How To Blur A Whole Movie Clip?

Hi Buddies!

Hope all of you are doing great.

Could any body please describe How To Blur A Whole Movie Clip? Specially when the movie starts normally and on some action or from specific keframe, it satrts blurring?

I am really curiouse to know this. Could any one please help?

Thank you.

To Your Success!

The Blut