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Old 27th December 2009, 05:15   #7  |  Link
seanxu_2010
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Join Date: Nov 2009
Posts: 12
Quote:
Originally Posted by Dark Shikari View Post
That isn't how ratetol works.

Here's what you actually mean:

--bitrate 800 --vbv-maxrate 800 --vbv-bufsize 8000
thanks, there may be some misunderstanding, I know the ratetol is relative with overflow, what I mean is set a bigger value for ratetol instead of the default value 1, so permit a higher overflow for abr.

And I just view some threads about CBR, you suggest me to use VBV buffer model, and according to my understanding, X264 set a 10 second video buffer for imitating the stream buffer at decoder, in purpose that X264 can distribute less bits for the low complexed scene, and more bits for the high ones, but the distribution is limited by the size of buffer to ensure the decoder stream buffer is not overflow and underflow, in a word, that means it produces a stream with constant bitrate in 10 seconds perspective and if we see the curve of bitrate, it must be fluctuant around --vbv-maxrate. is it correct? if so, what is --bitrate used for? and when we set VBV, has the --rc-lookahead been set as a default value? because, if not, how the x264 can guarantee the constant bitrate in a 10 seconds perspective?

Last edited by seanxu_2010; 27th December 2009 at 05:52.
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