How to remove an image that's inserted into a video?

I have a video that has an added image (in this case a star) to block part of the video. I need to see what's behind this star.

What kind of program can reveal the original video footage? I tried a normal video editor but there's nothing in the video track that I can remove.

Any help will be much appreciated.

To be more clearer, the video is of a person talking. And the person that edited this video added an effect or image to block something that's on the wall behind this person.