scripts/camera-setup.sh

#!/usr/bin/env bash
# Re-apply camera settings for the stand (they reset when a camera is replugged).
# Cameras are found by USB port, so this works even if /dev/videoN numbers shift.
set -euo pipefail

declare -A PORTS=( [left]=3-12 [right]=3-11 [grip]=3-13.1 )

find_dev() {  # print the /dev/videoN capture node for a USB port
  for d in /sys/class/video4linux/video*; do
    [[ "$(basename "$(readlink -f "$d/device")")" == "$1:1.0" ]] || continue
    [[ "$(cat "$d/index")" == 0 ]] && { echo "/dev/$(basename "$d")"; return; }
  done
}

for name in left grip right; do
  dev=$(find_dev "${PORTS[$name]}")
  [[ -n "$dev" ]] || { echo "$name: not found on USB ${PORTS[$name]}" >&2; continue; }
  v4l2-ctl -d "$dev" -c power_line_frequency=2            # 60 Hz mains
  if [[ $name == grip ]]; then
    v4l2-ctl -d "$dev" -c brightness=-16 -c backlight_compensation=0   # stop jaws blowing out
  fi
  echo "$name -> $dev ($(cat /sys/class/video4linux/$(basename "$dev")/name))"
done