Force focus on webcams (because autofocus is 💩 sometimes)

fixedfocus.sh

#!/bin/sh

setcam() {
  FOCUS=$1
  echo "Configuring camera $NAME on /dev/$DEV."
  echo "Setting fixed focus to $FOCUS."
  v4l2-ctl --device /dev/$DEV -c focus_auto=0
  v4l2-ctl --device /dev/$DEV -c focus_absolute=$FOCUS
  echo "Setting power line frequency to 50Hz."
  v4l2-ctl --device /dev/$DEV -c power_line_frequency=1
}

cd /sys/class/video4linux
for DEV in *; do
  # Only work with device index=0
  # (the other indexes are typically metadata devices,
  # we don't care about them)
  grep -q ^0$ $DEV/index || continue
  NAME=$(cat $DEV/name)
  case $NAME in
    "HD Pro Webcam C920")
      setcam 30
      ;;
    "Logitech StreamCam")
      setcam 20
      ;;
    "Razer Kiyo")
      setcam 180
      ;;
    *)
      echo "Skipping unknown camera $NAME on /dev/$DEV."
      ;;
  esac
done