[MEncoder-users] ffdshow spp for Doom9 codec comparison

[Michael Niedermayer]

Hi

On Tue, Dec 06, 2005 at 01:32:52PM +0100, Matthias Wieser wrote:
> Am Dienstag, 6. Dezember 2005 04:41 schrieb Corey Hickey:
> > Hello Milan,
> >
> > I'm working on finding the best encoding and decoding settings for
> > libavcodec MPEG-4 so I can send them to Doom9 for the 2005 codec
> > comparison.
> >
> > According to my own tests, the best-looking decoding setting with
> > mplayer is '-vf spp=2'.
> 
> In the TOOLS directory of mplayer there is a script named psnr-video.sh.
> 
> You can use it do compare different postprocessing settings:
> 
> recompressed video + -vf spp=2, scale=1024:-2
> vs.
> Original video + vf scale=1024:-2
> 
> It outputs the PSNR value for the differences between the original frames 
> and the recompressed frames. You should use short test videos because 
> this script needs much temporary disk space.
> 
> I do know that high PSNR does not necessarily mean high quality but at 
> least it can help a bit to decide if spp=2 or fspp=2 or pp=ac or... is 
> nearer to the original video.

hmm, somehow i feel that it will rather find which filters add a +1 or so
by mistake ...
IMHO for such a comparission the difference of means should be shown too

[...]
-- 
Michael