Support HEVC with Alpha (Screen recordings on macOS)
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Bret Fisher
This would allow for windows with round corners and OS-based drop shadows to be used when importing a HEVC file from macOS. This was added to macOS in 2019: https://developer.apple.com/videos/play/wwdc2019/506/
Because it appears HEVC is supported but Alpha channel isn't, those imported videos of screen sharing from macOS will just have big black borders around the Window that was recorded. (Recorder.app) supports recording in HEVC with Alpha.
Canny AI
Merged in a post:
Support HEVC with Alpha Transparency
M
Michael Walker
Could Descript support Apple’s HEVC codec with transparency (alpha channel)?
We’re working with a lot of transparent background videos and currently exporting in ProRes 4444, which creates huge files. For example, a 4-minute video ends up around 10GB. That same file exported in HEVC+alpha is only 500MB — almost 20x smaller — and still looks great in Final Cut.
The issue is: when we import those HEVC+alpha files into Descript, the transparency isn’t preserved — it comes in with a black background instead.
This support would be a game changer for our workflow. Without it, we’re stuck managing massive ProRes files, which adds up quickly in both cloud storage and time.
Here’s a quick video walkthrough:
M
Michael Walker
Yes +1! HEVC support with alpha transparency would be a game changer