[MPlayer-users] Re: Low bitrate using 2-pass with libavcodec

[marcogi at libero.it]

On Sun, 21 Apr 2002, Rémi Guyomarch wrote:

> > > > I did so, but still second pass video has lower quality than first pass.
> > > 
> > > Make sure you deleted frameno.avi before -pass 1.
> > 
> > And where third pass take audio from? I should rencode it again?
> 
> > > Make sure you deleted frameno.avi before -pass 1.
                                        ^^^^^^^^^^^^^^
Oh Yeah!!! :)
But...
Perhaps you mean before _first pass_ not before -pass 1.
In 3-pass mode "-pass 1" option appears into _second pass_
Anyway, what I did was:
1) rm frameno.avi

2) mencoder -dvd 1 -aid 131 -ovc frameno -lameopts q=4 -o frameno.avi

3)mencoder -dvd 1 -oac copy -vop scale=512:256,crop=720:346:0:112 -ovc lavc
-lavcopts vcodec=mpeg4:vbitrate=785:vme=5:vqmin=2 -pass 1 -o pass1.avi 

4)mencoder -dvd 1 -oac copy -vop scale=512:256,crop=720:346:0:112 -ovc lavc
-lavcopts vcodec=mpeg4:vbitrate=840:vhq:vme=5:vqmin=2 -pass 2 -o pass2.avi

pass2.avi has lower quality than pass1.avi having about the same size.

--
Regards,  Marco Gigante
Student at Pisa University - Computer Engineering