webcam_linux.md

Webcams in linux

(Personally, I've got a cheap Logitech C615 and a fancier C930e. Well, plus a C920S which I'm getting to replace the C615.)

The main software to control the settings on these cameras is v4l2-ctl. Here's a relevant blog post and the man page

• install software:

  sudo apt update
  sudo apt install v4l-utils
  

• list devices

  v4l2-ctl --list-devices
  
  # HD Webcam C615 (usb-0000:00:14.0-5.1.6):
  #   /dev/video0
  #   /dev/video1
  

• list controls

  v4l2-ctl -d /dev/video0 --list-ctrls
  

  Note: can also use -d 0 or just leave that off if /dev/video0

  I'm most interested in focus_auto and exposure_auto

  v4l2-ctl -d /dev/video0 --set-ctrl=focus_auto=0
  v4l2-ctl -d /dev/video0 --set-ctrl=exposure_auto=1
  
  v4l2-ctl -d /dev/video0 --set-ctrl=white_balance_temperature_auto=0
  v4l2-ctl -d /dev/video0 --set-ctrl=white_balance_temperature=3200
  
  v4l2-ctl --set-ctrl=zoom_absolute=2
  

• list possible resolutions

  v4l2-ctl --list-framesizes=YUYV
  
  

• set resolution

  v4l2-ctl --set-fmt-video=width=960,height=720,pixelformat=YUYV
  

  I can't really see whether this works

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GUI guvcview

I also added guvcview via pop-shop; it gives the same control with a GUI and with ability to preview what you're doing.