Resizing Videos with if Statement in ffmpeg: A Comprehensive Guide
The ffmpeg tool is a powerful command-line video editing tool that can be used to perform various operations on video files, including resizing.
The if statement in ffmpeg allows you to conditionally apply a filter to a video based on a specified condition. This can be useful for tasks such as resizing videos only if they meet certain criteria.
1. Resizing Videos with a Height Greater than 480p
To resize videos whose height is 480p or more, you can use the following command:
-i input.mp4 -c:v libx264 -crf 31 -me_method umh -bf 0 -vf scale='if(gte(ih\,480)\,480\,iw)':-2 out.mp4
This command will rescale videos whose height is 480 or more. The scale filter is used to resize the video, and the if statement is used to conditionally apply the filter based on the height of the video.
2. Checking if Height is Greater than 480p
To check if the height of a video is greater than 480p, you can use the following command:
-vf scale=-2:'if(gte(ih\,480)\,480\,0)'
This command will use the scale filter to resize the video if its height is greater than 480p. If the height is not greater than 480p, the scale filter will not be applied.
3. Avoiding Upscaling
To avoid upscaling videos, you can use the following command:
-vf "scale=-2:'min(480,ih)'"
This command will use the scale filter to resize the video to a maximum height of 480p. If the video's height is already less than 480p, it will not be resized.
Conclusion
The if statement in ffmpeg is a powerful tool that can be used to conditionally apply filters to videos based on a specified condition. This can be useful for tasks such as resizing videos only if they meet certain criteria.