1/*
2Copyright 2011 Google Inc. All Rights Reserved.
3
4Licensed under the Apache License, Version 2.0 (the "License");
5you may not use this file except in compliance with the License.
6You may obtain a copy of the License at
7
8    http://www.apache.org/licenses/LICENSE-2.0
9
10Unless required by applicable law or agreed to in writing, software
11distributed under the License is distributed on an "AS IS" BASIS,
12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13See the License for the specific language governing permissions and
14limitations under the License.
15
16Author: lode.vandevenne@gmail.com (Lode Vandevenne)
17Author: jyrki.alakuijala@gmail.com (Jyrki Alakuijala)
18*/
19
20#ifndef ZOPFLI_DEFLATE_H_
21#define ZOPFLI_DEFLATE_H_
22
23/*
24Functions to compress according to the DEFLATE specification, using the
25"squeeze" LZ77 compression backend.
26*/
27
28#include "zopfli.h"
29
30#ifdef __cplusplus
31extern "C" {
32#endif
33
34/*
35Compresses according to the deflate specification and append the compressed
36result to the output.
37This function will usually output multiple deflate blocks. If final is 1, then
38the final bit will be set on the last block.
39
40options: global program options
41btype: the deflate block type. Use 2 for best compression.
42  -0: non compressed blocks (00)
43  -1: blocks with fixed tree (01)
44  -2: blocks with dynamic tree (10)
45final: whether this is the last section of the input, sets the final bit to the
46  last deflate block.
47in: the input bytes
48insize: number of input bytes
49bp: bit pointer for the output array. This must initially be 0, and for
50  consecutive calls must be reused (it can have values from 0-7). This is
51  because deflate appends blocks as bit-based data, rather than on byte
52  boundaries.
53out: pointer to the dynamic output array to which the result is appended. Must
54  be freed after use.
55outsize: pointer to the dynamic output array size.
56*/
57void ZopfliDeflate(const ZopfliOptions* options, int btype, int final,
58                   const unsigned char* in, size_t insize,
59                   unsigned char* bp, unsigned char** out, size_t* outsize);
60
61/*
62Like ZopfliDeflate, but allows to specify start and end byte with instart and
63inend. Only that part is compressed, but earlier bytes are still used for the
64back window.
65*/
66void ZopfliDeflatePart(const ZopfliOptions* options, int btype, int final,
67                       const unsigned char* in, size_t instart, size_t inend,
68                       unsigned char* bp, unsigned char** out,
69                       size_t* outsize);
70
71/*
72Calculates block size in bits.
73litlens: lz77 lit/lengths
74dists: ll77 distances
75lstart: start of block
76lend: end of block (not inclusive)
77*/
78double ZopfliCalculateBlockSize(const unsigned short* litlens,
79                                const unsigned short* dists,
80                                size_t lstart, size_t lend, int btype);
81
82#ifdef __cplusplus
83}  // extern "C"
84#endif
85
86#endif  /* ZOPFLI_DEFLATE_H_ */
87