……和从上层调用到RTMediaPlayer类似。 frameworks\base\media\java\android\media：MediaPlayer public MediaPlayer() { …… native_setup(new WeakReference(this)); } frameworks\base\media\jni：android_media_MediaPlayer static void android_media_MediaPlayer_native_setup(JNIEnv *env, jobject thiz, jobject weak_this) { sp mp = new MediaPlayer(); } frameworks\av\media\libmedia：MediaPlayer.cpp MediaPlayer::MediaPlayer() { ALOGV(“constructor”); mListener = NULL; mCookie = NULL; mStreamType = AUDIO_STREAM_MUSIC; mAudioAttributesParcel = NULL; mCurrentPosition = -1; mCurrentSeekMode = MediaPlayerSeekMode::SEEK_PREVIOUS_SYNC; mSeekPosition = -1; mSeekMode = MediaPlayerSeekMode::SEEK_PREVIOUS_SYNC; mCurrentState = MEDIA_PLAYER_IDLE; mPrepareSync = false; mPrepareStatus = NO_ERROR; mLoop = false; mLeftVolume = mRightVolume = 1.0; mVideoWidth = mVideoHeight = 0; mLockThreadId = 0; mAudioSessionId = (audio_session_t) AudioSystem::newAudioUniqueId(AUDIO_UNIQUE_ID_USE_SESSION); AudioSystem::acquireAudioSessionId(mAudioSessionId, -1); mSendLevel = 0; mRetransmitEndpointValid = false; } .java中的setDataSource最终会调用到MediaPlayer.cpp的setDataSource 会去调用下面的函数： class NuPlayerFactory : public MediaPlayerFactory::IFactory { …… virtual sp createPlayer(pid_t pid) { ALOGV(” create NuPlayer”); return new NuPlayerDriver(pid); } }; 构造函数： NuPlayerDriver::NuPlayerDriver(pid_t pid) : mState(STATE_IDLE),//状态 …… mLooper(new ALooper), mPlayer(new NuPlayer(pid)), …… ALOGD(“NuPlayerDriver(%p) created, clientPid(%d)”, this, pid); mLooper->setName(“NuPlayerDriver Looper”); // set up an analytics record mAnalyticsItem = new MediaAnalyticsItem(kKeyPlayer); mAnalyticsItem->generateSessionID(); mLooper->start( false, /* runOnCallingThread */ true, /* canCallJava */ PRIORITY_AUDIO); mLooper->registerHandler(mPlayer); mPlayer->setDriver(this); } 首先关注NuPlayer的状态有哪些：
再关注new的ALooper
再关注new的NuPlayer 这里创建了NuPlayer赋值给mPlayer 再mLooper->start，会： mThread = new LooperThread(this, canCallJava); status_t err = mThread->run( mName.empty() ? “ALooper” : mName.c_str(), priority); 再mPlayer->setDriver(this); mPlayer持有NuPlayerDriver实例
