is it possible for 2 different apps to use the same camera simultaneously?

Question

I'd like to be able to use the video stream from the camera (or even a few frames per second) while another app is also using the camera. Is this possible?

Answer 1

No. Access to a camera is exclusive.

See the Camera documentation, which says:

If your application does not properly release the camera, all subsequent attempts to access the camera, including those by your own application, will fail and may cause your or other applications to be shut down.