QNAP TS-664 Docker, Hardware transcoding not working

Server Version#: 1.40.0.7998
Player Version#: Web/iPhone

I followed:
https://support.plex.tv/articles/115002178853-using-hardware-accelerated-streaming
https://github.com/plexinc/pms-docker#intel-quick-sync-hardware-transcoding-support

Mar 07, 2024 13:43:26.269 [139698033597240] Debug — [Req#3a66/Transcode] Codecs: testing h264 (decoder) with hwdevice vaapi
Mar 07, 2024 13:43:26.269 [139698033597240] Debug — [Req#3a66/Transcode] Codecs: hardware transcoding: testing API vaapi for device ‘/dev/dri/renderD128’ (JasperLake [UHD Graphics])
Mar 07, 2024 13:43:26.269 [139698033597240] Error — [Req#3a66/Transcode] [FFMPEG] - No VA display found for device /dev/dri/renderD128.
Mar 07, 2024 13:43:26.269 [139698033597240] Debug — [Req#3a66/Transcode] Codecs: hardware transcoding: opening hw device failed - probably not supported by this system, error: Invalid argument
Mar 07, 2024 13:43:26.269 [139698033597240] Debug — [Req#3a66/Transcode] Could not create hardware context for h264
Mar 07, 2024 13:43:26.270 [139698033597240] Debug — [Req#3a66/Transcode] MDE: Selected protocol hls; container: mp4
Mar 07, 2024 13:43:26.270 [139698033597240] Debug — [Req#3a66/Transcode] MDE: analyzing media item 6300
Mar 07, 2024 13:43:26.270 [139698033597240] Debug — [Req#3a66/Transcode] MDE: Star Wars: Episode V - The Empire Strikes Back (1980): no direct play video profile exists for http/mkv/h264
Mar 07, 2024 13:43:26.270 [139698033597240] Debug — [Req#3a66/Transcode] MDE: Star Wars: Episode V - The Empire Strikes Back (1980): no direct play video profile exists for http/mkv/h264/dca
Mar 07, 2024 13:43:26.270 [139698033597240] Debug — [Req#3a66/Transcode] Star Wars: Episode V - The Empire Strikes Back - audio.channels limitation applies: 7 > 6
Mar 07, 2024 13:43:26.270 [139698033597240] Debug — [Req#3a66/Transcode] MDE: Star Wars: Episode V - The Empire Strikes Back (1980): selected subtitle cannot be converted to a compatible format, burning into video stream
Mar 07, 2024 13:43:26.270 [139698033597240] Debug — [Req#3a66/Transcode] MDE: Star Wars: Episode V - The Empire Strikes Back (1980): avoiding video remux due to burned subtitle stream
Mar 07, 2024 13:43:26.270 [139698033597240] Debug — [Req#3a66/Transcode] MDE: Star Wars: Episode V - The Empire Strikes Back (1980): no remuxable profile found, so video stream will be transcoded
Mar 07, 2024 13:43:26.270 [139698033597240] Debug — [Req#3a66/Transcode] MDE: Cannot direct stream video stream due to profile or setting limitations
Mar 07, 2024 13:43:26.270 [139698033597240] Debug — [Req#3a66/Transcode] Codecs: testing h264 (decoder) with hwdevice vaapi
Mar 07, 2024 13:43:26.271 [139698033597240] Debug — [Req#3a66/Transcode] Codecs: hardware transcoding: testing API vaapi for device ‘/dev/dri/renderD128’ (JasperLake [UHD Graphics])
Mar 07, 2024 13:43:26.271 [139698033597240] Error — [Req#3a66/Transcode] [FFMPEG] - No VA display found for device /dev/dri/renderD128.

Running Plex in a container:

plex:

container_name: plex

image: plexinc/pms-docker:public

restart: unless-stopped

logging:

driver: json-file

environment:

- PUID=$PUID

- PGID=$PGID

- TZ=$TZ

- UMASK=002

- DEBUG=no

- PLEX_CLAIM=$PLEX_CLAIM

- PLEX_PASS=$PLEX_PASS

- ADVERTISE_IP=$PLEX_ADVERTISE_IP

volumes:

- /etc/localtime:/etc/localtime:ro

- ./plex:/config:rw

- ./plex:/transcode:rw

- /share/2watch/tv:/media/tv:rw

devices:

- /dev/dri:/dev/dri

network_mode: host

My CPU supports JasperLake (Intel Celeron® N5095).

Please help…
thx
br Jörg

seems related to:
https://github.com/linuxserver/docker-plex/issues/207

after setting permissions, it worked

https://github.com/linuxserver/docker-jellyfin/issues/26

howto fix this permanently?

Add the user to the group “render” fixes the problem.
Would be nice to have this documented in the guide…