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