How to cut a video in equal pieces

Sometimes I need a quick way to cut a video into smaller pieces.

For example Instagram used to allow you to post an Instagram (Video) Story that takes max 15 seconds.
So if you have a 2min long video, it’s interesting to cut this (long) video in smaller chunks.

Steps

1. Download ffmpeg
   This basically a OpenSource video manipulation tool
2. Use this oneliner to cut it into pieces
   

   ffmpeg -i longvideo.mp4 -c copy -map 0 -segment_time 00:00:15 -f segment smaller_part%03d.mp4