Alpha Channel Difference jumping from M1 Monterey to M4 Sequoia

[Pruitt]

Hola! 

Do we know about an issue about how Qlab/Mac handles alpha channels jumping from an M1 running Monterey/Qlab 5.5.5  to an M4 running Sequoia/Qlab 5.9? Specifically, it's manifesting in .mov videos using transparency. It does not manifest with png stills with alpha channels. 

This is a running show that's been fine for several months on the M1 Max running three screens. I recently bought a new M4 Max which came with Sequoia and moved the show to that machine, as an upgrade. But now any .mov files with alpha channels show as "black" instead of transparent. This isn't an urgent issue as the older machine will just stay in use until I can solve the problem, but it seems odd. 

Both computers are running the latest version of Monterey/Sequoia. The new machine has Qlab 5.9. The older machine is running Qlab 5.5.5 and I was planning on bringing it up to date when my current run of shows is complete after this weekend, but now I will hold off until I can find an answer for why they are handling transparencies differently. 

Cheers!

Stephen

[Pruitt]

No one else has had an issue with this? Strange to not get any replies at all. 

[micpool]

This is a question that you could probably have resolved by now, by contacting support.

You could also have investigated whether this was likely  a QLab 5.5.5, 5.5.9,  Monterey vs Sequoia, or M1 vs M4 issue. Both machines could run 5.5.5 and 5.5.9 and you could temporarily install both versions on both machines.

Both machines will run Sequoia and you could make a Sequoia boot disk on an external SSD to temporarily run your M1 under Sequoia.

These 2 tests should pin down the problem to QLab, OS, or Processor.

After that it's probably a matter of looking at how your .mov files with alpha were made, what codec is used, and if the alpha is straight or pre multiplied.

Mic