[MPlayer-users] Re: [POOL] Moderate some users (was: Re: [-] Re: divx 6)

[Vladimir Mosgalin]

Hi Matthias Wieser!

 On 2006.05.06 at 17:10:49 +0200, Matthias Wieser wrote next:

> > No, PSNR proves nothing, especially so close. Differences in the type
> > of motion comp (which gmc is) will make differences on this scale
> > without reflecting anything about quality. You'll need to use a better
> > metric or doubleblind viewing test to get any useful information.
> 
> I need nothing. You will need to prove your claims. I'f you can't it's your 
> problem. I took a random video (with much panning) and surprise, surprise, 
> GMC improved psnr nearly 0.1 dB. If you wan't to use a better metric or 

PSNR PROVES NOTHING.

Now read this again as many times as you need to remember it.

0.1 dB improvement - I can only laugh at that. Even 0.5 dB difference in
PSNR doesn't mean that one of the encoded version looks better.

For example, why do you use mpeg_quant? It improves quality, but very
often reduces psnr.

I've seen so many cases when psnr and my eye tell me opposite, so now I
don't even try to compare psnr. In some cases quality difference is
obvious at the first sight, in other cases you need to look harder, but
that's exactly when psnr starts to fail too.

-- 

Vladimir