Webcam

This article is a stub. Please help out by expanding it - how to get started.

Resources

Wikipedia

This article has some todo items:

Check kernel options

This article will provide information on setting up and using a webcam on Gentoo using v4l-utils.

Installation

Kernel

KERNEL Enable Webcam support

Device Drivers --->
  LED Support --->
    {*} LED Class Support Search for <code>CONFIG_LEDS_CLASS</code> to find this item.
    <*> LED Flash Class Support Search for <code>CONFIG_LEDS_CLASS_FLASH</code> to find this item.
  <*> Multimedia support Search for <code>CONFIG_MEDIA_SUPPORT</code> to find this item. --->
    [*] Filter media drivers Search for <code>CONFIG_MEDIA_SUPPORT_FILTER</code> to find this item.
    Media device types --->
      [*] Cameras and video grabbers Search for <code>CONFIG_CAMERA_SUPPORT</code> to find this item.
    Video4Linux options --->
      <M> V4L2 flash API for LED flash class devices Search for <code>CONFIG_V4L2_FLASH_LED_CLASS</code> to find this item.
    Media drivers  ---> 
      [*] Media USB Adapters Search for <code>CONFIG_MEDIA_USB_SUPPORT</code> to find this item. ---> 
        <M> USB Video Class (UVC) Search for <code>CONFIG_USB_VIDEO_CLASS</code> to find this item.
        [*] UVC input events device support Search for <code>CONFIG_USB_VIDEO_CLASS_INPUT_EVDEV</code> to find this item.

Note
To enable sound on webcams equipped with a microphone, separate options, such as "USB Audio/MIDI driver" (CONFIG_SND_USB_AUDIO), may need to be configured.

USE flags

Recommended USE flags for v4l include: opengl, qt5, and udev - at least qt5 will be needed to follow on with this article.

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: 2024-12-31 09:07 More information about USE flags

Emerge

Install media-libs/libv4l:

root #emerge --ask media-libs/libv4l

Additional software

There are several webcam viewer applications in the Gentoo ebuild repository, a few examples are:

Name	Package	Description
Cheese	media-video/cheese	Cheesy program to take pictures and videos from a webcam.
guvcview	media-video/guvcview	Simple Qt5 or GTK+3 interface for capturing and viewing video from v4l2 devices.
kamoso	kde-apps/kamoso	Application to take pictures and videos from a webcam, by KDE.
Motion	media-video/motion	Software motion detector.

Media players like VLC or mpv may be used to view or sometimes record video from a webcam.

See media-video for more video software.

Configuration

v4l-utils is used here to check/set the camera's preferences.

Configuration GUI and settings test

Launch the v4l GUI:

user $qv4l2

Note
The availability of the preceding command depends on the qt5 flag for the media-tv/v4l-utils package.

Get settings from video device

Example of using the video4linux control application to display supported video formats:

user $v4l2-ctl --list-formats-ext

Settings example

Some Cheap USB Cameras (like integrated models in thinkpad latops) always use a 640x480 resolution but are able to use 720p, it is possible to set this in v4l2-ctl:

user $v4l2-ctl --set-parm=30 --set-fmt-video=width=1280,height=720,pixelformat=MJPG --device /dev/video0

Explanation

--set-parm = Framerate (integer)

--set-fmt-video = Resolution + Compression

Check settings

Launch the v4l2 video capture viewer to test if the settings are working:

user $qvidcap

Note
The availability of the preceding command depends on the qt5 flag for the media-tv/v4l-utils package.

Make options persistent

Getting device info:

root #lsusb | grep Cam

Bus 003 Device 007: ID '''5986''':'''0268''' Acer, Inc SunplusIT INC. Integrated Camera

Creating a rule:

FILE /etc/udev/rules.d/99-v4linux.rulesExample udev rule

SUBSYSTEM=="video4linux", SUBSYSTEMS=="usb", ATTRS{idVendor}=="5986", ATTRS{idProduct}=="0268", PROGRAM="/usr/bin/v4l2-ctl --set-parm=30 --set-fmt-video=width=1280,height=720,pixelformat=MJPG --device /dev/%k"