[Ffmpeg-devel] Re: [RFC] mpeg2 422 encoding.

Michael Niedermayer michaelni
Sat Apr 1 04:42:15 CEST 2006


Hi

On Sat, Apr 01, 2006 at 04:32:50AM +0200, Michael Niedermayer wrote:
> Hi
> 
> On Fri, Mar 31, 2006 at 08:37:43PM -0500, Rich Felker wrote:
> > On Sat, Apr 01, 2006 at 03:03:37AM +0200, Baptiste COUDURIER wrote:
> > > Baptiste COUDURIER wrote:
> > > >[...]
> > > 
> > > Ok, a bit more. It works correctly for intra. It produces picture for P
> > > and B frames, though containing artifacts like blue/red blocks.
> > > Bistream is correct.
> > > 
> > > Im digging more into the code. It may be related to motion estimation.
> > > Michael, does motion estimation work in 422 chroma format ? If it is,
> > > then Im a bit lost here.
> > 
> > AFAIK motion estimation ignores chroma channels unless you override it
> > with a special option.
> 
> exactly
> 
> also motion estimation doesnt matter, set all MVs to arbitrary valid vectors
> and it should still work, i mean quality and bitrate will suck but there
> shouldnt be any blue or red blocks
> 
> here are a few random ideas ...
> try -debug 16384 it will vissually show MB types
> try -vismv ... it will show motion vectors
> try to force vectors or MB types to specific ones
> try valgrind
> do P frames with just intra blocks work?
> do P frames with just inter blocks with MV 0,0 work?
> ....

also check if dct_offset/2 is always what you think it is ...

[...]

-- 
Michael





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