BaseTools/Source/C/BrotliCompress/common/constants.h

   1 /* Copyright 2016 Google Inc. All Rights Reserved.
   2
   3    Distributed under MIT license.
   4    See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
   5 */
   6
   7 #ifndef BROTLI_COMMON_CONSTANTS_H_
   8 #define BROTLI_COMMON_CONSTANTS_H_
   9
  10 /* Specification: 7.3. Encoding of the context map */
  11 #define BROTLI_CONTEXT_MAP_MAX_RLE 16
  12
  13 /* Specification: 2. Compressed representation overview */
  14 #define BROTLI_MAX_NUMBER_OF_BLOCK_TYPES 256
  15
  16 /* Specification: 3.3. Alphabet sizes: insert-and-copy length */
  17 #define BROTLI_NUM_LITERAL_SYMBOLS 256
  18 #define BROTLI_NUM_COMMAND_SYMBOLS 704
  19 #define BROTLI_NUM_BLOCK_LEN_SYMBOLS 26
  20 #define BROTLI_MAX_CONTEXT_MAP_SYMBOLS (BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + \
  21                                         BROTLI_CONTEXT_MAP_MAX_RLE)
  22 #define BROTLI_MAX_BLOCK_TYPE_SYMBOLS (BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + 2)
  23
  24 /* Specification: 3.5. Complex prefix codes */
  25 #define BROTLI_REPEAT_PREVIOUS_CODE_LENGTH 16
  26 #define BROTLI_REPEAT_ZERO_CODE_LENGTH 17
  27 #define BROTLI_CODE_LENGTH_CODES (BROTLI_REPEAT_ZERO_CODE_LENGTH + 1)
  28 /* "code length of 8 is repeated" */
  29 #define BROTLI_INITIAL_REPEATED_CODE_LENGTH 8
  30
  31 /* Specification: 4. Encoding of distances */
  32 #define BROTLI_NUM_DISTANCE_SHORT_CODES 16
  33 #define BROTLI_MAX_NPOSTFIX 3
  34 #define BROTLI_MAX_NDIRECT 120
  35 /* BROTLI_NUM_DISTANCE_SYMBOLS == 520 */
  36 #define BROTLI_NUM_DISTANCE_SYMBOLS (BROTLI_NUM_DISTANCE_SHORT_CODES + \
  37                                      BROTLI_MAX_NDIRECT +              \
  38                                      (24 << (BROTLI_MAX_NPOSTFIX + 1)))
  39
  40 /* 7.1. Context modes and context ID lookup for literals */
  41 /* "context IDs for literals are in the range of 0..63" */
  42 #define BROTLI_LITERAL_CONTEXT_BITS 6
  43
  44 /* 7.2. Context ID for distances */
  45 #define BROTLI_DISTANCE_CONTEXT_BITS 2
  46
  47 #endif  /* BROTLI_COMMON_CONSTANTS_H_ */