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I have been successfully using v4l2loopback, with v4l2sink in OBS, to "send" my obs preview panel output to Zoom. The v4l2loopback devices have recently stopped showing in Zoom, Firefox & Brave. However, I can confirm the loopback is viewable in VLC.

I'm on:

  • Pop!_OS (20.10)
  • v4l2loopback-dkms (0.12.5-1)
  • OBS (with the v4l2sink plug-in) (26.0.2+dfsg1-1)
  • Zoom (5.4.3)

I normally start the loopback device with the following:

sudo modprobe v4l2loopback video_nr=99 card_label="OBS Video Source" exclusive_caps=1

This is usually run on boot via:

$ cat /etc/modprobe.d/v4l2loopback.conf 
options v4l2loopback video_nr=99 card_label="OBS Video Source" exclusive_caps=1

$ cat /etc/modules-load.d/v4l2loopback.conf
v4l2loopback

The device shows via v4l2-ctl:

v4l2-ctl --list-devices
OBS Video Source (platform:v4l2loopback-000):
    /dev/video99

Cam Link 4K: Cam Link 4K (usb-0000:06:00.1-4):
    /dev/video2
    /dev/video3

UVC Camera (046d:0990) (usb-0000:06:00.3-1):
    /dev/video0
    /dev/video1

and once I start the v4l2sink in OBS, I can view this in VLC. However, as mentioned, the OBS Video Source device is no longer showing up in any applications that I've tried, as a selectable source.

How can I get the OBS Video Source show up as a source in Zoom again?

1 Answer 1

2

supported colourspace/dimenion

many applications only support certain colourspaces and dimensions.

try to output the data with some common dimensions ("640x480", "1280x720") and a common colourspace ("YUY2" aka "YUYV").

just now, i've successfully connected zoom (5.4.53350.1027) to a YUY2:1280x720 loopback device, as output from OBS (25.0.7-325-ga2ad2c6ca)

buggy version of v4l2loopback-dkms

Ubuntu-20.04 is known to have patched the v4l2loopback-dkms sources to prevent an error - unfortunately the patch broke the functionality of the module.

if using a known-good resolution/colourspace doesn't help, try using the last upstream release (rather than the package).

however: in general, you should stick with the distribution-provided packages.

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  • I have been trying to make sure my code is backwards compatible with even 20.04 and many commands just don't work like they should, is it an effort that should be dropped because all the modern version bypass it? commands like adding and deleting devices just do not repond
    – Vass
    Mar 19 at 23:53

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