[MPlayer-users] -ovc copy changes aspect?

Josef Wolf jw at raven.inka.de
Tue Jan 11 20:03:37 CET 2005

On Tue, Jan 11, 2005 at 03:55:06AM -0500, The Wanderer wrote:

> >I just did the following in the hope that only audio would be
> >compressed and video would be left as is:
> >
> >mencoder in.avi -oac mp3lame -lameopts q=0:vbr=0:aq=0 -ovc copy -o out.avi
> >
> >But for some reason, this changes aspect ratio.  Is this by intent?
> Unless I'm very much mistaken, the only way this could possibly change
> the aspect ratio is if the original AVI contained an "aspect" header
> (specifying what aspect to play with) and the output AVI does not. Since
> nothing but MPlayer pays any attention to the "aspect" header AFAIK, if
> this is the case the two files should have the same aspect ratio if
> played back in another player.

Ummm... I find this something wired, because I created this file from a VDR
recording with mencoder: 

   mencoder 001.vdr -oac copy -o in.avi \
      -ovc lavc -lavcopts vcodec=mpeg4:vqmin=2:vhq

Then I noticed that I accidentally forgot to compress the audio.  To avoid
compressing the whole video a second time, I decided to use "-oac copy".

Now the wired thing is that the _first_ mencoder (which actually _did_
video compression) preserved the aspect as it was while the second
mencoder (which should just copy the video) changed it.

No software patents!
-- Josef Wolf -- jw at raven.inka.de --

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