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authorLasse Collin <lasse.collin@tukaani.org>2010-09-03 15:13:12 +0300
committerLasse Collin <lasse.collin@tukaani.org>2010-09-03 15:13:12 +0300
commitb4b1cbcb53624ab832f8b3189c74450dc7ea29b6 (patch)
tree35a7438ac266d7f967f3032048153b254eac1592
parentliblzma: Adjust default depth calculation for HC3 and HC4. (diff)
downloadxz-b4b1cbcb53624ab832f8b3189c74450dc7ea29b6.tar.xz
Tweak the compression presets -0 .. -5.
"Extreme" mode might need some further tweaking still. Docs were not updated yet.
-rw-r--r--src/liblzma/lzma/lzma_encoder_presets.c29
1 files changed, 19 insertions, 10 deletions
diff --git a/src/liblzma/lzma/lzma_encoder_presets.c b/src/liblzma/lzma/lzma_encoder_presets.c
index c4c9c146..2aa8fd03 100644
--- a/src/liblzma/lzma/lzma_encoder_presets.c
+++ b/src/liblzma/lzma/lzma_encoder_presets.c
@@ -23,9 +23,6 @@ lzma_lzma_preset(lzma_options_lzma *options, uint32_t preset)
if (level > 9 || (flags & ~supported_flags))
return true;
- const uint32_t dict_shift = level <= 1 ? 16 : level + 17;
- options->dict_size = UINT32_C(1) << dict_shift;
-
options->preset_dict = NULL;
options->preset_dict_size = 0;
@@ -33,19 +30,31 @@ lzma_lzma_preset(lzma_options_lzma *options, uint32_t preset)
options->lp = LZMA_LP_DEFAULT;
options->pb = LZMA_PB_DEFAULT;
- options->mode = level <= 2 ? LZMA_MODE_FAST : LZMA_MODE_NORMAL;
+ options->dict_size = UINT32_C(1) << (uint8_t []){
+ 18, 20, 21, 22, 22, 23, 23, 24, 25, 26 }[level];
- options->nice_len = level == 0 ? 8 : level <= 5 ? 32 : 64;
- options->mf = level <= 1 ? LZMA_MF_HC3 : level <= 2 ? LZMA_MF_HC4
- : LZMA_MF_BT4;
- options->depth = 0;
+ 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;
+ options->depth = (uint8_t []){ 4, 8, 24, 48 }[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->lc = 4; // FIXME?
options->mode = LZMA_MODE_NORMAL;
options->mf = LZMA_MF_BT4;
- options->nice_len = 273;
- options->depth = 512;
+ if (level == 3 || level == 5) {
+ options->nice_len = 192;
+ } else {
+ options->nice_len = 273;
+ options->depth = 512;
+ }
}
return false;