Linking FFTW into an Android NDK application

I am currently writing a genre classification application as my final year project in Computer Engineering. I initially wrote the feature extraction code (im开发者_JAVA技巧plementing FFTW) in C and now I need to implement it on Android via the NDK.

This is my first NDK project so I'm still getting the hang of things but I have compiled the FFTW3 library for Android according to this guide. I didn't do the very last step because I didn't think it was right for what I need.

My question is how do I, after the compile step, use the library in the main NDK application that calls on it? Do I everything normally in Application.mk just with LOCAL_STATIC_LIBRARIES set to the libfftw3.a that I just compiled? And then I don't need to have any -lfftw3 linker flags like I normally would right?

You can use prebuit FFTW library (no matter how did you build it).

Or you can build FFTW in Android.mk makefile with the whole project.

Android.mk content will be:

# Prebuilt FFTW library
include $(CLEAR_VARS)
LOCAL_MODULE := fftw
include $(PREBUILT_STATIC_LIBRARY)

# or

# Build FFTW library
include $(CLEAR_VARS)
LOCAL_MODULE := fftw
# TODO put your static libs build flags
include path_to_fftw_sources/$(LOCAL_MODULE).mk
include $(BUILD_STATIC_LIBRARY)

include $(CLEAR_VARS)
LOCAL_MODULE := YourProject
# TODO put your shared lib build flags
include path_to_your_project/$(LOCAL_MODULE).mk
LOCAL_STATIC_LIBRARIES += fftw
include $(BUILD_SHARED_LIBRARY)

I have written path_to_fftw_sources/$(LOCAL_MODULE).mk for building fftw static library and path_to_your_project/$(LOCAL_MODULE).mk for building your shared library. It is often better to put LOCAL_SRC_FILES and LOCAL_C_INCLUDES to the separate .mk file.

You can read more about Android.mk file in docs/ANDROID-MK.html document in your NDK distribution.