Crop, scale and compress a video

ffmpeg_center_crop_and_scale.sh

# Crop such that the output is heightxheight. Then scale to 640:640. finally videeo compression ("28", higher is more compression)
ffmpeg -i intput -filter:v "crop=ih:ih,scale=640:-2" -crf 28  output.mp4

# Split a video to 280 sec segments
ffmpeg -i input.mp4 -acodec copy -f segment -segment_time 280 -vcodec copy -reset_timestamps 1 -map 0 output_%d.mp4

# Crop with side by side merge (https://stackoverflow.com/questions/35349935/ffmpeg-crop-with-side-by-side-merge)
ffmpeg -i in0.mp4 -i in1.mp4 -filter_complex "[0:v]crop=iw/2:ih:0:0[left];  [1:v]crop=iw/2:ih:ow:0[right]; [left][right]hstack" output.mp4