Incorporating AVMultiCamPiP: Capturing from Multiple Cameras

[pundirmr]

How to achieve this : Simultaneously record the output from the front and back cameras into a single movie file by using a multi-camera capture session.
And stream this to RTMP.
https://developer.apple.com/documentation/avfoundation/cameras_and_media_capture/avmulticampip_capturing_from_multiple_cameras