V4L2-CTL(1) User Commands V4L2-CTL(1)
NAME
v4l2-ctl - An application to control video4linux drivers
SYNOPSIS
v4l2-ctl [-h] [-d <dev>] [many other options]
DESCRIPTION
The v4l2-ctl tool is used to control video4linux devices, either video,
vbi, radio or swradio, both input and output. It is able to control al-
most any aspect of such devices covering the full V4L2 API.
OPTIONS
-d, --device <dev>
Use device <dev> as the V4L2 device. if <dev> starts with a
digit, then /dev/video<dev> is used Otherwise if -z was speci-
fied earlier, then <dev> is the entity name or interface ID (if
prefixed with 0x) as found in the topology of the media device
with the bus info string as specified by the -z option.
-v, --verbose
Turn on verbose reporting.
--version
Show version information.
-w, --wrapper
Use the libv4l2 wrapper library for all V4L2 device accesses. By
default v4l2-ctl will directly access the V4L2 device, but with
this option all access will go via this wrapper library.
-h, --help
Prints the help message.
--help-io
Prints the help message for all options that get/set/list inputs
and outputs, both video and audio.
--help-misc
Prints the help message for miscellaneous options.
--help-overlay
Prints the help message for all options that get/set/list over-
lay and framebuffer formats.
--help-sdr
Prints the help message for all options that get/set/list soft-
ware defined radio formats.
--help-selection
Prints the help message for all options that deal with selec-
tions (cropping and composing).
--help-stds
Prints the help message for all options that deal with SDTV
standards and Digital Video timings.
--help-streaming
Prints the help message for all options that deal with stream-
ing.
--help-subdev
Prints the help message for all options that deal with v4l-sub-
devX devices.
--help-tuner
Prints the help message for all options that deal with tuners
and modulators.
--help-vbi
Prints the help message for all options that get/set/list VBI
formats.
--help-vidcap
Prints the help message for all options that get/set/list video
capture formats.
--help-vidout
Prints the help message for all options that get/set/list video
output formats.
--help-edid
Prints the help message for all options that get/set EDIDs.
--help-all
Prints the help message for all options.
--all Display all information available.
-C, --get-ctrl <ctrl>[,<ctrl>...]
Get the value of the controls [VIDIOC_G_EXT_CTRLS].
-c, --set-ctrl <ctrl>=<val>[,<ctrl>=<val>...]
Set the value of the controls [VIDIOC_S_EXT_CTRLS].
-D, --info
Show driver info [VIDIOC_QUERYCAP].
-e, --out-device <dev>
Use device <dev> for output streams instead of the default de-
vice as set with --device. If <dev> starts with a digit, then
/dev/video<dev> is used. Otherwise if -z was specified earlier,
then <dev> is the entity name or interface ID (if prefixed with
0x) as found in the topology of the media device with the bus
info string as specified by the -z option.
-E, --export-device <dev>
Use device <dev> for exporting DMA buffers. If <dev> starts
with a digit, then /dev/video<dev> is used. Otherwise if -z was
specified earlier, then <dev> is the entity name or interface ID
(if prefixed with 0x) as found in the topology of the media de-
vice with the bus info string as specified by the -z option.
-z, --media-bus-info <bus-info>
Find the media device with the given <bus-info> string. If set,
then -d, -e and -E options can use the entity name or interface
ID to refer to the device nodes. Example: v4l2-ctl -z plat-
form:vivid-000 -d vivid-000-vid-cap
-k, --concise
Be more concise if possible.
-l, --list-ctrls
Display all controls and their values [VIDIOC_QUERYCTRL].
-L, --list-ctrls-menus
Display all controls and their menus [VIDIOC_QUERYMENU].
-r, --subset <ctrl>[,<offset>,<size>]+
The subset of the N-dimensional array to get/set for control
<ctrl>, for every dimension an (<offset>, <size>) tuple is
given.
--list-devices
List all v4l devices. If -z was given, then list just the de-
vices of the media device with the bus info string as specified
by the -z option.
--log-status
Log the board status in the kernel log [VIDIOC_LOG_STATUS].
--get-priority
Query the current access priority [VIDIOC_G_PRIORITY].
--set-priority <prio>
Set the new access priority [VIDIOC_S_PRIORITY]. <prio> is 1
(background), 2 (interactive) or 3 (record).
--silent
Only set the result code, do not print any messages.
--sleep <secs>
Sleep <secs>, call QUERYCAP and close the file handle.
EXIT STATUS
On success, it returns 0. Otherwise, it will return the error code.
EXAMPLES
Query the device information of /dev/video1:
v4l2-ctl -d1 -D
Stream video using MMAP stream I/O from /dev/video0:
v4l2-ctl -d0 --stream-mmap
Stream one frame of video from /dev/video0 and store it in a file:
v4l2-ctl --stream-mmap --stream-count=1 --stream-to=file.raw
Stream video from /dev/video0 and stream it over the network:
v4l2-ctl --stream-mmap --stream-to-host <hostname>
Use 'qvidcap -p' on the host to view the video.
Stream video from /dev/video0 using DMABUFs exported from /dev/video2:
v4l2-ctl --stream-dmabuf --export-device /dev/video2
Stream video from a memory-to-memory device:
v4l2-ctl --stream-mmap --stream-out-mmap
Stream video from a capture video device (/dev/video1) to an output
video device (/dev/video2):
v4l2-ctl -d1 --stream-mmap --out-device /dev/video2 --stream-out-
dmabuf
BUGS
This manual page is a work in progress.
Bug reports or questions about this utility should be sent to the
linux-media@vger.kernel.org mailinglist.
v4l-utils 1.22.1 March 2015 V4L2-CTL(1)
Generated by dwww version 1.14 on Fri Jan 24 06:16:46 CET 2025.