SOLVED: Jellyfin transcodes as AV1 even though it's not allowed

[pitfallfritz]

It should transcode to HEVC with a compatible browser. Are you really sure it is transcoding to h264 even using safari on your Mac?

Absolutely, I just made sure again. Each client's playback settings explicitely state HEVC/AAC as preferred codecs (just making sure – ideally I would want this handled by default for all users). Server settings still say HEVC is "allowed" and AV1 is not.

Safari – H264/MP3
Chromium – VP9/OPUS
Chrome – H264/MP3
Firefox – H264/MP3 (as expected)
Edge – H264/MP3

Since MP3 can be direct played on everything, that's fine.

BTW, it looks like your build of chromium is not built with hevc and h264 support. I recommend this build on macOS if you hate google and still want decent chromium experience: https://formulae.brew.sh/cask/eloston-chromium

This one does support hardware accelerated HEVC.

True enough, Eloston-Chromium behaves as any other browser. Thanks for the tip! The one I was using was just for testing purposes and installed via brew install --cask chromium.

Maybe Jellyfin's implementation doesn't support this on AppleVideoToolbox, even if AppleVideoToolbox supports hardware HEVC encoding.

Please don’t say something like this because I am the exact person who implemented this in Jellyfin.

Hahah, okay I'll take note. Thank you for your work, I really appreciate it!

So, apparently Jellyfin still has VP9 "support" hidden somewhere. Which is only a problem if I'm using an exotic browser without even H264 support. I guess I can live with that.
But, either my HEVC preference is getting ignored or I'm missing something fundamental.

(The cheap old Atom in my old server just doesn't support HEVC encoding, period. But it should work on the M1 with VideoToolBox.)

Do you have any other idea what I could have overlooked or what I could try? Make a proper bug report somewhere?

Thank you for your help!