How to make vertical video with blurred background sides?

Hi, how I can make video explained here: https://stackoverflow.com/questions/30789367/ffmpeg-how-to-convert-vertical-video-with-black-sides-to-video-169-with-blur Thanks in advance.

[shanginn]

I did it like this:

with VideoFileClip(video_path) as video:
    if video.aspect_ratio < 1.7:
        video.write_videofile(
            new_video_path,
            ffmpeg_params=['-lavfi', '[0:v]scale=ih*16/9:-1,boxblur=luma_radius=min(h\,w)/20:luma_power=1:chroma_radius=min(cw\,ch)/20:chroma_power=1[bg];[bg][0:v]overlay=(W-w)/2:(H-h)/2,crop=h=iw*9/16']
        )

[keikoro]

Would anyone who commented or reacji’d on this issue create an example as suggested earlier? @shanginn, perhaps?