add Timestamp to Video

ffmpeg -i <video_in>.mp4 \ 
	-vf  "drawtext = fontfile=/usr/share/fonts/truetype/dejavu/DejaVuSerif.ttf: text = '%{pts:gmtime:0:%M\\\\:%S}':\x=80: y=125: fontsize=48: fontcolor=white@1.0: box=1: boxcolor=black@1.0" \
    	<video_out>.mp4