# given a course video that is 16:9
# that contains a video that is 24:9
# where the inner video is letterboxed
# but the bottom bar is slightly thicker
# crop the center of the inner video out
# assuming a 25:9 aspect ratio to account
# for the odd-sized bars so that you end up
# with a 16:9 non-letterboxed video

target_width="(in_w*16)/25" # in_w is an ffmpeg var representing the input width
target_height="(in_h*16)/25" # in_h is an ffmpeg var representing the input height
ffmpeg -y -i green-bar-input.mp4 -aspect 16:9 \
    -vf "crop=${target_width}:${target_height}:(in_w/2) - (${target_width}/2):(in_h/2) - (${target_height}/2), scale=-1:ih" \
    output-cropped.mp4