『漫游』酷论坛>『影音数码技术学习交流』>[聊天]x264开始使用mbtre ..

[聊天]x264开始使用mbtree了呢~

vempx@2009-08-07 21:21

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Macroblock-tree ratecontrol
On by default; can be turned off with --no-mbtree.
Uses a large lookahead to track temporal propagation of data and weight quality accordingly.
Requires a very large separate statsfile (2 bytes per macroblock) in multi-pass mode.
Doesn't work with b-pyramid yet.
Note that MB-tree inherently measures quality different from the standard qcomp method, so bitrates produced by CRF may change somewhat.
This makes the "medium" preset a bit slower. Accordingly, make "fast" slower as well, and introduce a new preset "faster" between "fast" and "veryfast".
All presets "fast" and above will have MB-tree on.
Add a new option, --rc-lookahead, to control the distance MB tree looks ahead to perform propagation analysis.
Default is 40; larger values will be slower and require more memory but give more accurate results.
This value will be used in the future to control ratecontrol lookahead (VBV).
Add a new option, --no-psy, to disable all psy optimizations that don't improve PSNR or SSIM.
This disables psy-RD/trellis, but also other more subtle internal psy optimizations that can't be controlled directly via external parameters.
Quality improvement from MB-tree is about 2-70% depending on content.
Strength of MB-tree adjustments can be tweaked using qcompress; higher values mean lower MB-tree strength.
Note that MB-tree may perform slightly suboptimally on fades; this will be fixed by weighted prediction, which is coming soon.


嘛，官方changelog是这么写的，2-70%的提升，嗯嗯，大家来讨论讨论~
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蓝の回忆@2009-08-07 23:33

其实我比较关心速度方面..
如果是多花一倍的时间去换那2%的提升就很不值了..70%的话肯定会选的.
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roozhou@2009-08-08 00:18

40帧的话，1080P就要多用118M内存
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ljwing@2009-08-08 07:15

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最初由 roozhou 发布
40帧的话，1080P就要多用118M内存

看了这个
缩了[/ku]
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BurySakura@2009-08-08 08:35

是不是现在没有GUI能跟上更新,..
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vempx@2009-08-08 09:52

MEGUI一直就没更新过……
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superkidx@2009-08-08 10:01

Doesn't work with b-pyramid yet

还有 --no-psy 和 mbtree 有什么关系?
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52wy@2009-08-08 12:06

具体有啥用，谁解释解释。
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海波湛蓝@2009-08-08 18:50

新版本压制40f就出错……还没动新参数 不过……
------------------------------------------------------------------
Seriously? How the hell can you get a 70% quality increase?

Magic.
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= =||……
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ki。曲奇@2009-08-08 18:52

新參數預設是開啓的
看看關閉後會否出錯
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海波湛蓝@2009-08-08 19:04

--no-mbtree

40帧之后又跳掉啦

--qcomp 去掉之后 42帧跳掉
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vempx@2009-08-08 21:47

我用了mbtree没有出错，你是不是RP了……囧
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ljwing@2009-08-08 22:42

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最初由 vempx 发布
我用了mbtree没有出错，你是不是RP了……囧

那用了之后感觉有啥区别[视觉观感上,qp，I，P，B，PSN.......]
不用--b-pyramid 带来的影响有多大
感觉一口气问太多了阿
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海波湛蓝@2009-08-08 22:51

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最初由 vempx 发布
我用了mbtree没有出错，你是不是RP了……囧


:(
下了个新的x264还是一样啊
片源播放正常 几天前还用过

用不用mb都错误呐
:(
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a4840639@2009-08-09 02:56

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最初由 ljwing 发布

那用了之后感觉有啥区别[视觉观感上,qp，I，P，B，PSN.......]
不用--b-pyramid 带来的影响有多大
感觉一口气问太多了阿

--b-pyramid貌似在某些解码器上不稳定
不用感觉也没什么大不了的
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