[MPlayer-dev-eng] samples which look bad when encoded with lavc 2-pass needed

[D Richard Felker III]

On Mon, Jul 22, 2002 at 02:39:08AM +0200, Michael Niedermayer wrote:
> > > > anyway i also experienced - and read on -users too - a possible bug:
> > > > when the input media is too low quality, so there are parts where the
> > > > maximum reachable bitrate (due to high qmin or missing data) is under
> > > > the wanted one (calculated by 2pass algo), it doesn't (or at least it
> > > > seems it doesn't) distribute these 'free' bits for the remaining part
> > > > of the movie.
> > >
> > > someone should upload such a file
> >
> > I think any movie with lots of very low motion scenes and some
> > high-motion ones should demonstrate the problem, if you tune the
> > bitrate appropriately. Ghost in the Shell DVD is my favorite example
> > of the problem.
> hmm, lets hope it works with divx3 gits too as i have no dvd drive (and dont 
> need one either)

Only if it's a very clean high quality copy to begin with. Otherwise
the distortion from bad encode will waste all the bits on still
scenes. If you don't have any luck, I can try hacking lavc to report
the quantifiers used during pass2 to a file, and then encode and send
you the data, but I likely won't get around to it for a while. Or, I
can try ripping maybe 10-20 minutes of the raw vob stream and let you
play with that... I just don't know if such a short clip is enough to
investigate the problem.

Rich