I have been trying to overlay graphics on a video using Blender (2.77), and part of that is setting the source movie as a background in the 3D view. As I was setting the movie clip (and getting frustrated trying to sync the times between the timeline and the VSE), I started wondering what the "Camera Clip" checkbox does in the "Movie Clip" tab. The tooltip says "Use Movie Clip from Active Scene Camera", but I don't know how to add a movie clip to the active scene camera except to add one as a "Background Image".
I've looked through lots of help articles and done lots of searches, but no one seems to have written a plain explanation of this checkbox. Can anyone please provide some insight?