[XviD-devel] pre-processing

[Marc FD]

----- Message d'origine -----
De : "Christoph Lampert" <chl@math.uni-bonn.de>
À : <xvid-devel@xvid.org>
Envoyé : samedi 14 septembre 2002 20:43
Objet : Re: [XviD-devel] pre-processing


> On Sat, 14 Sep 2002, Marc FD wrote:
>
> > Hi all ;)
> >
> > I'm making my first steps trying to improve XviD with "pre-processing"
> > I just wanted to know, can i say that -0.2 Db in PSNR and -12% in size
(@ quant 2) is an improvement ??
> > (for my eyes, it's perfect, but if you can see a 0.2 PSNR change, you've
damn good eyes !)
>
> You can't say it like that. To decide if size difference is better than
> PSNR drop, you should test at constant bitrate mode for that.
>
> But for preprocessing this is not really good, either. So maybe 12% size
> difference is very good, if the visual quality doesn't get worse.
>
> gruel
>
>

constant bitrate ?
thx gruel. a very good idea indeed.
so if i get a better PSNR at constant bitrate, it's a good improvement ?

I've made a 2pass test.. will give the results later.

MarcFD  marc.fd@libertysurf.fr