Calculate time sum of all mp4 files in current directory and subdirectories in bash

find . -iname "*.mp4" -exec \
ffprobe -v quiet -of csv=p=0 -show_entries format=duration "{}" ';' | \
awk '{sum += $1}; END{printf "%dhrs %02dmin %02dsec\n", sum/3600, (sum/60)%60, sum%60}'

Example output of 65h course:

65hrs 28min 22sec