[MPlayer-users] lavc vs. xvid (and improving lavc quality)

[Michael Niedermayer]

Hi

On Sunday 06 June 2004 17:24, Matthias Wieser wrote:
> Michael Niedermayer wrote:
> > Hi
> >
> > On Saturday 05 June 2004 23:20, Matthias Wieser wrote:
> > [...]
> >
> > > High motion scenes (with higher quantizer) with sky tend to produce
> > > block artifacts at the sky. It's understandable because the sky has
> > > nearly no detail but nevertheless it would need just a bit more
> > > bitrate than what mencoder allocates for the sky. If you use
> > > postprocessing the sky looks OK (a bit like blue plastic - with some
> > > noise it looks even better).
> > >
> > > IMHO there should be a possibility to tell mencoder or lavc "don't
> > > spend nearly all bits on those fast moving objects (nobody will see
> > > those details anyway) but reserve slightly more bits for seemingly
> > > simple flat areas like sky, streets, walls and so on. (Xvid mode ?)
> > > That would make mencoder/ lavc more tolerant to people that don't /
> > > can't use postprocessing.
> >
> > no u dont understand it, the blocking artefacts where even there at
> > qp=2,
>
> Why? With quantizer=2 I have never seen any block artefacts.
me neither, but some people do, its caused by incorrect gamma correction on 
the users system somewhere probably but that still doesnt explain why some 
other encoders do better, or at least some people claim they do better, it 
could also be caused by different encoding options, its impossible to say, as 
people who complain about quality rarely upload samples ...

>
> > thats the lowest lavc or xvid will use by default, so neither of
> > them could give these blocks more bits
> >
> >
> > anyway the problem may be fixed already, the only video with blocking
>
> I'm using CVS mencoder+lavc from 040502.
thats significantly too old

[...]
-- 
Michael
level[i]= get_vlc(); i+=get_vlc();		(violates patent EP0266049)
median(mv[y-1][x], mv[y][x-1], mv[y+1][x+1]);	(violates patent #5,905,535)
buf[i]= qp - buf[i-1];				(violates patent #?)
for more examples, see http://mplayerhq.hu/~michael/patent.html
stop it, see http://petition.eurolinux.org & http://petition.ffii.org/eubsa/en