Possible Duplicate:
Android Recording Incoming and Outgoing Calls
I have searched a lot about it and I am aware of the fact that Google does not provide any API for recording a call and its not supported much. But I still see a lot of call-recorder apps in the android market. I have read somewhere that they use kernel for those apps. I am also trying to create an app for recording a call(not on Microphone ofcourse). So can any one please tell me if it is possible or not? And if possible, then what are the steps to download and install the android kernel source code and how will we implement the changes in it for our particular app?