[MPlayer-dev-eng] Re: [MP] [PATCH] "turbo" mode

[Diego Biurrun]

D Richard Felker III writes:
> On Thu, Sep 16, 2004 at 10:57:37AM +0200, Guillaume POIRIER wrote:
> > 
> > Le jeu 16/09/2004 à 01:07, D Richard Felker III a écrit :
> > > of course qns degrades psnr, that's the whole point of noise shaping.
> > > :) it's a perceptual quality optimization, not a psnr optimization, so
> > > it's difficult to compare like this.
> > 
> > Thanks for the enlightenment rich... what's quite surprising is that
> > Romain Dolbeau (you know, the altivec guy) wrote a genetic exploration
> > software to find what was the best combination of options (PSNR-wise)
> > for a given sample of video... and qns was shinning out!
> > 
> > Ok now, Could you maybe tell me if when the description of qns is:
> > "Quantizer noise shaping, reduces ringing artifacts" is it supposed to
> > reduce ringing artifacts of the source video (pre-filter), or of the 
> > target video (post-filter)?
> > I guess it's the target video, but that isn't very clear....
> 
> target video. rather than choosing quantization to most closely match
> the source video in the psnr sense, it chooses quantization such that
> noise (usually ringing) will be masked by similar-frequency content in
> the image. or at least that's my understanding...

Guillaume, of course you know that you will have to update the man
page with the information you gather here ;-P

Diego