mirror of
https://github.com/google/brotli.git
synced 2024-11-23 12:10:07 +00:00
66 lines
2.2 KiB
C
66 lines
2.2 KiB
C
/* Copyright 2013 Google Inc. All Rights Reserved.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
|
|
Lookup tables to map prefix codes to value ranges. This is used during
|
|
decoding of the block lengths, literal insertion lengths and copy lengths.
|
|
*/
|
|
|
|
#ifndef BROTLI_DEC_PREFIX_H_
|
|
#define BROTLI_DEC_PREFIX_H_
|
|
|
|
/* Represents the range of values belonging to a prefix code: */
|
|
/* [offset, offset + 2^nbits) */
|
|
struct PrefixCodeRange {
|
|
int offset;
|
|
int nbits;
|
|
};
|
|
|
|
static const struct PrefixCodeRange kBlockLengthPrefixCode[] = {
|
|
{ 1, 2}, { 5, 2}, { 9, 2}, { 13, 2},
|
|
{ 17, 3}, { 25, 3}, { 33, 3}, { 41, 3},
|
|
{ 49, 4}, { 65, 4}, { 81, 4}, { 97, 4},
|
|
{ 113, 5}, { 145, 5}, { 177, 5}, { 209, 5},
|
|
{ 241, 6}, { 305, 6}, { 369, 7}, { 497, 8},
|
|
{ 753, 9}, { 1265, 10}, {2289, 11}, {4337, 12},
|
|
{8433, 13}, {16625, 24}
|
|
};
|
|
|
|
static const struct PrefixCodeRange kInsertLengthPrefixCode[] = {
|
|
{ 0, 0}, { 1, 0}, { 2, 0}, { 3, 0},
|
|
{ 4, 0}, { 5, 0}, { 6, 1}, { 8, 1},
|
|
{ 10, 2}, { 14, 2}, { 18, 3}, { 26, 3},
|
|
{ 34, 4}, { 50, 4}, { 66, 5}, { 98, 5},
|
|
{ 130, 6}, { 194, 7}, { 322, 8}, { 578, 9},
|
|
{1090, 10}, {2114, 12}, {6210, 14}, {22594, 24},
|
|
};
|
|
|
|
static const struct PrefixCodeRange kCopyLengthPrefixCode[] = {
|
|
{ 2, 0}, { 3, 0}, { 4, 0}, { 5, 0},
|
|
{ 6, 0}, { 7, 0}, { 8, 0}, { 9, 0},
|
|
{ 10, 1}, { 12, 1}, { 14, 2}, { 18, 2},
|
|
{ 22, 3}, { 30, 3}, { 38, 4}, { 54, 4},
|
|
{ 70, 5}, { 102, 5}, { 134, 6}, { 198, 7},
|
|
{326, 8}, { 582, 9}, {1094, 10}, {2118, 24},
|
|
};
|
|
|
|
static const int kInsertRangeLut[9] = {
|
|
0, 0, 8, 8, 0, 16, 8, 16, 16,
|
|
};
|
|
|
|
static const int kCopyRangeLut[9] = {
|
|
0, 8, 0, 8, 16, 0, 16, 8, 16,
|
|
};
|
|
|
|
#endif /* BROTLI_DEC_PREFIX_H_ */
|