问题
I'm getting strange undefined references at link time for Android::Mutex and Android::AudioTrack used by a project I have taken over.
Does anyone have any ideas? There is no Android static library to include is there?
SharedLibrary : **jni.so
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `__static_initialization_and_destruction_0':
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:29: undefined reference to `android::Mutex::Mutex()'
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:29: undefined reference to `android::Mutex::~Mutex()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `Autolock':
/Android/source/frameworks/base/include/utils/threads.h:232: undefined reference to `android::Mutex::lock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `~Autolock':
/Android/source/frameworks/base/include/utils/threads.h:234: undefined reference to `android::Mutex::unlock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `Autolock':
/Android/source/frameworks/base/include/utils/threads.h:232: undefined reference to `android::Mutex::lock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `android_mute':
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:263: undefined reference to `android::AudioTrack::mute(bool)'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `~Autolock':
/Android/source/frameworks/base/include/utils/threads.h:234: undefined reference to `android::Mutex::unlock()'
/Android/source/frameworks/base/include/utils/threads.h:234: undefined reference to `android::Mutex::unlock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `Autolock':
/Android/source/frameworks/base/include/utils/threads.h:232: undefined reference to `android::Mutex::lock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `android_resume':
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:255: undefined reference to `android::AudioTrack::start()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `~Autolock':
/Android/source/frameworks/base/include/utils/threads.h:234: undefined reference to `android::Mutex::unlock()'
/Android/source/frameworks/base/include/utils/threads.h:234: undefined reference to `android::Mutex::unlock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `Autolock':
/Android/source/frameworks/base/include/utils/threads.h:232: undefined reference to `android::Mutex::lock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `android_pause':
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:247: undefined reference to `android::AudioTrack::pause()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `~Autolock':
/Android/source/frameworks/base/include/utils/threads.h:234: undefined reference to `android::Mutex::unlock()'
/Android/source/frameworks/base/include/utils/threads.h:234: undefined reference to `android::Mutex::unlock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `android_get_delay':
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:237: undefined reference to `android::AudioTrack::latency() const'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `Autolock':
/Android/source/frameworks/base/include/utils/threads.h:232: undefined reference to `android::Mutex::lock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `android_uninit':
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:220: undefined reference to `android::AudioTrack::stop()'
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:228: undefined reference to `android::AudioTrack::~AudioTrack()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `~Autolock':
/Android/source/frameworks/base/include/utils/threads.h:234: undefined reference to `android::Mutex::unlock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `Autolock':
/Android/source/frameworks/base/include/utils/threads.h:232: undefined reference to `android::Mutex::lock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `android_start':
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:197: undefined reference to `android::AudioTrack::initCheck() const'
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:198: undefined reference to `android::AudioTrack::start()'
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:201: undefined reference to `android::AudioTrack::setVolume(float, float)'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `~Autolock':
/Android/source/frameworks/base/include/utils/threads.h:234: undefined reference to `android::Mutex::unlock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `android_start':
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:207: undefined reference to `android::AudioTrack::~AudioTrack()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `Autolock':
/Android/source/frameworks/base/include/utils/threads.h:232: undefined reference to `android::Mutex::lock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `android_init':
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:122: undefined reference to `android::AudioTrack::AudioTrack()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `~Autolock':
/Android/source/frameworks/base/include/utils/threads.h:234: undefined reference to `android::Mutex::unlock()'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `android_init':
/Users/kevin/Desktop/player2/videoplayer/LibPlayer/amadec/audio_out/android_out.cpp:139: undefined reference to `android::AudioTrack::set(int, unsigned int, int, int, int, unsigned int, void (*)(int, void*, void*), void*, int, android::sp<android::IMemory> const&, bool, int)'
/Users/kevin/Desktop/player2/videoplayer/videoplayer/obj/local/armeabi-v7a/libamadec.a(android_out.o): In function `~sp':
/Android/source/frameworks/base/include/utils/RefBase.h:378: undefined reference to `android::RefBase::decStrong(void const*) const'
collect2: ld returned 1 exit status
回答1:
This plagued me as well - but I finally resolved it by linking with Bionic's header (bionic/libc/include), and - the important part - #define'ing HAVE_PTHREADS (i.e. add LOCAL_CFLAGS += HAVE_PTHREADS).
回答2:
Well these are some strange errors... It looks like every time you reference something from the android::Mutex or the android::AudioTrack libraries the linker is unable to find those functions. All I can say is that since those libraries are not part of the android standard library, make sure you have them in your build path, otherwise best of luck.
来源：https://stackoverflow.com/questions/10984001/android-ndk-undefined-reference-to-androidmutex-androidaudiotrack