[FFmpeg-devel] [PATCH] libavfilter: yadif pix_fmt priority

[Reimar Döffinger]

On Sun, Dec 04, 2011 at 11:44:47AM +0100, Robert Nagy wrote:
> Warning, handwritten patch.
> 
> Problem: yuv420p is prioritized over yuv422p and yuv444p even though
> conversion to the higher quality formats is more appropriate, e.g.
> currently the graph will auto insert before the yadif filter the conversion
> uyvy422 -> yuv420p, instead of uyvy422 -> yuv422p.
> 
> Reverse the pixel format listing of these formats. *I'm not sure this patch
> solves the problem.*

That is a _very_ bad idea, it will convert e.g. UYVY to 444P even though
444P is larger, less supported and no better.
IMO the list should be sorted by what the user is most likely to want
(and I think it mostly is, except for the lack of RGB formats?!?)
However in addition a second list should be used that lists for
each input formats all lossless or otherwise preferable conversions.
So if input is UYVY, then 422P is what should be tried as the very
first alternative for example.