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