Need to play audio into a call

If my application records some audio with MediaRecorder, is it possible to play the recorded audio file into a call that was started with ACTION_CALL or ACTION_DIAL?

I see that I can start calls from an appli开发者_Python百科cation but is there a way for my application to know that the call was answered? At this point I would like to play a file of audio into the call. Then, is there a way for me to end the call?

This not yet possible on Android. See this feature request.

You can record your voice from microphone, but you can not record the sound of the other party.

android.intent.action.ANSWER may be what you are looking for, or possibly PhoneStateIntentReceiver.