DOKK / manpages / debian 11 / v4l2loopback-utils / v4l2loopback-ctl.1.en
V4L2LOOPBACK-CTL(1) User Commands V4L2LOOPBACK-CTL(1)

v4l2loopback-ctl - control v4l2 loopback devices

utils/v4l2loopback-ctl [command] [args]

Set device fps (if format is already negotiated).
Set timeout on device, and optionally the placeholder picture, instead of default null frame.
Fix format for the device (using GStreamer caps), so it will be maintained until reset, regardless of future readers/writers.

frames per second, either as integer ('30') or fraction ('50/2')
image file ("no-input.png"), or 'videotestsrc'
GStreamer caps ("video/x-raw, format=UYVY, width=640, height=480"), or 'any'
/dev/videoX
the v4l2-loopback device file you want to act on

Copyright © 2012 IOhannes m zmoelnig <zmoelnig@iem.at>
Copyright © 2012 Anton Novikov (random.plant@gmail.com)

April 2020 v4l2loopback-ctl 0.6