Android MediaPlayer getCurrentPosition() 返回错误值

Question

I have a service where I have created a MediaPlayer Object. I then bind to the service to get info about the media being played like current seek position. For testing purpose, created a button which invokes getCurrentPosition () method of the MediaPlayer . However each time it returns some random value. (I am calling getCurrentPosition only after the start() is called and the media is playing). getDuration () is returning correct duration of the song.

public class SongPlayService extends Service {

    private static final String SERVICE_INTENT_KEY = "com.example.strehan.galleryapp.SERVICE_INTENT_KEY";

    private SongPlayThread mSongPlayThread;
    private String mSongData;
    private SongPlayServiceHandler mHandler;
    private MediaPlayer mMediaPlayer;

    public class SongPlayServiceBinder extends Binder {

        public  SongPlayService getSongPlayService() {
            return SongPlayService.this;
        }
    }

    public void onCreate() {
        super.onCreate();
        Log.d("SongPlayService", "onCreate()");
        mHandler = new SongPlayServiceHandler();
        mSongPlayThread = new SongPlayThread("SongPlay Thread", mHandler, getApplicationContext());
        mSongPlayThread.start();
        mSongPlayThread.initHandler(mSongPlayThread.getLooper());
        mMediaPlayer = mSongPlayThread.createMediaPlayer();
    }

    public IBinder onBind(Intent intent) {
        Log.d("SongPlayService", "onBind()");
        return  new SongPlayServiceBinder();
    }

    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.d("SongPlayService", "onStartCommand()");
        mSongData  = intent.getStringExtra(SERVICE_INTENT_KEY);
        Log.d("SongPlayService", "Song data rcvd at service: " + mSongData);
        if (mSongData != null) {
            mSongPlayThread.resetMediaPlayer();
            mSongPlayThread.prepareSong(mSongData);
            playSong();
        }
        return START_NOT_STICKY;
    }

    public int getSeekInfo() {
        return mMediaPlayer.getCurrentPosition();
    }
}


public class SongPlayThread extends HandlerThread implements MediaPlayer.OnCompletionListener,
        MediaPlayer.OnErrorListener, MediaPlayer.OnPreparedListener {


    private Handler mRequestHandler;
    private Handler mResponseHandler;
    private MediaPlayer mMediaPlayer;
    private Context mContext;

    public void initHandler(Looper looper) {

        mRequestHandler = new Handler(looper) {

            public void handleMessage(Message msg) {
                switch (msg.what) {
                    case MSG_PREPARE_PLAYER:
                        Log.d("SongPlayThread", "Prepare song recvd: Song data:" + msg.obj);
                        Log.d("SongPlayThread", "Thread: " + Thread.currentThread().getName());
                        processPrepareMsg(msg.obj.toString());
                        break;

                    case  MSG_PLAY_SONG:
                        Log.d("SongPlayThread", "Play Song msg rcvd");
                        processPlayMsg();
                        break;
                }
            }
        };
    }

    private void processPlayMsg() {
        mMediaPlayer.start();
    }

    private void processPrepareMsg(String path) {
        try {

            Log.d("SongPlayThread", "Registering listeners: Thread: " + Thread.currentThread().getName());
            mMediaPlayer.setOnCompletionListener(this);
            mMediaPlayer.setOnErrorListener(this);

            Uri uri = Uri.fromFile(new File(path));
            mMediaPlayer.setDataSource(mContext, uri);
            mMediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
            mMediaPlayer.prepare();
        } catch (IOException ioException) {
                   ioException.printStackTrace();
        }
    }
}

 02-07 15:55:00.380 7379-7379/ D/SongPlayFragment﹕ Seek: 3275 02-07 15:55:00.825 7379-7379/ D/SongPlayFragment﹕ Seek Button pressed 02-07 15:55:00.825 7379-7379/ D/SongPlayFragment﹕ Service connected 02-07 15:55:00.826 7379-7379/ D/SongPlayFragment﹕ Seek: 3723 02-07 15:55:01.000 7379-7379/ D/SongPlayFragment﹕ Seek Button pressed 02-07 15:55:01.000 7379-7379/ D/SongPlayFragment﹕ Service connected 02-07 15:55:01.001 7379-7379/ D/SongPlayFragment﹕ Seek: 3898 02-07 15:55:01.194 7379-7379/ D/SongPlayFragment﹕ Seek Button pressed 02-07 15:55:01.194 7379-7379/ D/SongPlayFragment﹕ Service connected 02-07 15:55:01.196 7379-7379/ D/SongPlayFragment﹕ Seek: 4093 02-07 15:55:01.334 7379-7379/ D/SongPlayFragment﹕ Seek Button pressed 02-07 15:55:01.334 7379-7379/ D/SongPlayFragment﹕ Service connected 02-07 15:55:01.335 7379-7379/ D/SongPlayFragment﹕ Seek: 131 02-07 15:55:01.494 7379-7379/ D/SongPlayFragment﹕ Seek Button pressed 02-07 15:55:01.494 7379-7379/ D/SongPlayFragment﹕ Service connected 02-07 15:55:01.497 7379-7379/ D/SongPlayFragment﹕ Seek: 292 02-07 15:55:01.672 7379-7379/ D/SongPlayFragment﹕ Seek Button pressed 02-07 15:55:01.672 7379-7379/ D/SongPlayFragment﹕ Service connected 02-07 15:55:01.674 7379-7379/ D/SongPlayFragment﹕ Seek: 470

Answer 1

Unfortunately, the MediaPlayer has an old issue when sometimes currentPosition returns wrong values (1) , (2)

So here is workaround how to possibly handle it:

fun runPlayerDurationUpdate(mediaPlayer: MediaPlayer) {
    playerCurrentDuration.value = 0

    durationJob?.cancel()
    durationJob = viewModelScope.launch {
        while (mediaPlayer.currentPosition != mediaPlayer.duration) {
            val progress = mediaPlayer.currentPosition * 100 / mediaPlayer.duration
            if (progress < playerCurrentDuration.value!!) {
                continue
            } else {
                delay(PLAYER_DELAY)
                playerCurrentDuration.value = progress
            }
        }
    }
}

where

 private const val PLAYER_DELAY = 50L 
 private val playerCurrentDuration = MutableLiveData(0)