1 // Copyright 2013 Google Inc. All Rights Reserved. 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 // 15 // Functions for encoding of integers into prefix codes the amount of extra 16 // bits, and the actual values of the extra bits. 17 18 #ifndef BROTLI_ENC_PREFIX_H_ 19 #define BROTLI_ENC_PREFIX_H_ 20 21 #include <stdint.h> 22 23 namespace brotli { 24 25 static const int kNumInsertLenPrefixes = 24; 26 static const int kNumCopyLenPrefixes = 24; 27 static const int kNumCommandPrefixes = 704; 28 static const int kNumBlockLenPrefixes = 26; 29 static const int kNumDistanceShortCodes = 16; 30 static const int kNumDistancePrefixes = 520; 31 32 int CommandPrefix(int insert_length, int copy_length); 33 int InsertLengthExtraBits(int prefix); 34 int InsertLengthOffset(int prefix); 35 int CopyLengthExtraBits(int prefix); 36 int CopyLengthOffset(int prefix); 37 38 void PrefixEncodeCopyDistance(int distance_code, 39 int num_direct_codes, 40 int shift_bits, 41 uint16_t* prefix, 42 int* nbits, 43 uint32_t* extra_bits); 44 45 int BlockLengthPrefix(int length); 46 int BlockLengthExtraBits(int prefix); 47 int BlockLengthOffset(int prefix); 48 49 } // namespace brotli 50 51 #endif // BROTLI_ENC_PREFIX_H_ 52
