[MEncoder-users] Enforce aspectratio

[Dominik 'Rathann' Mierzejewski]

On Sunday, 13 April 2008 at 22:31, Andy Civil wrote:
> James Hastings-Trew wrote:
> > Al Bogner wrote:
> 
> >> If I play the avi file with mplayer the ascpect-ration is not recognized 
> >> correctly.
> 
> > Do AVI files keep aspect ratio information? If you were using mp4 you 
> > could add dsize=852:480 to your video filters, this would set the SAR. 
> > Dunno if that would work with AVI.
> 
> I think James suspected this:
> "AVI files do not contain pixel aspect ratio information."
> (from http://en.wikipedia.org/wiki/Audio_Video_Interleave#Continued_use )
> 
> I would infer from that, that the aspect ratio of an AVI file is assumed to be 
> the same as the ratio of width and height in pixels.

They do, but not many players support ODML headers. You can set the AR using
mencoder -ovc copy -oac copy -force-avi-aspect 16/9, for example. MPlayer
recognises that and prescales the image accordingly.

Regards,
R.

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