[FFmpeg-devel] [PATCH 3/3] vf_colorspace: Add support for smpte 431/432 (dci/display p3) primaries

[Ronald S. Bultje]

Hi Kieran,

On Sun, Oct 30, 2016 at 10:06 AM, Kieran O Leary <kieran.o.leary at gmail.com>
wrote:

> Hi,
>
> On Sun, Oct 30, 2016 at 7:07 AM, Vittorio Giovara <
> vittorio.giovara at gmail.com> wrote:
>
> > Signed-off-by: Vittorio Giovara <vittorio.giovara at gmail.com>
> > ---
> > I couldn't find any reference to the name of the whitepoint used for 431,
> > so I came up with DCI, since it looks like it is only used there.
> > Please CC.
> >
>
> Could this patch be used to convert XYZ Digital Cinema Packages to Rec.709?
> I've found that converting a DCP to a YUV format in ffmpeg results in
> colours and contrast that look different to how the image displays in
> EasyDCP player or a cinema screen. IIRC, -vf colorspace doesn't accept XYZ
> input, so is there some intermediate step that I could take to achieve this
> kind of transformation, or have I just misunderstood the patch?


Does -vf colorspace accept XYZ as input? No, not right now.

It could be made to work but since raw XYZ stored in files is such a fringe
feature, I didn't focus on implementing support for that. The current
filter accepts any YUV colorspace, converts that to XYZ and then converts
that back to any other YUV colorspace. You could conceptually skip half of
that and allow XYZ input and/or output, but like I said, right now it
doesn't support that yet.

Ronald