I am also "one of them" spending my whole day trying to get HW transcoding to work 😏
As far as I can tell, I did all the recommendations in the various threats, but when I play a .mkv I don't see my HW is being used.
What I did so far:
I am using an Intel CPU with QuickSync support
Added the following to my go file using the CA Config File editor and rebooted Unraid
modprobe i915
chmod -R 777 /dev/dri
Added --device=/dev/dri:/dev/dri to the extra parameters of the Jellyfin docker
Enabled HW transcoding, using VAAPI and restarted Jellyfin
When I hit the command /dev/dri I can access the folder (both from the server Terminal aswell in the Jellyfin _Console)
When I hit the command in the Jellyfin _Console for a HW transcode (thanks @sir_storealot), I see it starts using the HW transcoder using the Intel GPU tools
Even updated from Unraid 6.8.0 to Unraid 6.9.0 b35,rebooted the server, and hit the command to enable i915 support and did steps 5 and 6 again
When I however start playing the same .mkv from the web-browser or the Android app of Jellyfin, it only uses my CPU and shows 'Direct Play'. When I look at the Intel GPU tools, it is also only using the CPU instead of the engine.
Sorry for the details, but wanted to show what I did and not just gave up the first time it didn't work...
Any suggestions what I am missing here?