I would like to make an application similar to RedPhone on android. I took a look at SipDemo from developer.android.com and at the android.net.sip package.My question is, when you make/receive a call, how can you get the audio stream to encrypt/decrypt it before is being sent/played back to the user? Is there a tutorial about this somewhere? I am aware that I need a sip account and real devices with android 2.3. I would like to get the AudioStream before it's sent (for encryption) and to receive the AudioStream before it gets played-back to the user(for decryption).
please Help me out .
Thanks in advance :)