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///////////////////////////////////////////////////////////////////////////////
//
/// \file lzma_presets.c
/// \brief Encoder presets
/// \note xz needs this even when only decoding is enabled.
//
// Author: Lasse Collin
//
// This file has been put into the public domain.
// You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////
#include "common.h"
extern LZMA_API(lzma_bool)
lzma_lzma_preset(lzma_options_lzma *options, uint32_t preset)
{
const uint32_t level = preset & LZMA_PRESET_LEVEL_MASK;
const uint32_t flags = preset & ~LZMA_PRESET_LEVEL_MASK;
const uint32_t supported_flags = LZMA_PRESET_EXTREME;
if (level > 9 || (flags & ~supported_flags))
return true;
options->preset_dict = NULL;
options->preset_dict_size = 0;
options->lc = LZMA_LC_DEFAULT;
options->lp = LZMA_LP_DEFAULT;
options->pb = LZMA_PB_DEFAULT;
static const uint8_t dict_pow2[]
= { 18, 20, 21, 22, 22, 23, 23, 24, 25, 26 };
options->dict_size = UINT32_C(1) << dict_pow2[level];
if (level <= 3) {
options->mode = LZMA_MODE_FAST;
options->mf = level == 0 ? LZMA_MF_HC3 : LZMA_MF_HC4;
options->nice_len = level <= 1 ? 128 : 273;
static const uint8_t depths[] = { 4, 8, 24, 48 };
options->depth = depths[level];
} else {
options->mode = LZMA_MODE_NORMAL;
options->mf = LZMA_MF_BT4;
options->nice_len = level == 4 ? 16 : level == 5 ? 32 : 64;
options->depth = 0;
}
if (flags & LZMA_PRESET_EXTREME) {
options->mode = LZMA_MODE_NORMAL;
options->mf = LZMA_MF_BT4;
if (level == 3 || level == 5) {
options->nice_len = 192;
options->depth = 0;
} else {
options->nice_len = 273;
options->depth = 512;
}
}
return false;
}
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