[Ffmpeg-devel] [BUG] DV in QuickTime - Aspect Ratio

Roman Shaposhnik rvs
Thu Mar 15 03:30:02 CET 2007


On Thu, 2007-03-15 at 01:39 +0000, M?ns Rullg?rd wrote:
> >> I'm not quite sure if all of this is needed for QuickTime? 
> >
> >   My assumption all along has been that it is usually container's
> > job to store things like SAR, DAR, etc. But since DV is both
> > a container and a codec format I have nothing against moving 
> > SAR initialization to libavcodec. Unless somebody tells me
> > its a stupid idea.
> 
> Many codecs indicate SAR or DAR in the stream headers, whereas only a
> few containers do so.
 
  Hm. That's an interesting point. Are you saying that it is actually
more common for codecs to do that or that the world is so screwed up
that nobody actually cares ? ;-)

> >> Using the command that herve posted would create a video that the
> >> QuickTime player recognizes as 16:9, but ffmpeg reading does not.
> >
> >   Right. And that's because QuickTime gives precedence to the DV
> > metadata and not the container, ffmpeg is the other way around.
> > I'm not really sure which way I prefer.
> 
> When the container does indicate aspect ratio, I've found that a large
> proportion of files in the wild have different values in container and
> elementary stream, neither being correct more frequently.

  I see :-( 

Thanks,
Roman.





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