[x264-devel] VBV-maxrate and VBV-bufsize

[Jason Garrett-Glaser]

On Wed, May 15, 2013 at 7:31 AM, Karthick Kumar <karthik1990r at gmail.com> wrote:
> Suppose 100 yuv frames are to be encoded using x264 and vbv-maxrate =
> 500kbps, vbv-bufsize = 1000kb, fps = 25. How x264 would assign frame size
> for each frame with respect to those vbv parameters. Will it try to restrict
> the output bit-rate to vbv-maxrate or restrict each frame size to
> vbv-bufsize(even if the bit-rate exceeds the vbv-maxrate).
>
> The above question arised because:
> The bandwidth for my application with vbv-maxrate = vbv-bufsize, is
> sometimes more than the vbv-maxrate. So I need to reduce vbv-bufsize by
> 25%,to make sure that the bandwidth doesn/t exceed vbv-max rate.

VBV-bufsize and VBV-maxrate are completely independent parameters.
The former is the size of the buffer in your application, and the
latter is the bandwidth available.

Jason