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

Michael Niedermayer michaelni at gmx.at
Sat Dec 17 20:02:06 CET 2005


Hi

On Sat, Dec 17, 2005 at 12:47:27PM +0100, Matthias Wieser wrote:
> Am Freitag, 16. Dezember 2005 22:27 schrieb Rich Felker:
> 
> > How far in the past? These issues weren't known until September 2005.
> > BTW here are screenshots of XVID decoded with both XVID IDCT and
> > ffmpeg's default mpeg4 idct:
> >
> > XviD: http://img39.imageshack.us/img39/3341/154xvid6xt.png
> > libavcodec: http://img39.imageshack.us/img39/4590/154avcodec2da.png
> >
> > XviD: http://img39.imageshack.us/img39/6135/283xvid3tg.png
> > libavcodec: http://img39.imageshack.us/img39/573/283avcodec5xl.png
> >
> > As you can see, the ones decoded with the 'wrong' idct look bad in the
> > same way (or at least a very similar way) that lavc mpeg4 looked bad
> > in the doom9 tests!
> 
> "And just in case, I still gave ffdshow a go in the lobby shootout and 
> found that while decoders do tend to decode a bit differently, it has no 
> effect on how you rate codecs in relation to each other." 
> http://www.doom9.org/index.html?/codecs-quali-105-1.htm

personally i think the main problem with lavc was and is the ratecontrol
not the idct missmatch but ateme still might be a bigger disadvantage
for lavc then lavc is for xvid, the reason is that lavc will use the xvid
idct for xvid so, theres no missmatch if ffdshow is used but an unknown one
for ateme

[...]

-- 
Michael




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