[FFmpeg-devel] [PATCH 4/4] avcodec/libx265: encode dovi RPUs

[Vittorio Giovara]

On Tue, Mar 19, 2024 at 7:04 PM Niklas Haas <ffmpeg at haasn.xyz> wrote:

> On Tue, 19 Mar 2024 21:59:53 +0000 Cosmin Stejerean via ffmpeg-devel <
> ffmpeg-devel at ffmpeg.org> wrote:
> >
> >
> > > On Mar 19, 2024, at 2:39 PM, Derek Buitenhuis <
> derek.buitenhuis at gmail.com> wrote:
> > >
> > > The reason I never implemented this back when I adde RPU side data is
> that
> > > there is a strong chance of generating broken files.
> > >
> > > That's because if we do anything to the video with swscale, etc., we're
> > > now encoding RPUs that aren't meant to be applied to that converted
> video.
> > >
> > > For example, this could end up propagating RPUs when the user is
> tonemapping.
> >
> > Would it be possible to only propagate RPUs if the color params are not
> changing? If there's any change from say PQ to HLG or HLG to PQ or
> tonemapping then we wouldn't want to propagate RPUs. If the color params
> are not changing then propagating RPUs by default seems sensible, and
> perhaps a filter can be added to explicitly clear RPUs if they should not
> be propagated.
>
> One way to accomplish this would be to simply strip the metadata in all
> filters
> that can change the colorspace. Maybe we should do the same for HDR+ etc.
> metadata.
>
> Probably it would make sense to add a common helper function for this.
> I'll see
> what I can do.
>

In the meantime maybe just adding an encoder option to preserve existing
metadata would help?
-- 
Vittorio