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