ffmpeg -f x11grab -video_size 1600x900 -framerate 30 -i :0.0 \
-f v4l2 -video_size 320x240 -framerate 30 -i /dev/video0 \
-f alsa -ac 2 -i pulse -filter_complex \
"[0:v]scale=1024:-1,setpts=PTS-STARTPTS[bg]; \
 [1:v]scale=120:-1,setpts=PTS-STARTPTS[fg]; \
 [bg][fg]overlay=W-w-10:10,format=yuv420p[out]" \
-map "[out]" -map 2:a $STREAM_URL