I am having trouble figuring out how to deal with a problem of a person moving their shoulder and hand in front of a TV monitor, which I need to place video into. I have managed to insert the video everywhere except in this clip. Is it possible to create a moving mask (to accommodate for the camera moves), and then insert a video into it? Please help!:) Thanks!
It's a two-stage process, and there are two possible variations of the second stage.
First step is to motion-track your insert video on top of the background, so that it matches the movement of the TV screen. Then you *either* use animated masks to hide the parts of the video that need to be covered up by the shoulder and hand, *or* you duplicate your background, put it on top of your motion-tracked insert video, and use animated masks to comp just the hand and shoulder back over the top of the insert video.
The second variation of stage 2 is probably the simplest, because it's easier to see where you need to draw your masks. As far as animating the masks goes, you just draw the first one, turn on keyframe recording, step forward a frame, reposition the mask control points as necessary, step forward again, and repeat until bored ;)