How to crop a video with ffmpeg

About

This article shows you how to crop ¹⁾ a video with ffmpeg.

The crop filter

once you have installed it, you can use the crop filter to crop your video.

the crop is a filter that accepts the parameters such as the following

• w, out_w: the width of the output video.
• h, out_h: The height of the output video
• x: The horizontal position, in the input video, of the left edge of the output video.
• y: The vertical position, in the input video, of the top edge of the output video.
• … more see the documentation ²⁾

How to

How to crop towards the center ?

By default, ffmpeg will crop towards the center if the positions of the output egde are not given.

Crop the central input area with size 100×100:

• crop option by position

ffmpeg -i "input.mp4" -vf crop=100:100 "output.mp4"

• crop option by name

ffmpeg -i "input.mp4" -vf crop=w=100:h=100 "output.mp4"

How to crop an area at a position ?

Crop area with size 100×100 at position (12,34). ³⁾

• crop option by position

ffmpeg -i "input.mp4" -vf crop=100:100:12:34 "output.mp4"

• crop option by name

ffmpeg -i "input.mp4" -vf crop=w=100:h=100:x=12:y=34 "output.mp4"

How to crop the black areas ?

The standard procedure to eliminate these black areas is to run first the cropdetect filter ⁴⁾ and then run the crop filter.

Example: ⁵⁾ Find video area surrounded by black borders

ffmpeg -i file.mp4 -vf cropdetect,metadata=mode=print -f null -