I have a video in which a person is speaking something. He is right in the middle of the frame. I want to blur out all of his surroundings like you have when you shoot a photograph or a video with a shallow depth of field. I am in post-production.
I am using Sony Vegas Movie Studio 11 HD.
If the shape to be blurred was rectangular, I could overlay two duplicate tracks and blur out the section from the frames in the top track, but I want to blur out everything around the person's body, which happens not to be a geometrically named shape.
How do I do that?