v4l2-ctl
TLDR
List all video devices
$ v4l2-ctl --list-devices
List supported formats and resolutions$ v4l2-ctl --list-formats-ext
List formats for specific device$ v4l2-ctl -d /dev/video0 --list-formats-ext
Show all details of a device$ v4l2-ctl -d /dev/video0 --all
List controls and their values$ v4l2-ctl -d /dev/video0 --list-ctrls
Set control value$ v4l2-ctl -d /dev/video0 --set-ctrl brightness=128
Capture a JPEG photo$ v4l2-ctl -d /dev/video0 --set-fmt-video=width=1920,height=1080,pixelformat=MJPG --stream-mmap --stream-to=photo.jpg --stream-count=1
Capture video stream$ v4l2-ctl -d /dev/video0 --stream-mmap --stream-to=video.raw --stream-count=100
SYNOPSIS
v4l2-ctl [-h] [-d dev] [options]
DESCRIPTION
v4l2-ctl is used to control video4linux devices, including video, VBI, radio, and swradio devices, both input and output. It provides access to nearly all V4L2 API functionality for querying and configuring video devices.
PARAMETERS
-d, --device DEV
Specify target video device (default: /dev/video0)-D, --info
Display driver capabilities--all
Show comprehensive device information--list-devices
List all video devices--list-formats-ext
List supported formats with frame sizes-l, --list-ctrls
List all available controls-C, --get-ctrl
Get control value-c, --set-ctrl
Set control value--set-fmt-video
Set video capture format (width, height, pixelformat)--stream-mmap
Capture using memory-mapped I/O--stream-dmabuf
Capture using DMA buffers--stream-to FILE
Write captured stream to file--stream-count N
Capture N frames-e, --out-device DEV
Specify output device for streaming-v, --verbose
Enable detailed output--help-all
Show complete option documentation
CAVEATS
The default device is /dev/video0 if not specified. Format settings must match device capabilities. Raw video output requires conversion with tools like ffmpeg for playback.
HISTORY
v4l2-ctl is part of the v4l-utils package, providing user-space utilities for Video4Linux2 API devices on Linux systems.
SEE ALSO
v4l2-compliance(1), ffmpeg(1), cheese(1)
