You need to install the Android SDK and NDK
SDK: http://developer.android.com/sdk/index.html?utm_source=weibolife
NDK: https://developer.android.com/tools/sdk/ndk/index.html (native lib)
Important: you have to set the path in the system.
For Win 7 -> How to add android tools dir to windows 7 path?
If the path is not right you will get some errors like "Android NDK not found" ..
In the root folder from linphone you will find a readme. Follow the steps.
Maybe you have to use linux or mac. I dont know if its work on Win 7 well.
Let me know if its worked.
Greetz