Building Shared Library from static Library *.a file

Building Shared Library from static Library *.a file

I have read other questions similar to this on stack overflow but they are
not having same like scenario.
I have FreeImage.a(23 MB file ) file which precompild static library for
android. I also have source code of FreeImage Project which have header
files.
I want to build .SO file from (.a) file I have with my JNI
code(FreeImageCompilation.cpp) Below code compiles fine but it does
produces SO File of (5KB only ) whre (*.a file is 23 MB )?
can somebody check if my code below for using *.a file is correct or not ?
In My Android.mk I have following code.
LOCAL_PATH := $(call my-dir)
include $(CLEAR_VARS)
LOCAL_MODULE := FreeImage
LOCAL_SRC_FILES := libFreeImage.a
LOCAL_EXPORT_C_INCLUDES := $(LOCAL_PATH)/FreeImage/Source/
include $(PREBUILT_STATIC_LIBRARY)
#My Own SO file
LOCAL_STATIC_LIBRARIES := FreeImage
include $(CLEAR_VARS)
LOCAL_MODULE := FreeImageSo
LOCAL_SRC_FILES := FreeImageCompilation.cpp
LOCAL_STATIC_LIBRARIES := FreeImage
include $(BUILD_SHARED_LIBRARY)