[FFmpeg-user] blend filter

[Michael Koch]

Am 30.09.2021 um 19:05 schrieb Michael Koch:
> I like the sample images for the blend filter that Paul has added here:
> https://trac.ffmpeg.org/wiki/Blend

In the documentation for the "opacity" options for the blend filter is 
written:
"Only used in combination with pixel component blend modes."

What is a "pixel component blend mode"?

It seems that the opacity options are used for many (or all?) predefined 
modes that are set with all_mode=...
however the opacity options aren't used if a user-defined mode is set 
with all_expr=...

Is this correct?

Michael