Zhuowei ZhangJul 7, 2023
What's the best way to encode a video with an alpha channel?
Show threadZhuowei ZhangJul 7, 2023
The Internet says the best way is to encode two videos, one video holding YUV and one video holding the alpha channel, then during decoding time recombine. Not sure how to interleave them in .
(Or I could just key out one colour, but visionOS's e.g. app icon grid probably won't look good without full alpha...)
Show threadKeith AhernJul 7, 2023
@zhuowei I played around with this using OBS and chroma keying out colours while looking at blocks of colour in the sim. Due to the inherent alpha blending of the app icon grid and frosted glass panels it didn't look great. Are you able to isolate the layers pre-composition?
Show threadZhuowei Zhang
@keithahern Not sure yet: I'll have to take a look. I remember visionOS supports rendering environment to a separate layer (see createPatchAndUpdateWithFrameDescription:(etc)), so might be able to use that.
Jul 7, 2023 at 3:52pmWeb