[MEncoder-users] Bad mencoder video with -ss and -endpos

[Phil Ehrens]

D Richard Felker III wrote:
> On Wed, Jan 12, 2005 at 11:41:46AM +0100, Greger Bergman wrote:
> > Hello,
> > 
> > I am trying to extract a small sample from an avi movie. The video 
> > quality of the sample is not good in the beginning. My question is why?
> > 
> > The movie was encoded from a dvd:
> > 
> >     mencoder dvd://1 -oac mp3lame -lameopts abr:br=128 -aid 128 \
> >       -ovc frameno -o frameno.avi
> > 
> >     mencoder dvd://1 -oac copy -ovc xvid -xvidencopts pass=1 \
> >       -vf crop=704:416:2:80,scale=640:272 -o /dev/null
> > 
> >     menoder dvd://1 -oac copy -ovc xvid -xvidencopts pass=2:bitrate=867 \
> >       -vf crop=704:416:2:80,scale=640:272 -o movie.avi
> > 
> > The sample:
> > 
> >     mencoder -oac copy -ovc copy -ss 00:54:05 -endpos 60 \
> >       -o sample.avi movie.avi
> > 
> > 
> > If I encode the sample with -nosound the video looks good:
> > 
> >     mencoder -nosound -ovc copy -ss 00:54:05 -endpos 60 \
> >       -o sample.avi movie.avi
> > 
> > It seems to me that the audio is my problem.
> > 
> > Any tips on how to solve this problem would be much appreciated.
> 
> -mc 0 -noskip

Could you please explain the significance of these options
in this context? Since no -ofps is specified, why would
frames be skipped? I would really like to understand this!

-- 
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