add text to video ffmpeg code example

Example: embeed text into video ffmpeg

ffmpeg -i input.mp4 -vf drawtext="fontfile=/path/to/font.ttf: \
text='Stack Overflow': fontcolor=white: fontsize=24: box=1: [email protected]: \
boxborderw=5: x=(w-text_w)/2: y=(h-text_h)/2" -codec:a copy output.mp4