I am trying to set up Plex with HW transcoding with my Intel ARC gpu. The problem is that some codecs won't play, it shows get high cpu load (30%+) and constant buffer. In the Plex Media Server log shows errors:
"Failed to initialise VAAPI connection: -1 (unknown libva error)"
"hardware transcoding: opening hw device failed - probably not supported by this system, error: I/O error"
Which leads to plex not being able to create hardware context for the codecs ("could not create hardware context for h264_vaapi").