Change voice during phone call android
I want to make an android application that allow user change the voice during phone call. For example: You are a man, you can change the voice to a woman or robot when talking over phone. It is like a funny prank.
I work around android's API and google for some days but still have no idea. Some one told is impossible but I see some app on google play can do: https://play.google.com/store/apps/details?id=com.gridmob.android.funnycall So I think there are some ways to do that.
I think about recording and play back by using AudioTracker but I have 2more problem: 1. I cannot mute the voice from phone call, so the phone only play my sound after processing 2. record and process will make a long delay (slow-realtime)
Can any one share some solution for this?
Answer
The app you linked isn't changing voices on the phone: it uses SIP (or similar) to place a call through the authors' servers and the voice changing happens there. That's why you only get a small number of free minutes of use before you have to pay them.