v4l2loopback-ctl - Man Page
control v4l2 loopback devices
Synopsis
v4l2loopback-ctl [Options]
v4l2loopback-ctl add [Options] [<outputdevice> [<capturedevice>]]
v4l2loopback-ctl delete <device>
v4l2loopback-ctl list [Options]
v4l2loopback-ctl query [Options] <device>
v4l2loopback-ctl set-fps <device> <fps>
v4l2loopback-ctl get-fps <device>
v4l2loopback-ctl set-caps <device> <caps>
v4l2loopback-ctl get-caps <device>
v4l2loopback-ctl set-timeout-image [Options] <device> <image>
Description
Manage v4l2 loopback devices.
The general invocation uses a verb (like 'add' or 'delete') that defines an action to be executed. Each verb has their own options and arguments.
Options
- -h
- , -?, --help: print this help and exit
- -v, ā--version
- : print version and exit
Verbs and Their Arguments
v4l2loopback-ctl add [OPTIONS] [<outputdevice> [<capturedevice>]]
create/add a new loopback-device
- -b <num>, --buffers <num>
buffers to queue
- -h <h>, --max-height <h>
maximum allowed frame height
- -n <name>, --name <name>
pretty name for the device
-o <num>, --max-openers <num> maximum allowed concurrent openers
- -v, --verbose
verbose mode (print properties of device after successfully creating it)
- -w <w>, --max-width <w>
maximum allowed frame width
- -x <x>, --exclusive-caps <x>
whether to announce OUTPUT/CAPTURE capabilities exclusively
- --min-width <w>
minimum allowed frame width
- --min-height <w>
minimum allowed frame height
- -?, --help
print this help and exit
- <outputdevice>
if given, create a specific device (otherwise just create a free one).
either specify a device name (e.g. '/dev/video1') or a device number ('1').
- <capturedevice>
if given, use separate output & capture devices (otherwise they are the same).
v4l2loopback-ctl delete <device>
delete/remove an unused loopback device
- <device>
can be given one more more times (to delete multiple devices at once). either specify a device name (e.g. '/dev/video1') or a device number ('1').
v4l2loopback-ctl list [OPTIONS]
list all available loopback-devices
- -e, --escape
escape control-characters in (device) names
- -h, --help
print this help and exit
v4l2loopback-ctl query [OPTIONS] <device>
query information about a loopback device
- -e, --escape
escape control-characters in (device) names
- -h, --help
print this help and exit
- <device>
can be given one more more times (to query multiple devices at once). either specify a device name (e.g. '/dev/video1') or a device number ('1').
v4l2loopback-ctl set-fps <device> <fps>
set the default framerate for a loopback device
- <device>
either specify a device name (e.g. '/dev/video1') or a device number ('1').
- <fps>
frames per second, either as integer ('30') or fraction ('50/2').
v4l2loopback-ctl get-fps <device>
query the framerate of a loopback device
v4l2loopback-ctl set-caps <device> <caps>
set format/dimension/framerate of a loopback device
- <device>
either specify a device name (e.g. '/dev/video1') or a device number ('1').
- <caps>
format specification as '<fourcc>:<width>x<height>@<fps>' (e.g. 'UYVY:1024x768@60/1') unset the current caps with the special value 'any'
v4l2loopback-ctl get-caps <device>
get current format/dimension/framerate of a loopback device
v4l2loopback-ctl set-timeout-image [OPTIONS] <device> <image>
set a fallback image to be used if a video producer does not send new frames in time.
- <flags>
any of the following flags may be present
- -h, --help
print this help and exit
- -t <timeout>, --timeout <timeout>
timeout (in ms)
- -v, --verbose
raise verbosity (print what is being done)
- <device>
either specify a device name (e.g. '/dev/video1') or a device number ('1').
- <image>
image file
Reporting Bugs
Issue tracker: https://github.com/umlaeute/v4l2loopback/issues
Security Issue tracker: https://git.iem.at/zmoelnig/v4l2loopback/-/issues