--- /dev/null
+/*
+ * Copyright (c) 2020-2021 Samsung Electronics Co., Ltd. All rights reserved.
+
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+/*
+ LodePNG version 20200306
+
+ Copyright (c) 2005-2020 Lode Vandevenne
+
+ This software is provided 'as-is', without any express or implied
+ warranty. In no event will the authors be held liable for any damages
+ arising from the use of this software.
+
+ Permission is granted to anyone to use this software for any purpose,
+ including commercial applications, and to alter it and redistribute it
+ freely, subject to the following restrictions:
+
+ 1. The origin of this software must not be misrepresented; you must not
+ claim that you wrote the original software. If you use this software
+ in a product, an acknowledgment in the product documentation would be
+ appreciated but is not required.
+
+ 2. Altered source versions must be plainly marked as such, and must not be
+ misrepresented as being the original software.
+
+ 3. This notice may not be removed or altered from any sourcedistribution.
+*/
+
+#include <cstdlib>
+#include "tvgLodePng.h"
+
+
+/************************************************************************/
+/* Internal Class Implementation */
+/************************************************************************/
+
+#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*/
+ #pragma warning( disable : 4996 ) /*VS does not like fopen, but fopen_s is not standard C so unusable here*/
+#endif /*_MSC_VER */
+
+
+/* convince the compiler to inline a function, for use when this measurably improves performance */
+/* inline is not available in C90, but use it when supported by the compiler */
+#if (defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L)) || (defined(__cplusplus) && (__cplusplus >= 199711L))
+ #define LODEPNG_INLINE inline
+#else
+ #define LODEPNG_INLINE /* not available */
+#endif
+
+/* restrict is not available in C90, but use it when supported by the compiler */
+#if (defined(__GNUC__) && (__GNUC__ > 3 || (__GNUC__ == 3 && __GNUC_MINOR__ >= 1))) ||\
+ (defined(_MSC_VER) && (_MSC_VER >= 1400)) || \
+ (defined(__WATCOMC__) && (__WATCOMC__ >= 1250) && !defined(__cplusplus))
+ #define LODEPNG_RESTRICT __restrict
+#else
+ #define LODEPNG_RESTRICT /* not available */
+#endif
+
+#define LODEPNG_MAX(a, b) (((a) > (b)) ? (a) : (b))
+#define LODEPNG_MIN(a, b) (((a) < (b)) ? (a) : (b))
+#define LODEPNG_ABS(x) ((x) < 0 ? -(x) : (x))
+
+
+/* Replacements for C library functions such as memcpy and strlen, to support platforms
+where a full C library is not available. The compiler can recognize them and compile
+to something as fast. */
+
+static void lodepng_memcpy(void* LODEPNG_RESTRICT dst, const void* LODEPNG_RESTRICT src, size_t size)
+{
+ size_t i;
+ for (i = 0; i < size; i++) ((char*)dst)[i] = ((const char*)src)[i];
+}
+
+
+static void lodepng_memset(void* LODEPNG_RESTRICT dst, int value, size_t num)
+{
+ size_t i;
+ for (i = 0; i < num; i++) ((char*)dst)[i] = (char)value;
+}
+
+
+/* does not check memory out of bounds, do not use on untrusted data */
+static size_t lodepng_strlen(const char* a)
+{
+ const char* orig = a;
+ /* avoid warning about unused function in case of disabled COMPILE... macros */
+ (void)(&lodepng_strlen);
+ while (*a) a++;
+ return (size_t)(a - orig);
+}
+
+
+/* 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 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 a + b > c, even if overflow could happen. */
+static int lodepng_gtofl(size_t a, size_t b, size_t c)
+{
+ size_t d;
+ if (lodepng_addofl(a, b, &d)) return 1;
+ return d > c;
+}
+
+
+/*
+ Often in case of an error a value is assigned to a variable and then it breaks
+ out of a loop (to go to the cleanup phase of a function). This macro does that.
+ It makes the error handling code shorter and more readable.
+
+ Example: if(!uivector_resize(&lz77_encoded, datasize)) ERROR_BREAK(83);
+*/
+#define CERROR_BREAK(errorvar, code){\
+ errorvar = code;\
+ break;\
+}
+
+/* version of CERROR_BREAK that assumes the common case where the error variable is named "error" */
+#define ERROR_BREAK(code) CERROR_BREAK(error, code)
+
+/* Set error var to the error code, and return it.*/
+#define CERROR_RETURN_ERROR(errorvar, code){\
+ errorvar = code;\
+ return code;\
+}
+
+/* Try the code, if it returns error, also return the error. */
+#define CERROR_TRY_RETURN(call){\
+ unsigned error = call;\
+ if(error) return error;\
+}
+
+/* Set error var to the error code, and return from the void function. */
+#define CERROR_RETURN(errorvar, code){\
+ errorvar = code;\
+ return;\
+}
+
+
+/* dynamic vector of unsigned chars */
+struct ucvector
+{
+ unsigned char* data;
+ size_t size; /*used size*/
+ size_t allocsize; /*allocated size*/
+};
+
+
+/* returns 1 if success, 0 if failure ==> nothing done */
+static unsigned ucvector_resize(ucvector* p, size_t size)
+{
+ if (size > p->allocsize) {
+ size_t newsize = size + (p->allocsize >> 1u);
+ void* data = realloc(p->data, newsize);
+ if(data) {
+ p->allocsize = newsize;
+ p->data = (unsigned char*)data;
+ }
+ else return 0; /*error: not enough memory*/
+ }
+ p->size = size;
+ return 1; /*success*/
+}
+
+
+static ucvector ucvector_init(unsigned char* buffer, size_t size)
+{
+ ucvector v;
+ v.data = buffer;
+ v.allocsize = v.size = size;
+ return v;
+}
+
+
+static unsigned lodepng_read32bitInt(const unsigned char* buffer)
+{
+ return (((unsigned)buffer[0] << 24u) | ((unsigned)buffer[1] << 16u) | ((unsigned)buffer[2] << 8u) | (unsigned)buffer[3]);
+}
+
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // End of common code and tools. Begin of Zlib related code. // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+struct LodePNGBitReader
+{
+ const unsigned char* data;
+ size_t size; /*size of data in bytes*/
+ size_t bitsize; /*size of data in bits, end of valid bp values, should be 8*size*/
+ size_t bp;
+ unsigned buffer; /*buffer for reading bits. NOTE: 'unsigned' must support at least 32 bits*/
+};
+
+
+/* data size argument is in bytes. Returns error if size too large causing overflow */
+static unsigned LodePNGBitReader_init(LodePNGBitReader* reader, const unsigned char* data, size_t size)
+{
+ size_t temp;
+ reader->data = data;
+ reader->size = size;
+ /* size in bits, return error if overflow (if size_t is 32 bit this supports up to 500MB) */
+ if (lodepng_mulofl(size, 8u, &reader->bitsize)) return 105;
+ /*ensure incremented bp can be compared to bitsize without overflow even when it would be incremented 32 too much and
+ trying to ensure 32 more bits*/
+ if (lodepng_addofl(reader->bitsize, 64u, &temp)) return 105;
+ reader->bp = 0;
+ reader->buffer = 0;
+ return 0; /*ok*/
+ }
+
+/*
+ ensureBits functions:
+ Ensures the reader can at least read nbits bits in one or more readBits calls,
+ safely even if not enough bits are available.
+ Returns 1 if there are enough bits available, 0 if not.
+*/
+
+/*See ensureBits documentation above. This one ensures exactly 1 bit */
+/*static unsigned ensureBits1(LodePNGBitReader* reader) {
+ if(reader->bp >= reader->bitsize) return 0;
+ reader->buffer = (unsigned)reader->data[reader->bp >> 3u] >> (reader->bp & 7u);
+ return 1;
+}*/
+
+/*See ensureBits documentation above. This one ensures up to 9 bits */
+static unsigned ensureBits9(LodePNGBitReader* reader, size_t nbits)
+{
+ size_t start = reader->bp >> 3u;
+ size_t size = reader->size;
+ if (start + 1u < size) {
+ reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u);
+ reader->buffer >>= (reader->bp & 7u);
+ return 1;
+ } else {
+ reader->buffer = 0;
+ if (start + 0u < size) reader->buffer |= reader->data[start + 0];
+ reader->buffer >>= (reader->bp & 7u);
+ return reader->bp + nbits <= reader->bitsize;
+ }
+}
+
+
+/*See ensureBits documentation above. This one ensures up to 17 bits */
+static unsigned ensureBits17(LodePNGBitReader* reader, size_t nbits)
+{
+ size_t start = reader->bp >> 3u;
+ size_t size = reader->size;
+ if (start + 2u < size) {
+ reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) | ((unsigned)reader->data[start + 2] << 16u);
+ reader->buffer >>= (reader->bp & 7u);
+ return 1;
+ } else {
+ reader->buffer = 0;
+ if (start + 0u < size) reader->buffer |= reader->data[start + 0];
+ if (start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u);
+ reader->buffer >>= (reader->bp & 7u);
+ return reader->bp + nbits <= reader->bitsize;
+ }
+}
+
+
+/*See ensureBits documentation above. This one ensures up to 25 bits */
+static LODEPNG_INLINE unsigned ensureBits25(LodePNGBitReader* reader, size_t nbits)
+{
+ size_t start = reader->bp >> 3u;
+ size_t size = reader->size;
+ if (start + 3u < size) {
+ reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) | ((unsigned)reader->data[start + 2] << 16u) | ((unsigned)reader->data[start + 3] << 24u);
+ reader->buffer >>= (reader->bp & 7u);
+ return 1;
+ } else {
+ reader->buffer = 0;
+ if (start + 0u < size) reader->buffer |= reader->data[start + 0];
+ if (start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u);
+ if (start + 2u < size) reader->buffer |= ((unsigned)reader->data[start + 2] << 16u);
+ reader->buffer >>= (reader->bp & 7u);
+ return reader->bp + nbits <= reader->bitsize;
+ }
+}
+
+
+/*See ensureBits documentation above. This one ensures up to 32 bits */
+static LODEPNG_INLINE unsigned ensureBits32(LodePNGBitReader* reader, size_t nbits)
+{
+ size_t start = reader->bp >> 3u;
+ size_t size = reader->size;
+ if(start + 4u < size) {
+ reader->buffer = (unsigned)reader->data[start + 0] | ((unsigned)reader->data[start + 1] << 8u) | ((unsigned)reader->data[start + 2] << 16u) | ((unsigned)reader->data[start + 3] << 24u);
+ reader->buffer >>= (reader->bp & 7u);
+ reader->buffer |= (((unsigned)reader->data[start + 4] << 24u) << (8u - (reader->bp & 7u)));
+ return 1;
+ } else {
+ reader->buffer = 0;
+ if (start + 0u < size) reader->buffer |= reader->data[start + 0];
+ if (start + 1u < size) reader->buffer |= ((unsigned)reader->data[start + 1] << 8u);
+ if (start + 2u < size) reader->buffer |= ((unsigned)reader->data[start + 2] << 16u);
+ if (start + 3u < size) reader->buffer |= ((unsigned)reader->data[start + 3] << 24u);
+ reader->buffer >>= (reader->bp & 7u);
+ return reader->bp + nbits <= reader->bitsize;
+ }
+}
+
+
+/* Get bits without advancing the bit pointer. Must have enough bits available with ensureBits. Max nbits is 31. */
+static unsigned peekBits(LodePNGBitReader* reader, size_t nbits)
+{
+ /* The shift allows nbits to be only up to 31. */
+ return reader->buffer & ((1u << nbits) - 1u);
+}
+
+
+/* Must have enough bits available with ensureBits */
+static void advanceBits(LodePNGBitReader* reader, size_t nbits)
+{
+ reader->buffer >>= nbits;
+ reader->bp += nbits;
+}
+
+
+/* Must have enough bits available with ensureBits */
+static unsigned readBits(LodePNGBitReader* reader, size_t nbits)
+{
+ unsigned result = peekBits(reader, nbits);
+ advanceBits(reader, nbits);
+ return result;
+}
+
+
+/* Public for testing only. steps and result must have numsteps values. */
+unsigned lode_png_test_bitreader(const unsigned char* data, size_t size, size_t numsteps, const size_t* steps, unsigned* result)
+{
+ size_t i;
+ LodePNGBitReader reader;
+ unsigned error = LodePNGBitReader_init(&reader, data, size);
+ if (error) return 0;
+ for (i = 0; i < numsteps; i++) {
+ size_t step = steps[i];
+ unsigned ok;
+ if (step > 25) ok = ensureBits32(&reader, step);
+ else if (step > 17) ok = ensureBits25(&reader, step);
+ else if (step > 9) ok = ensureBits17(&reader, step);
+ else ok = ensureBits9(&reader, step);
+ if (!ok) return 0;
+ result[i] = readBits(&reader, step);
+ }
+ return 1;
+}
+
+
+static unsigned reverseBits(unsigned bits, unsigned num)
+{
+ /*TODO: implement faster lookup table based version when needed*/
+ unsigned i, result = 0;
+ for (i = 0; i < num; i++) result |= ((bits >> (num - i - 1u)) & 1u) << i;
+ return result;
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Deflate - Huffman / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+#define FIRST_LENGTH_CODE_INDEX 257
+#define LAST_LENGTH_CODE_INDEX 285
+/*256 literals, the end code, some length codes, and 2 unused codes*/
+#define NUM_DEFLATE_CODE_SYMBOLS 288
+/*the distance codes have their own symbols, 30 used, 2 unused*/
+#define NUM_DISTANCE_SYMBOLS 32
+/*the code length codes. 0-15: code lengths, 16: copy previous 3-6 times, 17: 3-10 zeros, 18: 11-138 zeros*/
+#define NUM_CODE_LENGTH_CODES 19
+
+/*the base lengths represented by codes 257-285*/
+static const unsigned LENGTHBASE[29]
+ = {3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31, 35, 43, 51, 59,
+ 67, 83, 99, 115, 131, 163, 195, 227, 258};
+
+/*the extra bits used by codes 257-285 (added to base length)*/
+static const unsigned LENGTHEXTRA[29]
+ = {0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3,
+ 4, 4, 4, 4, 5, 5, 5, 5, 0};
+
+/*the base backwards distances (the bits of distance codes appear after length codes and use their own huffman tree)*/
+static const unsigned DISTANCEBASE[30]
+ = {1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193, 257, 385, 513,
+ 769, 1025, 1537, 2049, 3073, 4097, 6145, 8193, 12289, 16385, 24577};
+
+/*the extra bits of backwards distances (added to base)*/
+static const unsigned DISTANCEEXTRA[30]
+ = {0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8,
+ 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13};
+
+/*the order in which "code length alphabet code lengths" are stored as specified by deflate, out of this the huffman
+tree of the dynamic huffman tree lengths is generated*/
+static const unsigned CLCL_ORDER[NUM_CODE_LENGTH_CODES]
+ = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+Huffman tree struct, containing multiple representations of the tree
+*/
+struct HuffmanTree
+{
+ unsigned* codes; /*the huffman codes (bit patterns representing the symbols)*/
+ unsigned* lengths; /*the lengths of the huffman codes*/
+ unsigned maxbitlen; /*maximum number of bits a single code can get*/
+ unsigned numcodes; /*number of symbols in the alphabet = number of codes*/
+ /* for reading only */
+ unsigned char* table_len; /*length of symbol from lookup table, or max length if secondary lookup needed*/
+ unsigned short* table_value; /*value of symbol from lookup table, or pointer to secondary table if needed*/
+};
+
+
+static void HuffmanTree_init(HuffmanTree* tree)
+{
+ tree->codes = 0;
+ tree->lengths = 0;
+ tree->table_len = 0;
+ tree->table_value = 0;
+}
+
+
+static void HuffmanTree_cleanup(HuffmanTree* tree)
+{
+ free(tree->codes);
+ free(tree->lengths);
+ free(tree->table_len);
+ free(tree->table_value);
+}
+
+
+/* amount of bits for first huffman table lookup (aka root bits), see HuffmanTree_makeTable and huffmanDecodeSymbol.*/
+/* values 8u and 9u work the fastest */
+#define FIRSTBITS 9u
+
+/* a symbol value too big to represent any valid symbol, to indicate reading disallowed huffman bits combination,
+which is possible in case of only 0 or 1 present symbols. */
+#define INVALIDSYMBOL 65535u
+
+/* make table for huffman decoding */
+static unsigned HuffmanTree_makeTable(HuffmanTree* tree)
+{
+ static const unsigned headsize = 1u << FIRSTBITS; /*size of the first table*/
+ static const unsigned mask = (1u << FIRSTBITS) /*headsize*/ - 1u;
+ size_t i, numpresent, pointer, size; /*total table size*/
+ unsigned* maxlens = (unsigned*)malloc(headsize * sizeof(unsigned));
+ if (!maxlens) return 83; /*alloc fail*/
+
+ /* compute maxlens: max total bit length of symbols sharing prefix in the first table*/
+ lodepng_memset(maxlens, 0, headsize * sizeof(*maxlens));
+ for (i = 0; i < tree->numcodes; i++) {
+ unsigned symbol = tree->codes[i];
+ unsigned l = tree->lengths[i];
+ unsigned index;
+ if(l <= FIRSTBITS) continue; /*symbols that fit in first table don't increase secondary table size*/
+ /*get the FIRSTBITS MSBs, the MSBs of the symbol are encoded first. See later comment about the reversing*/
+ index = reverseBits(symbol >> (l - FIRSTBITS), FIRSTBITS);
+ maxlens[index] = LODEPNG_MAX(maxlens[index], l);
+ }
+ /* compute total table size: size of first table plus all secondary tables for symbols longer than FIRSTBITS */
+ size = headsize;
+ for (i = 0; i < headsize; ++i) {
+ unsigned l = maxlens[i];
+ if (l > FIRSTBITS) size += (1u << (l - FIRSTBITS));
+ }
+ tree->table_len = (unsigned char*)malloc(size * sizeof(*tree->table_len));
+ tree->table_value = (unsigned short*)malloc(size * sizeof(*tree->table_value));
+ if (!tree->table_len || !tree->table_value) {
+ free(maxlens);
+ /* freeing tree->table values is done at a higher scope */
+ return 83; /*alloc fail*/
+ }
+ /*initialize with an invalid length to indicate unused entries*/
+ for (i = 0; i < size; ++i) tree->table_len[i] = 16;
+
+ /*fill in the first table for long symbols: max prefix size and pointer to secondary tables*/
+ pointer = headsize;
+ for (i = 0; i < headsize; ++i) {
+ unsigned l = maxlens[i];
+ if(l <= FIRSTBITS) continue;
+ tree->table_len[i] = l;
+ tree->table_value[i] = pointer;
+ pointer += (1u << (l - FIRSTBITS));
+ }
+ free(maxlens);
+
+ /*fill in the first table for short symbols, or secondary table for long symbols*/
+ numpresent = 0;
+ for (i = 0; i < tree->numcodes; ++i) {
+ unsigned l = tree->lengths[i];
+ unsigned symbol = tree->codes[i]; /*the huffman bit pattern. i itself is the value.*/
+ /*reverse bits, because the huffman bits are given in MSB first order but the bit reader reads LSB first*/
+ unsigned reverse = reverseBits(symbol, l);
+ if (l == 0) continue;
+ numpresent++;
+
+ if (l <= FIRSTBITS) {
+ /*short symbol, fully in first table, replicated num times if l < FIRSTBITS*/
+ unsigned num = 1u << (FIRSTBITS - l);
+ unsigned j;
+ for (j = 0; j < num; ++j) {
+ /*bit reader will read the l bits of symbol first, the remaining FIRSTBITS - l bits go to the MSB's*/
+ unsigned index = reverse | (j << l);
+ if(tree->table_len[index] != 16) return 55; /*invalid tree: long symbol shares prefix with short symbol*/
+ tree->table_len[index] = l;
+ tree->table_value[index] = i;
+ }
+ } else {
+ /*long symbol, shares prefix with other long symbols in first lookup table, needs second lookup*/
+ /*the FIRSTBITS MSBs of the symbol are the first table index*/
+ unsigned index = reverse & mask;
+ unsigned maxlen = tree->table_len[index];
+ /*log2 of secondary table length, should be >= l - FIRSTBITS*/
+ unsigned tablelen = maxlen - FIRSTBITS;
+ unsigned start = tree->table_value[index]; /*starting index in secondary table*/
+ unsigned num = 1u << (tablelen - (l - FIRSTBITS)); /*amount of entries of this symbol in secondary table*/
+ unsigned j;
+ if (maxlen < l) return 55; /*invalid tree: long symbol shares prefix with short symbol*/
+ for (j = 0; j < num; ++j) {
+ unsigned reverse2 = reverse >> FIRSTBITS; /* l - FIRSTBITS bits */
+ unsigned index2 = start + (reverse2 | (j << (l - FIRSTBITS)));
+ tree->table_len[index2] = l;
+ tree->table_value[index2] = i;
+ }
+ }
+ }
+
+ if (numpresent < 2) {
+ /* In case of exactly 1 symbol, in theory the huffman symbol needs 0 bits,
+ but deflate uses 1 bit instead. In case of 0 symbols, no symbols can
+ appear at all, but such huffman tree could still exist (e.g. if distance
+ codes are never used). In both cases, not all symbols of the table will be
+ filled in. Fill them in with an invalid symbol value so returning them from
+ huffmanDecodeSymbol will cause error. */
+ for (i = 0; i < size; ++i) {
+ if (tree->table_len[i] == 16) {
+ /* As length, use a value smaller than FIRSTBITS for the head table,
+ and a value larger than FIRSTBITS for the secondary table, to ensure
+ valid behavior for advanceBits when reading this symbol. */
+ tree->table_len[i] = (i < headsize) ? 1 : (FIRSTBITS + 1);
+ tree->table_value[i] = INVALIDSYMBOL;
+ }
+ }
+ } else {
+ /* A good huffman tree has N * 2 - 1 nodes, of which N - 1 are internal nodes.
+ If that is not the case (due to too long length codes), the table will not
+ have been fully used, and this is an error (not all bit combinations can be
+ decoded): an oversubscribed huffman tree, indicated by error 55. */
+ for (i = 0; i < size; ++i) {
+ if (tree->table_len[i] == 16) return 55;
+ }
+ }
+ return 0;
+}
+
+
+/*
+ Second step for the ...makeFromLengths and ...makeFromFrequencies functions.
+ numcodes, lengths and maxbitlen must already be filled in correctly. return
+ value is error.
+*/
+static unsigned HuffmanTree_makeFromLengths2(HuffmanTree* tree)
+{
+ unsigned* blcount;
+ unsigned* nextcode;
+ unsigned error = 0;
+ unsigned bits, n;
+
+ tree->codes = (unsigned*)malloc(tree->numcodes * sizeof(unsigned));
+ blcount = (unsigned*)malloc((tree->maxbitlen + 1) * sizeof(unsigned));
+ nextcode = (unsigned*)malloc((tree->maxbitlen + 1) * sizeof(unsigned));
+ if (!tree->codes || !blcount || !nextcode) error = 83; /*alloc fail*/
+
+ if (!error) {
+ for (n = 0; n != tree->maxbitlen + 1; n++) blcount[n] = nextcode[n] = 0;
+ /*step 1: count number of instances of each code length*/
+ for (bits = 0; bits != tree->numcodes; ++bits) ++blcount[tree->lengths[bits]];
+ /*step 2: generate the nextcode values*/
+ for(bits = 1; bits <= tree->maxbitlen; ++bits) {
+ nextcode[bits] = (nextcode[bits - 1] + blcount[bits - 1]) << 1u;
+ }
+ /*step 3: generate all the codes*/
+ for (n = 0; n != tree->numcodes; ++n) {
+ if (tree->lengths[n] != 0) {
+ tree->codes[n] = nextcode[tree->lengths[n]]++;
+ /*remove superfluous bits from the code*/
+ tree->codes[n] &= ((1u << tree->lengths[n]) - 1u);
+ }
+ }
+ }
+
+ free(blcount);
+ free(nextcode);
+
+ if (!error) error = HuffmanTree_makeTable(tree);
+ return error;
+}
+
+
+/*
+ given the code lengths (as stored in the PNG file), generate the tree as defined
+ by Deflate. maxbitlen is the maximum bits that a code in the tree can have.
+ return value is error.
+*/
+static unsigned HuffmanTree_makeFromLengths(HuffmanTree* tree, const unsigned* bitlen, size_t numcodes, unsigned maxbitlen)
+{
+ unsigned i;
+ tree->lengths = (unsigned*)malloc(numcodes * sizeof(unsigned));
+ if (!tree->lengths) return 83; /*alloc fail*/
+ for (i = 0; i != numcodes; ++i) tree->lengths[i] = bitlen[i];
+ tree->numcodes = (unsigned)numcodes; /*number of symbols*/
+ tree->maxbitlen = maxbitlen;
+ return HuffmanTree_makeFromLengths2(tree);
+}
+
+
+/*get the literal and length code tree of a deflated block with fixed tree, as per the deflate specification*/
+static unsigned generateFixedLitLenTree(HuffmanTree* tree)
+{
+ unsigned i, error = 0;
+ unsigned* bitlen = (unsigned*)malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
+ if (!bitlen) return 83; /*alloc fail*/
+
+ /*288 possible codes: 0-255=literals, 256=endcode, 257-285=lengthcodes, 286-287=unused*/
+ for (i = 0; i <= 143; ++i) bitlen[i] = 8;
+ for (i = 144; i <= 255; ++i) bitlen[i] = 9;
+ for (i = 256; i <= 279; ++i) bitlen[i] = 7;
+ for (i = 280; i <= 287; ++i) bitlen[i] = 8;
+
+ error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DEFLATE_CODE_SYMBOLS, 15);
+
+ free(bitlen);
+ return error;
+}
+
+
+/*get the distance code tree of a deflated block with fixed tree, as specified in the deflate specification*/
+static unsigned generateFixedDistanceTree(HuffmanTree* tree)
+{
+ unsigned i, error = 0;
+ unsigned* bitlen = (unsigned*)malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
+ if (!bitlen) return 83; /*alloc fail*/
+
+ /*there are 32 distance codes, but 30-31 are unused*/
+ for (i = 0; i != NUM_DISTANCE_SYMBOLS; ++i) bitlen[i] = 5;
+ error = HuffmanTree_makeFromLengths(tree, bitlen, NUM_DISTANCE_SYMBOLS, 15);
+
+ free(bitlen);
+ return error;
+}
+
+
+/*
+ returns the code. The bit reader must already have been ensured at least 15 bits
+*/
+static unsigned huffmanDecodeSymbol(LodePNGBitReader* reader, const HuffmanTree* codetree)
+{
+ unsigned short code = peekBits(reader, FIRSTBITS);
+ unsigned short l = codetree->table_len[code];
+ unsigned short value = codetree->table_value[code];
+ if (l <= FIRSTBITS) {
+ advanceBits(reader, l);
+ return value;
+ } else {
+ unsigned index2;
+ advanceBits(reader, FIRSTBITS);
+ index2 = value + peekBits(reader, l - FIRSTBITS);
+ advanceBits(reader, codetree->table_len[index2] - FIRSTBITS);
+ return codetree->table_value[index2];
+ }
+}
+
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Inflator (Decompressor) / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*get the tree of a deflated block with fixed tree, as specified in the deflate specification
+Returns error code.*/
+static unsigned getTreeInflateFixed(HuffmanTree* tree_ll, HuffmanTree* tree_d)
+{
+ unsigned error = generateFixedLitLenTree(tree_ll);
+ if (error) return error;
+ return generateFixedDistanceTree(tree_d);
+}
+
+
+/*get the tree of a deflated block with dynamic tree, the tree itself is also Huffman compressed with a known tree*/
+static unsigned getTreeInflateDynamic(HuffmanTree* tree_ll, HuffmanTree* tree_d, LodePNGBitReader* reader)
+{
+ /*make sure that length values that aren't filled in will be 0, or a wrong tree will be generated*/
+ unsigned error = 0;
+ unsigned n, HLIT, HDIST, HCLEN, i;
+
+ /*see comments in deflateDynamic for explanation of the context and these variables, it is analogous*/
+ unsigned* bitlen_ll = 0; /*lit,len code lengths*/
+ unsigned* bitlen_d = 0; /*dist code lengths*/
+ /*code length code lengths ("clcl"), the bit lengths of the huffman tree used to compress bitlen_ll and bitlen_d*/
+ unsigned* bitlen_cl = 0;
+ HuffmanTree tree_cl; /*the code tree for code length codes (the huffman tree for compressed huffman trees)*/
+
+ if (!ensureBits17(reader, 14)) return 49; /*error: the bit pointer is or will go past the memory*/
+
+ /*number of literal/length codes + 257. Unlike the spec, the value 257 is added to it here already*/
+ HLIT = readBits(reader, 5) + 257;
+ /*number of distance codes. Unlike the spec, the value 1 is added to it here already*/
+ HDIST = readBits(reader, 5) + 1;
+ /*number of code length codes. Unlike the spec, the value 4 is added to it here already*/
+ HCLEN = readBits(reader, 4) + 4;
+
+ bitlen_cl = (unsigned*)malloc(NUM_CODE_LENGTH_CODES * sizeof(unsigned));
+ if(!bitlen_cl) return 83 /*alloc fail*/;
+
+ HuffmanTree_init(&tree_cl);
+
+ while (!error) {
+ /*read the code length codes out of 3 * (amount of code length codes) bits*/
+ if (lodepng_gtofl(reader->bp, HCLEN * 3, reader->bitsize)) {
+ ERROR_BREAK(50); /*error: the bit pointer is or will go past the memory*/
+ }
+ for (i = 0; i != HCLEN; ++i) {
+ ensureBits9(reader, 3); /*out of bounds already checked above */
+ bitlen_cl[CLCL_ORDER[i]] = readBits(reader, 3);
+ }
+ for (i = HCLEN; i != NUM_CODE_LENGTH_CODES; ++i) {
+ bitlen_cl[CLCL_ORDER[i]] = 0;
+ }
+
+ error = HuffmanTree_makeFromLengths(&tree_cl, bitlen_cl, NUM_CODE_LENGTH_CODES, 7);
+ if(error) break;
+
+ /*now we can use this tree to read the lengths for the tree that this function will return*/
+ bitlen_ll = (unsigned*)malloc(NUM_DEFLATE_CODE_SYMBOLS * sizeof(unsigned));
+ bitlen_d = (unsigned*)malloc(NUM_DISTANCE_SYMBOLS * sizeof(unsigned));
+ if (!bitlen_ll || !bitlen_d) ERROR_BREAK(83 /*alloc fail*/);
+ lodepng_memset(bitlen_ll, 0, NUM_DEFLATE_CODE_SYMBOLS * sizeof(*bitlen_ll));
+ lodepng_memset(bitlen_d, 0, NUM_DISTANCE_SYMBOLS * sizeof(*bitlen_d));
+
+ /*i is the current symbol we're reading in the part that contains the code lengths of lit/len and dist codes*/
+ i = 0;
+ while (i < HLIT + HDIST) {
+ unsigned code;
+ ensureBits25(reader, 22); /* up to 15 bits for huffman code, up to 7 extra bits below*/
+ code = huffmanDecodeSymbol(reader, &tree_cl);
+ if (code <= 15) /*a length code*/ {
+ if (i < HLIT) bitlen_ll[i] = code;
+ else bitlen_d[i - HLIT] = code;
+ ++i;
+ } else if (code == 16) /*repeat previous*/ {
+ unsigned replength = 3; /*read in the 2 bits that indicate repeat length (3-6)*/
+ unsigned value; /*set value to the previous code*/
+
+ if (i == 0) ERROR_BREAK(54); /*can't repeat previous if i is 0*/
+
+ replength += readBits(reader, 2);
+
+ if (i < HLIT + 1) value = bitlen_ll[i - 1];
+ else value = bitlen_d[i - HLIT - 1];
+ /*repeat this value in the next lengths*/
+ for (n = 0; n < replength; ++n) {
+ if (i >= HLIT + HDIST) ERROR_BREAK(13); /*error: i is larger than the amount of codes*/
+ if (i < HLIT) bitlen_ll[i] = value;
+ else bitlen_d[i - HLIT] = value;
+ ++i;
+ }
+ } else if(code == 17) /*repeat "0" 3-10 times*/ {
+ unsigned replength = 3; /*read in the bits that indicate repeat length*/
+ replength += readBits(reader, 3);
+
+ /*repeat this value in the next lengths*/
+ for (n = 0; n < replength; ++n) {
+ if (i >= HLIT + HDIST) ERROR_BREAK(14); /*error: i is larger than the amount of codes*/
+
+ if (i < HLIT) bitlen_ll[i] = 0;
+ else bitlen_d[i - HLIT] = 0;
+ ++i;
+ }
+ } else if(code == 18) /*repeat "0" 11-138 times*/ {
+ unsigned replength = 11; /*read in the bits that indicate repeat length*/
+ replength += readBits(reader, 7);
+
+ /*repeat this value in the next lengths*/
+ for (n = 0; n < replength; ++n) {
+ if(i >= HLIT + HDIST) ERROR_BREAK(15); /*error: i is larger than the amount of codes*/
+
+ if(i < HLIT) bitlen_ll[i] = 0;
+ else bitlen_d[i - HLIT] = 0;
+ ++i;
+ }
+ } else /*if(code == INVALIDSYMBOL)*/ {
+ ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
+ }
+ /*check if any of the ensureBits above went out of bounds*/
+ if (reader->bp > reader->bitsize) {
+ /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
+ (10=no endcode, 11=wrong jump outside of tree)*/
+ /* TODO: revise error codes 10,11,50: the above comment is no longer valid */
+ ERROR_BREAK(50); /*error, bit pointer jumps past memory*/
+ }
+ }
+ if (error) break;
+
+ if (bitlen_ll[256] == 0) ERROR_BREAK(64); /*the length of the end code 256 must be larger than 0*/
+
+ /*now we've finally got HLIT and HDIST, so generate the code trees, and the function is done*/
+ error = HuffmanTree_makeFromLengths(tree_ll, bitlen_ll, NUM_DEFLATE_CODE_SYMBOLS, 15);
+ if (error) break;
+ error = HuffmanTree_makeFromLengths(tree_d, bitlen_d, NUM_DISTANCE_SYMBOLS, 15);
+
+ break; /*end of error-while*/
+ }
+
+ free(bitlen_cl);
+ free(bitlen_ll);
+ free(bitlen_d);
+ HuffmanTree_cleanup(&tree_cl);
+
+ return error;
+}
+
+
+/*inflate a block with dynamic of fixed Huffman tree. btype must be 1 or 2.*/
+static unsigned inflateHuffmanBlock(ucvector* out, LodePNGBitReader* reader, unsigned btype)
+{
+ unsigned error = 0;
+ HuffmanTree tree_ll; /*the huffman tree for literal and length codes*/
+ HuffmanTree tree_d; /*the huffman tree for distance codes*/
+
+ HuffmanTree_init(&tree_ll);
+ HuffmanTree_init(&tree_d);
+
+ if (btype == 1) error = getTreeInflateFixed(&tree_ll, &tree_d);
+ else /*if(btype == 2)*/ error = getTreeInflateDynamic(&tree_ll, &tree_d, reader);
+
+ while (!error) /*decode all symbols until end reached, breaks at end code*/ {
+ /*code_ll is literal, length or end code*/
+ unsigned code_ll;
+ ensureBits25(reader, 20); /* up to 15 for the huffman symbol, up to 5 for the length extra bits */
+ code_ll = huffmanDecodeSymbol(reader, &tree_ll);
+ if (code_ll <= 255) /*literal symbol*/ {
+ if (!ucvector_resize(out, out->size + 1)) ERROR_BREAK(83 /*alloc fail*/);
+ out->data[out->size - 1] = (unsigned char)code_ll;
+ } else if (code_ll >= FIRST_LENGTH_CODE_INDEX && code_ll <= LAST_LENGTH_CODE_INDEX) /*length code*/ {
+ unsigned code_d, distance;
+ unsigned numextrabits_l, numextrabits_d; /*extra bits for length and distance*/
+ size_t start, backward, length;
+
+ /*part 1: get length base*/
+ length = LENGTHBASE[code_ll - FIRST_LENGTH_CODE_INDEX];
+
+ /*part 2: get extra bits and add the value of that to length*/
+ numextrabits_l = LENGTHEXTRA[code_ll - FIRST_LENGTH_CODE_INDEX];
+ if (numextrabits_l != 0) {
+ /* bits already ensured above */
+ length += readBits(reader, numextrabits_l);
+ }
+
+ /*part 3: get distance code*/
+ ensureBits32(reader, 28); /* up to 15 for the huffman symbol, up to 13 for the extra bits */
+ code_d = huffmanDecodeSymbol(reader, &tree_d);
+ if (code_d > 29) {
+ if (code_d <= 31) {
+ ERROR_BREAK(18); /*error: invalid distance code (30-31 are never used)*/
+ } else /* if(code_d == INVALIDSYMBOL) */{
+ ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
+ }
+ }
+ distance = DISTANCEBASE[code_d];
+
+ /*part 4: get extra bits from distance*/
+ numextrabits_d = DISTANCEEXTRA[code_d];
+ if (numextrabits_d != 0) {
+ /* bits already ensured above */
+ distance += readBits(reader, numextrabits_d);
+ }
+
+ /*part 5: fill in all the out[n] values based on the length and dist*/
+ start = out->size;
+ if (distance > start) ERROR_BREAK(52); /*too long backward distance*/
+ backward = start - distance;
+
+ if (!ucvector_resize(out, out->size + length)) ERROR_BREAK(83 /*alloc fail*/);
+ if (distance < length) {
+ size_t forward;
+ lodepng_memcpy(out->data + start, out->data + backward, distance);
+ start += distance;
+ for (forward = distance; forward < length; ++forward) {
+ out->data[start++] = out->data[backward++];
+ }
+ } else {
+ lodepng_memcpy(out->data + start, out->data + backward, length);
+ }
+ } else if (code_ll == 256) {
+ break; /*end code, break the loop*/
+ } else /*if(code_ll == INVALIDSYMBOL)*/ {
+ ERROR_BREAK(16); /*error: tried to read disallowed huffman symbol*/
+ }
+ /*check if any of the ensureBits above went out of bounds*/
+ if (reader->bp > reader->bitsize) {
+ /*return error code 10 or 11 depending on the situation that happened in huffmanDecodeSymbol
+ (10=no endcode, 11=wrong jump outside of tree)*/
+ /* TODO: revise error codes 10,11,50: the above comment is no longer valid */
+ ERROR_BREAK(51); /*error, bit pointer jumps past memory*/
+ }
+ }
+
+ HuffmanTree_cleanup(&tree_ll);
+ HuffmanTree_cleanup(&tree_d);
+
+ return error;
+}
+
+
+static unsigned inflateNoCompression(ucvector* out, LodePNGBitReader* reader, const LodePNGDecompressSettings* settings)
+{
+ size_t bytepos;
+ size_t size = reader->size;
+ unsigned LEN, NLEN, error = 0;
+
+ /*go to first boundary of byte*/
+ bytepos = (reader->bp + 7u) >> 3u;
+
+ /*read LEN (2 bytes) and NLEN (2 bytes)*/
+ if (bytepos + 4 >= size) return 52; /*error, bit pointer will jump past memory*/
+ LEN = (unsigned)reader->data[bytepos] + ((unsigned)reader->data[bytepos + 1] << 8u); bytepos += 2;
+ NLEN = (unsigned)reader->data[bytepos] + ((unsigned)reader->data[bytepos + 1] << 8u); bytepos += 2;
+
+ /*check if 16-bit NLEN is really the one's complement of LEN*/
+ if (!settings->ignore_nlen && LEN + NLEN != 65535) {
+ return 21; /*error: NLEN is not one's complement of LEN*/
+ }
+
+ if (!ucvector_resize(out, out->size + LEN)) return 83; /*alloc fail*/
+
+ /*read the literal data: LEN bytes are now stored in the out buffer*/
+ if (bytepos + LEN > size) return 23; /*error: reading outside of in buffer*/
+
+ lodepng_memcpy(out->data + out->size - LEN, reader->data + bytepos, LEN);
+ bytepos += LEN;
+
+ reader->bp = bytepos << 3u;
+
+ return error;
+}
+
+
+static unsigned lodepng_inflatev(ucvector* out, const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings)
+{
+ unsigned BFINAL = 0;
+ LodePNGBitReader reader;
+ unsigned error = LodePNGBitReader_init(&reader, in, insize);
+
+ if (error) return error;
+
+ while (!BFINAL) {
+ unsigned BTYPE;
+ if (!ensureBits9(&reader, 3)) return 52; /*error, bit pointer will jump past memory*/
+ BFINAL = readBits(&reader, 1);
+ BTYPE = readBits(&reader, 2);
+
+ if (BTYPE == 3) return 20; /*error: invalid BTYPE*/
+ else if (BTYPE == 0) error = inflateNoCompression(out, &reader, settings); /*no compression*/
+ else error = inflateHuffmanBlock(out, &reader, BTYPE); /*compression, BTYPE 01 or 10*/
+
+ if (error) return error;
+ }
+
+ return error;
+}
+
+
+static unsigned inflatev(ucvector* out, const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings)
+{
+ if (settings->custom_inflate) {
+ unsigned error = settings->custom_inflate(&out->data, &out->size, in, insize, settings);
+ out->allocsize = out->size;
+ return error;
+ } else {
+ return lodepng_inflatev(out, in, insize, settings);
+ }
+}
+
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Adler32 / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+static unsigned update_adler32(unsigned adler, const unsigned char* data, unsigned len)
+{
+ unsigned s1 = adler & 0xffffu;
+ unsigned s2 = (adler >> 16u) & 0xffffu;
+
+ while (len != 0u) {
+ unsigned i;
+ /*at least 5552 sums can be done before the sums overflow, saving a lot of module divisions*/
+ unsigned amount = len > 5552u ? 5552u : len;
+ len -= amount;
+ for (i = 0; i != amount; ++i) {
+ s1 += (*data++);
+ s2 += s1;
+ }
+ s1 %= 65521u;
+ s2 %= 65521u;
+ }
+
+ return (s2 << 16u) | s1;
+}
+
+/*Return the adler32 of the bytes data[0..len-1]*/
+static unsigned adler32(const unsigned char* data, unsigned len)
+{
+ return update_adler32(1u, data, len);
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Zlib / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+static unsigned lodepng_zlib_decompressv(ucvector* out, const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings)
+{
+ unsigned error = 0;
+ unsigned CM, CINFO, FDICT;
+
+ if (insize < 2) return 53; /*error, size of zlib data too small*/
+ /*read information from zlib header*/
+ if ((in[0] * 256 + in[1]) % 31 != 0) {
+ /*error: 256 * in[0] + in[1] must be a multiple of 31, the FCHECK value is supposed to be made that way*/
+ return 24;
+ }
+
+ CM = in[0] & 15;
+ CINFO = (in[0] >> 4) & 15;
+ /*FCHECK = in[1] & 31;*/ /*FCHECK is already tested above*/
+ FDICT = (in[1] >> 5) & 1;
+ /*FLEVEL = (in[1] >> 6) & 3;*/ /*FLEVEL is not used here*/
+
+ if (CM != 8 || CINFO > 7) {
+ /*error: only compression method 8: inflate with sliding window of 32k is supported by the PNG spec*/
+ return 25;
+ }
+ if (FDICT != 0) {
+ /*error: the specification of PNG says about the zlib stream:
+ "The additional flags shall not specify a preset dictionary."*/
+ return 26;
+ }
+
+ error = inflatev(out, in + 2, insize - 2, settings);
+ if (error) return error;
+
+ if (!settings->ignore_adler32) {
+ unsigned ADLER32 = lodepng_read32bitInt(&in[insize - 4]);
+ unsigned checksum = adler32(out->data, (unsigned)(out->size));
+ if(checksum != ADLER32) return 58; /*error, adler checksum not correct, data must be corrupted*/
+ }
+
+ return 0; /*no error*/
+}
+
+
+/*expected_size is expected output size, to avoid intermediate allocations. Set to 0 if not known. */
+static unsigned zlib_decompress(unsigned char** out, size_t* outsize, size_t expected_size, const unsigned char* in, size_t insize, const LodePNGDecompressSettings* settings)
+{
+ if(settings->custom_zlib) {
+ return settings->custom_zlib(out, outsize, in, insize, settings);
+ } else {
+ unsigned error;
+ ucvector v = ucvector_init(*out, *outsize);
+ if (expected_size) {
+ /*reserve the memory to avoid intermediate reallocations*/
+ ucvector_resize(&v, *outsize + expected_size);
+ v.size = *outsize;
+ }
+ error = lodepng_zlib_decompressv(&v, in, insize, settings);
+ *out = v.data;
+ *outsize = v.size;
+ return error;
+ }
+}
+
+
+static void lodepng_decompress_settings_init(LodePNGDecompressSettings* settings)
+{
+ settings->ignore_adler32 = 0;
+ settings->ignore_nlen = 0;
+ settings->custom_zlib = 0;
+ settings->custom_inflate = 0;
+ settings->custom_context = 0;
+}
+
+
+const LodePNGDecompressSettings lodepng_default_decompress_settings = {0, 0, 0, 0, 0};
+
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* // End of Zlib related code. Begin of PNG related code. // */
+/* ////////////////////////////////////////////////////////////////////////// */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+
+#if 0 //thorvg don't use 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
+};
+
+
+/* Calculate CRC32 of buffer
+ Return the CRC of the bytes buf[0..len-1]. */
+static 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]) & 0xffu] ^ (r >> 8u);
+ }
+ return r ^ 0xffffffffu;
+}
+#endif
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Reading and writing PNG color channel bits / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/* The color channel bits of less-than-8-bit pixels are read with the MSB of bytes first,
+so LodePNGBitWriter and LodePNGBitReader can't be used for those. */
+
+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;
+}
+
+
+/* TODO: make this faster */
+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 <<= 1u;
+ result |= (unsigned)readBitFromReversedStream(bitpointer, bitstream);
+ }
+ return result;
+}
+
+
+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) >> 3u] &= (unsigned char)(~(1u << (7u - ((*bitpointer) & 7u))));
+ else bitstream[(*bitpointer) >> 3u] |= (1u << (7u - ((*bitpointer) & 7u)));
+ ++(*bitpointer);
+}
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / PNG chunks / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*
+ The lodepng_chunk functions are normally not needed, except to traverse the
+ unknown chunks stored in the LodePNGInfo struct, or add new ones to it.
+ It also allows traversing the chunks of an encoded PNG file yourself.
+
+ The chunk pointer always points to the beginning of the chunk itself, that is
+ the first byte of the 4 length bytes.
+
+ In the PNG file format, chunks have the following format:
+ -4 bytes length: length of the data of the chunk in bytes (chunk itself is 12 bytes longer)
+ -4 bytes chunk type (ASCII a-z,A-Z only, see below)
+ -length bytes of data (may be 0 bytes if length was 0)
+ -4 bytes of CRC, computed on chunk name + data
+
+ The first chunk starts at the 8th byte of the PNG file, the entire rest of the file
+ exists out of concatenated chunks with the above format.
+
+ PNG standard chunk ASCII naming conventions:
+ -First byte: uppercase = critical, lowercase = ancillary
+ -Second byte: uppercase = public, lowercase = private
+ -Third byte: must be uppercase
+ -Fourth byte: uppercase = unsafe to copy, lowercase = safe to copy
+*/
+
+
+/*
+ Gets the length of the data of the chunk. Total chunk length has 12 bytes more.
+ There must be at least 4 bytes to read from. If the result value is too large,
+ it may be corrupt data.
+*/
+static unsigned lodepng_chunk_length(const unsigned char* chunk)
+{
+ return lodepng_read32bitInt(&chunk[0]);
+}
+
+
+/* check if the type is the given type */
+static unsigned char lodepng_chunk_type_equals(const unsigned char* chunk, const char* type)
+{
+ if (lodepng_strlen(type) != 4) return 0;
+ return (chunk[4] == type[0] && chunk[5] == type[1] && chunk[6] == type[2] && chunk[7] == type[3]);
+}
+
+
+/* 0: it's one of the critical chunk types, 1: it's an ancillary chunk (see PNG standard) */
+static unsigned char lodepng_chunk_ancillary(const unsigned char* chunk)
+{
+ return ((chunk[4] & 32) != 0);
+}
+
+
+static const unsigned char* lodepng_chunk_data_const(const unsigned char* chunk)
+{
+ return &chunk[8];
+}
+
+#if 0 //thorvg don't use crc
+/* returns 0 if the crc is correct, 1 if it's incorrect (0 for OK as usual!) */
+static 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;
+}
+#endif
+
+static const unsigned char* lodepng_chunk_next_const(const unsigned char* chunk, const unsigned char* end)
+{
+ if (chunk >= end || end - chunk < 12) return end; /*too small to contain a 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 {
+ size_t total_chunk_length;
+ const unsigned char* result;
+ if (lodepng_addofl(lodepng_chunk_length(chunk), 12, &total_chunk_length)) return end;
+ result = chunk + total_chunk_length;
+ if (result < chunk) return end; /*pointer overflow*/
+ return result;
+ }
+}
+
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / Color types, channels, bits / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+/*checks if the colortype is valid and the bitdepth bd is allowed for this colortype.
+Return value is a LodePNG error code.*/
+static unsigned checkColorValidity(LodePNGColorType colortype, unsigned bd)
+{
+ switch(colortype) {
+ case LCT_GREY: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 || bd == 16)) return 37; break;
+ case LCT_RGB: if(!( bd == 8 || bd == 16)) return 37; break;
+ case LCT_PALETTE: if(!(bd == 1 || bd == 2 || bd == 4 || bd == 8 )) return 37; break;
+ case LCT_GREY_ALPHA: if(!( bd == 8 || bd == 16)) return 37; break;
+ case LCT_RGBA: if(!( bd == 8 || bd == 16)) return 37; break;
+ case LCT_MAX_OCTET_VALUE: return 31; /* invalid color type */
+ default: return 31; /* invalid color type */
+ }
+ return 0; /*allowed color type / bits combination*/
+}
+
+
+static unsigned getNumColorChannels(LodePNGColorType colortype)
+{
+ switch(colortype) {
+ case LCT_GREY: return 1;
+ case LCT_RGB: return 3;
+ case LCT_PALETTE: return 1;
+ case LCT_GREY_ALPHA: return 2;
+ case LCT_RGBA: return 4;
+ case LCT_MAX_OCTET_VALUE: return 0; /* invalid color type */
+ default: return 0; /*invalid 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;
+}
+
+
+static 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;
+}
+
+
+/*allocates palette memory if needed, and initializes all colors to black*/
+static void lodepng_color_mode_alloc_palette(LodePNGColorMode* info)
+{
+ size_t i;
+ /*if the palette is already allocated, it will have size 1024 so no reallocation needed in that case*/
+ /*the palette must have room for up to 256 colors with 4 bytes each.*/
+ if (!info->palette) info->palette = (unsigned char*)malloc(1024);
+ if (!info->palette) return; /*alloc fail*/
+ for (i = 0; i != 256; ++i) {
+ /*Initialize all unused colors with black, the value used for invalid palette indices.
+ This is an error according to the PNG spec, but common PNG decoders make it black instead.
+ That makes color conversion slightly faster due to no error handling needed.*/
+ info->palette[i * 4 + 0] = 0;
+ info->palette[i * 4 + 1] = 0;
+ info->palette[i * 4 + 2] = 0;
+ info->palette[i * 4 + 3] = 255;
+ }
+}
+
+static void lodepng_palette_clear(LodePNGColorMode* info)
+{
+ if (info->palette) free(info->palette);
+ info->palette = 0;
+ info->palettesize = 0;
+}
+
+
+static void lodepng_color_mode_cleanup(LodePNGColorMode* info)
+{
+ lodepng_palette_clear(info);
+}
+
+
+/*return value is error code (0 means no error)*/
+static unsigned lodepng_color_mode_copy(LodePNGColorMode* dest, const LodePNGColorMode* source)
+{
+ lodepng_color_mode_cleanup(dest);
+ lodepng_memcpy(dest, source, sizeof(LodePNGColorMode));
+ if (source->palette) {
+ dest->palette = (unsigned char*)malloc(1024);
+ if (!dest->palette && source->palettesize) return 83; /*alloc fail*/
+ lodepng_memcpy(dest->palette, source->palette, source->palettesize * 4);
+ }
+ return 0;
+}
+
+
+static int lodepng_color_mode_equal(const LodePNGColorMode* a, const LodePNGColorMode* b)
+{
+ size_t i;
+ if (a->colortype != b->colortype) return 0;
+ if (a->bitdepth != b->bitdepth) return 0;
+ if (a->key_defined != b->key_defined) return 0;
+ if (a->key_defined) {
+ if(a->key_r != b->key_r) return 0;
+ if(a->key_g != b->key_g) return 0;
+ if(a->key_b != b->key_b) return 0;
+ }
+ if (a->palettesize != b->palettesize) return 0;
+ for (i = 0; i != a->palettesize * 4; ++i) {
+ if (a->palette[i] != b->palette[i]) return 0;
+ }
+ return 1;
+}
+
+
+static 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 / 8u) * bpp) + ((n & 7u) * bpp + 7u) / 8u;
+}
+
+
+/* Returns the byte size of a raw image buffer with given width, height and color mode */
+static 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);
+}
+
+
+/*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. Set h to 1 to get the size of 1 row including filter byte. */
+static size_t lodepng_get_raw_size_idat(unsigned w, unsigned h, unsigned bpp)
+{
+ /* + 1 for the filter byte, and possibly plus padding bits per line. */
+ /* Ignoring casts, the expression is equal to (w * bpp + 7) / 8 + 1, but avoids overflow of w * bpp */
+ size_t line = ((size_t)(w / 8u) * bpp) + 1u + ((w & 7u) * bpp + 7u) / 8u;
+ return (size_t)h * line;
+}
+
+
+/* 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_lct(pngcolor->colortype, pngcolor->bitdepth), lodepng_get_bpp_lct(rawcolor->colortype, rawcolor->bitdepth));
+ 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 / 8u) * bpp) + ((w & 7u) * bpp + 7u) / 8u" */
+ if (lodepng_mulofl((size_t)(w / 8u), bpp, &line)) return 1;
+ if (lodepng_addofl(line, ((w & 7u) * bpp + 7u) / 8u, &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 */
+}
+
+
+static void lodepng_info_init(LodePNGInfo* info)
+{
+ lodepng_color_mode_init(&info->color);
+ info->interlace_method = 0;
+ info->compression_method = 0;
+ info->filter_method = 0;
+}
+
+
+static void lodepng_info_cleanup(LodePNGInfo* info)
+{
+ lodepng_color_mode_cleanup(&info->color);
+}
+
+
+/* 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 / 8u] = in;
+ else out[index * bits / 8u] |= in;
+}
+
+/*
+ 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)
+{
+ lodepng_memset(tree->children, 0, 16 * sizeof(*tree->children));
+ 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]);
+ 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;
+}
+
+
+/* color is not allowed to already exist.
+ Index should be >= 0 (it's signed to be compatible with using -1 for "doesn't exist")
+ Returns error code, or 0 if ok */
+static unsigned 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*)malloc(sizeof(ColorTree));
+ if (!tree->children[i]) return 83; /*alloc fail*/
+ color_tree_init(tree->children[i]);
+ }
+ tree = tree->children[i];
+ }
+ tree->index = (int)index;
+ return 0;
+}
+
+/* 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 gray = r; /*((unsigned short)r + g + b) / 3u;*/
+ if (mode->bitdepth == 8) out[i] = gray;
+ else if (mode->bitdepth == 16) out[i * 2 + 0] = out[i * 2 + 1] = gray;
+ else {
+ /*take the most significant bits of gray*/
+ gray = ((unsigned)gray >> (8u - mode->bitdepth)) & ((1u << mode->bitdepth) - 1u);
+ addColorBits(out, i, mode->bitdepth, gray);
+ }
+ } 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 gray = r; /*((unsigned short)r + g + b) / 3u;*/
+ if (mode->bitdepth == 8) {
+ out[i * 2 + 0] = gray;
+ out[i * 2 + 1] = a;
+ } else if (mode->bitdepth == 16) {
+ out[i * 4 + 0] = out[i * 4 + 1] = gray;
+ 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 gray = r; /*((unsigned)r + g + b) / 3u;*/
+ out[i * 2 + 0] = (gray >> 8) & 255;
+ out[i * 2 + 1] = gray & 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 gray = r; /*((unsigned)r + g + b) / 3u;*/
+ out[i * 4 + 0] = (gray >> 8) & 255;
+ out[i * 4 + 1] = gray & 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);
+ }
+ /* out of bounds of palette not checked: see lodepng_color_mode_alloc_palette. */
+ *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 the common case of RGBA with 8 bit per channel. buffer must be RGBA with
+ enough memory.*/
+static void getPixelColorsRGBA8(unsigned char* LODEPNG_RESTRICT buffer, size_t numpixels, const unsigned char* LODEPNG_RESTRICT in, const LodePNGColorMode* mode)
+{
+ unsigned num_channels = 4;
+ 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];
+ buffer[3] = 255;
+ }
+ if (mode->key_defined) {
+ buffer -= numpixels * num_channels;
+ for (i = 0; i != numpixels; ++i, buffer += num_channels) {
+ if(buffer[0] == mode->key_r) buffer[3] = 0;
+ }
+ }
+ } else if (mode->bitdepth == 16) {
+ for (i = 0; i != numpixels; ++i, buffer += num_channels) {
+ buffer[0] = buffer[1] = buffer[2] = in[i * 2];
+ 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;
+ 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) {
+ //lodepng_memcpy(buffer, &in[i * 3], 3);
+ //Convert colortype to LCT_BGR?
+ buffer[0] = in[i * 3 + 2];
+ buffer[1] = in[i * 3 + 1];
+ buffer[2] = in[i * 3 + 0];
+ buffer[3] = 255;
+ }
+ if (mode->key_defined) {
+ buffer -= numpixels * num_channels;
+ for (i = 0; i != numpixels; ++i, buffer += num_channels) {
+ if (buffer[0] == mode->key_r && buffer[1]== mode->key_g && buffer[2] == mode->key_b) buffer[3] = 0;
+ }
+ }
+ } 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];
+ 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) {
+ if (mode->bitdepth == 8) {
+ for (i = 0; i != numpixels; ++i, buffer += num_channels) {
+ unsigned index = in[i];
+ /* out of bounds of palette not checked: see lodepng_color_mode_alloc_palette. */
+ lodepng_memcpy(buffer, &mode->palette[index * 4], 4);
+ }
+ } else {
+ size_t j = 0;
+ for (i = 0; i != numpixels; ++i, buffer += num_channels) {
+ unsigned index = readBitsFromReversedStream(&j, in, mode->bitdepth);
+ /* out of bounds of palette not checked: see lodepng_color_mode_alloc_palette. */
+ lodepng_memcpy(buffer, &mode->palette[index * 4], 4);
+ }
+ }
+ } 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];
+ 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];
+ buffer[3] = in[i * 4 + 2];
+ }
+ }
+ } else if (mode->colortype == LCT_RGBA) {
+ if (mode->bitdepth == 8) {
+ lodepng_memcpy(buffer, in, numpixels * 4);
+ } 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];
+ buffer[3] = in[i * 8 + 6];
+ }
+ }
+ }
+}
+
+
+/* Similar to getPixelColorsRGBA8, but with 3-channel RGB output. */
+static void getPixelColorsRGB8(unsigned char* LODEPNG_RESTRICT buffer, size_t numpixels, const unsigned char* LODEPNG_RESTRICT in, const LodePNGColorMode* mode)
+{
+ const unsigned num_channels = 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];
+ }
+ } else if (mode->bitdepth == 16) {
+ for (i = 0; i != numpixels; ++i, buffer += num_channels) {
+ buffer[0] = buffer[1] = buffer[2] = in[i * 2];
+ }
+ } 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;
+ }
+ }
+ } else if (mode->colortype == LCT_RGB) {
+ if (mode->bitdepth == 8) {
+ lodepng_memcpy(buffer, in, numpixels * 3);
+ } 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];
+ }
+ }
+ } else if (mode->colortype == LCT_PALETTE) {
+ if (mode->bitdepth == 8) {
+ for (i = 0; i != numpixels; ++i, buffer += num_channels) {
+ unsigned index = in[i];
+ /* out of bounds of palette not checked: see lodepng_color_mode_alloc_palette. */
+ lodepng_memcpy(buffer, &mode->palette[index * 4], 3);
+ }
+ } else {
+ size_t j = 0;
+ for (i = 0; i != numpixels; ++i, buffer += num_channels) {
+ unsigned index = readBitsFromReversedStream(&j, in, mode->bitdepth);
+ /* out of bounds of palette not checked: see lodepng_color_mode_alloc_palette. */
+ lodepng_memcpy(buffer, &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];
+ }
+ } else {
+ for (i = 0; i != numpixels; ++i, buffer += num_channels) {
+ buffer[0] = buffer[1] = buffer[2] = in[i * 4 + 0];
+ }
+ }
+ } else if (mode->colortype == LCT_RGBA) {
+ if (mode->bitdepth == 8) {
+ for(i = 0; i != numpixels; ++i, buffer += num_channels) {
+ lodepng_memcpy(buffer, &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];
+ }
+ }
+ }
+}
+
+
+/* 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];
+ }
+}
+
+/*
+ Converts raw buffer from one color type to another color type, based on
+ LodePNGColorMode structs to describe the input and output color type.
+ See the reference manual at the end of this header file to see which color conversions are supported.
+ return value = LodePNG error code (0 if all went ok, an error if the conversion isn't supported)
+ The out buffer must have size (w * h * bpp + 7) / 8, where bpp is the bits per pixel
+ of the output color type (lodepng_get_bpp).
+ For < 8 bpp images, there should not be padding bits at the end of scanlines.
+ For 16-bit per channel colors, uses big endian format like PNG does.
+ Return value is LodePNG error code
+*/
+static 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 (mode_in->colortype == LCT_PALETTE && !mode_in->palette) {
+ return 107; /* error: must provide palette if input mode is palette */
+ }
+
+ if (lodepng_color_mode_equal(mode_out, mode_in)) {
+ size_t numbytes = lodepng_get_raw_size(w, h, mode_in);
+ lodepng_memcpy(out, in, numbytes);
+ 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);
+ lodepng_memcpy(out, in, numbytes);
+ return 0;
+ }
+ }
+ if (palettesize < palsize) palsize = palettesize;
+ color_tree_init(&tree);
+ for (i = 0; i != palsize; ++i) {
+ const unsigned char* p = &palette[i * 4];
+ error = color_tree_add(&tree, p[0], p[1], p[2], p[3], (unsigned)i);
+ if (error) break;
+ }
+ }
+
+ if (!error) {
+ 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, in, mode_in);
+ } else if(mode_out->bitdepth == 8 && mode_out->colortype == LCT_RGB) {
+ getPixelColorsRGB8(out, numpixels, 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;
+}
+
+
+/* Paeth predictor, 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 = LODEPNG_ABS(b - c);
+ short pb = LODEPNG_ABS(a - c);
+ short pc = LODEPNG_ABS(a + b - c - c);
+ /* return input value associated with smallest of pa, pb, pc (with certain priority if equal) */
+ if (pb < pa) { a = b; pa = pb; }
+ return (pc < pa) ? c : 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] * (1u + (passw[i] * bpp + 7u) / 8u) : 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 + 7u) / 8u);
+ /* only padded at end of reduced image */
+ passstart[i + 1] = passstart[i] + (passh[i] * passw[i] * bpp + 7u) / 8u;
+ }
+}
+
+
+/* ////////////////////////////////////////////////////////////////////////// */
+/* / PNG Decoder / */
+/* ////////////////////////////////////////////////////////////////////////// */
+
+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] >> 1u);
+ for (i = bytewidth; i < length; ++i) recon[i] = scanline[i] + ((recon[i - bytewidth] + precon[i]) >> 1u);
+ } else {
+ for (i = 0; i != bytewidth; ++i) recon[i] = scanline[i];
+ for (i = bytewidth; i < length; ++i) recon[i] = scanline[i] + (recon[i - bytewidth] >> 1u);
+ }
+ 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]*/
+ }
+
+ /* Unroll independent paths of the paeth predictor. A 6x and 8x version would also be possible but that
+ adds too much code. Whether this actually speeds anything up at all depends on compiler and settings. */
+ if (bytewidth >= 4) {
+ for (; i + 3 < length; i += 4) {
+ size_t j = i - bytewidth;
+ unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1], s2 = scanline[i + 2], s3 = scanline[i + 3];
+ unsigned char r0 = recon[j + 0], r1 = recon[j + 1], r2 = recon[j + 2], r3 = recon[j + 3];
+ unsigned char p0 = precon[i + 0], p1 = precon[i + 1], p2 = precon[i + 2], p3 = precon[i + 3];
+ unsigned char q0 = precon[j + 0], q1 = precon[j + 1], q2 = precon[j + 2], q3 = precon[j + 3];
+ recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
+ recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
+ recon[i + 2] = s2 + paethPredictor(r2, p2, q2);
+ recon[i + 3] = s3 + paethPredictor(r3, p3, q3);
+ }
+ } else if (bytewidth >= 3) {
+ for (; i + 2 < length; i += 3) {
+ size_t j = i - bytewidth;
+ unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1], s2 = scanline[i + 2];
+ unsigned char r0 = recon[j + 0], r1 = recon[j + 1], r2 = recon[j + 2];
+ unsigned char p0 = precon[i + 0], p1 = precon[i + 1], p2 = precon[i + 2];
+ unsigned char q0 = precon[j + 0], q1 = precon[j + 1], q2 = precon[j + 2];
+ recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
+ recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
+ recon[i + 2] = s2 + paethPredictor(r2, p2, q2);
+ }
+ } else if (bytewidth >= 2) {
+ for (; i + 1 < length; i += 2) {
+ size_t j = i - bytewidth;
+ unsigned char s0 = scanline[i + 0], s1 = scanline[i + 1];
+ unsigned char r0 = recon[j + 0], r1 = recon[j + 1];
+ unsigned char p0 = precon[i + 0], p1 = precon[i + 1];
+ unsigned char q0 = precon[j + 0], q1 = precon[j + 1];
+ recon[i + 0] = s0 + paethPredictor(r0, p0, q0);
+ recon[i + 1] = s1 + paethPredictor(r1, p1, q1);
+ }
+ }
+
+ for (; 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: invalid 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 + 7u) / 8u;
+ /* the width of a scanline in bytes, not including the filter type */
+ size_t linebytes = lodepng_get_raw_size_idat(w, 1, bpp) - 1u;
+
+ 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 / 8u;
+ 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] + (size_t)y * ADAM7_DY[i]) * (size_t)w + ADAM7_IX[i] + (size_t)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] + (size_t)y * ADAM7_DY[i]) * olinebits + (ADAM7_IX[i] + (size_t)x * ADAM7_DX[i]) * bpp;
+ for (b = 0; b < bpp; ++b) {
+ unsigned char bit = readBitFromReversedStream(&ibp, in);
+ setBitOfReversedStream(&obp, out, bit);
+ }
+ }
+ }
+ }
+}
+
+
+static void removePaddingBits(unsigned char* out, const unsigned char* in, size_t olinebits, size_t ilinebits, unsigned h)
+{
+ /* After filtering there are still padding bits if scanlines have non multiple of 8 bit amounts. They need
+ to be removed (except at last scanline of (Adam7-reduced) image) before working with pure image buffers
+ for the Adam7 code, the color convert code and the output to the user.
+ in and out are allowed to be the same buffer, in may also be higher but still overlapping; in must
+ have >= ilinebits*h bits, out must have >= olinebits*h bits, olinebits must be <= ilinebits
+ also used to move bits after earlier such operations happened, e.g. in a sequence of reduced images from Adam7
+ only useful if (ilinebits - olinebits) is a value in the range 1..7 */
+ unsigned y;
+ size_t diff = ilinebits - olinebits;
+ size_t ibp = 0, obp = 0; /*input and output bit pointers*/
+ for (y = 0; y < h; ++y) {
+ size_t x;
+ for (x = 0; x < olinebits; ++x) {
+ unsigned char bit = readBitFromReversedStream(&ibp, in);
+ setBitOfReversedStream(&obp, out, bit);
+ }
+ ibp += diff;
+ }
+}
+
+
+/* out must be buffer big enough to contain full image, and in must contain the full decompressed data from
+ the IDAT chunks (with filter index bytes and possible padding bits)
+ return value is error */
+static unsigned postProcessScanlines(unsigned char* out, unsigned char* in, unsigned w, unsigned h, const LodePNGInfo* info_png)
+{
+ /* This function converts the filtered-padded-interlaced data into pure 2D image buffer with the PNG's colortype.
+ Steps:
+ *) if no Adam7: 1) unfilter 2) remove padding bits (= possible extra bits per scanline if bpp < 8)
+ *) if adam7: 1) 7x unfilter 2) 7x remove padding bits 3) Adam7_deinterlace
+ NOTE: the in buffer will be overwritten with intermediate data! */
+ unsigned bpp = lodepng_get_bpp_lct(info_png->color.colortype, info_png->color.bitdepth);
+ if (bpp == 0) return 31; /* error: invalid colortype */
+
+ if (info_png->interlace_method == 0) {
+ if (bpp < 8 && w * bpp != ((w * bpp + 7u) / 8u) * 8u) {
+ CERROR_TRY_RETURN(unfilter(in, in, w, h, bpp));
+ removePaddingBits(out, in, w * bpp, ((w * bpp + 7u) / 8u) * 8u, 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 + 7u) / 8u) * 8u, passh[i]);
+ }
+ }
+ Adam7_deinterlace(out, in, w, h, bpp);
+ }
+ return 0;
+}
+
+
+static unsigned readChunk_PLTE(LodePNGColorMode* color, const unsigned char* data, size_t chunkLength)
+{
+ unsigned pos = 0, i;
+ color->palettesize = chunkLength / 3u;
+ if (color->palettesize == 0 || color->palettesize > 256) return 38; /* error: palette too small or big */
+ lodepng_color_mode_alloc_palette(color);
+ if (!color->palette && color->palettesize) {
+ color->palettesize = 0;
+ return 83; /* alloc fail */
+ }
+
+ 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 grayscale 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 */
+}
+
+
+/* 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;
+ unsigned char* idat; /*the data from idat chunks, zlib compressed*/
+ size_t idatsize = 0;
+ unsigned char* scanlines = 0;
+ size_t scanlines_size = 0, expected_size = 0;
+ size_t outsize = 0;
+
+ /* safe output values in case error happens */
+ *out = 0;
+ *w = *h = 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*/
+ }
+
+ /*the input filesize is a safe upper bound for the sum of idat chunks size*/
+ idat = (unsigned char*)malloc(insize);
+ if (!idat) CERROR_RETURN(state->error, 83); /*alloc fail*/
+
+ 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);
+
+ /*for unknown chunk order*/
+ //unsigned unknown = 0;
+
+ /*IDAT chunk, containing compressed image data*/
+ if (lodepng_chunk_type_equals(chunk, "IDAT")) {
+ size_t newsize;
+ if (lodepng_addofl(idatsize, chunkLength, &newsize)) CERROR_BREAK(state->error, 95);
+ if (newsize > insize) CERROR_BREAK(state->error, 95);
+ lodepng_memcpy(idat + idatsize, data, chunkLength);
+ idatsize += chunkLength;
+ } 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);
+ }
+ //unknown = 1;
+ }
+
+#if 0 //We don't use CRC
+ 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*/
+ }
+#endif
+ if (!IEND) chunk = lodepng_chunk_next_const(chunk, in + insize);
+ }
+
+ if (state->info_png.color.colortype == LCT_PALETTE && !state->info_png.color.palette) {
+ state->error = 106; /* error: PNG file must have PLTE chunk if color type is palette */
+ }
+
+ if (!state->error) {
+ /*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) {
+ size_t bpp = lodepng_get_bpp_lct(state->info_png.color.colortype, state->info_png.color.bitdepth);
+ expected_size = lodepng_get_raw_size_idat(*w, *h, bpp);
+ } else {
+ size_t bpp = lodepng_get_bpp_lct(state->info_png.color.colortype, state->info_png.color.bitdepth);
+ /*Adam-7 interlaced: expected size is the sum of the 7 sub-images sizes*/
+ expected_size = 0;
+ expected_size += lodepng_get_raw_size_idat((*w + 7) >> 3, (*h + 7) >> 3, bpp);
+ if (*w > 4) expected_size += lodepng_get_raw_size_idat((*w + 3) >> 3, (*h + 7) >> 3, bpp);
+ expected_size += lodepng_get_raw_size_idat((*w + 3) >> 2, (*h + 3) >> 3, bpp);
+ if (*w > 2) expected_size += lodepng_get_raw_size_idat((*w + 1) >> 2, (*h + 3) >> 2, bpp);
+ expected_size += lodepng_get_raw_size_idat((*w + 1) >> 1, (*h + 1) >> 2, bpp);
+ if (*w > 1) expected_size += lodepng_get_raw_size_idat((*w + 0) >> 1, (*h + 1) >> 1, bpp);
+ expected_size += lodepng_get_raw_size_idat((*w + 0), (*h + 0) >> 1, bpp);
+ }
+ state->error = zlib_decompress(&scanlines, &scanlines_size, expected_size, idat, idatsize, &state->decoder.zlibsettings);
+ }
+
+ if (!state->error && scanlines_size != expected_size) state->error = 91; /*decompressed size doesn't match prediction*/
+ free(idat);
+
+ if (!state->error) {
+ outsize = lodepng_get_raw_size(*w, *h, &state->info_png.color);
+ *out = (unsigned char*)malloc(outsize);
+ if (!*out) state->error = 83; /*alloc fail*/
+ }
+ if (!state->error) {
+ lodepng_memset(*out, 0, outsize);
+ state->error = postProcessScanlines(*out, scanlines, *w, *h, &state->info_png);
+ }
+ free(scanlines);
+}
+
+
+static 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);
+}
+
+
+/************************************************************************/
+/* External Class Implementation */
+/************************************************************************/
+
+/*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]);
+ /*TODO: remove the undocumented feature that allows to give null pointers to width or height*/
+ if (w) *w = width;
+ if (h) *h = height;
+ 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];
+
+ /*errors returned only after the parsing so other values are still output*/
+
+ /*error: invalid image size*/
+ if (width == 0 || height == 0) CERROR_RETURN_ERROR(state->error, 93);
+ /*error: invalid colortype or bitdepth combination*/
+ state->error = checkColorValidity(info->color.colortype, info->color.bitdepth);
+ if (state->error) return state->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);
+
+#if 0 //thorvg don't use crc
+ 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*/
+ }
+ }
+#endif
+ return state->error;
+}
+
+
+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*/
+ unsigned char* data = *out;
+ size_t outsize;
+
+ /*TODO: check if this works according to the statement in the documentation: "The converter can convert
+ from grayscale input color type, to 8-bit grayscale or grayscale 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*)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);
+ free(data);
+ }
+ return state->error;
+}
+
+
+void lodepng_state_init(LodePNGState* state)
+{
+ lodepng_decoder_settings_init(&state->decoder);
+ 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);
+}
\ No newline at end of file
projects / platform / core / graphics / tizenvg.git / commitdiff