Tracking/Input from a video rather than webcam?

[Victor]

I was wondering if anyone more experienced than me could answer a question!
I wasn't sure if there was way to track an avatar from a pre-recorded video. If I recorded a vlog for example, somewhere I didn't have access to a PC, and then brought the vlog back home; Could I use the video footage provided its properly lit and framed instead of a webcam?
I was having a few issues trying to research on my own because I wasn't sure how to even phrase exactly what I was looking for, if it even is possible and I was unsure if use of a webcam had to be direct, and a video wouldn't work.

[Sue]

What you are looking for is a virtual webcam like ManyCam or SplitCam, but if you want something free and you probably already have, you can use OBS.
Put your video with a face to a scene then press the Start virtual camera button (instead of recording / streaming), then on VTS pick OBS Virtual Cam as your webcam video input.