V4l2loopback does not work as a video input

Description

I use OBS with a v4l2 loopback to be able to ‘chroma’ my background while video-chating. It is useful for me, it really gives me flexibility to share screen+video etc. I am unable to feed from the v4l2loopback to jitsi. The setup is working everywhere else, hangouts, googlemeet, skype web, and even webcamtests.com. Issue seems to match #1964

Current behavior

Jitsi refuses to accept the v4l2loopback input. It is not listed at the browser pop-up that asks for permissions. It can be listed in the settings within the chat-roomt, but it refuses to use it. I can see it advertised in the browser jsconsole in: [features/base/devices]

Expected Behavior

Being able to choose v4l2loopback as a video device.

Environment details

I am using Linux 5.5.8 with Firefox 73. It happens with other browsers (chromium) and linux versions.
OBS 24 and v4l2loopback-dkms 0.12.3. obs-v4l2sink as plugin.

Steps to reproduce

install all the above modprobe v4l2loopback exclusive_caps=1 obs»tools»v4l2sink start go to a room meet.jit.si the “dummy device” wont appear in the permission pop-up

[dromer]

For chromium you need to load the module with exclusive_caps=1

What I currently use: sudo modprobe v4l2loopback devices=1 video_nr=10 card_label="OBS Cam" exclusive_caps=1

[edit: ah you already are using this parameter. I ended up compiling obs + v4l2loopback + obs-v4l2sink from scratch because I wanted to root out anything to do with old versions. newer obs has nice features too]

[DavidS]

Using the instance at https://meet.jit.si/ chromium now picks up the virtual webcam automatically. Firefox still doesn’t offer it to choose when asking for permission.