brotli/enc/prefix.h
Zoltan Szabadka c66e4e3e4f Add brotli compressor
This commit is for the encoder for brotli compression format.
Brotli is a generic byte-level compression algorithm.
2013-10-23 13:06:13 +02:00

52 lines
1.7 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.
//
// Functions for encoding of integers into prefix codes the amount of extra
// bits, and the actual values of the extra bits.
#ifndef BROTLI_ENC_PREFIX_H_
#define BROTLI_ENC_PREFIX_H_
#include <stdint.h>
namespace brotli {
static const int kNumInsertLenPrefixes = 24;
static const int kNumCopyLenPrefixes = 24;
static const int kNumCommandPrefixes = 704;
static const int kNumBlockLenPrefixes = 26;
static const int kNumDistanceShortCodes = 16;
static const int kNumDistancePrefixes = 520;
int CommandPrefix(int insert_length, int copy_length);
int InsertLengthExtraBits(int prefix);
int InsertLengthOffset(int prefix);
int CopyLengthExtraBits(int prefix);
int CopyLengthOffset(int prefix);
void PrefixEncodeCopyDistance(int distance_code,
int num_direct_codes,
int shift_bits,
uint16_t* prefix,
int* nbits,
uint32_t* extra_bits);
int BlockLengthPrefix(int length);
int BlockLengthExtraBits(int prefix);
int BlockLengthOffset(int prefix);
} // namespace brotli
#endif // BROTLI_ENC_PREFIX_H_