play an audio file on a voice call

Question

I have a rather tricky question this time.
I want to know how to Inject audio to microphone source during a call.
I know I have read dozens of topics here and there

Answer 1

But what are you trying to achieve? Are you trying to implement some kind of answering machine? The only way you could inject audio during a call is if you release your own android version. Download the sources, modify them, and release. Good luck :)