How to integrate video content into static screens for user testing?

My team is in the middle of designing an online course comprised of educational videos. We're almost ready to put the designs in front of our users for usability testing, but we're not sure how to incorporate video content into the static screens of our designs in a way thats "real" enough for a live test. Invision has modest gif capability, but can't handle gif overlays, which is pretty much what the design calls for.

Does anyone have any experience w a prototyping or user-testing tool or any clever workaround for user-testing static screens with video content?

Thanks!