AE 23.4. Prores import flickering

[Rocketbottle]

Help!

Hardware acceleration is turned off in settings. Prores import is still flickering on AE 23.4 with M1 Mac!

Is it just me... or?

Mac Studio M1 Ultra

macOS Monterey V12.6.5

After Effects V23.4

Just got a client's comment for flickering renders. Nasty surprise.

Nothing helps - Clearing caches. Color management on or off (Adobe and OCIO tested both). Hardware acceleration on or off. Restarting Mac. 

Had to downgrade back to version 23.2.1 which I know works.

Anybody else experiencing this?

[Jessica McMillan]

Hello,

Thank you for reporting this issue as well as supplying the details of your AE installation and system. 

Would you be able to supply us with a version of this project to try to reproduce the problem internally? I know that sometimes isn't an option depending on the project/client. If you can, posting them on dropbox or your creative cloud shared space and send a link would be helpful.

All the best,
Jessica, After Effects Engineering Team

[Rocketbottle]

Hi & thanks for your reply

I send a PM to you.

Regards

[Jessica McMillan]

Is the flickering you see a shift to/from green tint? Or what does it visually look like? flicker to white/black? other?

So far we haven't reprodced it in house, though the QE that has tried on an M1 machine might not have the same plugins that you are using. Not sure if that is related yet or not.

Edited to note: QE was able to reproduce on another M1 machine they had and was resolved by turning off Hardware Accelerated Decoding (Preferences > Import > [uncheck] Enable hardware accelerated decoding (requires restart).

[Rocketbottle]

Hi

Yes. The hardware acceleration has been disabled all the time. This is something different from the green/magenta problem with hardware acceleration.

Flickering may not be immediately visible if you don't know what to watch. It is a slight luminance level drop after every few frames. It happens when I preview the timeline or render output. BUT if I advance the timeline frame by frame, it does not happen.
Original source is OK. Flickering varies in place if I reload the AE project or clear the cache - Can the cache disk have this effect!? [Edit: nope, changing the cache to another SSD did not have any effect.]

The level shift is easily visible if you lower the gamma extremely. Here is a very interesting-looking RGB waveform:

Same material in HDR space without any color management:

Hope this gives some idea of the cause.
Older AE version 23.2.1 works fine without any flickering, so I am positively hoping it cannot be a faulty hardware?

(In case anybody wonders, why not try 23.3? It has a broken Roto Brush tool.)

[Jessica McMillan]

I will add it to the report and check in with our formats team. Thanks!