X-Git-Url: https://pd.if.org/git/?a=blobdiff_plain;f=lzma%2Flzma%2Flzma_encoder_presets.c;fp=lzma%2Flzma%2Flzma_encoder_presets.c;h=711df0255296c195a02ac2def1912d383c5be07e;hb=32b8a6b26ed8843828e03e505d2256960bda0980;hp=0000000000000000000000000000000000000000;hpb=d48fc23a4bcf8ca3c406d6e8c8a6f8c6b0fa2f1e;p=zpackage

diff --git a/lzma/lzma/lzma_encoder_presets.c b/lzma/lzma/lzma_encoder_presets.c
new file mode 100644
index 0000000..711df02
--- /dev/null
+++ b/lzma/lzma/lzma_encoder_presets.c
@@ -0,0 +1,64 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       lzma_encoder_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;
+}