To add to what @Rick4F presented above… here is an example of a moving mask using @MaxZieb’s “ClipPath” method. The mask as seen in the linked file is a vector that was adjusted in shape as it moved. The linked file is a screen capture of a Hype preview. This Hype project was an experiment to test the possibilities.
Note: You can do simple masking (square or circle) by grouping the image and adjusting the group boundaries with “overflow” set to “hidden” in the "Metrics Inspector". To get a circle - adjust the corner radius of the Group (rectangle) in the “Element Inspector”.
You can have video & soundtracks play in Hype’s Editor window (what I call the “Stage”). Drag the video or soundtrack file onto the Stage and it will appear in the video track.
The key point for sound tracks is that they need to be saved as an “.mp4” which tricks Hype into placing it in the video track. You can only see one selection at a time on the video track but they can overlap, be dragged to various timeline locations, and be assigned various properties (the properties keyframes are always visible).
Below is a screen shot of an animated spotlight effect (video) fading onto the model’s face (also a video).
While not an ideal situation this set-up has proved functional for me in many projects - it might prove useful for You as well.