For a recent work project, I had to downscale a video to a fixed size to fit into our application as designed. Though I didn’t know the exact options, I new this was a perfect task for my good friend ffmpeg.

ffmpeg -i input.mp4 -vf "scale=400:600:force_original_aspect_ratio=decrease,pad=400:600:(ow-iw)/2:(oh-ih)/2:0xEFEFEF" output.mp4

Below is an explanation of each of the options in the above command:

• scale=400:600 - Scales the video to 400px wide by 600px tall.
• force_original_aspect_ratio=decrease - Downscales the video to the specified size while maintaining the original aspect ratio.
• pad=400:600 - Adds padding to the video to achieve the target resolution, filling the extra space with a specified color.
  • (ow-iw)/2:(oh-ih)/2 - Centers the video horizontally and vertically. ow is the output width, iw is the input width, etc.
  • color=0x0000FF - Specifies the padding color.