It looks like everything runs as root in the docker image by default. As a result, all of my recordings are owned by root. The linuxserver folks have docker images that let you specify PUID and PGID to have the containers create and use a user with those attributes internally so that files created/used by them in shared volumes will have the right ownership. Could something like that be adapted to channels-dvr?
Sadly, it’s not as simple as using the “–user” argument to Docker as that prevents the hardware transcoding feature from working as the device link is now inaccessible. It would need to create the user in the container, add that user to video, then start the app after switching to that user (via “USER username” in the Dockerfile).