[FFmpeg-devel] [PATCH] make fast option with h264 actually do something..

[Rich Felker]

On Wed, Feb 20, 2008 at 01:17:00AM +0000, M?ns Rullg?rd wrote:
> Rich Felker <dalias at aerifal.cx> writes:
> 
> > On Tue, Feb 19, 2008 at 09:22:31PM +0100, Michael Niedermayer wrote:
> >> On Tue, Feb 19, 2008 at 09:10:38PM +0100, Michael Niedermayer wrote:
> >> > On Tue, Feb 19, 2008 at 01:26:24AM -0500, Rich Felker wrote:
> >> > > Currently, the FAST flag for h264 only affects motion functions for
> >> > > non-ref frames, making it mostly useless. This patch makes it affect
> >> > > all motion compensation. Benchmarks on my K6, using mplayer
> >> > > -benchmark:
> >> > > 
> >> > > Without fast: 17.6 sec
> >> > > With current fast: 17.2 sec
> >> > > With patch applied: 16.6 sec
> >> > > 
> >> > > I did not notice any visible corruption, but even if there is some,
> >> > > that's the idea of the 'fast' flag...
> >> > > 
> >> > > Comments welcome.
> >> > 
> >> > patch ok
> >> 
> >> after some more carefull tests, i retract that approval, patch rejected,
> >> it breaks decoding of BA1_FT_C.264 with very vissible artifacts.
> >
> > Would it be possible to make the level configurable or to at least
> > apply the fast-mode to all B-frames instead of only non-reference
> > ones? Error should not have time to sufficiently accumulate during
> > B-frame sequences, only over long intervals between I-frames.
> 
> Rich, why can't you just accept that your K6 is too slow?

There's no fundamental reason why it should not be able to play
normal-resolution h264 video. But in the meantime until things are
sufficiently optimized, it would be nice if the 'fast' option really
did what it's supposed to do. :) Even nicer would be support for
lowres mode -- this would be useful not just to folks like me but to
people with fast computers who want to play HD content.

Rich