On an Android phone, I'm using a HDMI/SDI to USB grabber via a OTG adaptor.
This all works fine for getting video and audio into the phone and some Apps can see and use the video and audio this way. Its the same as plugging in a USB webcam into a phone.
The problem I have is other App only see the fount and back camera and won't see the video via the USB/OTG.
I need a way to replace the phone's camera output with the USB video, and tick Apps to see the USB video as a phone camera, In other words, make Apps think the USB video is the front or back phone camera.