[FFmpeg-devel] [PATCH] avfilter/vf_scale: Do not set YUV color range for RGB formats

[Michael Niedermayer]

On Wed, Mar 21, 2018 at 03:04:35PM +0100, wm4 wrote:
> On Tue, 20 Mar 2018 23:59:46 +0100
> Michael Niedermayer <michael at niedermayer.cc> wrote:
> 
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >  libavfilter/vf_scale.c | 7 ++++++-
> >  1 file changed, 6 insertions(+), 1 deletion(-)
> > 
> > diff --git a/libavfilter/vf_scale.c b/libavfilter/vf_scale.c
> > index 9f45032e85..2f6fa4791d 100644
> > --- a/libavfilter/vf_scale.c
> > +++ b/libavfilter/vf_scale.c
> > @@ -407,6 +407,7 @@ static int filter_frame(AVFilterLink *link, AVFrame *in)
> >      AVFilterLink *outlink = link->dst->outputs[0];
> >      AVFrame *out;
> >      const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
> > +    const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(outlink->format);
> >      char buf[32];
> >      int in_range;
> >  
> > @@ -497,7 +498,11 @@ static int filter_frame(AVFilterLink *link, AVFrame *in)
> >                                       table, out_full,
> >                                       brightness, contrast, saturation);
> >  
> > -        out->color_range = out_full ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
> > +        // color_range describes YUV, it is undefined for RGB
> > +        if ((out_desc->flags & AV_PIX_FMT_FLAG_RGB) && out_desc->nb_components != 1) {
> > +            out->color_range = AVCOL_RANGE_UNSPECIFIED;
> > +        } else
> > +            out->color_range = out_full ? AVCOL_RANGE_JPEG : AVCOL_RANGE_MPEG;
> >      }
> >  
> >      av_reduce(&out->sample_aspect_ratio.num, &out->sample_aspect_ratio.den,
> 
> Why is it not setting full range for gray? PNGs can use this for
> grayscale images, so they would be affected by this too.

I do not understand what you describe here. Please describe the issue
clearer and or provide a testcase.

there is no unique gray pixel format.
gray8 is not a AV_PIX_FMT_FLAG_RGB format, thus its treated the same as
before this patch



[...]

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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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