lzma_encoder_presets.c revision 207842 
1///////////////////////////////////////////////////////////////////////////////
2//
3/// \file       lzma_encoder_presets.c
4/// \brief      Encoder presets
5//
6//  Author:     Lasse Collin
7//
8//  This file has been put into the public domain.
9//  You can do whatever you want with this file.
10//
11///////////////////////////////////////////////////////////////////////////////
12
13#include "common.h"
14
15
16extern LZMA_API(lzma_bool)
17lzma_lzma_preset(lzma_options_lzma *options, uint32_t preset)
18{
19	const uint32_t level = preset & LZMA_PRESET_LEVEL_MASK;
20	const uint32_t flags = preset & ~LZMA_PRESET_LEVEL_MASK;
21	const uint32_t supported_flags = LZMA_PRESET_EXTREME;
22
23	if (level > 9 || (flags & ~supported_flags))
24		return true;
25
26	const uint32_t dict_shift = level <= 1 ? 16 : level + 17;
27	options->dict_size = UINT32_C(1) << dict_shift;
28
29	options->preset_dict = NULL;
30	options->preset_dict_size = 0;
31
32	options->lc = LZMA_LC_DEFAULT;
33	options->lp = LZMA_LP_DEFAULT;
34	options->pb = LZMA_PB_DEFAULT;
35
36	options->mode = level <= 2 ? LZMA_MODE_FAST : LZMA_MODE_NORMAL;
37
38	options->nice_len = level == 0 ? 8 : level <= 5 ? 32 : 64;
39	options->mf = level <= 1 ? LZMA_MF_HC3 : level <= 2 ? LZMA_MF_HC4
40			: LZMA_MF_BT4;
41	options->depth = 0;
42
43	if (flags & LZMA_PRESET_EXTREME) {
44		options->lc = 4; // FIXME?
45		options->mode = LZMA_MODE_NORMAL;
46		options->mf = LZMA_MF_BT4;
47		options->nice_len = 273;
48		options->depth = 512;
49	}
50
51	return false;
52}
53