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- /* Copyright 2016 Google Inc. All Rights Reserved.
- Distributed under MIT license.
- See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
- */
- #ifndef BROTLI_COMMON_CONSTANTS_H_
- #define BROTLI_COMMON_CONSTANTS_H_
- /* Specification: 7.3. Encoding of the context map */
- #define BROTLI_CONTEXT_MAP_MAX_RLE 16
- /* Specification: 2. Compressed representation overview */
- #define BROTLI_MAX_NUMBER_OF_BLOCK_TYPES 256
- /* Specification: 3.3. Alphabet sizes: insert-and-copy length */
- #define BROTLI_NUM_LITERAL_SYMBOLS 256
- #define BROTLI_NUM_COMMAND_SYMBOLS 704
- #define BROTLI_NUM_BLOCK_LEN_SYMBOLS 26
- #define BROTLI_MAX_CONTEXT_MAP_SYMBOLS (BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + \
- BROTLI_CONTEXT_MAP_MAX_RLE)
- #define BROTLI_MAX_BLOCK_TYPE_SYMBOLS (BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + 2)
- /* Specification: 3.5. Complex prefix codes */
- #define BROTLI_REPEAT_PREVIOUS_CODE_LENGTH 16
- #define BROTLI_REPEAT_ZERO_CODE_LENGTH 17
- #define BROTLI_CODE_LENGTH_CODES (BROTLI_REPEAT_ZERO_CODE_LENGTH + 1)
- /* "code length of 8 is repeated" */
- #define BROTLI_INITIAL_REPEATED_CODE_LENGTH 8
- /* Specification: 4. Encoding of distances */
- #define BROTLI_NUM_DISTANCE_SHORT_CODES 16
- #define BROTLI_MAX_NPOSTFIX 3
- #define BROTLI_MAX_NDIRECT 120
- /* BROTLI_NUM_DISTANCE_SYMBOLS == 520 */
- #define BROTLI_NUM_DISTANCE_SYMBOLS (BROTLI_NUM_DISTANCE_SHORT_CODES + \
- BROTLI_MAX_NDIRECT + \
- (24 << (BROTLI_MAX_NPOSTFIX + 1)))
- /* 7.1. Context modes and context ID lookup for literals */
- /* "context IDs for literals are in the range of 0..63" */
- #define BROTLI_LITERAL_CONTEXT_BITS 6
- /* 7.2. Context ID for distances */
- #define BROTLI_DISTANCE_CONTEXT_BITS 2
- #endif /* BROTLI_COMMON_CONSTANTS_H_ */
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