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

[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 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:
>>> ffplay -f lavfi "testsrc2=alpha=32[a];color=black[b];[b][a]overlay[out0]"
>>
>> if it is easy, please add a fate test when / after you push this
>>
>
> Ok, will do as a second step. I am going to apply this soon.

Applied.

Regards,
Marton