[MEncoder-users] new doom9 codec comparission (submission)

Rich Felker dalias at aerifal.cx
Thu Dec 15 11:00:49 CET 2005


On Thu, Dec 15, 2005 at 09:50:17AM +0100, Matthias Wieser wrote:
> Am Donnerstag, 15. Dezember 2005 08:02 schrieb Rich Felker:
> > On Wed, Dec 14, 2005 at 07:52:34PM -0800, Corey Hickey wrote:
> > > > Yeah, that does happen sometimes. I'm temporarily mirroring the
> > > > attachments (with zip file extracted) at:
> > > > http://fatooh.org/files/doom9tmp/attach/
> > > >
> > > >>Last but not least, I initially started reviewing with the VMR9
> > > >> renderless renderer in MPC, but found that both Theora and Snow
> > > >> (incidentally both decoded via ffdshow, where the rest of the
> > > >> codecs was decoded by ateme's filters, plus AviSynth is decoded by
> > > >> the Helix YV12 codec) were discolored,
> >
> > I'm confused... something other than lavc was used to decode lavc when
> > doing the quality tests? If so, that will *OBVIOUSLY* make lavc look
> > bad due to tiny differences in the idct implementations.
> 
> Come on, it seems you are trying very hard to find excuses for lavc 
> slightly loosing against xvid.

No, this is not "slightly", it's a HUGE difference. Reas the thread I
referenced where svid looked like shit because of wrong idct.

For YEARS AND YEARS all mplayer developers have known from experience
that lavc is superior in quality to xvid, while windows users have
known the opposite. This idct discrepency would explain it.

Just a few hours ago Dominik was reencoding a h264 file he had to make
it playable on his "slow" laptop. He tried both lavc and xvid and got
vastly superior results with lavc (2.32 avg quant versus 2.82 -- avg
quant is generally not a good metric of quality, but with this much
difference it probably is, and he reported the lavc file looked better
too).

So please stop trolling and accusing me of grasping at straws to prove
lavc is better. Those of us who know MPlayer know it is better, and if
it's performing badly in doom9's test we want to get to the bottom of
his mistakes in testing methodology rather than accepting incorrect
results.

> For many years lavc did not even have an own FOURCC - it has been nothing 
> unusual to use any compatible Mpeg4 codec for playback.

Yes, and it will look fine for watching. Doom9 is not testing casual
watching. He's zooming in on single still frames. And viewing on lcd
which hilights tiny artifacts that would be irrelevant on a nice crt.

Anyway if you think it doesn't matter then doom9 should decode xvid
with lavc and default lavc idct... :)

Rich




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