1 ///////////////////////////////////////////////////////////////////////////////
3 /// \file lzma_encoder_presets.c
4 /// \brief Encoder presets
6 // Author: Lasse Collin
8 // This file has been put into the public domain.
9 // You can do whatever you want with this file.
11 ///////////////////////////////////////////////////////////////////////////////
16 extern LZMA_API(lzma_bool)
17 lzma_lzma_preset(lzma_options_lzma *options, uint32_t preset)
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;
23 if (level > 9 || (flags & ~supported_flags))
26 options->preset_dict = NULL;
27 options->preset_dict_size = 0;
29 options->lc = LZMA_LC_DEFAULT;
30 options->lp = LZMA_LP_DEFAULT;
31 options->pb = LZMA_PB_DEFAULT;
33 options->dict_size = UINT32_C(1) << (uint8_t []){
34 18, 20, 21, 22, 22, 23, 23, 24, 25, 26 }[level];
37 options->mode = LZMA_MODE_FAST;
38 options->mf = level == 0 ? LZMA_MF_HC3 : LZMA_MF_HC4;
39 options->nice_len = level <= 1 ? 128 : 273;
40 options->depth = (uint8_t []){ 4, 8, 24, 48 }[level];
42 options->mode = LZMA_MODE_NORMAL;
43 options->mf = LZMA_MF_BT4;
44 options->nice_len = level == 4 ? 16 : level == 5 ? 32 : 64;
48 if (flags & LZMA_PRESET_EXTREME) {
49 options->mode = LZMA_MODE_NORMAL;
50 options->mf = LZMA_MF_BT4;
51 if (level == 3 || level == 5) {
52 options->nice_len = 192;
55 options->nice_len = 273;