X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=src%2Fthird_party%2Flibwebp%2Futils%2Fhuffman_encode.c;h=6421c2beedf857d0cb683b8bb3956558554b1750;hb=4a1a0bdd01eef90b0826a0e761d3379d3715c10f;hp=9c5986738d07a2b82eeefed9f588f21e975dfcc7;hpb=b1be5ca53587d23e7aeb77b26861fdc0a181ffd8;p=platform%2Fframework%2Fweb%2Fcrosswalk.git diff --git a/src/third_party/libwebp/utils/huffman_encode.c b/src/third_party/libwebp/utils/huffman_encode.c index 9c59867..6421c2b 100644 --- a/src/third_party/libwebp/utils/huffman_encode.c +++ b/src/third_party/libwebp/utils/huffman_encode.c @@ -28,13 +28,13 @@ static int ValuesShouldBeCollapsedToStrideAverage(int a, int b) { // Change the population counts in a way that the consequent // Huffman tree compression, especially its RLE-part, give smaller output. -static int OptimizeHuffmanForRle(int length, int* const counts) { - uint8_t* good_for_rle; +static void OptimizeHuffmanForRle(int length, uint8_t* const good_for_rle, + uint32_t* const counts) { // 1) Let's make the Huffman code more compatible with rle encoding. int i; for (; length >= 0; --length) { if (length == 0) { - return 1; // All zeros. + return; // All zeros. } if (counts[length - 1] != 0) { // Now counts[0..length - 1] does not have trailing zeros. @@ -43,15 +43,11 @@ static int OptimizeHuffmanForRle(int length, int* const counts) { } // 2) Let's mark all population counts that already can be encoded // with an rle code. - good_for_rle = (uint8_t*)calloc(length, 1); - if (good_for_rle == NULL) { - return 0; - } { // Let's not spoil any of the existing good rle codes. // Mark any seq of 0's that is longer as 5 as a good_for_rle. // Mark any seq of non-0's that is longer as 7 as a good_for_rle. - int symbol = counts[0]; + uint32_t symbol = counts[0]; int stride = 0; for (i = 0; i < length + 1; ++i) { if (i == length || counts[i] != symbol) { @@ -73,17 +69,17 @@ static int OptimizeHuffmanForRle(int length, int* const counts) { } // 3) Let's replace those population counts that lead to more rle codes. { - int stride = 0; - int limit = counts[0]; - int sum = 0; + uint32_t stride = 0; + uint32_t limit = counts[0]; + uint32_t sum = 0; for (i = 0; i < length + 1; ++i) { if (i == length || good_for_rle[i] || (i != 0 && good_for_rle[i - 1]) || !ValuesShouldBeCollapsedToStrideAverage(counts[i], limit)) { if (stride >= 4 || (stride >= 3 && sum == 0)) { - int k; + uint32_t k; // The stride must end, collapse what we have, if we have enough (4). - int count = (sum + stride / 2) / stride; + uint32_t count = (sum + stride / 2) / stride; if (count < 1) { count = 1; } @@ -119,17 +115,8 @@ static int OptimizeHuffmanForRle(int length, int* const counts) { } } } - free(good_for_rle); - return 1; } -typedef struct { - int total_count_; - int value_; - int pool_index_left_; - int pool_index_right_; -} HuffmanTree; - // A comparer function for two Huffman trees: sorts first by 'total count' // (more comes first), and then by 'value' (more comes first). static int CompareHuffmanTrees(const void* ptr1, const void* ptr2) { @@ -175,12 +162,12 @@ static void SetBitDepths(const HuffmanTree* const tree, // we are not planning to use this with extremely long blocks. // // See http://en.wikipedia.org/wiki/Huffman_coding -static int GenerateOptimalTree(const int* const histogram, int histogram_size, - int tree_depth_limit, - uint8_t* const bit_depths) { - int count_min; +static void GenerateOptimalTree(const uint32_t* const histogram, + int histogram_size, + HuffmanTree* tree, int tree_depth_limit, + uint8_t* const bit_depths) { + uint32_t count_min; HuffmanTree* tree_pool; - HuffmanTree* tree; int tree_size_orig = 0; int i; @@ -191,15 +178,9 @@ static int GenerateOptimalTree(const int* const histogram, int histogram_size, } if (tree_size_orig == 0) { // pretty optimal already! - return 1; + return; } - // 3 * tree_size is enough to cover all the nodes representing a - // population and all the inserted nodes combining two existing nodes. - // The tree pool needs 2 * (tree_size_orig - 1) entities, and the - // tree needs exactly tree_size_orig entities. - tree = (HuffmanTree*)WebPSafeMalloc(3ULL * tree_size_orig, sizeof(*tree)); - if (tree == NULL) return 0; tree_pool = tree + tree_size_orig; // For block sizes with less than 64k symbols we never need to do a @@ -215,7 +196,7 @@ static int GenerateOptimalTree(const int* const histogram, int histogram_size, int j; for (j = 0; j < histogram_size; ++j) { if (histogram[j] != 0) { - const int count = + const uint32_t count = (histogram[j] < count_min) ? count_min : histogram[j]; tree[idx].total_count_ = count; tree[idx].value_ = j; @@ -231,7 +212,7 @@ static int GenerateOptimalTree(const int* const histogram, int histogram_size, if (tree_size > 1) { // Normal case. int tree_pool_size = 0; while (tree_size > 1) { // Finish when we have only one root. - int count; + uint32_t count; tree_pool[tree_pool_size++] = tree[tree_size - 1]; tree_pool[tree_pool_size++] = tree[tree_size - 2]; count = tree_pool[tree_pool_size - 1].total_count_ + @@ -272,8 +253,6 @@ static int GenerateOptimalTree(const int* const histogram, int histogram_size, } } } - free(tree); - return 1; } // ----------------------------------------------------------------------------- @@ -424,17 +403,15 @@ static void ConvertBitDepthsToSymbols(HuffmanTreeCode* const tree) { // ----------------------------------------------------------------------------- // Main entry point -int VP8LCreateHuffmanTree(int* const histogram, int tree_depth_limit, - HuffmanTreeCode* const tree) { - const int num_symbols = tree->num_symbols; - if (!OptimizeHuffmanForRle(num_symbols, histogram)) { - return 0; - } - if (!GenerateOptimalTree(histogram, num_symbols, - tree_depth_limit, tree->code_lengths)) { - return 0; - } +void VP8LCreateHuffmanTree(uint32_t* const histogram, int tree_depth_limit, + uint8_t* const buf_rle, + HuffmanTree* const huff_tree, + HuffmanTreeCode* const huff_code) { + const int num_symbols = huff_code->num_symbols; + memset(buf_rle, 0, num_symbols * sizeof(*buf_rle)); + OptimizeHuffmanForRle(num_symbols, buf_rle, histogram); + GenerateOptimalTree(histogram, num_symbols, huff_tree, tree_depth_limit, + huff_code->code_lengths); // Create the actual bit codes for the bit lengths. - ConvertBitDepthsToSymbols(tree); - return 1; + ConvertBitDepthsToSymbols(huff_code); }