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Diffstat (limited to 'thirdparty/libwebp/utils/huffman_utils.h')
-rw-r--r-- | thirdparty/libwebp/utils/huffman_utils.h | 88 |
1 files changed, 0 insertions, 88 deletions
diff --git a/thirdparty/libwebp/utils/huffman_utils.h b/thirdparty/libwebp/utils/huffman_utils.h deleted file mode 100644 index c6dd6aaa45..0000000000 --- a/thirdparty/libwebp/utils/huffman_utils.h +++ /dev/null @@ -1,88 +0,0 @@ -// Copyright 2012 Google Inc. All Rights Reserved. -// -// Use of this source code is governed by a BSD-style license -// that can be found in the COPYING file in the root of the source -// tree. An additional intellectual property rights grant can be found -// in the file PATENTS. All contributing project authors may -// be found in the AUTHORS file in the root of the source tree. -// ----------------------------------------------------------------------------- -// -// Utilities for building and looking up Huffman trees. -// -// Author: Urvang Joshi (urvang@google.com) - -#ifndef WEBP_UTILS_HUFFMAN_H_ -#define WEBP_UTILS_HUFFMAN_H_ - -#include <assert.h> -#include "../webp/format_constants.h" -#include "../webp/types.h" - -#ifdef __cplusplus -extern "C" { -#endif - -#define HUFFMAN_TABLE_BITS 8 -#define HUFFMAN_TABLE_MASK ((1 << HUFFMAN_TABLE_BITS) - 1) - -#define LENGTHS_TABLE_BITS 7 -#define LENGTHS_TABLE_MASK ((1 << LENGTHS_TABLE_BITS) - 1) - - -// Huffman lookup table entry -typedef struct { - uint8_t bits; // number of bits used for this symbol - uint16_t value; // symbol value or table offset -} HuffmanCode; - -// long version for holding 32b values -typedef struct { - int bits; // number of bits used for this symbol, - // or an impossible value if not a literal code. - uint32_t value; // 32b packed ARGB value if literal, - // or non-literal symbol otherwise -} HuffmanCode32; - -#define HUFFMAN_PACKED_BITS 6 -#define HUFFMAN_PACKED_TABLE_SIZE (1u << HUFFMAN_PACKED_BITS) - -// Huffman table group. -// Includes special handling for the following cases: -// - is_trivial_literal: one common literal base for RED/BLUE/ALPHA (not GREEN) -// - is_trivial_code: only 1 code (no bit is read from bitstream) -// - use_packed_table: few enough literal symbols, so all the bit codes -// can fit into a small look-up table packed_table[] -// The common literal base, if applicable, is stored in 'literal_arb'. -typedef struct HTreeGroup HTreeGroup; -struct HTreeGroup { - HuffmanCode* htrees[HUFFMAN_CODES_PER_META_CODE]; - int is_trivial_literal; // True, if huffman trees for Red, Blue & Alpha - // Symbols are trivial (have a single code). - uint32_t literal_arb; // If is_trivial_literal is true, this is the - // ARGB value of the pixel, with Green channel - // being set to zero. - int is_trivial_code; // true if is_trivial_literal with only one code - int use_packed_table; // use packed table below for short literal code - // table mapping input bits to a packed values, or escape case to literal code - HuffmanCode32 packed_table[HUFFMAN_PACKED_TABLE_SIZE]; -}; - -// Creates the instance of HTreeGroup with specified number of tree-groups. -HTreeGroup* VP8LHtreeGroupsNew(int num_htree_groups); - -// Releases the memory allocated for HTreeGroup. -void VP8LHtreeGroupsFree(HTreeGroup* const htree_groups); - -// Builds Huffman lookup table assuming code lengths are in symbol order. -// The 'code_lengths' is pre-allocated temporary memory buffer used for creating -// the huffman table. -// Returns built table size or 0 in case of error (invalid tree or -// memory error). -int VP8LBuildHuffmanTable(HuffmanCode* const root_table, int root_bits, - const int code_lengths[], int code_lengths_size); - -#ifdef __cplusplus -} // extern "C" -#endif - -#endif // WEBP_UTILS_HUFFMAN_H_ |