- 1: Blind offset
- 2: Smart analysis
subme 10 qp-rd是啥？
这2个参数好像一直没见有人提过
cplxblur qblur
a4840639@2010-04-13 23:38
有好多都是加了好久的吧，比如说subme 10，我记得是mbtree还先出来，weightp也因为CoreAVC而天下皆知，--b-pyramid相比以前具体改了什么我没搞清
关掉scenecut以后不会根据侦测场景变化来插入i帧，估计是固定每X帧插入一个I帧吧。只适合特殊用途。
intra-refresh
Default: Off
Disables IDR-frames, instead x264 uses intra coding for each macroblock in the frame every keyint frames. Blocks are refreshed in a horizontally scrolling column - the 'refresh wave'. This benefits low-latency streaming by making it possible to achieve more constant frame sizes than is possible with standard IDR-frames. It also increases the resilience of the video stream to packet loss. This option does reduce compression efficiency, hence only use it when needed.
Fun facts:
* The first frame is still an IDR frame.
* Intra-blocks are placed only in P-frames - the refresh wave is wider in the first P-frame after one or more B-frames.
* The loss in compression efficiency comes primarily from the fact macroblocks on the 'new' (left) side of the refresh wave can't refer to data on the 'old' (right) side.
Recommendation: Default
反正也是适合要求低延迟的特殊运用。做法没太懂，似乎也禁用了scenecut?
constrained-intra
Default: Not Set
Enable constrained intra prediction, which is required for the base layer of SVC encodes.
Recommendation: Not set, since it significantly reduces compression.
同样只适合特殊用途
slices
Default: 0
Sets the number of slices per frame, and forces rectangular slices. (Overridden by either slice-max-size or slice-max-mbs if they are set.)
Recommendation: Don't use slices unless you are encoding for Blu-ray (since they hurt coding effiency), then use 4.
cplxblur
Default: 20
Apply a gaussian blur with the given radius to the quantizer curve. This means that the quantizer assigned to each frame is blurred temporally with its neighbours to limit quantizer fluctuations.
Default: 0.5
Apply a gaussian blur with the given radius to the quantizer curve, after curve compression. Not a very important setting.
这两貌似都没什么大影响
deblock 1:0:0是默认参数，有什么奇怪的？Banding多还是别的原因吧
superkidx@2010-04-13 23:50
多谢
一堆英文看得头大 明天再看了。。。
differ_cn@2010-04-22 10:15
我英语很一般，勉强翻译一下。
intra-refresh
内部更新
Default: Off
默认：关闭
Disables IDR-frames, instead x264 uses intra coding for each macroblock in the frame every keyint frames.
禁止IDR帧， 作为代替，X246.exe将使用宏块（macroblock ）
(作为其他帧的参考）。
Blocks are refreshed in a horizontally scrolling column - the 'refresh wave'.
这些（作为参考的）宏块按照特定的规则更新。（这句话严格按照原句翻译是：宏块由水平方向滚动的”更新波“列来更新）。
This benefits low-latency streaming by making it possible to achieve more constant frame sizes than is possible with standard IDR-frames.
这对播放延迟要求非常高的流媒体非常有利，在这种方式下，视频的每一帧的数据大小变动较小。
It also increases the resilience of the video stream to packet loss.
而且视频传输时即使出现一定的丢包，画面也只是出现一些小的瑕疵，而不会崩坏。
This option does reduce compression efficiency, hence only use it when needed.
这个参数会降低视频本身的压缩效率，所以只在的确是有需要的时候才使用它。
Fun facts:
功能特点
* The first frame is still an IDR frame.
第一帧依然是IDR帧，
* Intra-blocks are placed only in P-frames - the refresh wave is wider in the first P-frame after one or more B-frames.
作为参考的宏块只会在P帧出现。并且常常是在B帧后面所接的第一个P帧出现。
* The loss in compression efficiency comes primarily from the fact macroblocks on the 'new' (left) side of the refresh wave can't refer to data on the 'old' (right) side.
压缩效率降低的主要原因是应为作为参考的宏块不能使用“前面”（左边）的参考宏块所致。
Recommendation: Default
推荐：默认参数即可。
differ_cn@2010-04-22 10:21
constrained-intra
强制帧内预测。
Default: Not Set
默认：不开启。
Enable constrained intra prediction, which is required for the base layer of SVC encodes.
开启强制帧内预测需要基于SVC编码的基本层。（字面如此，具体的问我也不懂）
Recommendation: Not set, since it significantly reduces compression.
建议：不开启，因为开启这个选项会显著的降低压缩效率。
文字本身没有讲到开启这个会会显著的降低压缩效率的选项会带来什么好处。
不知道是基于兼容性还是编码解码速度的原因，有这个参数。
differ_cn@2010-04-22 10:32
slices
直接翻译是”切割“，
但这个是蓝光压缩技术方面的专有名词，我没见过中文翻译。
估计翻译成“切块”更合适些。
Default: 0
默认值：0
Sets the number of slices per frame, and forces rectangular slices.
设置每帧有多少的切块，每个切块按矩形切割。
(Overridden by either slice-max-size or slice-max-mbs if they are set.)
受slice-max-size （最大切块体积（指像素），和slice-max-mbs （最大切块
体积（指文件大小）限制。
Recommendation: Don't use slices unless you are encoding for Blu-ray (since they hurt coding effiency), then use 4.
为蓝光播放机刻盘而编码，需要设置为4，
不是为蓝光播放机刻盘而编码的话，建议默认设置 0。设置为0以外的参数会降低压缩效率。
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