정적 라이브러리에 cpufeatures 라이브러리를 추가하는것일 겁니다 = _- 

mk파일 건든지 오래되서 가물가물 합니다만, 그냥 저건 library이름일거에요. 

SharedLibrary  : libbasicplayer.so
E:/cygwin/home/Administrator/android-ndk-r7-windows/android-ndk-r7/myprojects/ffmpegplayer/obj/local/armeabi/objs/basicplayer/BasicPlayer.o: In function `openMovie':
E:/cygwin/home/Administrator/android-ndk-r7-windows/android-ndk-r7/myprojects/ffmpegplayer/jni/BasicPlayer/BasicPlayer.c:42: undefined reference to `av_open_input_file'
collect2: ld returned 1 exit status
/home/Administrator/android-ndk-r7-windows/android-ndk-r7/build/core/build-binary.mk:312: recipe for target `/home/Administrator/android-ndk-r7-windows/android-ndk-r7/myprojects/ffmpegplayer/obj/local/armeabi/libbasicplayer.so' failed
make: *** [/home/Administrator/android-ndk-r7-windows/android-ndk-r7/myprojects/ffmpegplayer/obj/local/armeabi/libbasicplayer.so] Error 1