[vlc-devel] [PATCH 3/3] swscale: scale the aspect-ratio of the output format
remi at remlab.net
Mon Mar 3 19:06:51 CET 2014
Le mardi 25 février 2014, 11:14:50 Felix Abecassis a écrit :
> 2014-02-23 15:44 GMT+01:00 Rémi Denis-Courmont <remi at remlab.net>:
> > By convention, conversion filters accept the format if they can do the
> > conversion and otherwise fail. Post-processing filters can modify their
> > input and output formats as they see fit. It really boils down to the
> > assumptions made by the different call sites: whether they take the
> > conversion for granted, or can add further conversion filters if the
> > output format is modified.
> I don't see when additional conversion filters would be needed if only
> the aspect ratio was changed.
With a given source resolution, source aspect ratio and target resolution, the
target aspect ratio is mathematically fixed. So a mismatch sounds like a bug
Well in principles, a mismatching aspect could mean that cropping is
necessary. But a well-behaving video output display should never request such
an video format, as it could involve in black bars in *both* dimensions. The
video output should instead place the picture correctly.
So I would guess either the video output is not computing the picture
placement correctly, or the aspect ratio gets corrupted at some point while
setting up the pipeline.
More information about the vlc-devel