[FFmpeg-devel] [PATCH 2/4] lavfi/opencl: Handle overlay input formats correctly.

[Li, Zhong]

> > -----Original Message-----
> > From: ffmpeg-devel [mailto:ffmpeg-devel-bounces at ffmpeg.org] On
> Behalf
> > Of Li, Zhong
> > Sent: Wednesday, November 7, 2018 4:37 PM
> > To: FFmpeg development discussions and patches
> > <ffmpeg-devel at ffmpeg.org>
> > Subject: Re: [FFmpeg-devel] [PATCH 2/4] lavfi/opencl: Handle overlay
> > input formats correctly.
> >
> > > > > > -----Original Message-----
> > > > > > From: Song, Ruiling
> > > > > > Sent: Monday, October 29, 2018 1:18 PM
> > > > > > To: ffmpeg-devel at ffmpeg.org
> > > > > > Cc: Song, Ruiling <ruiling.song at intel.com>
> > > > > > Subject: [PATCH 2/4] lavfi/opencl: Handle overlay input
> > > > > > formats
> > > correctly.
> > > > > >
> > > > > > The main input may have alpha channel, we just ignore it.
> > > > > > Also add some checks for incompatible input formats.
> > > > > >
> > > > > > Signed-off-by: Ruiling Song <ruiling.song at intel.com>
> > > > LGTM.
> > > > BTW, could the main input with alpha case be supported?
> > >
> > > I am not sure what kind of support do you mean?
> > > I simply ignore the alpha channel of the main input, and do the
> > > alpha blending using the overlay alpha.
> > > Before this patch, the filter will do it wrong if the main input has
> > > alpha channel. Now it works with this patch.
> > >
> > > Thanks!
> > > Ruiling
> >
> > I mean support alpha blending with alpha channel of main input when no
> > overlay alpha.
> I think I got your idea, this patch aims to fix the issues reported by Gyan.
> If people really want it (blending using alpha of main input) be supported, we
> can add it later.
> I am not sure whether this sounds ok?
> 
> Thanks!
> Ruiling

Sure, sound good.