src/liblzma/lzma/lzma_encoder_presets.c

   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
  16 extern LZMA_API(lzma_bool)
  17 lzma_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         options->preset_dict = NULL;
  27         options->preset_dict_size = 0;
  28
  29         options->lc = LZMA_LC_DEFAULT;
  30         options->lp = LZMA_LP_DEFAULT;
  31         options->pb = LZMA_PB_DEFAULT;
  32
  33         options->dict_size = UINT32_C(1) << (uint8_t []){
  34                         18, 20, 21, 22, 22, 23, 23, 24, 25, 26 }[level];
  35
  36         if (level <= 3) {
  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];
  41         } else {
  42                 options->mode = LZMA_MODE_NORMAL;
  43                 options->mf = LZMA_MF_BT4;
  44                 options->nice_len = level == 4 ? 16 : level == 5 ? 32 : 64;
  45                 options->depth = 0;
  46         }
  47
  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;
  53                         options->depth = 0;
  54                 } else {
  55                         options->nice_len = 273;
  56                         options->depth = 512;
  57                 }
  58         }
  59
  60         return false;
  61 }