Ability to crop incoming video capture

The Tile Pro output on the Xi has a picture in picture mode, where we can display an overlay.

In the Mock OR we can capture the vidoe feed straight from the DaVinci, but in situations where we use the Tile Pro the output that we capture on the laptop will be the raw feed + all the menus and picture in picture bits (which creates a recursive stream). Ideally we should be able to crop the incoming video feed to exclude all the tile pro stuff we don't want.

Example:

We want to just crop out the top part, which is the daVinci video input. This will be tricky, as the Tile Pro picture in picture has an adjustable size, so the area which we need to crop can change.