[theora] Poor encoding quality with etheora and aspect ratio problem

Manuel Dahmen manuel.dahmen at gmail.com
Fri Feb 29 10:44:33 PST 2008

On Fri, 29 Feb 2008 09:55:22 -0800
Ralph Giles <giles at xiph.org> wrote:

> On 29-Feb-08, at 2:19 AM, Manuel Dahmen wrote:
> > And when I play the movie with mplayer or totem, the video
> > resolution is changed from 640x480 to 854x480 (when i use  
> > ETHEORA_ASPECT_NORMAL in etheora_enc_setup).
> This is a bug in etheora. It's passing the frame aspect ratio where  
> libtheora expects the pixel aspect ratio, which is why it looks  
> stretched.
> For 640x480 computer-sourced video like processing produces, the  
> pixels are square anyway, but ETHEORA_ASPECT_PRESERVE is  
> unfortunately also wrong (it sets a square frame aspect ratio). So  
> you'll just have to wait until the bug is fixed.
> (if you want to hack it, change the default aspect_numerator and  
> aspect_denominator in etheora.c to 1 and use ASPECT_PRESERVE.)
>   -r

Thank you, -r.

I'll take a look at etheora.c and try to find a solution.


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Manuel Dahmen

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