Yes, you can use a video, even more of them, as an input for creating 3D models inside RealityCapture.
You can import videos via the Workflow tab - part Import & Metadata - button Video Sequence. You can find more…
https://dev.epicgames.com/community/learning/knowledge-base/8y3Y/capturing-reality-can-your-software-create-a-3d-model-from-a-video