README: add documentation about video support

README.md

@@ -32,3 +32,40 @@ On some systems, you may need to add `--security-opt seccomp=unconfined` to allo
 
 Once running, you should be able to access the UI via http://localhost:8080. 
 
+### Video
+
+QueueCube supports video as well. Just set the environment variable `ENABLE_VIDEO=1`. 
+
+#### Video + Docker
+
+When running in a Docker container, there are a few extra steps needed to make this work. 
+
+First, make sure you're passing in `/dev/dri` as a volume in the container. Since mpd is capable of rendering directly to the GPU, this would be the most performant. 
+
+```
+volumes:
+    - /dev/dri:/dev/dri
+```
+
+as well as the X11 socket:
+
+```
+    - /tmp/.X11-unix:/tmp/.X11-unix
+```
+
+In order to be able to interact with the X session from the Docker container, you may also need to explicitly allow connections to the host via:
+
+```
+$ xhost +local:
+```
+
+Since the container will also need to be able to access the GPU device, it may be required to run the container in "privileged" mode:
+
+```
+privileged: true
+```
+
+(or `--privileged`). 
+
+On Podman rootless, it seems to be enough to just run it with the "unconfined" security profile (`seccomp=unconfined`). 
+