[FFmpeg-devel] [PATCH] avfilter/vf_scale: reset color matrix in case of identity & non-RGB

[Michael Niedermayer]

On Fri, Aug 27, 2021 at 01:02:31AM +0300, Jan Ekström wrote:
> On Sun, Aug 22, 2021 at 11:55 PM Jan Ekström <jeebjp at gmail.com> wrote:
> >
> > Fixes passing through mismatching metadata from the input side
> > when RGB input (from f.ex. H.264 or HEVC) gets converted to YCbCr.
> >
> > Fixes #9132
> > ---
> >  libavfilter/vf_scale.c | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> >
> > diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
> > index ce39217515..7ca833bbb1 100644
> > --- a/libavfilter/vf_scale.c
> > +++ b/libavfilter/vf_scale.c
> > @@ -738,6 +738,15 @@ scale:
> >      out->width  = outlink->w;
> >      out->height = outlink->h;
> >
> > +    // Sanity check: If we've got the RGB/XYZ (identity) matrix configured, and
> > +    //               the output is no longer RGB, unset the matrix.
> > +    //               In theory this should be in swscale itself as the AVFrame
> > +    //               based API gets in, so that not every swscale API user has
> > +    //               to go through duplicating such sanity checks.
> > +    if (out->colorspace == AVCOL_SPC_RGB &&
> > +        !(av_pix_fmt_desc_get(out->format)->flags & AV_PIX_FMT_FLAG_RGB))
> > +        out->colorspace = AVCOL_SPC_UNSPECIFIED;
> > +
> >      if (scale->output_is_pal)
> >          avpriv_set_systematic_pal2((uint32_t*)out->data[1], outlink->format == AV_PIX_FMT_PAL8 ? AV_PIX_FMT_BGR8 : outlink->format);
> >
> > --
> > 2.31.1
> >
> 
> Unless there are objections, I will pull this in soon. I will also
> attempt to see if I can add a programmatic FATE test for all of the
> allowed configurations of vf_scale, to see if there are any other
> clear-cut cases where not all metadata from the input AVFrame can be
> passed on as-is and has to be reset.

no objections

thx

[...]
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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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