[vlc-devel] [PATCH 3/3] swscale: scale the aspect-ratio of the output format

Felix Abecassis felix.abecassis at gmail.com
Tue Feb 25 11:14:50 CET 2014

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.

> Then again, there is b_allow_fmt_out_change, which I am not sure is properly
> intiailized in all cases.
Yes I'm not sure it's meant to be used for conversion filters, I will
take a look.

I understand your point, but again, it was done this way before so
this is more a bug fix than a feature change.
We used to rely on aspect-ratio modification by swscale to have video
rotation correctly working, with the current state of the code I don't
know if it's possible to do it differently.


Félix Abecassis

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