Timelapse screen capture for macOS

capture_timelapse.sh

# Start a 1fps screen capture to `~/Movies/timelapse - <end-datetime>.webm`.
# Requires ffmpeg+libvpx installed: `brew install ffmpeg`.
# Press `q` to stop.
capture_timelapse() {
  local output="$HOME/Movies/timelapse - $(date '+%y-%m-%d %H%M%S').webm"
  local device=$(set +e +o pipefail; ffmpeg -f avfoundation -list_devices true -i '' 2>&1 | sed -En 's#^.*\[([a0-9]+)\] Capture screen 0#\1#p'; true)
  if [ -n "$device" ]
  then
    printf 'Capturing timelapse to "%s"…\nPress Q to stop.\n' "$output"
    ffmpeg \
      -hide_banner \
      -loglevel panic \
      -f avfoundation \
      -i "$device:none" \
      -r 30 \
      -filter:v "setpts=PTS/30" \
      "$output"
  fi
}