[MPlayer-users] xvid

[Pablo Morales]

Will this increase quality?
> min_iquant=1:min_pquant=1). lavc has a vqscale=1 (constant quantizer)

Thanx

----- Original Message ----- 
From: "Loren Merritt" <lorenm at u.washington.edu>
To: "MPlayer usage questions, features, bugreports"
<mplayer-users at mplayerhq.hu>
Cc: "Pablo Morales" <pablo.morales at abitab.com.uy>
Sent: Friday, April 02, 2004 3:25 PM
Subject: Re: [MPlayer-users] xvid


> On Fri, 2 Apr 2004, Alexei Khlebnikov wrote:
> > On Fri, 2 Apr 2004 13:41:13 -0300
> > "Pablo Morales" <pablo.morales at abitab.com.uy> wrote:
> >
> > > I've got a doubt, I'm encoding using xvid and I found me_quality,
range
> > > from 0 to 6, how do I interpret that.
> > > 0 better quality? or 6 better quality?
> > >
> > > Using xvid instead livac seems to solve  my problem that mplayer uses
the
> > > bitrate it  wants regardless the one I specify in vbitrate=X
> >
> > LAVC MPEG4 codec don't use full bitrate if it is not needed, i.e. if
maximum
> > quality with your settings has been reached. The common advice in this
case
> > is to increase the resolution to gain more quality.
> >
> > If developers don't think its pointless - they can change LAVC codec so
that it
> > uses P frames instead of (some) B frames, and/or I frames instead of
(some)
> > P frames if bitrate allows. It will largely increase bitrate and
slightly
> > improve quality. Maybe XVID does just that.
> > (I will certainly be flamed for such suggestion :)
>
> The reason (I infer) that XviD can fill any desired bitrate, and lavc
> can't, is that XviD supports quantizer 1 (-xvidencopts
> min_iquant=1:min_pquant=1). lavc has a vqscale=1 (constant quantizer), but
> doesn't respect vqmin=1 in 2-pass encodes.
>
> Despite what the lavc entry in the manpage says about quant 1 making
> little quality difference, XviD with min quant 1 looks much better than
> lavc when lavc maxes out with quant 2 at 800kbit/s (and I am encoding at
> unscaled dvd resolution).