| Title: Crop a video using ffmpeg | |
| Author: Solène | |
| Date: 20 December 2019 | |
| Tags: ffmpeg | |
| Description: | |
| 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 |