v4l-utils

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v4l-utils is a set of utilities for handling media devices contained in the Video4Linux library package which can be installed by enabling the utils USE flag.

See also
See the webcam article for instructions on how to use v4l-utils to set up a webcam for video capture.

Installation

USE flags

USE flags for media-libs/libv4l v4l-utils libraries and optional utilities

+utils	Build the v4l-utils collection of utilities
bpf	Enable support for IR BPF decoders
doc	Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally
dvb	Add support for DVB (Digital Video Broadcasting)
jpeg	Add JPEG image support
qt6	Add support for the Qt 6 application and UI framework
tracer	Build the v4l2-tracer tool and library

Data provided by the Gentoo Package Database · Last update: 2025-02-15 15:51 More information about USE flags

Emerge

Install media-libs/libv4l:

root #emerge --ask media-libs/libv4l

Additional packages

gtk-v4l

The GTK+ package media-tv/gtk-v4l is available for controlling webcam v4l preferences.

USE flags for media-tv/gtk-v4l A GTK+ application for controlling V4L preferences of a web cam device

Data provided by the Gentoo Package Database · Last update: 2021-11-25 15:42 More information about USE flags

v4l-dvb-saa716x

A driver for saa716x-based dvb cards is available at media-tv/v4l-dvb-saa716x.

USE flags for media-tv/v4l-dvb-saa716x driver for saa716x based dvb cards like TT S2-6400 or Skystar 2 eXpress HD

+strip	Allow symbol stripping to be performed by the ebuild for special files
dist-kernel	Enable subslot rebuilds on Distribution Kernel upgrades
modules-compress	Install compressed kernel modules (if kernel config enables module compression)
modules-sign	Cryptographically sign installed kernel modules (requires CONFIG_MODULE_SIG=y in the kernel)

Data provided by the Gentoo Package Database · Last update: 2024-06-23 19:43 More information about USE flags

v4l2loopback

media-video/v4l2loopback provides a v4l2 loopback device whose output is its own input.

USE flags for media-video/v4l2loopback v4l2 loopback device whose output is its own input

+strip	Allow symbol stripping to be performed by the ebuild for special files
dist-kernel	Enable subslot rebuilds on Distribution Kernel upgrades
examples	Install examples, usually source code
modules-compress	Install compressed kernel modules (if kernel config enables module compression)
modules-sign	Cryptographically sign installed kernel modules (requires CONFIG_MODULE_SIG=y in the kernel)

Data provided by the Gentoo Package Database · Last update: 2024-03-23 06:35 More information about USE flags

gst-plugins-v4l2

Finally, a gstreamer plugin package is available: media-plugins/gst-plugins-v4l2.

USE flags for media-plugins/gst-plugins-v4l2 plugin for gstreamer

udev	Enable virtual/udev integration (device discovery, power and storage device support, etc)

Data provided by the Gentoo Package Database · Last update: 2025-02-08 10:29 More information about USE flags

Usage

Invocation

user $v4l2-ctl --help

Expand

General/Common 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]
  -d, --device <dev> use device <dev> instead of /dev/video0
                     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, --out-device <dev> use device <dev> for output streams instead of the
                     default device 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 device 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.
  -h, --help         display this help message
  --help-all         all options
  --help-io          input/output options
  --help-meta        metadata format options
  --help-misc        miscellaneous options
  --help-overlay     overlay format options
  --help-sdr         SDR format options
  --help-selection   crop/selection options
  --help-stds        standards and other video timings options
  --help-streaming   streaming options
  --help-subdev      sub-device options
  --help-tuner       tuner/modulator options
  --help-vbi         VBI format options
  --help-vidcap      video capture format options
  --help-vidout      vidout output format options
  --help-edid        edid handling options
  -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.
  -w, --wrapper      use the libv4l2 wrapper library.
  --list-devices     list all v4l devices. If -z was given, then list just the
                     devices 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
  --verbose          turn on verbose ioctl status reporting

libcamera

media-libs/libcamera is available in GURU from various overlays.

Removal

Unmerge

root #emerge --ask --depclean --verbose media-libs/libv4l

See also

• darktable — a photography workflow application and RAW developer.
• Droidcam — a tool to use a smartphone's cameras as webcam on a computer
• Ffmpeg — a cross platform, free, open source media encoder/decoder toolkit.
• gPhoto
• Jellyfin — installation and management of the jellyfin media server
• Kodi — an open source home theater application.
• Motion
• MythTV — a powerful media center and video recording software system.
• OBS Studio — free software for video recording and live streaming.
• OpenShot — an open source, cross-platform, video editor, written in Python and C++
• Streamlink — a command-line utility that can extract video streams and pipe them into a video player.
• TV Tuner — configuring and using television (TV) tuners with Gentoo Linux

External resources

• Part I - Video for Linux API - the V4L2 API kernel specification.
• Video for Linux version 2 (V4L2) examples