mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
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73 lines
2.6 KiB
C
73 lines
2.6 KiB
C
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/* Copyright 2013 Google Inc. All Rights Reserved.
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Distributed under MIT license.
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See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
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*/
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/* Utilities for building Huffman decoding tables. */
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#ifndef BROTLI_DEC_HUFFMAN_H_
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#define BROTLI_DEC_HUFFMAN_H_
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#include "../common/platform.h"
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#include <brotli/types.h>
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#if defined(__cplusplus) || defined(c_plusplus)
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extern "C" {
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#endif
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#define BROTLI_HUFFMAN_MAX_CODE_LENGTH 15
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/* Maximum possible Huffman table size for an alphabet size of (index * 32),
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max code length 15 and root table bits 8. */
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static const uint16_t kMaxHuffmanTableSize[] = {
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256, 402, 436, 468, 500, 534, 566, 598, 630, 662, 694, 726, 758, 790, 822,
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854, 886, 920, 952, 984, 1016, 1048, 1080, 1112, 1144, 1176, 1208, 1240, 1272,
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1304, 1336, 1368, 1400, 1432, 1464, 1496, 1528};
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/* BROTLI_NUM_BLOCK_LEN_SYMBOLS == 26 */
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#define BROTLI_HUFFMAN_MAX_SIZE_26 396
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/* BROTLI_MAX_BLOCK_TYPE_SYMBOLS == 258 */
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#define BROTLI_HUFFMAN_MAX_SIZE_258 632
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/* BROTLI_MAX_CONTEXT_MAP_SYMBOLS == 272 */
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#define BROTLI_HUFFMAN_MAX_SIZE_272 646
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#define BROTLI_HUFFMAN_MAX_CODE_LENGTH_CODE_LENGTH 5
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typedef struct {
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uint8_t bits; /* number of bits used for this symbol */
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uint16_t value; /* symbol value or table offset */
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} HuffmanCode;
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/* Builds Huffman lookup table assuming code lengths are in symbol order. */
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BROTLI_INTERNAL void BrotliBuildCodeLengthsHuffmanTable(HuffmanCode* root_table,
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const uint8_t* const code_lengths, uint16_t* count);
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/* Builds Huffman lookup table assuming code lengths are in symbol order.
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Returns size of resulting table. */
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BROTLI_INTERNAL uint32_t BrotliBuildHuffmanTable(HuffmanCode* root_table,
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int root_bits, const uint16_t* const symbol_lists, uint16_t* count_arg);
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/* Builds a simple Huffman table. The |num_symbols| parameter is to be
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interpreted as follows: 0 means 1 symbol, 1 means 2 symbols,
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2 means 3 symbols, 3 means 4 symbols with lengths [2, 2, 2, 2],
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4 means 4 symbols with lengths [1, 2, 3, 3]. */
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BROTLI_INTERNAL uint32_t BrotliBuildSimpleHuffmanTable(HuffmanCode* table,
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int root_bits, uint16_t* symbols, uint32_t num_symbols);
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/* Contains a collection of Huffman trees with the same alphabet size. */
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/* max_symbol is needed due to simple codes since log2(alphabet_size) could be
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greater than log2(max_symbol). */
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typedef struct {
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HuffmanCode** htrees;
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HuffmanCode* codes;
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uint16_t alphabet_size;
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uint16_t max_symbol;
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uint16_t num_htrees;
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} HuffmanTreeGroup;
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#if defined(__cplusplus) || defined(c_plusplus)
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} /* extern "C" */
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#endif
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#endif /* BROTLI_DEC_HUFFMAN_H_ */
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