Show the keyframe indices in a video using ffprobe

showkeyframes.sh

show_keyframes() {
    ffprobe -loglevel error -select_streams v -show_frames -show_entries frame=pict_type -of csv $1 | grep -n I | cut -d ':' -f 1
}

# use like
# $ show_keyframes /tmp/video.mp4
# 1
# 31
# 61
# 91
# 121
# 151
# 181
# 211
# 241
# 271
# 301