How to mask footage video with text?
Thats rather simple if I understand correctly what you want to achieve. One way to do it is to right click your text layer and choose the "Create Masks from Text" option. Then pre-comp your video layer and copy the masks your just created (AE creates a new solid that contains the masks) onto the video comp layer. Now make the video comp layer 3D and you can animate your camera however you want in your master comp and also go into your video comp and animate the camera there as well for some parallax effect.