Hard transcoding Synology

Hello,
I have a problem to make hard transcoding work on my DS918 + NAS.

My docker-compose :

Transcoding setting :

User 1030 has access to /dev/dri/renderD128 (read/write/execute)

But I have an error when I start a reading in transcoding, in direct reading, no problem.

“PlaybackErrorNoCompatibleStream”

Transcoding must be set to “VAAPI”

RESOLVED