After Effect 2020 17.0.6 Prores 4444 Alpha

[alekseyk90454507]

Found some annoying bug with 4444 prores files with premult alpha.

After Effect 2020 17.0.6 ignores premult alpha and use straight on default, reselecting to ignore or to straight and back don't work.
If i use the same file in After Effects 2019 16.1.3 - everything ok.
Also ok if i use QT Animation - alpha works properly.

Tested on Windows 10 Pro 1909 and MacOs Catalina - everything the same.

Maybe someone have the same bug?

[Deepwell]

Yes - I can confirm this. Tested on macOS Mojave (10.14.6) on MacBook Pro 2017 and MacPro Trashcan.

Having this issue with ProRes files I created myself as well as with ProRes files from ActionVFX.

To make sure I re-installed AE 2019 on one of the machines again - worked fine there.

Flipping the straight/premult switch in Interpret Footage also does nothing.

Somehow they broke the Apple ProRes Alpha...:((

Which is a shame because a lot of pro VFX stock footage comes in ProRes4444

[Deepwell]

The only workaround I found so far is to add the Remove Color Matting effect to the layer.

You might want to work in 32bit for that (so the unnecessary multiplication/division turnaround does not hurt the edges).