[FFmpeg-devel] [PATCH] mov auto crop

Stefano Sabatini stefano.sabatini-lala
Sat Oct 2 18:39:05 CEST 2010


On date Saturday 2010-10-02 18:20:15 +0200, Michael Niedermayer encoded:
> On Sat, Oct 02, 2010 at 05:58:52PM +0200, Stefano Sabatini wrote:
> > On date Saturday 2010-10-02 14:57:43 +0200, Benjamin Larsson encoded:
> > > On 10/02/2010 04:51 AM, Baptiste Coudurier wrote:
> > > > Hi guys,
> > > > 
> > > > $subject.
> > > > 
> > > > Please keep in mind that this issue has been present for _years_ and
> > > > nobody dared to fix it. I believe the patch is not so hackish/ugly.
> > > > 
> > > > I restrict it to codecs not supporting arbitrary resolutions that can be
> > > > stored in .mov by quicktime.
> > > > 
> > > > Maybe exporting to "crop", "wxh" is better, I don't know.
> > > > 
> > > > I plan to add auto-rotate for iphone 3gs files this way as well :)
> > > > 
> > > 
> > > Jolly good. But would it be possible to move this code to the api and
> > > just not in the ffmpeg commandline tool? Ie so the users of the api also
> > > would get these fixes. Other then that I like the idea.
> > 
> > An idea could be to provide a callback to the MOV format context,
> > which could be initialized by the application and which would instruct
> > the application about what to do when such cropping/rotation
> > operations are required. But I agree that this looks more bloated and
> > provides little gain.
> 
> > But maybe we should at least do a check, and
> > enable the cropping only if the format is MOV.
> 
> well if someone stream copies mov to some other container we would want to
> preserve the croping information and use it ideally

What happens for example if we convert MOV -> AVI and re-scale during
this operation?

When converting again AVI to something else we'll crop again, which
doesn't necessarily look like the correct thing to do. From what I can
understand cropping metadata info should be used *only* if the format
is MOV, other containers should not take care of interpreting that
information as filtering instructions at all.

Regards.
-- 
FFmpeg = Free and Fanciful Mastering Programmable Extensive Gnome



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