I hear good things about the Intel Arc A380. You basically only need it to convert video and the Intel is not too bad at that for not too steep a price
Someone said that it is "not terribly performent" but it doesn't matter for transcoding. It can do multiple 4k streams of AV1 & HEVC. That is perfect.
According to benchmarks, it beat the 3080 and 6800XT when it was released for transcoding performance. That is what you have to look at in this case, you aren't gaming on it.
Just remember to enable all of the correct kernel modules to get it working. You often have to manually download the firmware git repo and move it to the firmware folder in Debian to get it working.
How do I need to configure jellyfin in order to work properly?
I added
device:
- /dev/dri
And I tried /dev/dri/renderD128 but both don't work. Moreover, I enabled encoding in HEVC format, hardware encoding and selected hardware accelleration with intel quicksync (QSV) and enabled hardware decoding for H264, HEVC, ...
But if that's enabled, transcoding doesn't work at all on the player.