[FFmpeg-devel] [PATCH 5/6] avcodec/apng: Add support for blending with GRAY8A pixel format

[Michael Niedermayer]

On Tue, Jun 02, 2015 at 08:21:36PM +0200, Paul B Mahol wrote:
> On 6/2/15, Donny Yang <work at kota.moe> wrote:
> > On 3 June 2015 at 03:38, Paul B Mahol <onemda at gmail.com> wrote:
> >
> >> Dana 2. 6. 2015. 17:50 osoba "Donny Yang" <work at kota.moe> napisala je:
> >> >
> >> > Signed-off-by: Donny Yang <work at kota.moe>
> >> > ---
> >> >  libavcodec/pngdec.c | 8 +++++++-
> >> >  1 file changed, 7 insertions(+), 1 deletion(-)
> >> >
> >> > diff --git a/libavcodec/pngdec.c b/libavcodec/pngdec.c
> >> > index 1f5c433..1667530 100644
> >> > --- a/libavcodec/pngdec.c
> >> > +++ b/libavcodec/pngdec.c
> >> > @@ -891,7 +891,8 @@ static int handle_p_frame_apng(AVCodecContext
> >> > *avctx,
> >> PNGDecContext *s,
> >> >          return AVERROR(ENOMEM);
> >> >
> >> >      if (s->blend_op == APNG_BLEND_OP_OVER &&
> >> > -        avctx->pix_fmt != AV_PIX_FMT_RGBA) {
> >> > +        avctx->pix_fmt != AV_PIX_FMT_RGBA &&
> >> > +        avctx->pix_fmt != AV_PIX_FMT_GRAY8A) {
> >> >          avpriv_request_sample(avctx, "Blending with pixel format %s",
> >> >                                av_get_pix_fmt_name(avctx->pix_fmt));
> >> >          return AVERROR_PATCHWELCOME;
> >> > @@ -935,6 +936,11 @@ static int handle_p_frame_apng(AVCodecContext
> >> *avctx, PNGDecContext *s,
> >> >                      foreground_alpha = foreground[3];
> >> >                      background_alpha = background[3];
> >> >                      break;
> >> > +
> >> > +                case AV_PIX_FMT_GRAY8A:
> >> > +                    foreground_alpha = foreground[1];
> >> > +                    background_alpha = background[1];
> >> > +                    break;
> >> >                  }
> >> >
> >> >                  if (foreground_alpha == 0)
> >> > --
> >> > 2.4.0
> >>
> >> Is there actual sample?
> >>
> >
> > I have not actually found an apng sample using gray8a, but this is
> > implemented through reading the spec and firefox's source and understanding
> > that gray8a is treated the same as rgba, just with less bytes.
> >
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel at ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >
> 
> ok, patch lgtm

this doesnt apply cleanly without the prior patches so i cant
apply it yet

[...]
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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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