[i])); - } - return 0; -} - -void lodepng_clear_itext(LodePNGInfo* info) { - LodePNGIText_cleanup(info); -} - -unsigned lodepng_add_itext(LodePNGInfo* info, const char* key, const char* langtag, - const char* transkey, const char* str) { - char** new_keys = (char**)(lodepng_realloc(info->itext_keys, sizeof(char*) * (info->itext_num + 1))); - char** new_langtags = (char**)(lodepng_realloc(info->itext_langtags, sizeof(char*) * (info->itext_num + 1))); - char** new_transkeys = (char**)(lodepng_realloc(info->itext_transkeys, sizeof(char*) * (info->itext_num + 1))); - char** new_strings = (char**)(lodepng_realloc(info->itext_strings, sizeof(char*) * (info->itext_num + 1))); - if(!new_keys || !new_langtags || !new_transkeys || !new_strings) { - lodepng_free(new_keys); - lodepng_free(new_langtags); - lodepng_free(new_transkeys); - lodepng_free(new_strings); - return 83; /*alloc fail*/ - } - - ++info->itext_num; - info->itext_keys = new_keys; - info->itext_langtags = new_langtags; - info->itext_transkeys = new_transkeys; - info->itext_strings = new_strings; - - info->itext_keys[info->itext_num - 1] = alloc_string(key); - info->itext_langtags[info->itext_num - 1] = alloc_string(langtag); - info->itext_transkeys[info->itext_num - 1] = alloc_string(transkey); - info->itext_strings[info->itext_num - 1] = alloc_string(str); - - return 0; -} - -/* same as set but does not delete */ -static unsigned lodepng_assign_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size) { - info->iccp_name = alloc_string(name); - info->iccp_profile = (unsigned char*)lodepng_malloc(profile_size); - - if(!info->iccp_name || !info->iccp_profile) return 83; /*alloc fail*/ - - memcpy(info->iccp_profile, profile, profile_size); - info->iccp_profile_size = profile_size; - - return 0; /*ok*/ -} - -unsigned lodepng_set_icc(LodePNGInfo* info, const char* name, const unsigned char* profile, unsigned profile_size) { - if(info->iccp_name) lodepng_clear_icc(info); - - return lodepng_assign_icc(info, name, profile, profile_size); -} - -void lodepng_clear_icc(LodePNGInfo* info) { - string_cleanup(&info->iccp_name); - lodepng_free(info->iccp_profile); - info->iccp_profile = NULL; - info->iccp_profile_size = 0; -} -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -void lodepng_info_init(LodePNGInfo* info) { - lodepng_color_mode_init(&info->color); - info->interlace_method = 0; - info->compression_method = 0; - info->filter_method = 0; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - info->background_defined = 0; - info->background_r = info->background_g = info->background_b = 0; - - LodePNGText_init(info); - LodePNGIText_init(info); - - info->time_defined = 0; - info->phys_defined = 0; - - info->gama_defined = 0; - info->chrm_defined = 0; - info->srgb_defined = 0; - info->iccp_defined = 0; - info->iccp_name = NULL; - info->iccp_profile = NULL; - - LodePNGUnknownChunks_init(info); -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -} - -void lodepng_info_cleanup(LodePNGInfo* info) { - lodepng_color_mode_cleanup(&info->color); -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - LodePNGText_cleanup(info); - LodePNGIText_cleanup(info); - - lodepng_clear_icc(info); - - LodePNGUnknownChunks_cleanup(info); -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ -} - -unsigned lodepng_info_copy(LodePNGInfo* dest, const LodePNGInfo* source) { - lodepng_info_cleanup(dest); - *dest = *source; - lodepng_color_mode_init(&dest->color); - CERROR_TRY_RETURN(lodepng_color_mode_copy(&dest->color, &source->color)); - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - CERROR_TRY_RETURN(LodePNGText_copy(dest, source)); - CERROR_TRY_RETURN(LodePNGIText_copy(dest, source)); - if(source->iccp_defined) { - CERROR_TRY_RETURN(lodepng_assign_icc(dest, source->iccp_name, source->iccp_profile, source->iccp_profile_size)); - } - - LodePNGUnknownChunks_init(dest); - CERROR_TRY_RETURN(LodePNGUnknownChunks_copy(dest, source)); -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - return 0; -} - -/* ////////////////////////////////////////////////////////////////////////// */ - -/*index: bitgroup index, bits: bitgroup size(1, 2 or 4), in: bitgroup value, out: octet array to add bits to*/ -static void addColorBits(unsigned char* out, size_t index, unsigned bits, unsigned in) { - unsigned m = bits == 1 ? 7 : bits == 2 ? 3 : 1; /*8 / bits - 1*/ - /*p = the partial index in the byte, e.g. with 4 palettebits it is 0 for first half or 1 for second half*/ - unsigned p = index & m; - in &= (1u << bits) - 1u; /*filter out any other bits of the input value*/ - in = in << (bits * (m - p)); - if(p == 0) out[index * bits / 8] = in; - else out[index * bits / 8] |= in; -} - -typedef struct ColorTree ColorTree; - -/* -One node of a color tree -This is the data structure used to count the number of unique colors and to get a palette -index for a color. It's like an octree, but because the alpha channel is used too, each -node has 16 instead of 8 children. -*/ -struct ColorTree { - ColorTree* children[16]; /*up to 16 pointers to ColorTree of next level*/ - int index; /*the payload. Only has a meaningful value if this is in the last level*/ -}; - -static void color_tree_init(ColorTree* tree) { - int i; - for(i = 0; i != 16; ++i) tree->children[i] = 0; - tree->index = -1; -} - -static void color_tree_cleanup(ColorTree* tree) { - int i; - for(i = 0; i != 16; ++i) { - if(tree->children[i]) { - color_tree_cleanup(tree->children[i]); - lodepng_free(tree->children[i]); - } - } -} - -/*returns -1 if color not present, its index otherwise*/ -static int color_tree_get(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) { - int bit = 0; - for(bit = 0; bit < 8; ++bit) { - int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1); - if(!tree->children[i]) return -1; - else tree = tree->children[i]; - } - return tree ? tree->index : -1; -} - -#ifdef LODEPNG_COMPILE_ENCODER -static int color_tree_has(ColorTree* tree, unsigned char r, unsigned char g, unsigned char b, unsigned char a) { - return color_tree_get(tree, r, g, b, a) >= 0; -} -#endif /*LODEPNG_COMPILE_ENCODER*/ - -/*color is not allowed to already exist. -Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")*/ -static void color_tree_add(ColorTree* tree, - unsigned char r, unsigned char g, unsigned char b, unsigned char a, unsigned index) { - int bit; - for(bit = 0; bit < 8; ++bit) { - int i = 8 * ((r >> bit) & 1) + 4 * ((g >> bit) & 1) + 2 * ((b >> bit) & 1) + 1 * ((a >> bit) & 1); - if(!tree->children[i]) { - tree->children[i] = (ColorTree*)lodepng_malloc(sizeof(ColorTree)); - color_tree_init(tree->children[i]); - } - tree = tree->children[i]; - } - tree->index = (int)index; -} - -/*put a pixel, given its RGBA color, into image of any color type*/ -static unsigned rgba8ToPixel(unsigned char* out, size_t i, - const LodePNGColorMode* mode, ColorTree* tree /*for palette*/, - unsigned char r, unsigned char g, unsigned char b, unsigned char a) { - if(mode->colortype == LCT_GREY) { - unsigned char grey = r; /*((unsigned short)r + g + b) / 3;*/ - if(mode->bitdepth == 8) out[i] = grey; - else if(mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = grey; - else { - /*take the most significant bits of grey*/ - grey = (grey >> (8 - mode->bitdepth)) & ((1 << mode->bitdepth) - 1); - addColorBits(out, i, mode->bitdepth, grey); - } - } else if(mode->colortype == LCT_RGB) { - if(mode->bitdepth == 8) { - out[i * 3 + 0] = r; - out[i * 3 + 1] = g; - out[i * 3 + 2] = b; - } else { - out[i * 6 + 0] = out[i * 6 + 1] = r; - out[i * 6 + 2] = out[i * 6 + 3] = g; - out[i * 6 + 4] = out[i * 6 + 5] = b; - } - } else if(mode->colortype == LCT_PALETTE) { - int index = color_tree_get(tree, r, g, b, a); - if(index < 0) return 82; /*color not in palette*/ - if(mode->bitdepth == 8) out[i] = index; - else addColorBits(out, i, mode->bitdepth, (unsigned)index); - } else if(mode->colortype == LCT_GREY_ALPHA) { - unsigned char grey = r; /*((unsigned short)r + g + b) / 3;*/ - if(mode->bitdepth == 8) { - out[i * 2 + 0] = grey; - out[i * 2 + 1] = a; - } else if(mode->bitdepth == 16) { - out[i * 4 + 0] = out[i * 4 + 1] = grey; - out[i * 4 + 2] = out[i * 4 + 3] = a; - } - } else if(mode->colortype == LCT_RGBA) { - if(mode->bitdepth == 8) { - out[i * 4 + 0] = r; - out[i * 4 + 1] = g; - out[i * 4 + 2] = b; - out[i * 4 + 3] = a; - } else { - out[i * 8 + 0] = out[i * 8 + 1] = r; - out[i * 8 + 2] = out[i * 8 + 3] = g; - out[i * 8 + 4] = out[i * 8 + 5] = b; - out[i * 8 + 6] = out[i * 8 + 7] = a; - } - } - - return 0; /*no error*/ -} - -/*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/ -static void rgba16ToPixel(unsigned char* out, size_t i, - const LodePNGColorMode* mode, - unsigned short r, unsigned short g, unsigned short b, unsigned short a) { - if(mode->colortype == LCT_GREY) { - unsigned short grey = r; /*((unsigned)r + g + b) / 3;*/ - out[i * 2 + 0] = (grey >> 8) & 255; - out[i * 2 + 1] = grey & 255; - } else if(mode->colortype == LCT_RGB) { - out[i * 6 + 0] = (r >> 8) & 255; - out[i * 6 + 1] = r & 255; - out[i * 6 + 2] = (g >> 8) & 255; - out[i * 6 + 3] = g & 255; - out[i * 6 + 4] = (b >> 8) & 255; - out[i * 6 + 5] = b & 255; - } else if(mode->colortype == LCT_GREY_ALPHA) { - unsigned short grey = r; /*((unsigned)r + g + b) / 3;*/ - out[i * 4 + 0] = (grey >> 8) & 255; - out[i * 4 + 1] = grey & 255; - out[i * 4 + 2] = (a >> 8) & 255; - out[i * 4 + 3] = a & 255; - } else if(mode->colortype == LCT_RGBA) { - out[i * 8 + 0] = (r >> 8) & 255; - out[i * 8 + 1] = r & 255; - out[i * 8 + 2] = (g >> 8) & 255; - out[i * 8 + 3] = g & 255; - out[i * 8 + 4] = (b >> 8) & 255; - out[i * 8 + 5] = b & 255; - out[i * 8 + 6] = (a >> 8) & 255; - out[i * 8 + 7] = a & 255; - } -} - -/*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/ -static void getPixelColorRGBA8(unsigned char* r, unsigned char* g, - unsigned char* b, unsigned char* a, - const unsigned char* in, size_t i, - const LodePNGColorMode* mode) { - if(mode->colortype == LCT_GREY) { - if(mode->bitdepth == 8) { - *r = *g = *b = in[i]; - if(mode->key_defined && *r == mode->key_r) *a = 0; - else *a = 255; - } else if(mode->bitdepth == 16) { - *r = *g = *b = in[i * 2 + 0]; - if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0; - else *a = 255; - } else { - unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ - size_t j = i * mode->bitdepth; - unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); - *r = *g = *b = (value * 255) / highest; - if(mode->key_defined && value == mode->key_r) *a = 0; - else *a = 255; - } - } else if(mode->colortype == LCT_RGB) { - if(mode->bitdepth == 8) { - *r = in[i * 3 + 0]; *g = in[i * 3 + 1]; *b = in[i * 3 + 2]; - if(mode->key_defined && *r == mode->key_r && *g == mode->key_g && *b == mode->key_b) *a = 0; - else *a = 255; - } else { - *r = in[i * 6 + 0]; - *g = in[i * 6 + 2]; - *b = in[i * 6 + 4]; - if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r - && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g - && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0; - else *a = 255; - } - } else if(mode->colortype == LCT_PALETTE) { - unsigned index; - if(mode->bitdepth == 8) index = in[i]; - else { - size_t j = i * mode->bitdepth; - index = readBitsFromReversedStream(&j, in, mode->bitdepth); - } - - if(index >= mode->palettesize) { - /*This is an error according to the PNG spec, but common PNG decoders make it black instead. - Done here too, slightly faster due to no error handling needed.*/ - *r = *g = *b = 0; - *a = 255; - } else { - *r = mode->palette[index * 4 + 0]; - *g = mode->palette[index * 4 + 1]; - *b = mode->palette[index * 4 + 2]; - *a = mode->palette[index * 4 + 3]; - } - } else if(mode->colortype == LCT_GREY_ALPHA) { - if(mode->bitdepth == 8) { - *r = *g = *b = in[i * 2 + 0]; - *a = in[i * 2 + 1]; - } else { - *r = *g = *b = in[i * 4 + 0]; - *a = in[i * 4 + 2]; - } - } else if(mode->colortype == LCT_RGBA) { - if(mode->bitdepth == 8) { - *r = in[i * 4 + 0]; - *g = in[i * 4 + 1]; - *b = in[i * 4 + 2]; - *a = in[i * 4 + 3]; - } else { - *r = in[i * 8 + 0]; - *g = in[i * 8 + 2]; - *b = in[i * 8 + 4]; - *a = in[i * 8 + 6]; - } - } -} - -/*Similar to getPixelColorRGBA8, but with all the for loops inside of the color -mode test cases, optimized to convert the colors much faster, when converting -to RGBA or RGB with 8 bit per cannel. buffer must be RGBA or RGB output with -enough memory, if has_alpha is true the output is RGBA. mode has the color mode -of the input buffer.*/ -static void getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels, - unsigned has_alpha, const unsigned char* in, - const LodePNGColorMode* mode) { - unsigned num_channels = has_alpha ? 4 : 3; - size_t i; - if(mode->colortype == LCT_GREY) { - if(mode->bitdepth == 8) { - for(i = 0; i != numpixels; ++i, buffer += num_channels) { - buffer[0] = buffer[1] = buffer[2] = in[i]; - if(has_alpha) buffer[3] = mode->key_defined && in[i] == mode->key_r ? 0 : 255; - } - } else if(mode->bitdepth == 16) { - for(i = 0; i != numpixels; ++i, buffer += num_channels) { - buffer[0] = buffer[1] = buffer[2] = in[i * 2]; - if(has_alpha) buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255; - } - } else { - unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ - size_t j = 0; - for(i = 0; i != numpixels; ++i, buffer += num_channels) { - unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); - buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest; - if(has_alpha) buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255; - } - } - } else if(mode->colortype == LCT_RGB) { - if(mode->bitdepth == 8) { - for(i = 0; i != numpixels; ++i, buffer += num_channels) { - buffer[0] = in[i * 3 + 0]; - buffer[1] = in[i * 3 + 1]; - buffer[2] = in[i * 3 + 2]; - if(has_alpha) buffer[3] = mode->key_defined && buffer[0] == mode->key_r - && buffer[1]== mode->key_g && buffer[2] == mode->key_b ? 0 : 255; - } - } else { - for(i = 0; i != numpixels; ++i, buffer += num_channels) { - buffer[0] = in[i * 6 + 0]; - buffer[1] = in[i * 6 + 2]; - buffer[2] = in[i * 6 + 4]; - if(has_alpha) buffer[3] = mode->key_defined - && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r - && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g - && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b ? 0 : 255; - } - } - } else if(mode->colortype == LCT_PALETTE) { - unsigned index; - size_t j = 0; - for(i = 0; i != numpixels; ++i, buffer += num_channels) { - if(mode->bitdepth == 8) index = in[i]; - else index = readBitsFromReversedStream(&j, in, mode->bitdepth); - - if(index >= mode->palettesize) { - /*This is an error according to the PNG spec, but most PNG decoders make it black instead. - Done here too, slightly faster due to no error handling needed.*/ - buffer[0] = buffer[1] = buffer[2] = 0; - if(has_alpha) buffer[3] = 255; - } else { - buffer[0] = mode->palette[index * 4 + 0]; - buffer[1] = mode->palette[index * 4 + 1]; - buffer[2] = mode->palette[index * 4 + 2]; - if(has_alpha) buffer[3] = mode->palette[index * 4 + 3]; - } - } - } else if(mode->colortype == LCT_GREY_ALPHA) { - if(mode->bitdepth == 8) { - for(i = 0; i != numpixels; ++i, buffer += num_channels) { - buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0]; - if(has_alpha) buffer[3] = in[i * 2 + 1]; - } - } else { - for(i = 0; i != numpixels; ++i, buffer += num_channels) { - buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0]; - if(has_alpha) buffer[3] = in[i * 4 + 2]; - } - } - } else if(mode->colortype == LCT_RGBA) { - if(mode->bitdepth == 8) { - for(i = 0; i != numpixels; ++i, buffer += num_channels) { - buffer[0] = in[i * 4 + 0]; - buffer[1] = in[i * 4 + 1]; - buffer[2] = in[i * 4 + 2]; - if(has_alpha) buffer[3] = in[i * 4 + 3]; - } - } else { - for(i = 0; i != numpixels; ++i, buffer += num_channels) { - buffer[0] = in[i * 8 + 0]; - buffer[1] = in[i * 8 + 2]; - buffer[2] = in[i * 8 + 4]; - if(has_alpha) buffer[3] = in[i * 8 + 6]; - } - } - } -} - -/*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with -given color type, but the given color type must be 16-bit itself.*/ -static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a, - const unsigned char* in, size_t i, const LodePNGColorMode* mode) { - if(mode->colortype == LCT_GREY) { - *r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1]; - if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0; - else *a = 65535; - } else if(mode->colortype == LCT_RGB) { - *r = 256u * in[i * 6 + 0] + in[i * 6 + 1]; - *g = 256u * in[i * 6 + 2] + in[i * 6 + 3]; - *b = 256u * in[i * 6 + 4] + in[i * 6 + 5]; - if(mode->key_defined - && 256u * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r - && 256u * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g - && 256u * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0; - else *a = 65535; - } else if(mode->colortype == LCT_GREY_ALPHA) { - *r = *g = *b = 256u * in[i * 4 + 0] + in[i * 4 + 1]; - *a = 256u * in[i * 4 + 2] + in[i * 4 + 3]; - } else if(mode->colortype == LCT_RGBA) { - *r = 256u * in[i * 8 + 0] + in[i * 8 + 1]; - *g = 256u * in[i * 8 + 2] + in[i * 8 + 3]; - *b = 256u * in[i * 8 + 4] + in[i * 8 + 5]; - *a = 256u * in[i * 8 + 6] + in[i * 8 + 7]; - } -} - -unsigned lodepng_convert(unsigned char* out, const unsigned char* in, - const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in, - unsigned w, unsigned h) { - size_t i; - ColorTree tree; - size_t numpixels = (size_t)w * (size_t)h; - unsigned error = 0; - - if(lodepng_color_mode_equal(mode_out, mode_in)) { - size_t numbytes = lodepng_get_raw_size(w, h, mode_in); - for(i = 0; i != numbytes; ++i) out[i] = in[i]; - return 0; - } - - if(mode_out->colortype == LCT_PALETTE) { - size_t palettesize = mode_out->palettesize; - const unsigned char* palette = mode_out->palette; - size_t palsize = (size_t)1u << mode_out->bitdepth; - /*if the user specified output palette but did not give the values, assume - they want the values of the input color type (assuming that one is palette). - Note that we never create a new palette ourselves.*/ - if(palettesize == 0) { - palettesize = mode_in->palettesize; - palette = mode_in->palette; - /*if the input was also palette with same bitdepth, then the color types are also - equal, so copy literally. This to preserve the exact indices that were in the PNG - even in case there are duplicate colors in the palette.*/ - if (mode_in->colortype == LCT_PALETTE && mode_in->bitdepth == mode_out->bitdepth) { - size_t numbytes = lodepng_get_raw_size(w, h, mode_in); - for(i = 0; i != numbytes; ++i) out[i] = in[i]; - return 0; - } - } - if(palettesize < palsize) palsize = palettesize; - color_tree_init(&tree); - for(i = 0; i != palsize; ++i) { - const unsigned char* p = &palette[i * 4]; - color_tree_add(&tree, p[0], p[1], p[2], p[3], (unsigned)i); - } - } - - if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16) { - for(i = 0; i != numpixels; ++i) { - unsigned short r = 0, g = 0, b = 0, a = 0; - getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); - rgba16ToPixel(out, i, mode_out, r, g, b, a); - } - } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA) { - getPixelColorsRGBA8(out, numpixels, 1, in, mode_in); - } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) { - getPixelColorsRGBA8(out, numpixels, 0, in, mode_in); - } else { - unsigned char r = 0, g = 0, b = 0, a = 0; - for(i = 0; i != numpixels; ++i) { - getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in); - error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a); - if (error) break; - } - } - - if(mode_out->colortype == LCT_PALETTE) { - color_tree_cleanup(&tree); - } - - return error; -} - - -/* Converts a single rgb color without alpha from one type to another, color bits truncated to -their bitdepth. In case of single channel (grey or palette), only the r channel is used. Slow -function, do not use to process all pixels of an image. Alpha channel not supported on purpose: -this is for bKGD, supporting alpha may prevent it from finding a color in the palette, from the -specification it looks like bKGD should ignore the alpha values of the palette since it can use -any palette index but doesn't have an alpha channel. Idem with ignoring color key. */ -unsigned lodepng_convert_rgb( - unsigned* r_out, unsigned* g_out, unsigned* b_out, - unsigned r_in, unsigned g_in, unsigned b_in, - const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in) { - unsigned r = 0, g = 0, b = 0; - unsigned mul = 65535 / ((1u << mode_in->bitdepth) - 1u); /*65535, 21845, 4369, 257, 1*/ - unsigned shift = 16 - mode_out->bitdepth; - - if(mode_in->colortype == LCT_GREY || mode_in->colortype == LCT_GREY_ALPHA) { - r = g = b = r_in * mul; - } else if(mode_in->colortype == LCT_RGB || mode_in->colortype == LCT_RGBA) { - r = r_in * mul; - g = g_in * mul; - b = b_in * mul; - } else if(mode_in->colortype == LCT_PALETTE) { - if(r_in >= mode_in->palettesize) return 82; - r = mode_in->palette[r_in * 4 + 0] * 257u; - g = mode_in->palette[r_in * 4 + 1] * 257u; - b = mode_in->palette[r_in * 4 + 2] * 257u; - } else { - return 31; - } - - /* now convert to output format */ - if(mode_out->colortype == LCT_GREY || mode_out->colortype == LCT_GREY_ALPHA) { - *r_out = r >> shift ; - } else if(mode_out->colortype == LCT_RGB || mode_out->colortype == LCT_RGBA) { - *r_out = r >> shift ; - *g_out = g >> shift ; - *b_out = b >> shift ; - } else if(mode_out->colortype == LCT_PALETTE) { - unsigned i; - /* a 16-bit color cannot be in the palette */ - if((r >> 8) != (r & 255) || (g >> 8) != (g & 255) || (b >> 8) != (b & 255)) return 82; - for(i = 0; i < mode_out->palettesize; i++) { - unsigned j = i * 4; - if((r >> 8) == mode_out->palette[j + 0] && (g >> 8) == mode_out->palette[j + 1] && - (b >> 8) == mode_out->palette[j + 2]) { - *r_out = i; - return 0; - } - } - return 82; - } else { - return 31; - } - - return 0; -} - -#ifdef LODEPNG_COMPILE_ENCODER - -void lodepng_color_profile_init(LodePNGColorProfile* profile) { - profile->colored = 0; - profile->key = 0; - profile->key_r = profile->key_g = profile->key_b = 0; - profile->alpha = 0; - profile->numcolors = 0; - profile->bits = 1; - profile->numpixels = 0; -} - -/*function used for debug purposes with C++*/ -/*void printColorProfile(LodePNGColorProfile* p) { - std::cout << "colored: " << (int)p->colored << ", "; - std::cout << "key: " << (int)p->key << ", "; - std::cout << "key_r: " << (int)p->key_r << ", "; - std::cout << "key_g: " << (int)p->key_g << ", "; - std::cout << "key_b: " << (int)p->key_b << ", "; - std::cout << "alpha: " << (int)p->alpha << ", "; - std::cout << "numcolors: " << (int)p->numcolors << ", "; - std::cout << "bits: " << (int)p->bits << std::endl; -}*/ - -/*Returns how many bits needed to represent given value (max 8 bit)*/ -static unsigned getValueRequiredBits(unsigned char value) { - if(value == 0 || value == 255) return 1; - /*The scaling of 2-bit and 4-bit values uses multiples of 85 and 17*/ - if(value % 17 == 0) return value % 85 == 0 ? 2 : 4; - return 8; -} - -/*profile must already have been inited. -It's ok to set some parameters of profile to done already.*/ -unsigned lodepng_get_color_profile(LodePNGColorProfile* profile, - const unsigned char* in, unsigned w, unsigned h, - const LodePNGColorMode* mode_in) { - unsigned error = 0; - size_t i; - ColorTree tree; - size_t numpixels = (size_t)w * (size_t)h; - - /* mark things as done already if it would be impossible to have a more expensive case */ - unsigned colored_done = lodepng_is_greyscale_type(mode_in) ? 1 : 0; - unsigned alpha_done = lodepng_can_have_alpha(mode_in) ? 0 : 1; - unsigned numcolors_done = 0; - unsigned bpp = lodepng_get_bpp(mode_in); - unsigned bits_done = (profile->bits == 1 && bpp == 1) ? 1 : 0; - unsigned sixteen = 0; /* whether the input image is 16 bit */ - unsigned maxnumcolors = 257; - if(bpp <= 8) maxnumcolors = LODEPNG_MIN(257, profile->numcolors + (1u << bpp)); - - profile->numpixels += numpixels; - - color_tree_init(&tree); - - /*If the profile was already filled in from previous data, fill its palette in tree - and mark things as done already if we know they are the most expensive case already*/ - if(profile->alpha) alpha_done = 1; - if(profile->colored) colored_done = 1; - if(profile->bits == 16) numcolors_done = 1; - if(profile->bits >= bpp) bits_done = 1; - if(profile->numcolors >= maxnumcolors) numcolors_done = 1; - - if(!numcolors_done) { - for(i = 0; i < profile->numcolors; i++) { - const unsigned char* color = &profile->palette[i * 4]; - color_tree_add(&tree, color[0], color[1], color[2], color[3], i); - } - } - - /*Check if the 16-bit input is truly 16-bit*/ - if(mode_in->bitdepth == 16 && !sixteen) { - unsigned short r, g, b, a; - for(i = 0; i != numpixels; ++i) { - getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); - if((r & 255) != ((r >> 8) & 255) || (g & 255) != ((g >> 8) & 255) || - (b & 255) != ((b >> 8) & 255) || (a & 255) != ((a >> 8) & 255)) /*first and second byte differ*/ { - profile->bits = 16; - sixteen = 1; - bits_done = 1; - numcolors_done = 1; /*counting colors no longer useful, palette doesn't support 16-bit*/ - break; - } - } - } - - if(sixteen) { - unsigned short r = 0, g = 0, b = 0, a = 0; - - for(i = 0; i != numpixels; ++i) { - getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); - - if(!colored_done && (r != g || r != b)) { - profile->colored = 1; - colored_done = 1; - } - - if(!alpha_done) { - unsigned matchkey = (r == profile->key_r && g == profile->key_g && b == profile->key_b); - if(a != 65535 && (a != 0 || (profile->key && !matchkey))) { - profile->alpha = 1; - profile->key = 0; - alpha_done = 1; - } else if(a == 0 && !profile->alpha && !profile->key) { - profile->key = 1; - profile->key_r = r; - profile->key_g = g; - profile->key_b = b; - } else if(a == 65535 && profile->key && matchkey) { - /* Color key cannot be used if an opaque pixel also has that RGB color. */ - profile->alpha = 1; - profile->key = 0; - alpha_done = 1; - } - } - if(alpha_done && numcolors_done && colored_done && bits_done) break; - } - - if(profile->key && !profile->alpha) { - for(i = 0; i != numpixels; ++i) { - getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); - if(a != 0 && r == profile->key_r && g == profile->key_g && b == profile->key_b) { - /* Color key cannot be used if an opaque pixel also has that RGB color. */ - profile->alpha = 1; - profile->key = 0; - alpha_done = 1; - } - } - } - } else /* < 16-bit */ { - unsigned char r = 0, g = 0, b = 0, a = 0; - for(i = 0; i != numpixels; ++i) { - getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in); - - if(!bits_done && profile->bits < 8) { - /*only r is checked, < 8 bits is only relevant for greyscale*/ - unsigned bits = getValueRequiredBits(r); - if(bits > profile->bits) profile->bits = bits; - } - bits_done = (profile->bits >= bpp); - - if(!colored_done && (r != g || r != b)) { - profile->colored = 1; - colored_done = 1; - if(profile->bits < 8) profile->bits = 8; /*PNG has no colored modes with less than 8-bit per channel*/ - } - - if(!alpha_done) { - unsigned matchkey = (r == profile->key_r && g == profile->key_g && b == profile->key_b); - if(a != 255 && (a != 0 || (profile->key && !matchkey))) { - profile->alpha = 1; - profile->key = 0; - alpha_done = 1; - if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ - } else if(a == 0 && !profile->alpha && !profile->key) { - profile->key = 1; - profile->key_r = r; - profile->key_g = g; - profile->key_b = b; - } else if(a == 255 && profile->key && matchkey) { - /* Color key cannot be used if an opaque pixel also has that RGB color. */ - profile->alpha = 1; - profile->key = 0; - alpha_done = 1; - if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ - } - } - - if(!numcolors_done) { - if(!color_tree_has(&tree, r, g, b, a)) { - color_tree_add(&tree, r, g, b, a, profile->numcolors); - if(profile->numcolors < 256) { - unsigned char* p = profile->palette; - unsigned n = profile->numcolors; - p[n * 4 + 0] = r; - p[n * 4 + 1] = g; - p[n * 4 + 2] = b; - p[n * 4 + 3] = a; - } - ++profile->numcolors; - numcolors_done = profile->numcolors >= maxnumcolors; - } - } - - if(alpha_done && numcolors_done && colored_done && bits_done) break; - } - - if(profile->key && !profile->alpha) { - for(i = 0; i != numpixels; ++i) { - getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in); - if(a != 0 && r == profile->key_r && g == profile->key_g && b == profile->key_b) { - /* Color key cannot be used if an opaque pixel also has that RGB color. */ - profile->alpha = 1; - profile->key = 0; - alpha_done = 1; - if(profile->bits < 8) profile->bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ - } - } - } - - /*make the profile's key always 16-bit for consistency - repeat each byte twice*/ - profile->key_r += (profile->key_r << 8); - profile->key_g += (profile->key_g << 8); - profile->key_b += (profile->key_b << 8); - } - - color_tree_cleanup(&tree); - return error; -} - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -/*Adds a single color to the color profile. The profile must already have been inited. The color must be given as 16-bit -(with 2 bytes repeating for 8-bit and 65535 for opaque alpha channel). This function is expensive, do not call it for -all pixels of an image but only for a few additional values. */ -static unsigned lodepng_color_profile_add(LodePNGColorProfile* profile, - unsigned r, unsigned g, unsigned b, unsigned a) { - unsigned error = 0; - unsigned char image[8]; - LodePNGColorMode mode; - lodepng_color_mode_init(&mode); - image[0] = r >> 8; image[1] = r; image[2] = g >> 8; image[3] = g; - image[4] = b >> 8; image[5] = b; image[6] = a >> 8; image[7] = a; - mode.bitdepth = 16; - mode.colortype = LCT_RGBA; - error = lodepng_get_color_profile(profile, image, 1, 1, &mode); - lodepng_color_mode_cleanup(&mode); - return error; -} -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -/*Autochoose color model given the computed profile. mode_in is to copy palette order from -when relevant.*/ -static unsigned auto_choose_color_from_profile(LodePNGColorMode* mode_out, - const LodePNGColorMode* mode_in, - const LodePNGColorProfile* prof) { - unsigned error = 0; - unsigned palettebits, palette_ok; - size_t i, n; - size_t numpixels = prof->numpixels; - - unsigned alpha = prof->alpha; - unsigned key = prof->key; - unsigned bits = prof->bits; - - mode_out->key_defined = 0; - - if(key && numpixels <= 16) { - alpha = 1; /*too few pixels to justify tRNS chunk overhead*/ - key = 0; - if(bits < 8) bits = 8; /*PNG has no alphachannel modes with less than 8-bit per channel*/ - } - n = prof->numcolors; - palettebits = n <= 2 ? 1 : (n <= 4 ? 2 : (n <= 16 ? 4 : 8)); - palette_ok = n <= 256 && bits <= 8; - if(numpixels < n * 2) palette_ok = 0; /*don't add palette overhead if image has only a few pixels*/ - if(!prof->colored && bits <= palettebits) palette_ok = 0; /*grey is less overhead*/ - - if(palette_ok) { - const unsigned char* p = prof->palette; - lodepng_palette_clear(mode_out); /*remove potential earlier palette*/ - for(i = 0; i != prof->numcolors; ++i) { - error = lodepng_palette_add(mode_out, p[i * 4 + 0], p[i * 4 + 1], p[i * 4 + 2], p[i * 4 + 3]); - if(error) break; - } - - mode_out->colortype = LCT_PALETTE; - mode_out->bitdepth = palettebits; - - if(mode_in->colortype == LCT_PALETTE && mode_in->palettesize >= mode_out->palettesize - && mode_in->bitdepth == mode_out->bitdepth) { - /*If input should have same palette colors, keep original to preserve its order and prevent conversion*/ - lodepng_color_mode_cleanup(mode_out); - lodepng_color_mode_copy(mode_out, mode_in); - } - } else /*8-bit or 16-bit per channel*/ { - mode_out->bitdepth = bits; - mode_out->colortype = alpha ? (prof->colored ? LCT_RGBA : LCT_GREY_ALPHA) - : (prof->colored ? LCT_RGB : LCT_GREY); - - if(key) { - unsigned mask = (1u << mode_out->bitdepth) - 1u; /*profile always uses 16-bit, mask converts it*/ - mode_out->key_r = prof->key_r & mask; - mode_out->key_g = prof->key_g & mask; - mode_out->key_b = prof->key_b & mask; - mode_out->key_defined = 1; - } - } - - return error; -} - -/*Automatically chooses color type that gives smallest amount of bits in the -output image, e.g. grey if there are only greyscale pixels, palette if there -are less than 256 colors, color key if only single transparent color, ... -Updates values of mode with a potentially smaller color model. mode_out should -contain the user chosen color model, but will be overwritten with the new chosen one.*/ -unsigned lodepng_auto_choose_color(LodePNGColorMode* mode_out, - const unsigned char* image, unsigned w, unsigned h, - const LodePNGColorMode* mode_in) { - unsigned error = 0; - LodePNGColorProfile prof; - lodepng_color_profile_init(&prof); - error = lodepng_get_color_profile(&prof, image, w, h, mode_in); - if(error) return error; - return auto_choose_color_from_profile(mode_out, mode_in, &prof); -} - -#endif /* #ifdef LODEPNG_COMPILE_ENCODER */ - -/* -Paeth predicter, used by PNG filter type 4 -The parameters are of type short, but should come from unsigned chars, the shorts -are only needed to make the paeth calculation correct. -*/ -static unsigned char paethPredictor(short a, short b, short c) { - short pa = abs(b - c); - short pb = abs(a - c); - short pc = abs(a + b - c - c); - - if(pc < pa && pc < pb) return (unsigned char)c; - else if(pb < pa) return (unsigned char)b; - else return (unsigned char)a; -} - -/*shared values used by multiple Adam7 related functions*/ - -static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/ -static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/ -static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/ -static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/ - -/* -Outputs various dimensions and positions in the image related to the Adam7 reduced images. -passw: output containing the width of the 7 passes -passh: output containing the height of the 7 passes -filter_passstart: output containing the index of the start and end of each - reduced image with filter bytes -padded_passstart output containing the index of the start and end of each - reduced image when without filter bytes but with padded scanlines -passstart: output containing the index of the start and end of each reduced - image without padding between scanlines, but still padding between the images -w, h: width and height of non-interlaced image -bpp: bits per pixel -"padded" is only relevant if bpp is less than 8 and a scanline or image does not - end at a full byte -*/ -static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8], - size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp) { - /*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/ - unsigned i; - - /*calculate width and height in pixels of each pass*/ - for(i = 0; i != 7; ++i) { - passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i]; - passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i]; - if(passw[i] == 0) passh[i] = 0; - if(passh[i] == 0) passw[i] = 0; - } - - filter_passstart[0] = padded_passstart[0] = passstart[0] = 0; - for(i = 0; i != 7; ++i) { - /*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/ - filter_passstart[i + 1] = filter_passstart[i] - + ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0); - /*bits padded if needed to fill full byte at end of each scanline*/ - padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8); - /*only padded at end of reduced image*/ - passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8; - } -} - -#ifdef LODEPNG_COMPILE_DECODER - -/* ////////////////////////////////////////////////////////////////////////// */ -/* / PNG Decoder / */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/*read the information from the header and store it in the LodePNGInfo. return value is error*/ -unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state, - const unsigned char* in, size_t insize) { - unsigned width, height; - LodePNGInfo* info = &state->info_png; - if(insize == 0 || in == 0) { - CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/ - } - if(insize < 33) { - CERROR_RETURN_ERROR(state->error, 27); /*error: the data length is smaller than the length of a PNG header*/ - } - - /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/ - /* TODO: remove this. One should use a new LodePNGState for new sessions */ - lodepng_info_cleanup(info); - lodepng_info_init(info); - - if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71 - || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) { - CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/ - } - if(lodepng_chunk_length(in + 8) != 13) { - CERROR_RETURN_ERROR(state->error, 94); /*error: header size must be 13 bytes*/ - } - if(!lodepng_chunk_type_equals(in + 8, "IHDR")) { - CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/ - } - - /*read the values given in the header*/ - width = lodepng_read32bitInt(&in[16]); - height = lodepng_read32bitInt(&in[20]); - info->color.bitdepth = in[24]; - info->color.colortype = (LodePNGColorType)in[25]; - info->compression_method = in[26]; - info->filter_method = in[27]; - info->interlace_method = in[28]; - - if(width == 0 || height == 0) { - CERROR_RETURN_ERROR(state->error, 93); - } - - if(w) *w = width; - if(h) *h = height; - - if(!state->decoder.ignore_crc) { - unsigned CRC = lodepng_read32bitInt(&in[29]); - unsigned checksum = lodepng_crc32(&in[12], 17); - if(CRC != checksum) { - CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/ - } - } - - /*error: only compression method 0 is allowed in the specification*/ - if(info->compression_method != 0) CERROR_RETURN_ERROR(state->error, 32); - /*error: only filter method 0 is allowed in the specification*/ - if(info->filter_method != 0) CERROR_RETURN_ERROR(state->error, 33); - /*error: only interlace methods 0 and 1 exist in the specification*/ - if(info->interlace_method > 1) CERROR_RETURN_ERROR(state->error, 34); - - state->error = checkColorValidity(info->color.colortype, info->color.bitdepth); - return state->error; -} - -static unsigned unfilterScanline(unsigned char* recon, const unsigned char* scanline, const unsigned char* precon, - size_t bytewidth, unsigned char filterType, size_t length) { - /* - For PNG filter method 0 - unfilter a PNG image scanline by scanline. when the pixels are smaller than 1 byte, - the filter works byte per byte (bytewidth = 1) - precon is the previous unfiltered scanline, recon the result, scanline the current one - the incoming scanlines do NOT include the filtertype byte, that one is given in the parameter filterType instead - recon and scanline MAY be the same memory address! precon must be disjoint. - */ - - size_t i; - switch(filterType) { - case 0: - for(i = 0; i != length; ++i) recon[i] = scanline[i]; - break; - case 1: - for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i]; - for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + recon[i - bytewidth]; - break; - case 2: - if(precon) { - for(i = 0; i != length; ++i) recon[i] = scanline[i] + precon[i]; - } else { - for(i = 0; i != length; ++i) recon[i] = scanline[i]; - } - break; - case 3: - if(precon) { - for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i] + (precon[i] >> 1); - for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) >> 1); - } else { - for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i]; - for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + (recon[i - bytewidth] >> 1); - } - break; - case 4: - if(precon) { - for(i = 0; i != bytewidth; ++i) { - recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/ - } - for(i = bytewidth; i < length; ++i) { - recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth])); - } - } else { - for(i = 0; i != bytewidth; ++i) { - recon[i] = scanline[i]; - } - for(i = bytewidth; i < length; ++i) { - /*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/ - recon[i] = (scanline[i] + recon[i - bytewidth]); - } - } - break; - default: return 36; /*error: unexisting filter type given*/ - } - return 0; -} - -static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) { - /* - For PNG filter method 0 - this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times) - out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline - w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel - in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes) - */ - - unsigned y; - unsigned char* prevline = 0; - - /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ - size_t bytewidth = (bpp + 7) / 8; - size_t linebytes = (w * bpp + 7) / 8; - - for(y = 0; y < h; ++y) { - size_t outindex = linebytes * y; - size_t inindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ - unsigned char filterType = in[inindex]; - - CERROR_TRY_RETURN(unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes)); - - prevline = &out[outindex]; - } - - return 0; -} - -/* -in: Adam7 interlaced image, with no padding bits between scanlines, but between - reduced images so that each reduced image starts at a byte. -out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h -bpp: bits per pixel -out has the following size in bits: w * h * bpp. -in is possibly bigger due to padding bits between reduced images. -out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation -(because that's likely a little bit faster) -NOTE: comments about padding bits are only relevant if bpp < 8 -*/ -static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) { - unsigned passw[7], passh[7]; - size_t filter_passstart[8], padded_passstart[8], passstart[8]; - unsigned i; - - Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); - - if(bpp >= 8) { - for(i = 0; i != 7; ++i) { - unsigned x, y, b; - size_t bytewidth = bpp / 8; - for(y = 0; y < passh[i]; ++y) - for(x = 0; x < passw[i]; ++x) { - size_t pixelinstart = passstart[i] + (y * passw[i] + x) * bytewidth; - size_t pixeloutstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth; - for(b = 0; b < bytewidth; ++b) { - out[pixeloutstart + b] = in[pixelinstart + b]; - } - } - } - } else /*bpp < 8: Adam7 with pixels < 8 bit is a bit trickier: with bit pointers*/ { - for(i = 0; i != 7; ++i) { - unsigned x, y, b; - unsigned ilinebits = bpp * passw[i]; - unsigned olinebits = bpp * w; - size_t obp, ibp; /*bit pointers (for out and in buffer)*/ - for(y = 0; y < passh[i]; ++y) - for(x = 0; x < passw[i]; ++x) { - ibp = (8 * passstart[i]) + (y * ilinebits + x * bpp); - obp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp; - for(b = 0; b < bpp; ++b) { - unsigned char bit = readBitFromReversedStream(&ibp, in); - /*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/ - setBitOfReversedStream0(&obp, out, bit); - } - } - } - } -} - -static void removePaddingBits(unsigned char* out, const unsigned char* in, - size_t olinebits, size_t ilinebits, unsigned h) { - /* - After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need - to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers - for the Adam7 code, the color convert code and the output to the user. - in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must - have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits - also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7 - only useful if (ilinebits - olinebits) is a value in the range 1..7 - */ - unsigned y; - size_t diff = ilinebits - olinebits; - size_t ibp = 0, obp = 0; /*input and output bit pointers*/ - for(y = 0; y < h; ++y) { - size_t x; - for(x = 0; x < olinebits; ++x) { - unsigned char bit = readBitFromReversedStream(&ibp, in); - setBitOfReversedStream(&obp, out, bit); - } - ibp += diff; +/*put a pixel, given its RGBA16 color, into image of any color 16-bitdepth type*/ +static void rgba16ToPixel(unsigned char* out, size_t i, + const LodePNGColorMode* mode, + unsigned short r, unsigned short g, unsigned short b, unsigned short a) { + if(mode->colortype == LCT_GREY) { + unsigned short grey = r; /*((unsigned)r + g + b) / 3;*/ + out[i * 2 + 0] = (grey >> 8) & 255; + out[i * 2 + 1] = grey & 255; + } else if(mode->colortype == LCT_RGB) { + out[i * 6 + 0] = (r >> 8) & 255; + out[i * 6 + 1] = r & 255; + out[i * 6 + 2] = (g >> 8) & 255; + out[i * 6 + 3] = g & 255; + out[i * 6 + 4] = (b >> 8) & 255; + out[i * 6 + 5] = b & 255; + } else if(mode->colortype == LCT_GREY_ALPHA) { + unsigned short grey = r; /*((unsigned)r + g + b) / 3;*/ + out[i * 4 + 0] = (grey >> 8) & 255; + out[i * 4 + 1] = grey & 255; + out[i * 4 + 2] = (a >> 8) & 255; + out[i * 4 + 3] = a & 255; + } else if(mode->colortype == LCT_RGBA) { + out[i * 8 + 0] = (r >> 8) & 255; + out[i * 8 + 1] = r & 255; + out[i * 8 + 2] = (g >> 8) & 255; + out[i * 8 + 3] = g & 255; + out[i * 8 + 4] = (b >> 8) & 255; + out[i * 8 + 5] = b & 255; + out[i * 8 + 6] = (a >> 8) & 255; + out[i * 8 + 7] = a & 255; } }
-/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from -the IDAT chunks (with filter index bytes and possible padding bits) -return value is error*/ -static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, - unsigned w, unsigned h, const LodePNGInfo* info_png) { - /* - This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype. - Steps: - *) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8) - *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace - NOTE: the in buffer will be overwritten with intermediate data! - */ - unsigned bpp = lodepng_get_bpp(&info_png->color); - if(bpp == 0) return 31; /*error: invalid colortype*/ - - if(info_png->interlace_method == 0) { - if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) { - CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp)); - removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h); +/*Get RGBA8 color of pixel with index i (y * width + x) from the raw image with given color type.*/ +static void getPixelColorRGBA8(unsigned char* r, unsigned char* g, + unsigned char* b, unsigned char* a, + const unsigned char* in, size_t i, + const LodePNGColorMode* mode) { + if(mode->colortype == LCT_GREY) { + if(mode->bitdepth == 8) { + *r = *g = *b = in[i]; + if(mode->key_defined && *r == mode->key_r) *a = 0; + else *a = 255; + } else if(mode->bitdepth == 16) { + *r = *g = *b = in[i * 2 + 0]; + if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0; + else *a = 255; + } else { + unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ + size_t j = i * mode->bitdepth; + unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); + *r = *g = *b = (value * 255) / highest; + if(mode->key_defined && value == mode->key_r) *a = 0; + else *a = 255; } - /*we can immediately filter into the out buffer, no other steps needed*/ - else CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp)); - } else /*interlace_method is 1 (Adam7)*/ { - unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; - unsigned i; - - Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); - - for(i = 0; i != 7; ++i) { - CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp)); - /*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline, - move bytes instead of bits or move not at all*/ - if(bpp < 8) { - /*remove padding bits in scanlines; after this there still may be padding - bits between the different reduced images: each reduced image still starts nicely at a byte*/ - removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp, - ((passw[i] * bpp + 7) / 8) * 8, passh[i]); - } + } else if(mode->colortype == LCT_RGB) { + if(mode->bitdepth == 8) { + *r = in[i * 3 + 0]; *g = in[i * 3 + 1]; *b = in[i * 3 + 2]; + if(mode->key_defined && *r == mode->key_r && *g == mode->key_g && *b == mode->key_b) *a = 0; + else *a = 255; + } else { + *r = in[i * 6 + 0]; + *g = in[i * 6 + 2]; + *b = in[i * 6 + 4]; + if(mode->key_defined && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r + && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g + && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0; + else *a = 255; + } + } else if(mode->colortype == LCT_PALETTE) { + unsigned index; + if(mode->bitdepth == 8) index = in[i]; + else { + size_t j = i * mode->bitdepth; + index = readBitsFromReversedStream(&j, in, mode->bitdepth); }
- Adam7_deinterlace(out, in, w, h, bpp); - } - - return 0; -} - -static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) { - unsigned pos = 0, i; - if(color->palette) lodepng_free(color->palette); - color->palettesize = chunkLength / 3; - color->palette = (unsigned char*)lodepng_malloc(4 * color->palettesize); - if(!color->palette && color->palettesize) { - color->palettesize = 0; - return 83; /*alloc fail*/ - } - if(color->palettesize > 256) return 38; /*error: palette too big*/ - - for(i = 0; i != color->palettesize; ++i) { - color->palette[4 * i + 0] = data[pos++]; /*R*/ - color->palette[4 * i + 1] = data[pos++]; /*G*/ - color->palette[4 * i + 2] = data[pos++]; /*B*/ - color->palette[4 * i + 3] = 255; /*alpha*/ - } - - return 0; /* OK */ -} - -static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) { - unsigned i; - if(color->colortype == LCT_PALETTE) { - /*error: more alpha values given than there are palette entries*/ - if(chunkLength > color->palettesize) return 39; - - for(i = 0; i != chunkLength; ++i) color->palette[4 * i + 3] = data[i]; - } else if(color->colortype == LCT_GREY) { - /*error: this chunk must be 2 bytes for greyscale image*/ - if(chunkLength != 2) return 30; - - color->key_defined = 1; - color->key_r = color->key_g = color->key_b = 256u * data[0] + data[1]; - } else if(color->colortype == LCT_RGB) { - /*error: this chunk must be 6 bytes for RGB image*/ - if(chunkLength != 6) return 41; - - color->key_defined = 1; - color->key_r = 256u * data[0] + data[1]; - color->key_g = 256u * data[2] + data[3]; - color->key_b = 256u * data[4] + data[5]; - } - else return 42; /*error: tRNS chunk not allowed for other color models*/ - - return 0; /* OK */ -} - - -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -/*background color chunk (bKGD)*/ -static unsigned readChunk_bKGD(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { - if(info->color.colortype == LCT_PALETTE) { - /*error: this chunk must be 1 byte for indexed color image*/ - if(chunkLength != 1) return 43; - - /*error: invalid palette index, or maybe this chunk appeared before PLTE*/ - if(data[0] >= info->color.palettesize) return 103; - - info->background_defined = 1; - info->background_r = info->background_g = info->background_b = data[0]; - } else if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) { - /*error: this chunk must be 2 bytes for greyscale image*/ - if(chunkLength != 2) return 44; - - /*the values are truncated to bitdepth in the PNG file*/ - info->background_defined = 1; - info->background_r = info->background_g = info->background_b = 256u * data[0] + data[1]; - } else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) { - /*error: this chunk must be 6 bytes for greyscale image*/ - if(chunkLength != 6) return 45; - - /*the values are truncated to bitdepth in the PNG file*/ - info->background_defined = 1; - info->background_r = 256u * data[0] + data[1]; - info->background_g = 256u * data[2] + data[3]; - info->background_b = 256u * data[4] + data[5]; - } - - return 0; /* OK */ -} - -/*text chunk (tEXt)*/ -static unsigned readChunk_tEXt(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { - unsigned error = 0; - char *key = 0, *str = 0; - unsigned i; - - while(!error) /*not really a while loop, only used to break on error*/ { - unsigned length, string2_begin; - - length = 0; - while(length < chunkLength && data[length] != 0) ++length; - /*even though it's not allowed by the standard, no error is thrown if - there's no null termination char, if the text is empty*/ - if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ - - key = (char*)lodepng_malloc(length + 1); - if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ - - key[length] = 0; - for(i = 0; i != length; ++i) key[i] = (char)data[i]; - - string2_begin = length + 1; /*skip keyword null terminator*/ - - length = (unsigned)(chunkLength < string2_begin ? 0 : chunkLength - string2_begin); - str = (char*)lodepng_malloc(length + 1); - if(!str) CERROR_BREAK(error, 83); /*alloc fail*/ - - str[length] = 0; - for(i = 0; i != length; ++i) str[i] = (char)data[string2_begin + i]; - - error = lodepng_add_text(info, key, str); - - break; - } - - lodepng_free(key); - lodepng_free(str); - - return error; -} - -/*compressed text chunk (zTXt)*/ -static unsigned readChunk_zTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, - const unsigned char* data, size_t chunkLength) { - unsigned error = 0; - unsigned i; - - unsigned length, string2_begin; - char *key = 0; - ucvector decoded; - - ucvector_init(&decoded); - - while(!error) /*not really a while loop, only used to break on error*/ { - for(length = 0; length < chunkLength && data[length] != 0; ++length) ; - if(length + 2 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/ - if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ - - key = (char*)lodepng_malloc(length + 1); - if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ - - key[length] = 0; - for(i = 0; i != length; ++i) key[i] = (char)data[i]; - - if(data[length + 1] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/ - - string2_begin = length + 2; - if(string2_begin > chunkLength) CERROR_BREAK(error, 75); /*no null termination, corrupt?*/ - - length = (unsigned)chunkLength - string2_begin; - /*will fail if zlib error, e.g. if length is too small*/ - error = zlib_decompress(&decoded.data, &decoded.size, - (unsigned char*)(&data[string2_begin]), - length, zlibsettings); - if(error) break; - ucvector_push_back(&decoded, 0); - - error = lodepng_add_text(info, key, (char*)decoded.data); - - break; - } - - lodepng_free(key); - ucvector_cleanup(&decoded); - - return error; -} - -/*international text chunk (iTXt)*/ -static unsigned readChunk_iTXt(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, - const unsigned char* data, size_t chunkLength) { - unsigned error = 0; - unsigned i; - - unsigned length, begin, compressed; - char *key = 0, *langtag = 0, *transkey = 0; - ucvector decoded; - ucvector_init(&decoded); /* TODO: only use in case of compressed text */ - - while(!error) /*not really a while loop, only used to break on error*/ { - /*Quick check if the chunk length isn't too small. Even without check - it'd still fail with other error checks below if it's too short. This just gives a different error code.*/ - if(chunkLength < 5) CERROR_BREAK(error, 30); /*iTXt chunk too short*/ - - /*read the key*/ - for(length = 0; length < chunkLength && data[length] != 0; ++length) ; - if(length + 3 >= chunkLength) CERROR_BREAK(error, 75); /*no null termination char, corrupt?*/ - if(length < 1 || length > 79) CERROR_BREAK(error, 89); /*keyword too short or long*/ - - key = (char*)lodepng_malloc(length + 1); - if(!key) CERROR_BREAK(error, 83); /*alloc fail*/ - - key[length] = 0; - for(i = 0; i != length; ++i) key[i] = (char)data[i]; - - /*read the compression method*/ - compressed = data[length + 1]; - if(data[length + 2] != 0) CERROR_BREAK(error, 72); /*the 0 byte indicating compression must be 0*/ - - /*even though it's not allowed by the standard, no error is thrown if - there's no null termination char, if the text is empty for the next 3 texts*/ - - /*read the langtag*/ - begin = length + 3; - length = 0; - for(i = begin; i < chunkLength && data[i] != 0; ++i) ++length; - - langtag = (char*)lodepng_malloc(length + 1); - if(!langtag) CERROR_BREAK(error, 83); /*alloc fail*/ - - langtag[length] = 0; - for(i = 0; i != length; ++i) langtag[i] = (char)data[begin + i]; - - /*read the transkey*/ - begin += length + 1; - length = 0; - for(i = begin; i < chunkLength && data[i] != 0; ++i) ++length; - - transkey = (char*)lodepng_malloc(length + 1); - if(!transkey) CERROR_BREAK(error, 83); /*alloc fail*/ - - transkey[length] = 0; - for(i = 0; i != length; ++i) transkey[i] = (char)data[begin + i]; - - /*read the actual text*/ - begin += length + 1; - - length = (unsigned)chunkLength < begin ? 0 : (unsigned)chunkLength - begin; - - if(compressed) { - /*will fail if zlib error, e.g. if length is too small*/ - error = zlib_decompress(&decoded.data, &decoded.size, - (unsigned char*)(&data[begin]), - length, zlibsettings); - if(error) break; - if(decoded.allocsize < decoded.size) decoded.allocsize = decoded.size; - ucvector_push_back(&decoded, 0); + if(index >= mode->palettesize) { + /*This is an error according to the PNG spec, but common PNG decoders make it black instead. + Done here too, slightly faster due to no error handling needed.*/ + *r = *g = *b = 0; + *a = 255; } else { - if(!ucvector_resize(&decoded, length + 1)) CERROR_BREAK(error, 83 /*alloc fail*/); - - decoded.data[length] = 0; - for(i = 0; i != length; ++i) decoded.data[i] = data[begin + i]; + *r = mode->palette[index * 4 + 0]; + *g = mode->palette[index * 4 + 1]; + *b = mode->palette[index * 4 + 2]; + *a = mode->palette[index * 4 + 3]; } - - error = lodepng_add_itext(info, key, langtag, transkey, (char*)decoded.data); - - break; - } - - lodepng_free(key); - lodepng_free(langtag); - lodepng_free(transkey); - ucvector_cleanup(&decoded); - - return error; -} - -static unsigned readChunk_tIME(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { - if(chunkLength != 7) return 73; /*invalid tIME chunk size*/ - - info->time_defined = 1; - info->time.year = 256u * data[0] + data[1]; - info->time.month = data[2]; - info->time.day = data[3]; - info->time.hour = data[4]; - info->time.minute = data[5]; - info->time.second = data[6]; - - return 0; /* OK */ -} - -static unsigned readChunk_pHYs(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { - if(chunkLength != 9) return 74; /*invalid pHYs chunk size*/ - - info->phys_defined = 1; - info->phys_x = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3]; - info->phys_y = 16777216u * data[4] + 65536u * data[5] + 256u * data[6] + data[7]; - info->phys_unit = data[8]; - - return 0; /* OK */ -} - -static unsigned readChunk_gAMA(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { - if(chunkLength != 4) return 96; /*invalid gAMA chunk size*/ - - info->gama_defined = 1; - info->gama_gamma = 16777216u * data[0] + 65536u * data[1] + 256u * data[2] + data[3]; - - return 0; /* OK */ -} - -static unsigned readChunk_cHRM(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { - if(chunkLength != 32) return 97; /*invalid cHRM chunk size*/ - - info->chrm_defined = 1; - info->chrm_white_x = 16777216u * data[ 0] + 65536u * data[ 1] + 256u * data[ 2] + data[ 3]; - info->chrm_white_y = 16777216u * data[ 4] + 65536u * data[ 5] + 256u * data[ 6] + data[ 7]; - info->chrm_red_x = 16777216u * data[ 8] + 65536u * data[ 9] + 256u * data[10] + data[11]; - info->chrm_red_y = 16777216u * data[12] + 65536u * data[13] + 256u * data[14] + data[15]; - info->chrm_green_x = 16777216u * data[16] + 65536u * data[17] + 256u * data[18] + data[19]; - info->chrm_green_y = 16777216u * data[20] + 65536u * data[21] + 256u * data[22] + data[23]; - info->chrm_blue_x = 16777216u * data[24] + 65536u * data[25] + 256u * data[26] + data[27]; - info->chrm_blue_y = 16777216u * data[28] + 65536u * data[29] + 256u * data[30] + data[31]; - - return 0; /* OK */ -} - -static unsigned readChunk_sRGB(LodePNGInfo* info, const unsigned char* data, size_t chunkLength) { - if(chunkLength != 1) return 98; /*invalid sRGB chunk size (this one is never ignored)*/ - - info->srgb_defined = 1; - info->srgb_intent = data[0]; - - return 0; /* OK */ -} - -static unsigned readChunk_iCCP(LodePNGInfo* info, const LodePNGDecompressSettings* zlibsettings, - const unsigned char* data, size_t chunkLength) { - unsigned error = 0; - unsigned i; - - unsigned length, string2_begin; - ucvector decoded; - - info->iccp_defined = 1; - if(info->iccp_name) lodepng_clear_icc(info); - - for(length = 0; length < chunkLength && data[length] != 0; ++length) ; - if(length + 2 >= chunkLength) return 75; /*no null termination, corrupt?*/ - if(length < 1 || length > 79) return 89; /*keyword too short or long*/ - - info->iccp_name = (char*)lodepng_malloc(length + 1); - if(!info->iccp_name) return 83; /*alloc fail*/ - - info->iccp_name[length] = 0; - for(i = 0; i != length; ++i) info->iccp_name[i] = (char)data[i]; - - if(data[length + 1] != 0) return 72; /*the 0 byte indicating compression must be 0*/ - - string2_begin = length + 2; - if(string2_begin > chunkLength) return 75; /*no null termination, corrupt?*/ - - length = (unsigned)chunkLength - string2_begin; - ucvector_init(&decoded); - error = zlib_decompress(&decoded.data, &decoded.size, - (unsigned char*)(&data[string2_begin]), - length, zlibsettings); - if(!error) { - info->iccp_profile_size = decoded.size; - info->iccp_profile = (unsigned char*)lodepng_malloc(decoded.size); - if(info->iccp_profile) { - memcpy(info->iccp_profile, decoded.data, decoded.size); + } else if(mode->colortype == LCT_GREY_ALPHA) { + if(mode->bitdepth == 8) { + *r = *g = *b = in[i * 2 + 0]; + *a = in[i * 2 + 1]; } else { - error = 83; /* alloc fail */ + *r = *g = *b = in[i * 4 + 0]; + *a = in[i * 4 + 2]; + } + } else if(mode->colortype == LCT_RGBA) { + if(mode->bitdepth == 8) { + *r = in[i * 4 + 0]; + *g = in[i * 4 + 1]; + *b = in[i * 4 + 2]; + *a = in[i * 4 + 3]; + } else { + *r = in[i * 8 + 0]; + *g = in[i * 8 + 2]; + *b = in[i * 8 + 4]; + *a = in[i * 8 + 6]; } } - ucvector_cleanup(&decoded); - return error; -} -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -unsigned lodepng_inspect_chunk(LodePNGState* state, size_t pos, - const unsigned char* in, size_t insize) { - const unsigned char* chunk = in + pos; - unsigned chunkLength; - const unsigned char* data; - unsigned unhandled = 0; - unsigned error = 0; - - if (pos + 4 > insize) return 30; - chunkLength = lodepng_chunk_length(chunk); - if(chunkLength > 2147483647) return 63; - data = lodepng_chunk_data_const(chunk); - if(data + chunkLength + 4 > in + insize) return 30; - - if(lodepng_chunk_type_equals(chunk, "PLTE")) { - error = readChunk_PLTE(&state->info_png.color, data, chunkLength); - } else if(lodepng_chunk_type_equals(chunk, "tRNS")) { - error = readChunk_tRNS(&state->info_png.color, data, chunkLength); -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - } else if(lodepng_chunk_type_equals(chunk, "bKGD")) { - error = readChunk_bKGD(&state->info_png, data, chunkLength); - } else if(lodepng_chunk_type_equals(chunk, "tEXt")) { - error = readChunk_tEXt(&state->info_png, data, chunkLength); - } else if(lodepng_chunk_type_equals(chunk, "zTXt")) { - error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); - } else if(lodepng_chunk_type_equals(chunk, "iTXt")) { - error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); - } else if(lodepng_chunk_type_equals(chunk, "tIME")) { - error = readChunk_tIME(&state->info_png, data, chunkLength); - } else if(lodepng_chunk_type_equals(chunk, "pHYs")) { - error = readChunk_pHYs(&state->info_png, data, chunkLength); - } else if(lodepng_chunk_type_equals(chunk, "gAMA")) { - error = readChunk_gAMA(&state->info_png, data, chunkLength); - } else if(lodepng_chunk_type_equals(chunk, "cHRM")) { - error = readChunk_cHRM(&state->info_png, data, chunkLength); - } else if(lodepng_chunk_type_equals(chunk, "sRGB")) { - error = readChunk_sRGB(&state->info_png, data, chunkLength); - } else if(lodepng_chunk_type_equals(chunk, "iCCP")) { - error = readChunk_iCCP(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - } else { - /* unhandled chunk is ok (is not an error) */ - unhandled = 1; - } - - if(!error && !unhandled && !state->decoder.ignore_crc) { - if(lodepng_chunk_check_crc(chunk)) return 57; /*invalid CRC*/ - } - - return error; }
-/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/ -static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h, - LodePNGState* state, - const unsigned char* in, size_t insize) { - unsigned char IEND = 0; - const unsigned char* chunk; +/*Similar to getPixelColorRGBA8, but with all the for loops inside of the color +mode test cases, optimized to convert the colors much faster, when converting +to RGBA or RGB with 8 bit per cannel. buffer must be RGBA or RGB output with +enough memory, if has_alpha is true the output is RGBA. mode has the color mode +of the input buffer.*/ +static void getPixelColorsRGBA8(unsigned char* buffer, size_t numpixels, + unsigned has_alpha, const unsigned char* in, + const LodePNGColorMode* mode) { + unsigned num_channels = has_alpha ? 4 : 3; size_t i; - ucvector idat; /*the data from idat chunks*/ - ucvector scanlines; - size_t predict; - size_t outsize = 0; - - /*for unknown chunk order*/ - unsigned unknown = 0; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - unsigned critical_pos = 1; /*1 = after IHDR, 2 = after PLTE, 3 = after IDAT*/ -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - - /*provide some proper output values if error will happen*/ - *out = 0; - - state->error = lodepng_inspect(w, h, state, in, insize); /*reads header and resets other parameters in state->info_png*/ - if(state->error) return; - - if(lodepng_pixel_overflow(*w, *h, &state->info_png.color, &state->info_raw)) { - CERROR_RETURN(state->error, 92); /*overflow possible due to amount of pixels*/ - } - - ucvector_init(&idat); - chunk = &in[33]; /*first byte of the first chunk after the header*/ - - /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk. - IDAT data is put at the start of the in buffer*/ - while(!IEND && !state->error) { - unsigned chunkLength; - const unsigned char* data; /*the data in the chunk*/ - - /*error: size of the in buffer too small to contain next chunk*/ - if((size_t)((chunk - in) + 12) > insize || chunk < in) { - if(state->decoder.ignore_end) break; /*other errors may still happen though*/ - CERROR_BREAK(state->error, 30); - } - - /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/ - chunkLength = lodepng_chunk_length(chunk); - /*error: chunk length larger than the max PNG chunk size*/ - if(chunkLength > 2147483647) { - if(state->decoder.ignore_end) break; /*other errors may still happen though*/ - CERROR_BREAK(state->error, 63); - } - - if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in) { - CERROR_BREAK(state->error, 64); /*error: size of the in buffer too small to contain next chunk*/ + if(mode->colortype == LCT_GREY) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = buffer[1] = buffer[2] = in[i]; + if(has_alpha) buffer[3] = mode->key_defined && in[i] == mode->key_r ? 0 : 255; + } + } else if(mode->bitdepth == 16) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = buffer[1] = buffer[2] = in[i * 2]; + if(has_alpha) buffer[3] = mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r ? 0 : 255; + } + } else { + unsigned highest = ((1U << mode->bitdepth) - 1U); /*highest possible value for this bit depth*/ + size_t j = 0; + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + unsigned value = readBitsFromReversedStream(&j, in, mode->bitdepth); + buffer[0] = buffer[1] = buffer[2] = (value * 255) / highest; + if(has_alpha) buffer[3] = mode->key_defined && value == mode->key_r ? 0 : 255; + } } - - data = lodepng_chunk_data_const(chunk); - - unknown = 0; - - /*IDAT chunk, containing compressed image data*/ - if(lodepng_chunk_type_equals(chunk, "IDAT")) { - size_t oldsize = idat.size; - size_t newsize; - if(lodepng_addofl(oldsize, chunkLength, &newsize)) CERROR_BREAK(state->error, 95); - if(!ucvector_resize(&idat, newsize)) CERROR_BREAK(state->error, 83 /*alloc fail*/); - for(i = 0; i != chunkLength; ++i) idat.data[oldsize + i] = data[i]; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - critical_pos = 3; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - } else if(lodepng_chunk_type_equals(chunk, "IEND")) { - /*IEND chunk*/ - IEND = 1; - } else if(lodepng_chunk_type_equals(chunk, "PLTE")) { - /*palette chunk (PLTE)*/ - state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength); - if(state->error) break; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - critical_pos = 2; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - } else if(lodepng_chunk_type_equals(chunk, "tRNS")) { - /*palette transparency chunk (tRNS). Even though this one is an ancillary chunk , it is still compiled - in without 'LODEPNG_COMPILE_ANCILLARY_CHUNKS' because it contains essential color information that - affects the alpha channel of pixels. */ - state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength); - if(state->error) break; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /*background color chunk (bKGD)*/ - } else if(lodepng_chunk_type_equals(chunk, "bKGD")) { - state->error = readChunk_bKGD(&state->info_png, data, chunkLength); - if(state->error) break; - } else if(lodepng_chunk_type_equals(chunk, "tEXt")) { - /*text chunk (tEXt)*/ - if(state->decoder.read_text_chunks) { - state->error = readChunk_tEXt(&state->info_png, data, chunkLength); - if(state->error) break; + } else if(mode->colortype == LCT_RGB) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = in[i * 3 + 0]; + buffer[1] = in[i * 3 + 1]; + buffer[2] = in[i * 3 + 2]; + if(has_alpha) buffer[3] = mode->key_defined && buffer[0] == mode->key_r + && buffer[1]== mode->key_g && buffer[2] == mode->key_b ? 0 : 255; } - } else if(lodepng_chunk_type_equals(chunk, "zTXt")) { - /*compressed text chunk (zTXt)*/ - if(state->decoder.read_text_chunks) { - state->error = readChunk_zTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); - if(state->error) break; + } else { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = in[i * 6 + 0]; + buffer[1] = in[i * 6 + 2]; + buffer[2] = in[i * 6 + 4]; + if(has_alpha) buffer[3] = mode->key_defined + && 256U * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r + && 256U * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g + && 256U * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b ? 0 : 255; } - } else if(lodepng_chunk_type_equals(chunk, "iTXt")) { - /*international text chunk (iTXt)*/ - if(state->decoder.read_text_chunks) { - state->error = readChunk_iTXt(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); - if(state->error) break; + } + } else if(mode->colortype == LCT_PALETTE) { + unsigned index; + size_t j = 0; + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + if(mode->bitdepth == 8) index = in[i]; + else index = readBitsFromReversedStream(&j, in, mode->bitdepth); + + if(index >= mode->palettesize) { + /*This is an error according to the PNG spec, but most PNG decoders make it black instead. + Done here too, slightly faster due to no error handling needed.*/ + buffer[0] = buffer[1] = buffer[2] = 0; + if(has_alpha) buffer[3] = 255; + } else { + buffer[0] = mode->palette[index * 4 + 0]; + buffer[1] = mode->palette[index * 4 + 1]; + buffer[2] = mode->palette[index * 4 + 2]; + if(has_alpha) buffer[3] = mode->palette[index * 4 + 3]; } - } else if(lodepng_chunk_type_equals(chunk, "tIME")) { - state->error = readChunk_tIME(&state->info_png, data, chunkLength); - if(state->error) break; - } else if(lodepng_chunk_type_equals(chunk, "pHYs")) { - state->error = readChunk_pHYs(&state->info_png, data, chunkLength); - if(state->error) break; - } else if(lodepng_chunk_type_equals(chunk, "gAMA")) { - state->error = readChunk_gAMA(&state->info_png, data, chunkLength); - if(state->error) break; - } else if(lodepng_chunk_type_equals(chunk, "cHRM")) { - state->error = readChunk_cHRM(&state->info_png, data, chunkLength); - if(state->error) break; - } else if(lodepng_chunk_type_equals(chunk, "sRGB")) { - state->error = readChunk_sRGB(&state->info_png, data, chunkLength); - if(state->error) break; - } else if(lodepng_chunk_type_equals(chunk, "iCCP")) { - state->error = readChunk_iCCP(&state->info_png, &state->decoder.zlibsettings, data, chunkLength); - if(state->error) break; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - } else /*it's not an implemented chunk type, so ignore it: skip over the data*/ { - /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/ - if(!state->decoder.ignore_critical && !lodepng_chunk_ancillary(chunk)) { - CERROR_BREAK(state->error, 69); + } + } else if(mode->colortype == LCT_GREY_ALPHA) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = buffer[1] = buffer[2] = in[i * 2 + 0]; + if(has_alpha) buffer[3] = in[i * 2 + 1]; } - - unknown = 1; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - if(state->decoder.remember_unknown_chunks) { - state->error = lodepng_chunk_append(&state->info_png.unknown_chunks_data[critical_pos - 1], - &state->info_png.unknown_chunks_size[critical_pos - 1], chunk); - if(state->error) break; + } else { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0]; + if(has_alpha) buffer[3] = in[i * 4 + 2]; } -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ } - - if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/ { - if(lodepng_chunk_check_crc(chunk)) CERROR_BREAK(state->error, 57); /*invalid CRC*/ + } else if(mode->colortype == LCT_RGBA) { + if(mode->bitdepth == 8) { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = in[i * 4 + 0]; + buffer[1] = in[i * 4 + 1]; + buffer[2] = in[i * 4 + 2]; + if(has_alpha) buffer[3] = in[i * 4 + 3]; + } + } else { + for(i = 0; i != numpixels; ++i, buffer += num_channels) { + buffer[0] = in[i * 8 + 0]; + buffer[1] = in[i * 8 + 2]; + buffer[2] = in[i * 8 + 4]; + if(has_alpha) buffer[3] = in[i * 8 + 6]; + } } - - if(!IEND) chunk = lodepng_chunk_next_const(chunk); - } - - ucvector_init(&scanlines); - /*predict output size, to allocate exact size for output buffer to avoid more dynamic allocation. - If the decompressed size does not match the prediction, the image must be corrupt.*/ - if(state->info_png.interlace_method == 0) { - predict = lodepng_get_raw_size_idat(*w, *h, &state->info_png.color); - } else { - /*Adam-7 interlaced: predicted size is the sum of the 7 sub-images sizes*/ - const LodePNGColorMode* color = &state->info_png.color; - predict = 0; - predict += lodepng_get_raw_size_idat((*w + 7) >> 3, (*h + 7) >> 3, color); - if(*w > 4) predict += lodepng_get_raw_size_idat((*w + 3) >> 3, (*h + 7) >> 3, color); - predict += lodepng_get_raw_size_idat((*w + 3) >> 2, (*h + 3) >> 3, color); - if(*w > 2) predict += lodepng_get_raw_size_idat((*w + 1) >> 2, (*h + 3) >> 2, color); - predict += lodepng_get_raw_size_idat((*w + 1) >> 1, (*h + 1) >> 2, color); - if(*w > 1) predict += lodepng_get_raw_size_idat((*w + 0) >> 1, (*h + 1) >> 1, color); - predict += lodepng_get_raw_size_idat((*w + 0), (*h + 0) >> 1, color); - } - if(!state->error && !ucvector_reserve(&scanlines, predict)) state->error = 83; /*alloc fail*/ - if(!state->error) { - state->error = zlib_decompress(&scanlines.data, &scanlines.size, idat.data, - idat.size, &state->decoder.zlibsettings); - if(!state->error && scanlines.size != predict) state->error = 91; /*decompressed size doesn't match prediction*/ - } - ucvector_cleanup(&idat); - - if(!state->error) { - outsize = lodepng_get_raw_size(*w, *h, &state->info_png.color); - *out = (unsigned char*)lodepng_malloc(outsize); - if(!*out) state->error = 83; /*alloc fail*/ - } - if(!state->error) { - for(i = 0; i < outsize; i++) (*out)[i] = 0; - state->error = postProcessScanlines(*out, scanlines.data, *w, *h, &state->info_png); } - ucvector_cleanup(&scanlines); }
-unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h, - LodePNGState* state, - const unsigned char* in, size_t insize) { - *out = 0; - decodeGeneric(out, w, h, state, in, insize); - if(state->error) return state->error; - if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color)) { - /*same color type, no copying or converting of data needed*/ - /*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype - the raw image has to the end user*/ - if(!state->decoder.color_convert) { - state->error = lodepng_color_mode_copy(&state->info_raw, &state->info_png.color); - if(state->error) return state->error; - } - } else { - /*color conversion needed; sort of copy of the data*/ - unsigned char* data = *out; - size_t outsize; - - /*TODO: check if this works according to the statement in the documentation: "The converter can convert - from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/ - if(!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA) - && !(state->info_raw.bitdepth == 8)) { - return 56; /*unsupported color mode conversion*/ - } - - outsize = lodepng_get_raw_size(*w, *h, &state->info_raw); - *out = (unsigned char*)lodepng_malloc(outsize); - if(!(*out)) { - state->error = 83; /*alloc fail*/ - } - else state->error = lodepng_convert(*out, data, &state->info_raw, - &state->info_png.color, *w, *h); - lodepng_free(data); +/*Get RGBA16 color of pixel with index i (y * width + x) from the raw image with +given color type, but the given color type must be 16-bit itself.*/ +static void getPixelColorRGBA16(unsigned short* r, unsigned short* g, unsigned short* b, unsigned short* a, + const unsigned char* in, size_t i, const LodePNGColorMode* mode) { + if(mode->colortype == LCT_GREY) { + *r = *g = *b = 256 * in[i * 2 + 0] + in[i * 2 + 1]; + if(mode->key_defined && 256U * in[i * 2 + 0] + in[i * 2 + 1] == mode->key_r) *a = 0; + else *a = 65535; + } else if(mode->colortype == LCT_RGB) { + *r = 256u * in[i * 6 + 0] + in[i * 6 + 1]; + *g = 256u * in[i * 6 + 2] + in[i * 6 + 3]; + *b = 256u * in[i * 6 + 4] + in[i * 6 + 5]; + if(mode->key_defined + && 256u * in[i * 6 + 0] + in[i * 6 + 1] == mode->key_r + && 256u * in[i * 6 + 2] + in[i * 6 + 3] == mode->key_g + && 256u * in[i * 6 + 4] + in[i * 6 + 5] == mode->key_b) *a = 0; + else *a = 65535; + } else if(mode->colortype == LCT_GREY_ALPHA) { + *r = *g = *b = 256u * in[i * 4 + 0] + in[i * 4 + 1]; + *a = 256u * in[i * 4 + 2] + in[i * 4 + 3]; + } else if(mode->colortype == LCT_RGBA) { + *r = 256u * in[i * 8 + 0] + in[i * 8 + 1]; + *g = 256u * in[i * 8 + 2] + in[i * 8 + 3]; + *b = 256u * in[i * 8 + 4] + in[i * 8 + 5]; + *a = 256u * in[i * 8 + 6] + in[i * 8 + 7]; } - return state->error; -} - -unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, - size_t insize, LodePNGColorType colortype, unsigned bitdepth) { - unsigned error; - LodePNGState state; - lodepng_state_init(&state); - state.info_raw.colortype = colortype; - state.info_raw.bitdepth = bitdepth; - error = lodepng_decode(out, w, h, &state, in, insize); - lodepng_state_cleanup(&state); - return error; -} - -unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) { - return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8); -} - -unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) { - return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8); -} - -#ifdef LODEPNG_COMPILE_DISK -unsigned lodepng_decode_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename, - LodePNGColorType colortype, unsigned bitdepth) { - unsigned char* buffer = 0; - size_t buffersize; - unsigned error; - error = lodepng_load_file(&buffer, &buffersize, filename); - if(!error) error = lodepng_decode_memory(out, w, h, buffer, buffersize, colortype, bitdepth); - lodepng_free(buffer); - return error; -} - -unsigned lodepng_decode32_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) { - return lodepng_decode_file(out, w, h, filename, LCT_RGBA, 8); -} - -unsigned lodepng_decode24_file(unsigned char** out, unsigned* w, unsigned* h, const char* filename) { - return lodepng_decode_file(out, w, h, filename, LCT_RGB, 8); -} -#endif /*LODEPNG_COMPILE_DISK*/ - -void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) { - settings->color_convert = 1; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - settings->read_text_chunks = 1; - settings->remember_unknown_chunks = 0; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - settings->ignore_crc = 0; - settings->ignore_critical = 0; - settings->ignore_end = 0; - lodepng_decompress_settings_init(&settings->zlibsettings); -} - -#endif /*LODEPNG_COMPILE_DECODER*/ - -#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) - -void lodepng_state_init(LodePNGState* state) { -#ifdef LODEPNG_COMPILE_DECODER - lodepng_decoder_settings_init(&state->decoder); -#endif /*LODEPNG_COMPILE_DECODER*/ -#ifdef LODEPNG_COMPILE_ENCODER - lodepng_encoder_settings_init(&state->encoder); -#endif /*LODEPNG_COMPILE_ENCODER*/ - lodepng_color_mode_init(&state->info_raw); - lodepng_info_init(&state->info_png); - state->error = 1; -} - -void lodepng_state_cleanup(LodePNGState* state) { - lodepng_color_mode_cleanup(&state->info_raw); - lodepng_info_cleanup(&state->info_png); -} - -void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source) { - lodepng_state_cleanup(dest); - *dest = *source; - lodepng_color_mode_init(&dest->info_raw); - lodepng_info_init(&dest->info_png); - dest->error = lodepng_color_mode_copy(&dest->info_raw, &source->info_raw); if(dest->error) return; - dest->error = lodepng_info_copy(&dest->info_png, &source->info_png); if(dest->error) return; -} - -#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */ - -#ifdef LODEPNG_COMPILE_ENCODER - -/* ////////////////////////////////////////////////////////////////////////// */ -/* / PNG Encoder / */ -/* ////////////////////////////////////////////////////////////////////////// */ - -/*chunkName must be string of 4 characters*/ -static unsigned addChunk(ucvector* out, const char* chunkName, const unsigned char* data, size_t length) { - CERROR_TRY_RETURN(lodepng_chunk_create(&out->data, &out->size, (unsigned)length, chunkName, data)); - out->allocsize = out->size; /*fix the allocsize again*/ - return 0; -} - -static void writeSignature(ucvector* out) { - /*8 bytes PNG signature, aka the magic bytes*/ - ucvector_push_back(out, 137); - ucvector_push_back(out, 80); - ucvector_push_back(out, 78); - ucvector_push_back(out, 71); - ucvector_push_back(out, 13); - ucvector_push_back(out, 10); - ucvector_push_back(out, 26); - ucvector_push_back(out, 10); }
-static unsigned addChunk_IHDR(ucvector* out, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth, unsigned interlace_method) { +unsigned lodepng_convert(unsigned char* out, const unsigned char* in, + const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in, + unsigned w, unsigned h) { + size_t i; + ColorTree tree; + size_t numpixels = (size_t)w * (size_t)h; unsigned error = 0; - ucvector header; - ucvector_init(&header); - - lodepng_add32bitInt(&header, w); /*width*/ - lodepng_add32bitInt(&header, h); /*height*/ - ucvector_push_back(&header, (unsigned char)bitdepth); /*bit depth*/ - ucvector_push_back(&header, (unsigned char)colortype); /*color type*/ - ucvector_push_back(&header, 0); /*compression method*/ - ucvector_push_back(&header, 0); /*filter method*/ - ucvector_push_back(&header, interlace_method); /*interlace method*/ - - error = addChunk(out, "IHDR", header.data, header.size); - ucvector_cleanup(&header);
- return error; -} - -static unsigned addChunk_PLTE(ucvector* out, const LodePNGColorMode* info) { - unsigned error = 0; - size_t i; - ucvector PLTE; - ucvector_init(&PLTE); - for(i = 0; i != info->palettesize * 4; ++i) { - /*add all channels except alpha channel*/ - if(i % 4 != 3) ucvector_push_back(&PLTE, info->palette[i]); + if(lodepng_color_mode_equal(mode_out, mode_in)) { + size_t numbytes = lodepng_get_raw_size(w, h, mode_in); + for(i = 0; i != numbytes; ++i) out[i] = in[i]; + return 0; } - error = addChunk(out, "PLTE", PLTE.data, PLTE.size); - ucvector_cleanup(&PLTE); - - return error; -}
-static unsigned addChunk_tRNS(ucvector* out, const LodePNGColorMode* info) { - unsigned error = 0; - size_t i; - ucvector tRNS; - ucvector_init(&tRNS); - if(info->colortype == LCT_PALETTE) { - size_t amount = info->palettesize; - /*the tail of palette values that all have 255 as alpha, does not have to be encoded*/ - for(i = info->palettesize; i != 0; --i) { - if(info->palette[4 * (i - 1) + 3] == 255) --amount; - else break; + if(mode_out->colortype == LCT_PALETTE) { + size_t palettesize = mode_out->palettesize; + const unsigned char* palette = mode_out->palette; + size_t palsize = (size_t)1u << mode_out->bitdepth; + /*if the user specified output palette but did not give the values, assume + they want the values of the input color type (assuming that one is palette). + Note that we never create a new palette ourselves.*/ + if(palettesize == 0) { + palettesize = mode_in->palettesize; + palette = mode_in->palette; + /*if the input was also palette with same bitdepth, then the color types are also + equal, so copy literally. This to preserve the exact indices that were in the PNG + even in case there are duplicate colors in the palette.*/ + if (mode_in->colortype == LCT_PALETTE && mode_in->bitdepth == mode_out->bitdepth) { + size_t numbytes = lodepng_get_raw_size(w, h, mode_in); + for(i = 0; i != numbytes; ++i) out[i] = in[i]; + return 0; + } } - /*add only alpha channel*/ - for(i = 0; i != amount; ++i) ucvector_push_back(&tRNS, info->palette[4 * i + 3]); - } else if(info->colortype == LCT_GREY) { - if(info->key_defined) { - ucvector_push_back(&tRNS, (unsigned char)(info->key_r >> 8)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_r & 255)); + if(palettesize < palsize) palsize = palettesize; + color_tree_init(&tree); + for(i = 0; i != palsize; ++i) { + const unsigned char* p = &palette[i * 4]; + color_tree_add(&tree, p[0], p[1], p[2], p[3], (unsigned)i); + } + } + + if(mode_in->bitdepth == 16 && mode_out->bitdepth == 16) { + for(i = 0; i != numpixels; ++i) { + unsigned short r = 0, g = 0, b = 0, a = 0; + getPixelColorRGBA16(&r, &g, &b, &a, in, i, mode_in); + rgba16ToPixel(out, i, mode_out, r, g, b, a); } - } else if(info->colortype == LCT_RGB) { - if(info->key_defined) { - ucvector_push_back(&tRNS, (unsigned char)(info->key_r >> 8)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_r & 255)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_g >> 8)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_g & 255)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_b >> 8)); - ucvector_push_back(&tRNS, (unsigned char)(info->key_b & 255)); + } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGBA) { + getPixelColorsRGBA8(out, numpixels, 1, in, mode_in); + } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) { + getPixelColorsRGBA8(out, numpixels, 0, in, mode_in); + } else { + unsigned char r = 0, g = 0, b = 0, a = 0; + for(i = 0; i != numpixels; ++i) { + getPixelColorRGBA8(&r, &g, &b, &a, in, i, mode_in); + error = rgba8ToPixel(out, i, mode_out, &tree, r, g, b, a); + if (error) break; } }
- error = addChunk(out, "tRNS", tRNS.data, tRNS.size); - ucvector_cleanup(&tRNS); - - return error; -} - -static unsigned addChunk_IDAT(ucvector* out, const unsigned char* data, size_t datasize, - LodePNGCompressSettings* zlibsettings) { - ucvector zlibdata; - unsigned error = 0; - - /*compress with the Zlib compressor*/ - ucvector_init(&zlibdata); - error = zlib_compress(&zlibdata.data, &zlibdata.size, data, datasize, zlibsettings); - if(!error) error = addChunk(out, "IDAT", zlibdata.data, zlibdata.size); - ucvector_cleanup(&zlibdata); - - return error; -} + if(mode_out->colortype == LCT_PALETTE) { + color_tree_cleanup(&tree); + }
-static unsigned addChunk_IEND(ucvector* out) { - unsigned error = 0; - error = addChunk(out, "IEND", 0, 0); return error; }
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS
-static unsigned addChunk_tEXt(ucvector* out, const char* keyword, const char* textstring) { - unsigned error = 0; - size_t i; - ucvector text; - ucvector_init(&text); - for(i = 0; keyword[i] != 0; ++i) ucvector_push_back(&text, (unsigned char)keyword[i]); - if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/ - ucvector_push_back(&text, 0); /*0 termination char*/ - for(i = 0; textstring[i] != 0; ++i) ucvector_push_back(&text, (unsigned char)textstring[i]); - error = addChunk(out, "tEXt", text.data, text.size); - ucvector_cleanup(&text); - - return error; -} +/* Converts a single rgb color without alpha from one type to another, color bits truncated to +their bitdepth. In case of single channel (grey or palette), only the r channel is used. Slow +function, do not use to process all pixels of an image. Alpha channel not supported on purpose: +this is for bKGD, supporting alpha may prevent it from finding a color in the palette, from the +specification it looks like bKGD should ignore the alpha values of the palette since it can use +any palette index but doesn't have an alpha channel. Idem with ignoring color key. */ +unsigned lodepng_convert_rgb( + unsigned* r_out, unsigned* g_out, unsigned* b_out, + unsigned r_in, unsigned g_in, unsigned b_in, + const LodePNGColorMode* mode_out, const LodePNGColorMode* mode_in) { + unsigned r = 0, g = 0, b = 0; + unsigned mul = 65535 / ((1u << mode_in->bitdepth) - 1u); /*65535, 21845, 4369, 257, 1*/ + unsigned shift = 16 - mode_out->bitdepth;
-static unsigned addChunk_zTXt(ucvector* out, const char* keyword, const char* textstring, - LodePNGCompressSettings* zlibsettings) { - unsigned error = 0; - ucvector data, compressed; - size_t i, textsize = strlen(textstring); - - ucvector_init(&data); - ucvector_init(&compressed); - for(i = 0; keyword[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)keyword[i]); - if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/ - ucvector_push_back(&data, 0); /*0 termination char*/ - ucvector_push_back(&data, 0); /*compression method: 0*/ - - error = zlib_compress(&compressed.data, &compressed.size, - (unsigned char*)textstring, textsize, zlibsettings); - if(!error) { - for(i = 0; i != compressed.size; ++i) ucvector_push_back(&data, compressed.data[i]); - error = addChunk(out, "zTXt", data.data, data.size); + if(mode_in->colortype == LCT_GREY || mode_in->colortype == LCT_GREY_ALPHA) { + r = g = b = r_in * mul; + } else if(mode_in->colortype == LCT_RGB || mode_in->colortype == LCT_RGBA) { + r = r_in * mul; + g = g_in * mul; + b = b_in * mul; + } else if(mode_in->colortype == LCT_PALETTE) { + if(r_in >= mode_in->palettesize) return 82; + r = mode_in->palette[r_in * 4 + 0] * 257u; + g = mode_in->palette[r_in * 4 + 1] * 257u; + b = mode_in->palette[r_in * 4 + 2] * 257u; + } else { + return 31; }
- ucvector_cleanup(&compressed); - ucvector_cleanup(&data); - return error; -} - -static unsigned addChunk_iTXt(ucvector* out, unsigned compressed, const char* keyword, const char* langtag, - const char* transkey, const char* textstring, LodePNGCompressSettings* zlibsettings) { - unsigned error = 0; - ucvector data; - size_t i, textsize = strlen(textstring); - - ucvector_init(&data); - - for(i = 0; keyword[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)keyword[i]); - if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/ - ucvector_push_back(&data, 0); /*null termination char*/ - ucvector_push_back(&data, compressed ? 1 : 0); /*compression flag*/ - ucvector_push_back(&data, 0); /*compression method*/ - for(i = 0; langtag[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)langtag[i]); - ucvector_push_back(&data, 0); /*null termination char*/ - for(i = 0; transkey[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)transkey[i]); - ucvector_push_back(&data, 0); /*null termination char*/ - - if(compressed) { - ucvector compressed_data; - ucvector_init(&compressed_data); - error = zlib_compress(&compressed_data.data, &compressed_data.size, - (unsigned char*)textstring, textsize, zlibsettings); - if(!error) { - for(i = 0; i != compressed_data.size; ++i) ucvector_push_back(&data, compressed_data.data[i]); + /* now convert to output format */ + if(mode_out->colortype == LCT_GREY || mode_out->colortype == LCT_GREY_ALPHA) { + *r_out = r >> shift ; + } else if(mode_out->colortype == LCT_RGB || mode_out->colortype == LCT_RGBA) { + *r_out = r >> shift ; + *g_out = g >> shift ; + *b_out = b >> shift ; + } else if(mode_out->colortype == LCT_PALETTE) { + unsigned i; + /* a 16-bit color cannot be in the palette */ + if((r >> 8) != (r & 255) || (g >> 8) != (g & 255) || (b >> 8) != (b & 255)) return 82; + for(i = 0; i < mode_out->palettesize; i++) { + unsigned j = i * 4; + if((r >> 8) == mode_out->palette[j + 0] && (g >> 8) == mode_out->palette[j + 1] && + (b >> 8) == mode_out->palette[j + 2]) { + *r_out = i; + return 0; + } } - ucvector_cleanup(&compressed_data); - } else /*not compressed*/ { - for(i = 0; textstring[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)textstring[i]); + return 82; + } else { + return 31; }
- if(!error) error = addChunk(out, "iTXt", data.data, data.size); - ucvector_cleanup(&data); - return error; + return 0; }
-static unsigned addChunk_bKGD(ucvector* out, const LodePNGInfo* info) { - unsigned error = 0; - ucvector bKGD; - ucvector_init(&bKGD); - if(info->color.colortype == LCT_GREY || info->color.colortype == LCT_GREY_ALPHA) { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r >> 8)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_r & 255)); - } else if(info->color.colortype == LCT_RGB || info->color.colortype == LCT_RGBA) { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r >> 8)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_r & 255)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_g >> 8)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_g & 255)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_b >> 8)); - ucvector_push_back(&bKGD, (unsigned char)(info->background_b & 255)); - } else if(info->color.colortype == LCT_PALETTE) { - ucvector_push_back(&bKGD, (unsigned char)(info->background_r & 255)); /*palette index*/ - } +static short abs(short i) { + if (i < 0) + return -i; + return i; +}
- error = addChunk(out, "bKGD", bKGD.data, bKGD.size); - ucvector_cleanup(&bKGD); +/* +Paeth predicter, used by PNG filter type 4 +The parameters are of type short, but should come from unsigned chars, the shorts +are only needed to make the paeth calculation correct. +*/ +static unsigned char paethPredictor(short a, short b, short c) { + short pa = abs(b - c); + short pb = abs(a - c); + short pc = abs(a + b - c - c);
- return error; + if(pc < pa && pc < pb) return (unsigned char)c; + else if(pb < pa) return (unsigned char)b; + else return (unsigned char)a; }
-static unsigned addChunk_tIME(ucvector* out, const LodePNGTime* time) { - unsigned error = 0; - unsigned char* data = (unsigned char*)lodepng_malloc(7); - if(!data) return 83; /*alloc fail*/ - data[0] = (unsigned char)(time->year >> 8); - data[1] = (unsigned char)(time->year & 255); - data[2] = (unsigned char)time->month; - data[3] = (unsigned char)time->day; - data[4] = (unsigned char)time->hour; - data[5] = (unsigned char)time->minute; - data[6] = (unsigned char)time->second; - error = addChunk(out, "tIME", data, 7); - lodepng_free(data); - return error; -} +/*shared values used by multiple Adam7 related functions*/
-static unsigned addChunk_pHYs(ucvector* out, const LodePNGInfo* info) { - unsigned error = 0; - ucvector data; - ucvector_init(&data); +static const unsigned ADAM7_IX[7] = { 0, 4, 0, 2, 0, 1, 0 }; /*x start values*/ +static const unsigned ADAM7_IY[7] = { 0, 0, 4, 0, 2, 0, 1 }; /*y start values*/ +static const unsigned ADAM7_DX[7] = { 8, 8, 4, 4, 2, 2, 1 }; /*x delta values*/ +static const unsigned ADAM7_DY[7] = { 8, 8, 8, 4, 4, 2, 2 }; /*y delta values*/
- lodepng_add32bitInt(&data, info->phys_x); - lodepng_add32bitInt(&data, info->phys_y); - ucvector_push_back(&data, info->phys_unit); +/* +Outputs various dimensions and positions in the image related to the Adam7 reduced images. +passw: output containing the width of the 7 passes +passh: output containing the height of the 7 passes +filter_passstart: output containing the index of the start and end of each + reduced image with filter bytes +padded_passstart output containing the index of the start and end of each + reduced image when without filter bytes but with padded scanlines +passstart: output containing the index of the start and end of each reduced + image without padding between scanlines, but still padding between the images +w, h: width and height of non-interlaced image +bpp: bits per pixel +"padded" is only relevant if bpp is less than 8 and a scanline or image does not + end at a full byte +*/ +static void Adam7_getpassvalues(unsigned passw[7], unsigned passh[7], size_t filter_passstart[8], + size_t padded_passstart[8], size_t passstart[8], unsigned w, unsigned h, unsigned bpp) { + /*the passstart values have 8 values: the 8th one indicates the byte after the end of the 7th (= last) pass*/ + unsigned i;
- error = addChunk(out, "pHYs", data.data, data.size); - ucvector_cleanup(&data); + /*calculate width and height in pixels of each pass*/ + for(i = 0; i != 7; ++i) { + passw[i] = (w + ADAM7_DX[i] - ADAM7_IX[i] - 1) / ADAM7_DX[i]; + passh[i] = (h + ADAM7_DY[i] - ADAM7_IY[i] - 1) / ADAM7_DY[i]; + if(passw[i] == 0) passh[i] = 0; + if(passh[i] == 0) passw[i] = 0; + }
- return error; + filter_passstart[0] = padded_passstart[0] = passstart[0] = 0; + for(i = 0; i != 7; ++i) { + /*if passw[i] is 0, it's 0 bytes, not 1 (no filtertype-byte)*/ + filter_passstart[i + 1] = filter_passstart[i] + + ((passw[i] && passh[i]) ? passh[i] * (1 + (passw[i] * bpp + 7) / 8) : 0); + /*bits padded if needed to fill full byte at end of each scanline*/ + padded_passstart[i + 1] = padded_passstart[i] + passh[i] * ((passw[i] * bpp + 7) / 8); + /*only padded at end of reduced image*/ + passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7) / 8; + } }
-static unsigned addChunk_gAMA(ucvector* out, const LodePNGInfo* info) { - unsigned error = 0; - ucvector data; - ucvector_init(&data); - - lodepng_add32bitInt(&data, info->gama_gamma); - - error = addChunk(out, "gAMA", data.data, data.size); - ucvector_cleanup(&data); - - return error; -} +#ifdef LODEPNG_COMPILE_DECODER
-static unsigned addChunk_cHRM(ucvector* out, const LodePNGInfo* info) { - unsigned error = 0; - ucvector data; - ucvector_init(&data); +/* ////////////////////////////////////////////////////////////////////////// */ +/* / PNG Decoder / */ +/* ////////////////////////////////////////////////////////////////////////// */
- lodepng_add32bitInt(&data, info->chrm_white_x); - lodepng_add32bitInt(&data, info->chrm_white_y); - lodepng_add32bitInt(&data, info->chrm_red_x); - lodepng_add32bitInt(&data, info->chrm_red_y); - lodepng_add32bitInt(&data, info->chrm_green_x); - lodepng_add32bitInt(&data, info->chrm_green_y); - lodepng_add32bitInt(&data, info->chrm_blue_x); - lodepng_add32bitInt(&data, info->chrm_blue_y); +/*read the information from the header and store it in the LodePNGInfo. return value is error*/ +unsigned lodepng_inspect(unsigned* w, unsigned* h, LodePNGState* state, + const unsigned char* in, size_t insize) { + unsigned width, height; + LodePNGInfo* info = &state->info_png; + if(insize == 0 || in == 0) { + CERROR_RETURN_ERROR(state->error, 48); /*error: the given data is empty*/ + } + if(insize < 33) { + CERROR_RETURN_ERROR(state->error, 27); /*error: the data length is smaller than the length of a PNG header*/ + }
- error = addChunk(out, "cHRM", data.data, data.size); - ucvector_cleanup(&data); + /*when decoding a new PNG image, make sure all parameters created after previous decoding are reset*/ + /* TODO: remove this. One should use a new LodePNGState for new sessions */ + lodepng_info_cleanup(info); + lodepng_info_init(info);
- return error; -} + if(in[0] != 137 || in[1] != 80 || in[2] != 78 || in[3] != 71 + || in[4] != 13 || in[5] != 10 || in[6] != 26 || in[7] != 10) { + CERROR_RETURN_ERROR(state->error, 28); /*error: the first 8 bytes are not the correct PNG signature*/ + } + if(lodepng_chunk_length(in + 8) != 13) { + CERROR_RETURN_ERROR(state->error, 94); /*error: header size must be 13 bytes*/ + } + if(!lodepng_chunk_type_equals(in + 8, "IHDR")) { + CERROR_RETURN_ERROR(state->error, 29); /*error: it doesn't start with a IHDR chunk!*/ + }
-static unsigned addChunk_sRGB(ucvector* out, const LodePNGInfo* info) { - unsigned char data = info->srgb_intent; - return addChunk(out, "sRGB", &data, 1); -} + /*read the values given in the header*/ + width = lodepng_read32bitInt(&in[16]); + height = lodepng_read32bitInt(&in[20]); + info->color.bitdepth = in[24]; + info->color.colortype = (LodePNGColorType)in[25]; + info->compression_method = in[26]; + info->filter_method = in[27]; + info->interlace_method = in[28];
-static unsigned addChunk_iCCP(ucvector* out, const LodePNGInfo* info, LodePNGCompressSettings* zlibsettings) { - unsigned error = 0; - ucvector data, compressed; - size_t i; + if(width == 0 || height == 0) { + CERROR_RETURN_ERROR(state->error, 93); + }
- ucvector_init(&data); - ucvector_init(&compressed); - for(i = 0; info->iccp_name[i] != 0; ++i) ucvector_push_back(&data, (unsigned char)info->iccp_name[i]); - if(i < 1 || i > 79) return 89; /*error: invalid keyword size*/ - ucvector_push_back(&data, 0); /*0 termination char*/ - ucvector_push_back(&data, 0); /*compression method: 0*/ + if(w) *w = width; + if(h) *h = height;
- error = zlib_compress(&compressed.data, &compressed.size, - info->iccp_profile, info->iccp_profile_size, zlibsettings); - if(!error) { - for(i = 0; i != compressed.size; ++i) ucvector_push_back(&data, compressed.data[i]); - error = addChunk(out, "iCCP", data.data, data.size); + if(!state->decoder.ignore_crc) { + unsigned CRC = lodepng_read32bitInt(&in[29]); + unsigned checksum = lodepng_crc32(&in[12], 17); + if(CRC != checksum) { + CERROR_RETURN_ERROR(state->error, 57); /*invalid CRC*/ + } }
- ucvector_cleanup(&compressed); - ucvector_cleanup(&data); - return error; + /*error: only compression method 0 is allowed in the specification*/ + if(info->compression_method != 0) CERROR_RETURN_ERROR(state->error, 32); + /*error: only filter method 0 is allowed in the specification*/ + if(info->filter_method != 0) CERROR_RETURN_ERROR(state->error, 33); + /*error: only interlace methods 0 and 1 exist in the specification*/ + if(info->interlace_method > 1) CERROR_RETURN_ERROR(state->error, 34); + + state->error = checkColorValidity(info->color.colortype, info->color.bitdepth); + return state->error; }
-#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ +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. + */
-static void filterScanline(unsigned char* out, const unsigned char* scanline, const unsigned char* prevline, - size_t length, size_t bytewidth, unsigned char filterType) { size_t i; switch(filterType) { - case 0: /*None*/ - for(i = 0; i != length; ++i) out[i] = scanline[i]; + case 0: + for(i = 0; i != length; ++i) recon[i] = scanline[i]; break; - case 1: /*Sub*/ - for(i = 0; i != bytewidth; ++i) out[i] = scanline[i]; - for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - scanline[i - bytewidth]; + 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: /*Up*/ - if(prevline) { - for(i = 0; i != length; ++i) out[i] = scanline[i] - prevline[i]; + case 2: + if(precon) { + for(i = 0; i != length; ++i) recon[i] = scanline[i] + precon[i]; } else { - for(i = 0; i != length; ++i) out[i] = scanline[i]; + for(i = 0; i != length; ++i) recon[i] = scanline[i]; } break; - case 3: /*Average*/ - if(prevline) { - for(i = 0; i != bytewidth; ++i) out[i] = scanline[i] - (prevline[i] >> 1); - for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - ((scanline[i - bytewidth] + prevline[i]) >> 1); + case 3: + if(precon) { + for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i] + (precon[i] >> 1); + for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) >> 1); } else { - for(i = 0; i != bytewidth; ++i) out[i] = scanline[i]; - for(i = bytewidth; i < length; ++i) out[i] = scanline[i] - (scanline[i - bytewidth] >> 1); + for(i = 0; i != bytewidth; ++i) recon[i] = scanline[i]; + for(i = bytewidth; i < length; ++i) recon[i] = scanline[i] + (recon[i - bytewidth] >> 1); } break; - case 4: /*Paeth*/ - if(prevline) { - /*paethPredictor(0, prevline[i], 0) is always prevline[i]*/ - for(i = 0; i != bytewidth; ++i) out[i] = (scanline[i] - prevline[i]); + case 4: + if(precon) { + for(i = 0; i != bytewidth; ++i) { + recon[i] = (scanline[i] + precon[i]); /*paethPredictor(0, precon[i], 0) is always precon[i]*/ + } for(i = bytewidth; i < length; ++i) { - out[i] = (scanline[i] - paethPredictor(scanline[i - bytewidth], prevline[i], prevline[i - bytewidth])); + recon[i] = (scanline[i] + paethPredictor(recon[i - bytewidth], precon[i], precon[i - bytewidth])); } } else { - for(i = 0; i != bytewidth; ++i) out[i] = scanline[i]; - /*paethPredictor(scanline[i - bytewidth], 0, 0) is always scanline[i - bytewidth]*/ - for(i = bytewidth; i < length; ++i) out[i] = (scanline[i] - scanline[i - bytewidth]); + for(i = 0; i != bytewidth; ++i) { + recon[i] = scanline[i]; + } + for(i = bytewidth; i < length; ++i) { + /*paethPredictor(recon[i - bytewidth], 0, 0) is always recon[i - bytewidth]*/ + recon[i] = (scanline[i] + recon[i - bytewidth]); + } } break; - default: return; /*unexisting filter type given*/ + default: return 36; /*error: unexisting filter type given*/ } + return 0; }
-/* log2 approximation. A slight bit faster than std::log. */ -static float flog2(float f) { - float result = 0; - while(f > 32) { result += 4; f /= 16; } - while(f > 2) { ++result; f /= 2; } - return result + 1.442695f * (f * f * f / 3 - 3 * f * f / 2 + 3 * f - 1.83333f); -} - -static unsigned filter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, - const LodePNGColorMode* info, const LodePNGEncoderSettings* settings) { +static unsigned unfilter(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) { /* 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 + this function unfilters a single image (e.g. without interlacing this is called once, with Adam7 seven times) + out must have enough bytes allocated already, in must have the scanlines + 1 filtertype byte per scanline + w and h are image dimensions or dimensions of reduced image, bpp is bits per pixel + in and out are allowed to be the same memory address (but aren't the same size since in has the extra filter bytes) */
- unsigned bpp = lodepng_get_bpp(info); - /*the width of a scanline in bytes, not including the filter type*/ - size_t linebytes = (w * bpp + 7) / 8; + unsigned y; + unsigned char* prevline = 0; + /*bytewidth is used for filtering, is 1 when bpp < 8, number of bytes per pixel otherwise*/ size_t bytewidth = (bpp + 7) / 8; - const unsigned char* prevline = 0; - unsigned x, y; - unsigned error = 0; - LodePNGFilterStrategy strategy = settings->filter_strategy; - - /* - There is a heuristic called the minimum sum of absolute differences heuristic, suggested by the PNG standard: - * If the image type is Palette, or the bit depth is smaller than 8, then do not filter the image (i.e. - use fixed filtering, with the filter None). - * (The other case) If the image type is Grayscale or RGB (with or without Alpha), and the bit depth is - not smaller than 8, then use adaptive filtering heuristic as follows: independently for each row, apply - all five filters and select the filter that produces the smallest sum of absolute values per row. - This heuristic is used if filter strategy is LFS_MINSUM and filter_palette_zero is true. - - If filter_palette_zero is true and filter_strategy is not LFS_MINSUM, the above heuristic is followed, - but for "the other case", whatever strategy filter_strategy is set to instead of the minimum sum - heuristic is used. - */ - if(settings->filter_palette_zero && - (info->colortype == LCT_PALETTE || info->bitdepth < 8)) strategy = LFS_ZERO; - - if(bpp == 0) return 31; /*error: invalid color type*/ - - if(strategy == LFS_ZERO) { - for(y = 0; y != h; ++y) { - size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ - size_t inindex = linebytes * y; - out[outindex] = 0; /*filter type byte*/ - filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, 0); - prevline = &in[inindex]; - } - } else if(strategy == LFS_MINSUM) { - /*adaptive filtering*/ - size_t sum[5]; - unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/ - size_t smallest = 0; - unsigned char type, bestType = 0; - - for(type = 0; type != 5; ++type) { - attempt[type] = (unsigned char*)lodepng_malloc(linebytes); - if(!attempt[type]) return 83; /*alloc fail*/ - } - - if(!error) { - for(y = 0; y != h; ++y) { - /*try the 5 filter types*/ - for(type = 0; type != 5; ++type) { - filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); - - /*calculate the sum of the result*/ - sum[type] = 0; - if(type == 0) { - for(x = 0; x != linebytes; ++x) sum[type] += (unsigned char)(attempt[type][x]); - } else { - for(x = 0; x != linebytes; ++x) { - /*For differences, each byte should be treated as signed, values above 127 are negative - (converted to signed char). Filtertype 0 isn't a difference though, so use unsigned there. - This means filtertype 0 is almost never chosen, but that is justified.*/ - unsigned char s = attempt[type][x]; - sum[type] += s < 128 ? s : (255U - s); - } - } - - /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/ - if(type == 0 || sum[type] < smallest) { - bestType = type; - smallest = sum[type]; - } - } - - prevline = &in[y * linebytes]; - - /*now fill the out values*/ - out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ - for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x]; - } - } - - for(type = 0; type != 5; ++type) lodepng_free(attempt[type]); - } else if(strategy == LFS_ENTROPY) { - float sum[5]; - unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/ - float smallest = 0; - unsigned type, bestType = 0; - unsigned count[256]; - - for(type = 0; type != 5; ++type) { - attempt[type] = (unsigned char*)lodepng_malloc(linebytes); - if(!attempt[type]) return 83; /*alloc fail*/ - } - - for(y = 0; y != h; ++y) { - /*try the 5 filter types*/ - for(type = 0; type != 5; ++type) { - filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); - for(x = 0; x != 256; ++x) count[x] = 0; - for(x = 0; x != linebytes; ++x) ++count[attempt[type][x]]; - ++count[type]; /*the filter type itself is part of the scanline*/ - sum[type] = 0; - for(x = 0; x != 256; ++x) { - float p = count[x] / (float)(linebytes + 1); - sum[type] += count[x] == 0 ? 0 : flog2(1 / p) * p; - } - /*check if this is smallest sum (or if type == 0 it's the first case so always store the values)*/ - if(type == 0 || sum[type] < smallest) { - bestType = type; - smallest = sum[type]; - } - } + size_t linebytes = (w * bpp + 7) / 8;
- prevline = &in[y * linebytes]; + 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];
- /*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][x]; - } + CERROR_TRY_RETURN(unfilterScanline(&out[outindex], &in[inindex + 1], prevline, bytewidth, filterType, linebytes));
- for(type = 0; type != 5; ++type) lodepng_free(attempt[type]); - } else if(strategy == LFS_PREDEFINED) { - for(y = 0; y != h; ++y) { - size_t outindex = (1 + linebytes) * y; /*the extra filterbyte added to each row*/ - size_t inindex = linebytes * y; - unsigned char type = settings->predefined_filters[y]; - out[outindex] = type; /*filter type byte*/ - filterScanline(&out[outindex + 1], &in[inindex], prevline, linebytes, bytewidth, type); - prevline = &in[inindex]; - } - } else if(strategy == LFS_BRUTE_FORCE) { - /*brute force filter chooser. - deflate the scanline after every filter attempt to see which one deflates best. - This is very slow and gives only slightly smaller, sometimes even larger, result*/ - size_t size[5]; - unsigned char* attempt[5]; /*five filtering attempts, one for each filter type*/ - size_t smallest = 0; - unsigned type = 0, bestType = 0; - unsigned char* dummy; - LodePNGCompressSettings zlibsettings = settings->zlibsettings; - /*use fixed tree on the attempts so that the tree is not adapted to the filtertype on purpose, - to simulate the true case where the tree is the same for the whole image. Sometimes it gives - better result with dynamic tree anyway. Using the fixed tree sometimes gives worse, but in rare - cases better compression. It does make this a bit less slow, so it's worth doing this.*/ - zlibsettings.btype = 1; - /*a custom encoder likely doesn't read the btype setting and is optimized for complete PNG - images only, so disable it*/ - zlibsettings.custom_zlib = 0; - zlibsettings.custom_deflate = 0; - for(type = 0; type != 5; ++type) { - attempt[type] = (unsigned char*)lodepng_malloc(linebytes); - if(!attempt[type]) return 83; /*alloc fail*/ - } - for(y = 0; y != h; ++y) /*try the 5 filter types*/ { - for(type = 0; type != 5; ++type) { - unsigned testsize = (unsigned)linebytes; - /*if(testsize > 8) testsize /= 8;*/ /*it already works good enough by testing a part of the row*/ - - filterScanline(attempt[type], &in[y * linebytes], prevline, linebytes, bytewidth, type); - size[type] = 0; - dummy = 0; - zlib_compress(&dummy, &size[type], attempt[type], testsize, &zlibsettings); - lodepng_free(dummy); - /*check if this is smallest size (or if type == 0 it's the first case so always store the values)*/ - if(type == 0 || size[type] < smallest) { - bestType = type; - smallest = size[type]; - } - } - prevline = &in[y * linebytes]; - out[y * (linebytes + 1)] = bestType; /*the first byte of a scanline will be the filter type*/ - for(x = 0; x != linebytes; ++x) out[y * (linebytes + 1) + 1 + x] = attempt[bestType][x]; - } - for(type = 0; type != 5; ++type) lodepng_free(attempt[type]); + prevline = &out[outindex]; } - else return 88; /* unknown filter strategy */ - - return error; -}
-static void addPaddingBits(unsigned char* out, const unsigned char* in, - size_t olinebits, size_t ilinebits, unsigned h) { - /*The opposite of the removePaddingBits function - olinebits must be >= ilinebits*/ - unsigned y; - size_t diff = olinebits - ilinebits; - size_t obp = 0, ibp = 0; /*bit pointers*/ - for(y = 0; y != h; ++y) { - size_t x; - for(x = 0; x < ilinebits; ++x) { - unsigned char bit = readBitFromReversedStream(&ibp, in); - setBitOfReversedStream(&obp, out, bit); - } - /*obp += diff; --> no, fill in some value in the padding bits too, to avoid - "Use of uninitialised value of size ###" warning from valgrind*/ - for(x = 0; x != diff; ++x) setBitOfReversedStream(&obp, out, 0); - } + return 0; }
/* -in: non-interlaced image with size w*h -out: the same pixels, but re-ordered according to PNG's Adam7 interlacing, with - no padding bits between scanlines, but between reduced images so that each - reduced image starts at a byte. +in: Adam7 interlaced image, with no padding bits between scanlines, but between + reduced images so that each reduced image starts at a byte. +out: the same pixels, but re-ordered so that they're now a non-interlaced image with size w*h bpp: bits per pixel -there are no padding bits, not between scanlines, not between reduced images -in has the following size in bits: w * h * bpp. -out is possibly bigger due to padding bits between reduced images +out has the following size in bits: w * h * bpp. +in is possibly bigger due to padding bits between reduced images. +out must be big enough AND must be 0 everywhere if bpp < 8 in the current implementation +(because that's likely a little bit faster) NOTE: comments about padding bits are only relevant if bpp < 8 */ -static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) { +static void Adam7_deinterlace(unsigned char* out, const unsigned char* in, unsigned w, unsigned h, unsigned bpp) { unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; unsigned i; @@ -5219,8 +2099,8 @@ static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigne size_t bytewidth = bpp / 8; for(y = 0; y < passh[i]; ++y) for(x = 0; x < passw[i]; ++x) { - size_t pixelinstart = ((ADAM7_IY[i] + y * ADAM7_DY[i]) * w + ADAM7_IX[i] + x * ADAM7_DX[i]) * bytewidth; - size_t pixeloutstart = passstart[i] + (y * passw[i] + x) * bytewidth; + 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]; } @@ -5234,437 +2114,390 @@ static void Adam7_interlace(unsigned char* out, const unsigned char* in, unsigne size_t obp, ibp; /*bit pointers (for out and in buffer)*/ for(y = 0; y < passh[i]; ++y) for(x = 0; x < passw[i]; ++x) { - ibp = (ADAM7_IY[i] + y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + x * ADAM7_DX[i]) * bpp; - obp = (8 * passstart[i]) + (y * ilinebits + x * bpp); + 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); - setBitOfReversedStream(&obp, out, bit); + /*note that this function assumes the out buffer is completely 0, use setBitOfReversedStream otherwise*/ + setBitOfReversedStream0(&obp, out, bit); } } } } }
-/*out must be buffer big enough to contain uncompressed IDAT chunk data, and in must contain the full image. -return value is error**/ -static unsigned preProcessScanlines(unsigned char** out, size_t* outsize, const unsigned char* in, - unsigned w, unsigned h, - const LodePNGInfo* info_png, const LodePNGEncoderSettings* settings) { +static void removePaddingBits(unsigned char* out, const unsigned char* in, + size_t olinebits, size_t ilinebits, unsigned h) { + /* + After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need + to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers + for the Adam7 code, the color convert code and the output to the user. + in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must + have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits + also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7 + only useful if (ilinebits - olinebits) is a value in the range 1..7 + */ + unsigned y; + size_t diff = ilinebits - olinebits; + size_t ibp = 0, obp = 0; /*input and output bit pointers*/ + for(y = 0; y < h; ++y) { + size_t x; + for(x = 0; x < olinebits; ++x) { + unsigned char bit = readBitFromReversedStream(&ibp, in); + setBitOfReversedStream(&obp, out, bit); + } + ibp += diff; + } +} + +/*out must be buffer big enough to contain full image, and in must contain the full decompressed data from +the IDAT chunks (with filter index bytes and possible padding bits) +return value is error*/ +static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, + unsigned w, unsigned h, const LodePNGInfo* info_png) { /* - This function converts the pure 2D image with the PNG's colortype, into filtered-padded-interlaced data. Steps: - *) if no Adam7: 1) add padding bits (= posible extra bits per scanline if bpp < 8) 2) filter - *) if adam7: 1) Adam7_interlace 2) 7x add padding bits 3) 7x filter + This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype. + Steps: + *) if no Adam7: 1) unfilter 2) remove padding bits (= posible extra bits per scanline if bpp < 8) + *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace + NOTE: the in buffer will be overwritten with intermediate data! */ unsigned bpp = lodepng_get_bpp(&info_png->color); - unsigned error = 0; + if(bpp == 0) return 31; /*error: invalid colortype*/
if(info_png->interlace_method == 0) { - *outsize = h + (h * ((w * bpp + 7) / 8)); /*image size plus an extra byte per scanline + possible padding bits*/ - *out = (unsigned char*)lodepng_malloc(*outsize); - if(!(*out) && (*outsize)) error = 83; /*alloc fail*/ - - if(!error) { - /*non multiple of 8 bits per scanline, padding bits needed per scanline*/ - if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) { - unsigned char* padded = (unsigned char*)lodepng_malloc(h * ((w * bpp + 7) / 8)); - if(!padded) error = 83; /*alloc fail*/ - if(!error) { - addPaddingBits(padded, in, ((w * bpp + 7) / 8) * 8, w * bpp, h); - error = filter(*out, padded, w, h, &info_png->color, settings); - } - lodepng_free(padded); - } else { - /*we can immediately filter into the out buffer, no other steps needed*/ - error = filter(*out, in, w, h, &info_png->color, settings); + if(bpp < 8 && w * bpp != ((w * bpp + 7) / 8) * 8) { + CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp)); + removePaddingBits(out, in, w * bpp, ((w * bpp + 7) / 8) * 8, h); + } + /*we can immediately filter into the out buffer, no other steps needed*/ + else CERROR_TRY_RETURN(unfilter(out, in, w, h, bpp)); + } else /*interlace_method is 1 (Adam7)*/ { + unsigned passw[7], passh[7]; size_t filter_passstart[8], padded_passstart[8], passstart[8]; + unsigned i; + + Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); + + for(i = 0; i != 7; ++i) { + CERROR_TRY_RETURN(unfilter(&in[padded_passstart[i]], &in[filter_passstart[i]], passw[i], passh[i], bpp)); + /*TODO: possible efficiency improvement: if in this reduced image the bits fit nicely in 1 scanline, + move bytes instead of bits or move not at all*/ + if(bpp < 8) { + /*remove padding bits in scanlines; after this there still may be padding + bits between the different reduced images: each reduced image still starts nicely at a byte*/ + removePaddingBits(&in[passstart[i]], &in[padded_passstart[i]], passw[i] * bpp, + ((passw[i] * bpp + 7) / 8) * 8, passh[i]); } } - } else /*interlace_method is 1 (Adam7)*/ { - unsigned passw[7], passh[7]; - size_t filter_passstart[8], padded_passstart[8], passstart[8]; - unsigned char* adam7;
- Adam7_getpassvalues(passw, passh, filter_passstart, padded_passstart, passstart, w, h, bpp); + Adam7_deinterlace(out, in, w, h, bpp); + } + + return 0; +} + +static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) { + unsigned pos = 0, i; + if(color->palette) lodepng_free(color->palette); + color->palettesize = chunkLength / 3; + color->palette = (unsigned char*)lodepng_malloc(4 * color->palettesize); + if(!color->palette && color->palettesize) { + color->palettesize = 0; + return 83; /*alloc fail*/ + } + if(color->palettesize > 256) return 38; /*error: palette too big*/ + + for(i = 0; i != color->palettesize; ++i) { + color->palette[4 * i + 0] = data[pos++]; /*R*/ + color->palette[4 * i + 1] = data[pos++]; /*G*/ + color->palette[4 * i + 2] = data[pos++]; /*B*/ + color->palette[4 * i + 3] = 255; /*alpha*/ + } + + return 0; /* OK */ +} + +static unsigned readChunk_tRNS(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength) { + unsigned i; + if(color->colortype == LCT_PALETTE) { + /*error: more alpha values given than there are palette entries*/ + if(chunkLength > color->palettesize) return 39; + + for(i = 0; i != chunkLength; ++i) color->palette[4 * i + 3] = data[i]; + } else if(color->colortype == LCT_GREY) { + /*error: this chunk must be 2 bytes for greyscale image*/ + if(chunkLength != 2) return 30; + + color->key_defined = 1; + color->key_r = color->key_g = color->key_b = 256u * data[0] + data[1]; + } else if(color->colortype == LCT_RGB) { + /*error: this chunk must be 6 bytes for RGB image*/ + if(chunkLength != 6) return 41; + + color->key_defined = 1; + color->key_r = 256u * data[0] + data[1]; + color->key_g = 256u * data[2] + data[3]; + color->key_b = 256u * data[4] + data[5]; + } + else return 42; /*error: tRNS chunk not allowed for other color models*/ + + return 0; /* OK */ +} + +unsigned lodepng_inspect_chunk(LodePNGState* state, size_t pos, + const unsigned char* in, size_t insize) { + const unsigned char* chunk = in + pos; + unsigned chunkLength; + const unsigned char* data; + unsigned unhandled = 0; + unsigned error = 0; + + if (pos + 4 > insize) return 30; + chunkLength = lodepng_chunk_length(chunk); + if(chunkLength > 2147483647) return 63; + data = lodepng_chunk_data_const(chunk); + if(data + chunkLength + 4 > in + insize) return 30; + + if(lodepng_chunk_type_equals(chunk, "PLTE")) { + error = readChunk_PLTE(&state->info_png.color, data, chunkLength); + } else if(lodepng_chunk_type_equals(chunk, "tRNS")) { + error = readChunk_tRNS(&state->info_png.color, data, chunkLength); + } else { + /* unhandled chunk is ok (is not an error) */ + unhandled = 1; + } + + if(!error && !unhandled && !state->decoder.ignore_crc) { + if(lodepng_chunk_check_crc(chunk)) return 57; /*invalid CRC*/ + } + + return error; +} + +/*read a PNG, the result will be in the same color type as the PNG (hence "generic")*/ +static void decodeGeneric(unsigned char** out, unsigned* w, unsigned* h, + LodePNGState* state, + const unsigned char* in, size_t insize) { + unsigned char IEND = 0; + const unsigned char* chunk; + size_t i; + ucvector idat; /*the data from idat chunks*/ + ucvector scanlines; + size_t predict; + size_t outsize = 0; + + /*for unknown chunk order*/ + unsigned unknown = 0; + + /*provide some proper output values if error will happen*/ + *out = 0; + + state->error = lodepng_inspect(w, h, state, in, insize); /*reads header and resets other parameters in state->info_png*/ + if(state->error) return; + + if(lodepng_pixel_overflow(*w, *h, &state->info_png.color, &state->info_raw)) { + CERROR_RETURN(state->error, 92); /*overflow possible due to amount of pixels*/ + } + + ucvector_init(&idat); + chunk = &in[33]; /*first byte of the first chunk after the header*/ + + /*loop through the chunks, ignoring unknown chunks and stopping at IEND chunk. + IDAT data is put at the start of the in buffer*/ + while(!IEND && !state->error) { + unsigned chunkLength; + const unsigned char* data; /*the data in the chunk*/ + + /*error: size of the in buffer too small to contain next chunk*/ + if((size_t)((chunk - in) + 12) > insize || chunk < in) { + if(state->decoder.ignore_end) break; /*other errors may still happen though*/ + CERROR_BREAK(state->error, 30); + } + + /*length of the data of the chunk, excluding the length bytes, chunk type and CRC bytes*/ + chunkLength = lodepng_chunk_length(chunk); + /*error: chunk length larger than the max PNG chunk size*/ + if(chunkLength > 2147483647) { + if(state->decoder.ignore_end) break; /*other errors may still happen though*/ + CERROR_BREAK(state->error, 63); + } + + if((size_t)((chunk - in) + chunkLength + 12) > insize || (chunk + chunkLength + 12) < in) { + CERROR_BREAK(state->error, 64); /*error: size of the in buffer too small to contain next chunk*/ + } + + data = lodepng_chunk_data_const(chunk);
- *outsize = filter_passstart[7]; /*image size plus an extra byte per scanline + possible padding bits*/ - *out = (unsigned char*)lodepng_malloc(*outsize); - if(!(*out)) error = 83; /*alloc fail*/ - - adam7 = (unsigned char*)lodepng_malloc(passstart[7]); - if(!adam7 && passstart[7]) error = 83; /*alloc fail*/ - - if(!error) { - unsigned i; - - Adam7_interlace(adam7, in, w, h, bpp); - for(i = 0; i != 7; ++i) { - if(bpp < 8) { - unsigned char* padded = (unsigned char*)lodepng_malloc(padded_passstart[i + 1] - padded_passstart[i]); - if(!padded) ERROR_BREAK(83); /*alloc fail*/ - addPaddingBits(padded, &adam7[passstart[i]], - ((passw[i] * bpp + 7) / 8) * 8, passw[i] * bpp, passh[i]); - error = filter(&(*out)[filter_passstart[i]], padded, - passw[i], passh[i], &info_png->color, settings); - lodepng_free(padded); - } else { - error = filter(&(*out)[filter_passstart[i]], &adam7[padded_passstart[i]], - passw[i], passh[i], &info_png->color, settings); - } + unknown = 0;
- if(error) break; + /*IDAT chunk, containing compressed image data*/ + if(lodepng_chunk_type_equals(chunk, "IDAT")) { + size_t oldsize = idat.size; + size_t newsize; + if(lodepng_addofl(oldsize, chunkLength, &newsize)) CERROR_BREAK(state->error, 95); + if(!ucvector_resize(&idat, newsize)) CERROR_BREAK(state->error, 83 /*alloc fail*/); + for(i = 0; i != chunkLength; ++i) idat.data[oldsize + i] = data[i]; + } else if(lodepng_chunk_type_equals(chunk, "IEND")) { + /*IEND chunk*/ + IEND = 1; + } else if(lodepng_chunk_type_equals(chunk, "PLTE")) { + /*palette chunk (PLTE)*/ + state->error = readChunk_PLTE(&state->info_png.color, data, chunkLength); + if(state->error) break; + } else if(lodepng_chunk_type_equals(chunk, "tRNS")) { + /*palette transparency chunk (tRNS). Even though this one is an ancillary chunk , it is still compiled + in without 'LODEPNG_COMPILE_ANCILLARY_CHUNKS' because it contains essential color information that + affects the alpha channel of pixels. */ + state->error = readChunk_tRNS(&state->info_png.color, data, chunkLength); + if(state->error) break; + } else /*it's not an implemented chunk type, so ignore it: skip over the data*/ { + /*error: unknown critical chunk (5th bit of first byte of chunk type is 0)*/ + if(!state->decoder.ignore_critical && !lodepng_chunk_ancillary(chunk)) { + CERROR_BREAK(state->error, 69); } - } - - lodepng_free(adam7); - }
- return error; -} + unknown = 1; + }
-/* -palette must have 4 * palettesize bytes allocated, and given in format RGBARGBARGBARGBA... -returns 0 if the palette is opaque, -returns 1 if the palette has a single color with alpha 0 ==> color key -returns 2 if the palette is semi-translucent. -*/ -static unsigned getPaletteTranslucency(const unsigned char* palette, size_t palettesize) { - size_t i; - unsigned key = 0; - unsigned r = 0, g = 0, b = 0; /*the value of the color with alpha 0, so long as color keying is possible*/ - for(i = 0; i != palettesize; ++i) { - if(!key && palette[4 * i + 3] == 0) { - r = palette[4 * i + 0]; g = palette[4 * i + 1]; b = palette[4 * i + 2]; - key = 1; - i = (size_t)(-1); /*restart from beginning, to detect earlier opaque colors with key's value*/ + if(!state->decoder.ignore_crc && !unknown) /*check CRC if wanted, only on known chunk types*/ { + if(lodepng_chunk_check_crc(chunk)) CERROR_BREAK(state->error, 57); /*invalid CRC*/ } - else if(palette[4 * i + 3] != 255) return 2; - /*when key, no opaque RGB may have key's RGB*/ - else if(key && r == palette[i * 4 + 0] && g == palette[i * 4 + 1] && b == palette[i * 4 + 2]) return 2; - } - return key; -}
-#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS -static unsigned addUnknownChunks(ucvector* out, unsigned char* data, size_t datasize) { - unsigned char* inchunk = data; - while((size_t)(inchunk - data) < datasize) { - CERROR_TRY_RETURN(lodepng_chunk_append(&out->data, &out->size, inchunk)); - out->allocsize = out->size; /*fix the allocsize again*/ - inchunk = lodepng_chunk_next(inchunk); + if(!IEND) chunk = lodepng_chunk_next_const(chunk); } - return 0; -} - -static unsigned isGreyICCProfile(const unsigned char* profile, unsigned size) { - /* - It is a grey profile if bytes 16-19 are "GRAY", rgb profile if bytes 16-19 - are "RGB ". We do not perform any full parsing of the ICC profile here, other - than check those 4 bytes to grayscale profile. Other than that, validity of - the profile is not checked. This is needed only because the PNG specification - requires using a non-grey color model if there is an ICC profile with "RGB " - (sadly limiting compression opportunities if the input data is greyscale RGB - data), and requires using a grey color model if it is "GRAY". - */ - if(size < 20) return 0; - return profile[16] == 'G' && profile[17] == 'R' && profile[18] == 'A' && profile[19] == 'Y'; -} - -static unsigned isRGBICCProfile(const unsigned char* profile, unsigned size) { - /* See comment in isGreyICCProfile*/ - if(size < 20) return 0; - return profile[16] == 'R' && profile[17] == 'G' && profile[18] == 'B' && profile[19] == ' '; -} -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - -unsigned lodepng_encode(unsigned char** out, size_t* outsize, - const unsigned char* image, unsigned w, unsigned h, - LodePNGState* state) { - unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/ - size_t datasize = 0; - ucvector outv; - LodePNGInfo info;
- ucvector_init(&outv); - lodepng_info_init(&info); - - /*provide some proper output values if error will happen*/ - *out = 0; - *outsize = 0; - state->error = 0; - - /*check input values validity*/ - if((state->info_png.color.colortype == LCT_PALETTE || state->encoder.force_palette) - && (state->info_png.color.palettesize == 0 || state->info_png.color.palettesize > 256)) { - state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/ - goto cleanup; - } - if(state->encoder.zlibsettings.btype > 2) { - state->error = 61; /*error: unexisting btype*/ - goto cleanup; - } - if(state->info_png.interlace_method > 1) { - state->error = 71; /*error: unexisting interlace mode*/ - goto cleanup; + ucvector_init(&scanlines); + /*predict output size, to allocate exact size for output buffer to avoid more dynamic allocation. + If the decompressed size does not match the prediction, the image must be corrupt.*/ + if(state->info_png.interlace_method == 0) { + predict = lodepng_get_raw_size_idat(*w, *h, &state->info_png.color); + } else { + /*Adam-7 interlaced: predicted size is the sum of the 7 sub-images sizes*/ + const LodePNGColorMode* color = &state->info_png.color; + predict = 0; + predict += lodepng_get_raw_size_idat((*w + 7) >> 3, (*h + 7) >> 3, color); + if(*w > 4) predict += lodepng_get_raw_size_idat((*w + 3) >> 3, (*h + 7) >> 3, color); + predict += lodepng_get_raw_size_idat((*w + 3) >> 2, (*h + 3) >> 3, color); + if(*w > 2) predict += lodepng_get_raw_size_idat((*w + 1) >> 2, (*h + 3) >> 2, color); + predict += lodepng_get_raw_size_idat((*w + 1) >> 1, (*h + 1) >> 2, color); + if(*w > 1) predict += lodepng_get_raw_size_idat((*w + 0) >> 1, (*h + 1) >> 1, color); + predict += lodepng_get_raw_size_idat((*w + 0), (*h + 0) >> 1, color); } - state->error = checkColorValidity(state->info_png.color.colortype, state->info_png.color.bitdepth); - if(state->error) goto cleanup; /*error: unexisting color type given*/ - state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth); - if(state->error) goto cleanup; /*error: unexisting color type given*/ - - /* color convert and compute scanline filter types */ - lodepng_info_copy(&info, &state->info_png); - if(state->encoder.auto_convert) { -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - if(state->info_png.background_defined) { - unsigned bg_r = state->info_png.background_r; - unsigned bg_g = state->info_png.background_g; - unsigned bg_b = state->info_png.background_b; - unsigned r = 0, g = 0, b = 0; - LodePNGColorProfile prof; - LodePNGColorMode mode16 = lodepng_color_mode_make(LCT_RGB, 16); - lodepng_convert_rgb(&r, &g, &b, bg_r, bg_g, bg_b, &mode16, &state->info_png.color); - lodepng_color_profile_init(&prof); - state->error = lodepng_get_color_profile(&prof, image, w, h, &state->info_raw); - if(state->error) goto cleanup; - lodepng_color_profile_add(&prof, r, g, b, 65535); - state->error = auto_choose_color_from_profile(&info.color, &state->info_raw, &prof); - if(state->error) goto cleanup; - if(lodepng_convert_rgb(&info.background_r, &info.background_g, &info.background_b, - bg_r, bg_g, bg_b, &info.color, &state->info_png.color)) { - state->error = 104; - goto cleanup; - } - } - else -#endif /* LODEPNG_COMPILE_ANCILLARY_CHUNKS */ - { - state->error = lodepng_auto_choose_color(&info.color, image, w, h, &state->info_raw); - if(state->error) goto cleanup; - } + if(!state->error && !ucvector_reserve(&scanlines, predict)) state->error = 83; /*alloc fail*/ + if(!state->error) { + state->error = zlib_decompress(&scanlines.data, &scanlines.size, idat.data, + idat.size, &state->decoder.zlibsettings); + if(!state->error && scanlines.size != predict) state->error = 91; /*decompressed size doesn't match prediction*/ } -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - if(state->info_png.iccp_defined) { - unsigned grey_icc = isGreyICCProfile(state->info_png.iccp_profile, state->info_png.iccp_profile_size); - unsigned grey_png = info.color.colortype == LCT_GREY || info.color.colortype == LCT_GREY_ALPHA; - /* TODO: perhaps instead of giving errors or less optimal compression, we can automatically modify - the ICC profile here to say "GRAY" or "RGB " to match the PNG color type, unless this will require - non trivial changes to the rest of the ICC profile */ - if(!grey_icc && !isRGBICCProfile(state->info_png.iccp_profile, state->info_png.iccp_profile_size)) { - state->error = 100; /* Disallowed profile color type for PNG */ - goto cleanup; - } - if(!state->encoder.auto_convert && grey_icc != grey_png) { - /* Non recoverable: encoder not allowed to convert color type, and requested color type not - compatible with ICC color type */ - state->error = 101; - goto cleanup; - } - if(grey_icc && !grey_png) { - /* Non recoverable: trying to set greyscale ICC profile while colored pixels were given */ - state->error = 102; - goto cleanup; - /* NOTE: this relies on the fact that lodepng_auto_choose_color never returns palette for greyscale pixels */ - } - if(!grey_icc && grey_png) { - /* Recoverable but an unfortunate loss in compression density: We have greyscale pixels but - are forced to store them in more expensive RGB format that will repeat each value 3 times - because the PNG spec does not allow an RGB ICC profile with internal greyscale color data */ - if(info.color.colortype == LCT_GREY) info.color.colortype = LCT_RGB; - if(info.color.colortype == LCT_GREY_ALPHA) info.color.colortype = LCT_RGBA; - if(info.color.bitdepth < 8) info.color.bitdepth = 8; - } + ucvector_cleanup(&idat); + + if(!state->error) { + outsize = lodepng_get_raw_size(*w, *h, &state->info_png.color); + *out = (unsigned char*)lodepng_malloc(outsize); + if(!*out) state->error = 83; /*alloc fail*/ } -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - if(!lodepng_color_mode_equal(&state->info_raw, &info.color)) { - unsigned char* converted; - size_t size = ((size_t)w * (size_t)h * (size_t)lodepng_get_bpp(&info.color) + 7) / 8; - - converted = (unsigned char*)lodepng_malloc(size); - if(!converted && size) state->error = 83; /*alloc fail*/ - if(!state->error) { - state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h); - } - if(!state->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder); - lodepng_free(converted); - if(state->error) goto cleanup; + if(!state->error) { + for(i = 0; i < outsize; i++) (*out)[i] = 0; + state->error = postProcessScanlines(*out, scanlines.data, *w, *h, &state->info_png); } - else preProcessScanlines(&data, &datasize, image, w, h, &info, &state->encoder); - - /* output all PNG chunks */ { -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - size_t i; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - /*write signature and chunks*/ - writeSignature(&outv); - /*IHDR*/ - addChunk_IHDR(&outv, w, h, info.color.colortype, info.color.bitdepth, info.interlace_method); -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /*unknown chunks between IHDR and PLTE*/ - if(info.unknown_chunks_data[0]) { - state->error = addUnknownChunks(&outv, info.unknown_chunks_data[0], info.unknown_chunks_size[0]); - if(state->error) goto cleanup; - } - /*color profile chunks must come before PLTE */ - if(info.iccp_defined) addChunk_iCCP(&outv, &info, &state->encoder.zlibsettings); - if(info.srgb_defined) addChunk_sRGB(&outv, &info); - if(info.gama_defined) addChunk_gAMA(&outv, &info); - if(info.chrm_defined) addChunk_cHRM(&outv, &info); -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - /*PLTE*/ - if(info.color.colortype == LCT_PALETTE) { - addChunk_PLTE(&outv, &info.color); - } - if(state->encoder.force_palette && (info.color.colortype == LCT_RGB || info.color.colortype == LCT_RGBA)) { - addChunk_PLTE(&outv, &info.color); - } - /*tRNS*/ - if(info.color.colortype == LCT_PALETTE && getPaletteTranslucency(info.color.palette, info.color.palettesize) != 0) { - addChunk_tRNS(&outv, &info.color); - } - if((info.color.colortype == LCT_GREY || info.color.colortype == LCT_RGB) && info.color.key_defined) { - addChunk_tRNS(&outv, &info.color); - } -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /*bKGD (must come between PLTE and the IDAt chunks*/ - if(info.background_defined) { - state->error = addChunk_bKGD(&outv, &info); - if(state->error) goto cleanup; - } - /*pHYs (must come before the IDAT chunks)*/ - if(info.phys_defined) addChunk_pHYs(&outv, &info); + ucvector_cleanup(&scanlines); +}
- /*unknown chunks between PLTE and IDAT*/ - if(info.unknown_chunks_data[1]) { - state->error = addUnknownChunks(&outv, info.unknown_chunks_data[1], info.unknown_chunks_size[1]); - if(state->error) goto cleanup; - } -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - /*IDAT (multiple IDAT chunks must be consecutive)*/ - state->error = addChunk_IDAT(&outv, data, datasize, &state->encoder.zlibsettings); - if(state->error) goto cleanup; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - /*tIME*/ - if(info.time_defined) addChunk_tIME(&outv, &info.time); - /*tEXt and/or zTXt*/ - for(i = 0; i != info.text_num; ++i) { - if(strlen(info.text_keys[i]) > 79) { - state->error = 66; /*text chunk too large*/ - goto cleanup; - } - if(strlen(info.text_keys[i]) < 1) { - state->error = 67; /*text chunk too small*/ - goto cleanup; - } - if(state->encoder.text_compression) { - addChunk_zTXt(&outv, info.text_keys[i], info.text_strings[i], &state->encoder.zlibsettings); - } else { - addChunk_tEXt(&outv, info.text_keys[i], info.text_strings[i]); - } - } - /*LodePNG version id in text chunk*/ - if(state->encoder.add_id) { - unsigned already_added_id_text = 0; - for(i = 0; i != info.text_num; ++i) { - if(!strcmp(info.text_keys[i], "LodePNG")) { - already_added_id_text = 1; - break; - } - } - if(already_added_id_text == 0) { - addChunk_tEXt(&outv, "LodePNG", LODEPNG_VERSION_STRING); /*it's shorter as tEXt than as zTXt chunk*/ - } +unsigned lodepng_decode(unsigned char** out, unsigned* w, unsigned* h, + LodePNGState* state, + const unsigned char* in, size_t insize) { + *out = 0; + decodeGeneric(out, w, h, state, in, insize); + if(state->error) return state->error; + if(!state->decoder.color_convert || lodepng_color_mode_equal(&state->info_raw, &state->info_png.color)) { + /*same color type, no copying or converting of data needed*/ + /*store the info_png color settings on the info_raw so that the info_raw still reflects what colortype + the raw image has to the end user*/ + if(!state->decoder.color_convert) { + state->error = lodepng_color_mode_copy(&state->info_raw, &state->info_png.color); + if(state->error) return state->error; } - /*iTXt*/ - for(i = 0; i != info.itext_num; ++i) { - if(strlen(info.itext_keys[i]) > 79) { - state->error = 66; /*text chunk too large*/ - goto cleanup; - } - if(strlen(info.itext_keys[i]) < 1) { - state->error = 67; /*text chunk too small*/ - goto cleanup; - } - addChunk_iTXt(&outv, state->encoder.text_compression, - info.itext_keys[i], info.itext_langtags[i], info.itext_transkeys[i], info.itext_strings[i], - &state->encoder.zlibsettings); + } else { + /*color conversion needed; sort of copy of the data*/ + unsigned char* data = *out; + size_t outsize; + + /*TODO: check if this works according to the statement in the documentation: "The converter can convert + from greyscale input color type, to 8-bit greyscale or greyscale with alpha"*/ + if(!(state->info_raw.colortype == LCT_RGB || state->info_raw.colortype == LCT_RGBA) + && !(state->info_raw.bitdepth == 8)) { + return 56; /*unsupported color mode conversion*/ }
- /*unknown chunks between IDAT and IEND*/ - if(info.unknown_chunks_data[2]) { - state->error = addUnknownChunks(&outv, info.unknown_chunks_data[2], info.unknown_chunks_size[2]); - if(state->error) goto cleanup; + outsize = lodepng_get_raw_size(*w, *h, &state->info_raw); + *out = (unsigned char*)lodepng_malloc(outsize); + if(!(*out)) { + state->error = 83; /*alloc fail*/ } -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ - addChunk_IEND(&outv); + else state->error = lodepng_convert(*out, data, &state->info_raw, + &state->info_png.color, *w, *h); + lodepng_free(data); } - -cleanup: - lodepng_info_cleanup(&info); - lodepng_free(data); - - /*instead of cleaning the vector up, give it to the output*/ - *out = outv.data; - *outsize = outv.size; - return state->error; }
-unsigned lodepng_encode_memory(unsigned char** out, size_t* outsize, const unsigned char* image, - unsigned w, unsigned h, LodePNGColorType colortype, unsigned bitdepth) { +unsigned lodepng_decode_memory(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, + size_t insize, LodePNGColorType colortype, unsigned bitdepth) { unsigned error; LodePNGState state; lodepng_state_init(&state); state.info_raw.colortype = colortype; state.info_raw.bitdepth = bitdepth; - state.info_png.color.colortype = colortype; - state.info_png.color.bitdepth = bitdepth; - lodepng_encode(out, outsize, image, w, h, &state); - error = state.error; + error = lodepng_decode(out, w, h, &state, in, insize); lodepng_state_cleanup(&state); return error; }
-unsigned lodepng_encode32(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) { - return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGBA, 8); +unsigned lodepng_decode32(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) { + return lodepng_decode_memory(out, w, h, in, insize, LCT_RGBA, 8); }
-unsigned lodepng_encode24(unsigned char** out, size_t* outsize, const unsigned char* image, unsigned w, unsigned h) { - return lodepng_encode_memory(out, outsize, image, w, h, LCT_RGB, 8); +unsigned lodepng_decode24(unsigned char** out, unsigned* w, unsigned* h, const unsigned char* in, size_t insize) { + return lodepng_decode_memory(out, w, h, in, insize, LCT_RGB, 8); }
-#ifdef LODEPNG_COMPILE_DISK -unsigned lodepng_encode_file(const char* filename, const unsigned char* image, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth) { - unsigned char* buffer; - size_t buffersize; - unsigned error = lodepng_encode_memory(&buffer, &buffersize, image, w, h, colortype, bitdepth); - if(!error) error = lodepng_save_file(buffer, buffersize, filename); - lodepng_free(buffer); - return error; +void lodepng_decoder_settings_init(LodePNGDecoderSettings* settings) { + settings->color_convert = 1; + settings->ignore_crc = 0; + settings->ignore_critical = 0; + settings->ignore_end = 0; + lodepng_decompress_settings_init(&settings->zlibsettings); }
-unsigned lodepng_encode32_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) { - return lodepng_encode_file(filename, image, w, h, LCT_RGBA, 8); +#endif /*LODEPNG_COMPILE_DECODER*/ + +#if defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) + +void lodepng_state_init(LodePNGState* state) { +#ifdef LODEPNG_COMPILE_DECODER + lodepng_decoder_settings_init(&state->decoder); +#endif /*LODEPNG_COMPILE_DECODER*/ + lodepng_color_mode_init(&state->info_raw); + lodepng_info_init(&state->info_png); + state->error = 1; }
-unsigned lodepng_encode24_file(const char* filename, const unsigned char* image, unsigned w, unsigned h) { - return lodepng_encode_file(filename, image, w, h, LCT_RGB, 8); +void lodepng_state_cleanup(LodePNGState* state) { + lodepng_color_mode_cleanup(&state->info_raw); + lodepng_info_cleanup(&state->info_png); } -#endif /*LODEPNG_COMPILE_DISK*/ - -void lodepng_encoder_settings_init(LodePNGEncoderSettings* settings) { - lodepng_compress_settings_init(&settings->zlibsettings); - settings->filter_palette_zero = 1; - settings->filter_strategy = LFS_MINSUM; - settings->auto_convert = 1; - settings->force_palette = 0; - settings->predefined_filters = 0; -#ifdef LODEPNG_COMPILE_ANCILLARY_CHUNKS - settings->add_id = 0; - settings->text_compression = 1; -#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/ + +void lodepng_state_copy(LodePNGState* dest, const LodePNGState* source) { + lodepng_state_cleanup(dest); + *dest = *source; + lodepng_color_mode_init(&dest->info_raw); + lodepng_info_init(&dest->info_png); + dest->error = lodepng_color_mode_copy(&dest->info_raw, &source->info_raw); if(dest->error) return; + dest->error = lodepng_info_copy(&dest->info_png, &source->info_png); if(dest->error) return; }
-#endif /*LODEPNG_COMPILE_ENCODER*/ +#endif /* defined(LODEPNG_COMPILE_DECODER) || defined(LODEPNG_COMPILE_ENCODER) */ + #endif /*LODEPNG_COMPILE_PNG*/
#ifdef LODEPNG_COMPILE_ERROR_TEXT @@ -5783,201 +2616,3 @@ const char* lodepng_error_text(unsigned code) { return "unknown error code"; } #endif /*LODEPNG_COMPILE_ERROR_TEXT*/ - -/* ////////////////////////////////////////////////////////////////////////// */ -/* ////////////////////////////////////////////////////////////////////////// */ -/* // C++ Wrapper // */ -/* ////////////////////////////////////////////////////////////////////////// */ -/* ////////////////////////////////////////////////////////////////////////// */ - -#ifdef LODEPNG_COMPILE_CPP -namespace lodepng { - -#ifdef LODEPNG_COMPILE_DISK -unsigned load_file(std::vector<unsigned char>& buffer, const std::string& filename) { - long size = lodepng_filesize(filename.c_str()); - if(size < 0) return 78; - buffer.resize((size_t)size); - return size == 0 ? 0 : lodepng_buffer_file(&buffer[0], (size_t)size, filename.c_str()); -} - -/*write given buffer to the file, overwriting the file, it doesn't append to it.*/ -unsigned save_file(const std::vector<unsigned char>& buffer, const std::string& filename) { - return lodepng_save_file(buffer.empty() ? 0 : &buffer[0], buffer.size(), filename.c_str()); -} -#endif /* LODEPNG_COMPILE_DISK */ - -#ifdef LODEPNG_COMPILE_ZLIB -#ifdef LODEPNG_COMPILE_DECODER -unsigned decompress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize, - const LodePNGDecompressSettings& settings) { - unsigned char* buffer = 0; - size_t buffersize = 0; - unsigned error = zlib_decompress(&buffer, &buffersize, in, insize, &settings); - if(buffer) { - out.insert(out.end(), &buffer[0], &buffer[buffersize]); - lodepng_free(buffer); - } - return error; -} - -unsigned decompress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, - const LodePNGDecompressSettings& settings) { - return decompress(out, in.empty() ? 0 : &in[0], in.size(), settings); -} -#endif /* LODEPNG_COMPILE_DECODER */ - -#ifdef LODEPNG_COMPILE_ENCODER -unsigned compress(std::vector<unsigned char>& out, const unsigned char* in, size_t insize, - const LodePNGCompressSettings& settings) { - unsigned char* buffer = 0; - size_t buffersize = 0; - unsigned error = zlib_compress(&buffer, &buffersize, in, insize, &settings); - if(buffer) { - out.insert(out.end(), &buffer[0], &buffer[buffersize]); - lodepng_free(buffer); - } - return error; -} - -unsigned compress(std::vector<unsigned char>& out, const std::vector<unsigned char>& in, - const LodePNGCompressSettings& settings) { - return compress(out, in.empty() ? 0 : &in[0], in.size(), settings); -} -#endif /* LODEPNG_COMPILE_ENCODER */ -#endif /* LODEPNG_COMPILE_ZLIB */ - - -#ifdef LODEPNG_COMPILE_PNG - -State::State() { - lodepng_state_init(this); -} - -State::State(const State& other) { - lodepng_state_init(this); - lodepng_state_copy(this, &other); -} - -State::~State() { - lodepng_state_cleanup(this); -} - -State& State::operator=(const State& other) { - lodepng_state_copy(this, &other); - return *this; -} - -#ifdef LODEPNG_COMPILE_DECODER - -unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const unsigned char* in, - size_t insize, LodePNGColorType colortype, unsigned bitdepth) { - unsigned char* buffer; - unsigned error = lodepng_decode_memory(&buffer, &w, &h, in, insize, colortype, bitdepth); - if(buffer && !error) { - State state; - state.info_raw.colortype = colortype; - state.info_raw.bitdepth = bitdepth; - size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw); - out.insert(out.end(), &buffer[0], &buffer[buffersize]); - lodepng_free(buffer); - } - return error; -} - -unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - const std::vector<unsigned char>& in, LodePNGColorType colortype, unsigned bitdepth) { - return decode(out, w, h, in.empty() ? 0 : &in[0], (unsigned)in.size(), colortype, bitdepth); -} - -unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - State& state, - const unsigned char* in, size_t insize) { - unsigned char* buffer = NULL; - unsigned error = lodepng_decode(&buffer, &w, &h, &state, in, insize); - if(buffer && !error) { - size_t buffersize = lodepng_get_raw_size(w, h, &state.info_raw); - out.insert(out.end(), &buffer[0], &buffer[buffersize]); - } - lodepng_free(buffer); - return error; -} - -unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, - State& state, - const std::vector<unsigned char>& in) { - return decode(out, w, h, state, in.empty() ? 0 : &in[0], in.size()); -} - -#ifdef LODEPNG_COMPILE_DISK -unsigned decode(std::vector<unsigned char>& out, unsigned& w, unsigned& h, const std::string& filename, - LodePNGColorType colortype, unsigned bitdepth) { - std::vector<unsigned char> buffer; - unsigned error = load_file(buffer, filename); - if(error) return error; - return decode(out, w, h, buffer, colortype, bitdepth); -} -#endif /* LODEPNG_COMPILE_DECODER */ -#endif /* LODEPNG_COMPILE_DISK */ - -#ifdef LODEPNG_COMPILE_ENCODER -unsigned encode(std::vector<unsigned char>& out, const unsigned char* in, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth) { - unsigned char* buffer; - size_t buffersize; - unsigned error = lodepng_encode_memory(&buffer, &buffersize, in, w, h, colortype, bitdepth); - if(buffer) { - out.insert(out.end(), &buffer[0], &buffer[buffersize]); - lodepng_free(buffer); - } - return error; -} - -unsigned encode(std::vector<unsigned char>& out, - const std::vector<unsigned char>& in, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth) { - if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84; - return encode(out, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth); -} - -unsigned encode(std::vector<unsigned char>& out, - const unsigned char* in, unsigned w, unsigned h, - State& state) { - unsigned char* buffer; - size_t buffersize; - unsigned error = lodepng_encode(&buffer, &buffersize, in, w, h, &state); - if(buffer) { - out.insert(out.end(), &buffer[0], &buffer[buffersize]); - lodepng_free(buffer); - } - return error; -} - -unsigned encode(std::vector<unsigned char>& out, - const std::vector<unsigned char>& in, unsigned w, unsigned h, - State& state) { - if(lodepng_get_raw_size(w, h, &state.info_raw) > in.size()) return 84; - return encode(out, in.empty() ? 0 : &in[0], w, h, state); -} - -#ifdef LODEPNG_COMPILE_DISK -unsigned encode(const std::string& filename, - const unsigned char* in, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth) { - std::vector<unsigned char> buffer; - unsigned error = encode(buffer, in, w, h, colortype, bitdepth); - if(!error) error = save_file(buffer, filename); - return error; -} - -unsigned encode(const std::string& filename, - const std::vector<unsigned char>& in, unsigned w, unsigned h, - LodePNGColorType colortype, unsigned bitdepth) { - if(lodepng_get_raw_size_lct(w, h, colortype, bitdepth) > in.size()) return 84; - return encode(filename, in.empty() ? 0 : &in[0], w, h, colortype, bitdepth); -} -#endif /* LODEPNG_COMPILE_DISK */ -#endif /* LODEPNG_COMPILE_ENCODER */ -#endif /* LODEPNG_COMPILE_PNG */ -} /* namespace lodepng */ -#endif /*LODEPNG_COMPILE_CPP*/ diff --git a/src/lodepng.h b/src/lodepng.h index 6f16160..8c157b8 100644 --- a/src/lodepng.h +++ b/src/lodepng.h @@ -26,7 +26,7 @@ freely, subject to the following restrictions: #ifndef LODEPNG_H #define LODEPNG_H
-#include <string.h> /*for size_t*/ +#include "string.h" /*for size_t*/
extern const char* LODEPNG_VERSION_STRING;