video target tracking?

Have an idea for a current project but before i start would like to get feedback.

2D image tracking allows you to track an image in your scene that is either stationary or moving.


Instead of an image I need to track a stationary video screen, replacing the content that appears on the video screen with augmented content and videos.


Can anyone suggest how this might be accomplished?


Does it help that the size or format of the video screen is always a 16:9 ratio (ie 1920x1080)?