[FFmpeg-devel] [PATCH v2 00/13] YUVJ removal

[Vittorio Giovara]

On Fri, Oct 20, 2023 at 7:30 AM Niklas Haas <ffmpeg at haasn.xyz> wrote:

> On Fri, 13 Oct 2023 14:33:11 -0400 Vittorio Giovara <
> vittorio.giovara at gmail.com> wrote:
> > On Fri, Oct 13, 2023 at 10:27 AM Niklas Haas <ffmpeg at haasn.xyz> wrote:
> >
> > > Changes since v1:
> > >
> > > - Remove unneeded patch (AVCodecContext.colorspace init)
> > > - Merge auto-range conversion into auto-scale filter
> > > - Replace vf_zscale by vf_colorspace in fftools
> > >
> >
> > Why is this? I haven't checked what vf_colorspace supports in a hot
> second,
> > but iirc zscale can handle non linear spaces better and hdr conversion
> > If it's because it's a built in filter, do you think we could first check
> > for zscale presence and fallback to colorspace?
> >
> > - Add some miscellaneous fixes for various FATE tests
> > > - Clean up some additional vestigiaul YUVJ remnants
> > >
>
> N.B.: Another issue with vf_scale/vf_colorspace is that vf_scale
> currently doesn't handle colorspace metadata at all, which is blocking
> the ability to add this (easily) to filter negotiation, since filter
> negotiation hard-codes the "scale" filter for auto-converting between
> any mismatch.
>

IMO having a solution that improves the status quo is welcome, so as long
as there is /a/ way in which ffmpeg can output correct colorspaces
automatically it should be added, even if this requires pulling in external
dependencies like for zscale. Like I believe that producing correct
conversion should be the priority, and once the design is good enough we
can address the presence of the functionality in the codebase or not.


> I am considering even just dropping the extended colorspace metadata
> (primaries, trc) from this series completely, or at least splitting them
> into separate patchsets. One to only remove YUVJ and add the color range
> + filter negotiation, and one to add all of the remaining colorspace
> metadata.


+1 to splitting the set a bit more, like proposed
-- 
Vittorio