ffmpeg -i input.mp4 -vf "drawtext=fontfile='/Users/joel/Library/Fonts/Calderock Inky.ttf':text='%{eif\:(NNN-t)/60\:d\:2}\:%{eif\:mod(NNN-t,60)\:d\:2}':fontcolor=white:fontsize=48:x=570:y=1100" -c:a copy output.mp4
where NNN = video length
learn • do • know
ffmpeg -i input.mp4 -vf "drawtext=fontfile='/Users/joel/Library/Fonts/Calderock Inky.ttf':text='%{eif\:(NNN-t)/60\:d\:2}\:%{eif\:mod(NNN-t,60)\:d\:2}':fontcolor=white:fontsize=48:x=570:y=1100" -c:a copy output.mp4
where NNN = video length