Render from camera to video file on Oculus Go?

I'd like to place a second camera in the scene, and render from that camera's view to a video file during a game.

I know how to grab an image and save it as a PNG file, but I doubt I can do that at 60 fps... and 4 minutes of 60 PNGs/second isn't a very pleasant experience for the user, either.

Is there any way to record to a video file in real time, that's likely to work on mobile hardware like the Go?