I am using apprtc-ios from https://github.com/ISBX/apprtc-ios for our video calling project. It is working fine on iOS 12 & iOS 11.
After upgrading to my device to iOS 13, it seems the front camera does not record video and send it to the other party - If phone A & phone B are having a video calling session, the little video preview square on phone A (iOS 13) turns black. On phone B (iOS 12), there is no video sent by phone A - The whole screen is black, except for the little preview square. The audio conversation is working fine, though.
I checked camera permission - it is on for the app.
And I traced the code. cameraID for the front camera (on iOS 13 phone) is successfully obtained during the video call session.
After several hours of trial and error, I still got no clue. Does anyone know how to fix it?