1/*
2Copyright 2013 Google Inc. All Rights Reserved.
3Author: lode@google.com (Lode Vandevenne)
4*/
5
6#ifndef UTIL_COMPRESSION_ZOPFLI_INTERNAL_ZOPFLI_H_
7#define UTIL_COMPRESSION_ZOPFLI_INTERNAL_ZOPFLI_H_
8
9#include <stdlib.h> /* for size_t */
10
11/*
12Options used throughout the program.
13*/
14typedef struct ZopfliOptions {
15  /* Whether to print output */
16  int verbose;
17
18  /*
19  Maximum amount of times to rerun forward and backward pass to optimize LZ77
20  compression cost. Good values: 10, 15 for small files, 5 for files over
21  several MB in size or it will be too slow.
22  */
23  int numiterations;
24
25  /*
26  If true, splits the data in multiple deflate blocks with optimal choice
27  for the block boundaries. Block splitting gives better compression. Default:
28  true (1).
29  */
30  int blocksplitting;
31
32  /*
33  If true, chooses the optimal block split points only after doing the iterative
34  LZ77 compression. If false, chooses the block split points first, then does
35  iterative LZ77 on each individual block. Depending on the file, either first
36  or last gives the best compression. Default: false (0).
37  */
38  int blocksplittinglast;
39
40  /*
41  Maximum amount of blocks to split into (0 for unlimited, but this can give
42  extreme results that hurt compression on some files). Default value: 15.
43  */
44  int blocksplittingmax;
45} ZopfliOptions;
46
47/* Initializes options with default values. */
48void ZopfliInitOptions(ZopfliOptions* options);
49
50/* Output format */
51typedef enum {
52  ZOPFLI_FORMAT_GZIP,
53  ZOPFLI_FORMAT_ZLIB,
54  ZOPFLI_FORMAT_DEFLATE
55} ZopfliFormat;
56
57/*
58Compresses according to the given output format and appends the result to the
59output.
60
61options: global program options
62output_type: the output format to use
63out: pointer to the dynamic output array to which the result is appended. Must
64  be freed after use
65outsize: pointer to the dynamic output array size
66*/
67void ZopfliCompress(const ZopfliOptions* options, ZopfliFormat output_type,
68                    const unsigned char* in, size_t insize,
69                    unsigned char** out, size_t* outsize);
70
71#endif  /* UTIL_COMPRESSION_ZOPFLI_INTERNAL_ZOPFLI_H_ */
72