ffmpeg

crop to portions

ffmpeg -i in.mp4 -filter:v "crop=720:320:0:320" -c:a copy out-1.mp4
ffmpeg -i in.mp4 -filter:v "crop=720:320:320:640" -c:a copy out-2.mp4
ffmpeg -i in.mp4 -filter:v "crop=720:320:640:960" -c:a copy out-3.mp4
ffmpeg -i in.mp4 -filter:v "crop=720:320:960:1280" -c:a copy out-4.mp4
ffmpeg -i in.mp4 -filter:v "crop=720:320:1280:1600" -c:a copy out-5.mp4

References:

https://video.stackexchange.com/questions/4563/how-can-i-crop-a-video-with-ffmpeg

https://stackoverflow.com/questions/28806816/use-ffmpeg-to-resize-image