I'd like to be able to capture input from a webcam to to separate programs. One for VoIP, and one for capture.

The problem is - Linux will allow only one process to access a V4L2 device, so once I run the videochat, the capture will get black frames, if I start the capture program first, the videochat will get black frames.

How can I solve this? Is there a way to allow multiple processes to access a single /dev/video device? Or maybe I can clone the /dev/video0 and create a /dev/video1 somehow?

1 Answer 1


You could use v4l2loopback to create multiple virtual devices, one per program that wants access to the stream, and then use a program such as tee to forward the video to the virtual devices.

  • Could you point me to some sources on how do I do this? I have no idea how v4l2loopback works.
    – unfa
    Jan 1, 2018 at 21:07
  • I have tried using g-streamer solution, but and it gave me a cloned /dev/video1, but /dev/video0 didn't work, so gain. I wasn't able to create 2 cloned devices.
    – unfa
    Jan 10, 2018 at 10:21
  • 1
    Related post
    – ignacio
    Apr 20, 2020 at 15:49
  • I have been using v4l2loopback for a long time. Recently, I've discovered that virtual devices can make multiple streams at the same time. Now, I wanted to know if phisical cameras can do that by configuring them in any way... could it be possible?
    – Mario Mey
    Sep 10, 2020 at 1:58

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