Hardware accelerated playback fails on MPEG2 DVD rips

[somechap]

Thanks, I've upgraded to 10.10.7, but am finding the permissions thing hard to configure right. I suspect my understanding of how users and groups are passed through to docker containers is sub-par, and the working week has got in the way of further investigation. I can say that my user account on the docker host can cat stuff from /dev/dri/renderD128, whereas my mapped user inside the docker container can't because of permissions. Hopefully I'll get to the bottom of it.