Latest commit a4f7139 Aug 23, 2018


v4l2loopback tests


this small sample application will write an image into a v4l2loopback device.
the image will be 640x480 pixels in UYVY colorspace (and since all pixels are
set to "0" it will be green).
the video-device defaults to /dev/video1 but you can specify another device on
the commandline

$ make test
$ ./test /dev/video2 &
$ xawtv -c /dev/video2

if you want to use another device you need to modify the VIDEO_DEVICE define at
the beginning of the code and recompile.

Copyright (C) 2011  Eric C. Cooper <>

Example using mplayer as a producer for the v4l2loopback driver:

$ mkfifo /tmp/pipe
$ ./yuv4mpeg_to_v4l2 < /tmp/pipe &
$ mplayer movie.mp4 -vo yuv4mpeg:file=/tmp/pipe

Copyright 2015,, GPLv3.
This will wait until something connects to pull frames then sends them.
It uses two threads and semaphores to do the testing.
It can setup and teardown the frame source.
The example just sends a different color each second.
It is 80x60 (it is a skeleton for hardware with this resolution)

$ make ondemandcam
$ ondemandcam /dev/videoX & # where X is the v4l2loopback device

It can be viewed with:

$ vlc v4l2:///dev/videoX # X is same device as above