[FFmpeg-devel] [PATCH] libx264: support for BUILD >= 63

Daniel G. Taylor dan
Wed Sep 17 17:33:27 CEST 2008

On Wed, 2008-09-17 at 09:44 -0500, Dion Galbreath wrote:
> The only worry I have is that when you use the latest x264 the bitrate
> might as well not even be there since it's not really used.. it will
> give you whatever it feels like. I have since been using  version 803
> which works great however these new changes now effectively kill that
> from working, and your forced to go back to new builds of x264 which the
> bitrate once again becomes a useless property...   any chance that that
> part of ffmpeg can be fixed, I'm guessing that at the time v803 was
> around ffmpeg was coded to use those properties but since 804 to now
> that property had changed? I never looked much into it, it's just hard
> to appreciate a fix in ffmpeg that degrades such a major encoding
> function as bitrate.....

I've noticed that qmax now defaults to around 31, which means you cannot
achieve low bitrates that degrade quality beyond q=31. You can fix this
by passing -qmax 51, which should allow any bitrate regardless of how
bad the quality will be.

I've had a quick look through the code to find where the lower qmax
value could be set but haven't had any luck. Anybody know anything about

Take care,
Daniel G. Taylor

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