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93 lines
3.0 KiB
C
93 lines
3.0 KiB
C
/*
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Copyright 2011 Google Inc. All Rights Reserved.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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Author: lode.vandevenne@gmail.com (Lode Vandevenne)
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Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
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*/
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#ifndef ZOPFLI_DEFLATE_H_
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#define ZOPFLI_DEFLATE_H_
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/*
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Functions to compress according to the DEFLATE specification, using the
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"squeeze" LZ77 compression backend.
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*/
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#include "lz77.h"
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#include "zopfli.h"
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#ifdef __cplusplus
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extern "C" {
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#endif
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/*
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Compresses according to the deflate specification and append the compressed
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result to the output.
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This function will usually output multiple deflate blocks. If final is 1, then
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the final bit will be set on the last block.
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options: global program options
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btype: the deflate block type. Use 2 for best compression.
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-0: non compressed blocks (00)
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-1: blocks with fixed tree (01)
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-2: blocks with dynamic tree (10)
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final: whether this is the last section of the input, sets the final bit to the
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last deflate block.
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in: the input bytes
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insize: number of input bytes
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bp: bit pointer for the output array. This must initially be 0, and for
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consecutive calls must be reused (it can have values from 0-7). This is
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because deflate appends blocks as bit-based data, rather than on byte
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boundaries.
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out: pointer to the dynamic output array to which the result is appended. Must
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be freed after use.
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outsize: pointer to the dynamic output array size.
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*/
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void ZopfliDeflate(const ZopfliOptions* options, int btype, int final,
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const unsigned char* in, size_t insize,
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unsigned char* bp, unsigned char** out, size_t* outsize);
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/*
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Like ZopfliDeflate, but allows to specify start and end byte with instart and
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inend. Only that part is compressed, but earlier bytes are still used for the
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back window.
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*/
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void ZopfliDeflatePart(const ZopfliOptions* options, int btype, int final,
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const unsigned char* in, size_t instart, size_t inend,
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unsigned char* bp, unsigned char** out,
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size_t* outsize);
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/*
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Calculates block size in bits.
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litlens: lz77 lit/lengths
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dists: ll77 distances
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lstart: start of block
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lend: end of block (not inclusive)
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*/
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double ZopfliCalculateBlockSize(const ZopfliLZ77Store* lz77,
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size_t lstart, size_t lend, int btype);
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/*
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Calculates block size in bits, automatically using the best btype.
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*/
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double ZopfliCalculateBlockSizeAutoType(const ZopfliLZ77Store* lz77,
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size_t lstart, size_t lend);
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#ifdef __cplusplus
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} // extern "C"
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#endif
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#endif /* ZOPFLI_DEFLATE_H_ */
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