broadcast

#!/usr/bin/env bash
# share the entire screen (X11) to v4l2 loopback device
# if file is passed then broadcast that instead

if [[ "$#" -eq 1 ]] ; then
  if [[ -r "$1" ]] ; then
    mimetype=$(file --mime-type "$1" | cut -d' ' -f2)
    if [[ "$mimetype" == "video/"* ]] ; then
      echo "Broadcasting file $1"
      command=(ffmpeg -re -i "$1" -f v4l2 -vcodec rawvideo -pix_fmt yuv420p)
    elif [[ "$mimetype" == "image/"* ]] ; then
      echo "Broadcasting image $1"
      command=(ffmpeg -loop 1 -re -i "$1" -f v4l2 -vcodec rawvideo -pix_fmt yuv420p)
    else
      echo "File $1 is not a video"
      exit 1
    fi
  else
    echo "File $1 not found"
    exit 1
  fi
else
  command=(ffmpeg -stream_loop -1 -f x11grab -framerate 60 -video_size 1920x1080 -i ":0.0+0,0" -f v4l2 -vcodec rawvideo -pix_fmt yuv420p)
fi

for device in /dev/video* ; do
    if [ -c "$device" ] ; then
      echo "Broadcasting to $device"
      "${command[@]}" "$device"
      if [[ $? -eq 0 || $? -eq 255 ]] ; then
        exit 0
      fi
    fi
done
echo "No video devices found"