A blured black and white mask is created and used to create a blurred edge around the video.
The blur may be used throughout the video or at any speciffied point.

In this example the same image is used in during the entire video.

----------- all the commands may be used in a bash script file ------------
ffmpeg -i vids/1280x720.mp4 -loop 1 -i images/mask.png -filter_complex "[0:v][1:v]alphamerge,hue=s=0,boxblur=8[fg]; \
 [0:v][fg]overlay[v]" -map "[v]" -map 0:a -c:a copy -t 30 vids/boxblur30r.mp4

Overlay Videos With Image - Cover video with Frame Image

In this video example we will cover an entire video with a 8mm frame Image with existing sound

This example uses a frame image

The video has a loop of the 'film' image over the entire video. This could of
course be changed to different images.

ffmpeg -i vids/1280x720.mp4 -i film-overlay.png -filter_complex \
"[0:v][1:v] overlay=(W-w)/2:(H-h)/2:enable='between(t,0,30)'" \
-pix_fmt yuv420p -c:a -t 30 copy vids/video-film-frame.mp4