About me: My name is Solène Rapenne, pronouns she/her. I like learning and sharing knowledge. Hobbies: '(BSD OpenBSD h+ Lisp cmdline gaming internet-stuff). I love percent and lambda characters. OpenBSD developer solene@.

Contact me: solene on Freenode, solene+www at dataswamp dot org or solene@bsd.network (mastodon). If for some reason you want to give me some money, I accept paypal at the address donate@perso.pw.

Crop a video using ffmpeg

Written by Solène, on 20 December 2019.
Tags: #ffmpeg

Comments on Mastodon

If you ever need to crop a video, which mean that you want to reduce the area of the video to a square of it to trim areas you don’t want.

This is possible with ffmpeg using the video filter crop. To make the example more readable, I replaced values with variables names:

  • WIDTH = width of output video
  • HEIGHT = height of output video
  • START_LEFT = relative position of the area compared to the left, left being 0
  • START_TOP = relative position of the area compared to the top, top being 0

So the actual commands look like

ffmpeg -i input_video.mp4 -filter:v "crop=$WIDTH:$HEIGHT:$START_LEFT:$START_TOP" output_video.mp4

If you want to crop the video to get a 320x240 video from the top-left position 500,100 the command would be

ffmpeg -i input_video.mp4 -filter:v "crop=320:240:500:100" output_video.mp4