Re: [FFmpeg-devel] [PATCH] avfilter/vf_overlay: fix alpha blending for planar formats with a transparent background

2017-08-10 Thread Marton Balint
On Mon, 7 Aug 2017, Marton Balint wrote: On Sat, 5 Aug 2017, Michael Niedermayer wrote: On Fri, Aug 04, 2017 at 10:23:55AM +0200, Marton Balint wrote: When the background had an alpha channel, the old code in blend_plane calculated premultiplied alpha from the destination plane colors

Re: [FFmpeg-devel] [PATCH] avfilter/vf_overlay: fix alpha blending for planar formats with a transparent background

2017-08-07 Thread Marton Balint
On Sat, 5 Aug 2017, Michael Niedermayer wrote: On Fri, Aug 04, 2017 at 10:23:55AM +0200, Marton Balint wrote: When the background had an alpha channel, the old code in blend_plane calculated premultiplied alpha from the destination plane colors instead of the destination alpha. Also the

Re: [FFmpeg-devel] [PATCH] avfilter/vf_overlay: fix alpha blending for planar formats with a transparent background

2017-08-05 Thread Michael Niedermayer
On Fri, Aug 04, 2017 at 10:23:55AM +0200, Marton Balint wrote: > When the background had an alpha channel, the old code in blend_plane > calculated premultiplied alpha from the destination plane colors instead of > the > destination alpha. > > Also the calculation of the output alpha should only

[FFmpeg-devel] [PATCH] avfilter/vf_overlay: fix alpha blending for planar formats with a transparent background

2017-08-04 Thread Marton Balint
When the background had an alpha channel, the old code in blend_plane calculated premultiplied alpha from the destination plane colors instead of the destination alpha. Also the calculation of the output alpha should only happen after the color planes are already finished. Fixes output of: