Select loopback-camera in firefox usually not easily possible

I use v4l2loopback on linux to create a virtual webcam. This works under very narrow circumstances with Jitsi Meet (it is not a general problem) but I would like to ask if this should be reported as a bug:

My system has one “regular” webcam at /dev/video0 which is used in OBS. OBS then creates an output in a virtual v4l2loopback sink that other tools (including Jitsi Meet) can pick up as a regular video source.

In Jitsi Meet in firefox, I need to do this elaborate dance to make it work:

  • close OBS
  • start jitsi to the point where my browser asks me to choose a video source (my virtual camera will be listed only if OBS is not running). Keep this dialog open (i.e. do not yet choose a camera!)
  • start OBS
  • select the (still choosable) virtual camera

Then the video works as expected. But if I have OBS running beforehand, the camera will not show up in the list. If I choose the virtual camera before starting OBS, it will fail (because no video is actually coming from it).

For other tools, Big Blue Button, for example, I can select that virtual video source at any time without doing that same dance. This is why I am guessing that there is something special to the way Jitsi Meet filters video devices.

I would love Jitsi Meet to change slightly to make selecting that camera easier.