Table of Contents

ffmpeg - Video - Crop

Crop a video

ffmpeg -i input.mp4 -filter:v "crop=out_w:out_h:x:y" out.mp4
 
ffmpeg -i input.mp4 -filter:v "crop=850:540:0:50" out.mp4

NOTE: The options are:

  • out_w - the width of the output rectangle.
  • out_h - the height of the output rectangle
  • x and y - specify the top left corner of the output rectangle (coordinates start at (0,0) in the top left corner of the input).

WARNING: The top & bottom, left & right margin values should not conflict.

  • For example, for a video of 300px height, when crop top margin = 200px, bottom margin cannot be more than 300-200 = 100px.
  • Otherwise, the output will be an empty video file.

Crop video using cuda acceleration (-hwaccel cuvid)

Pass the -crop flag with margins: top x bottom x left x right. 

ffmpeg -y -hwaccel cuvid -c:v h264_cuvid -crop 50x50x0x430 -i input.mp4 -c:v h264_nvenc output.mp4

NOTE: This crops the input video to the rectangle bounded by lines 50px from top and bottom side, 430px from right side, and left side of original video.