Hmm. I wasn’t trying to recommend privileged or non-privileged mode, just trying to use that to single in on the actual issue.

Alright, if it’s just av1, maybe try to use a tool like vainfo to find the supported codecs. I think it fails if an unsupported codec is explicitly specified. But take care if Encoding is mentioned. Some hardware has decoding capabilities only.

It’s a complicated topic. And it also took me 2 whole evenings to get the permissions and everything right. I’m using systemd-nspawn, so my experience doesn’t directly translate. And it’s not any easier than docker.

For video acceleration I found the arch wiki somewhat helpful. But it’s lots of info and not specific to Docker. Maybe it helps for debugging: wiki.archlinux.org/…/Hardware_video_acceleration