目前无法在Android上实现无间隙音频循环_Android_Android Audiomanager

目前无法在Android上实现无间隙音频循环

android

目前无法在Android上实现无间隙音频循环,android,android-audiomanager,Android,Android Audiomanager,我尝试了几乎所有的方法，但我没能在循环10-15秒的单曲之间实现无间隙音频播放我尝试过但失败的步骤：使用不同的音频文件格式.mp3.wav.ogg 设置循环（true）：创建两个MediaPlayer并使用 setOnCompletionListenersame未能无间隙循环使用setNextMediaPlayer（nextmp）。在完成前两个循环后，我们必须准备并重新开始 mp1.start(); mp1.setNextMediaPlayer(mp2); 更新： @Jeff Mi

我尝试了几乎所有的方法，但我没能在循环10-15秒的单曲之间实现无间隙音频播放

我尝试过但失败的步骤：

使用不同的音频文件格式

.mp3

.wav

.ogg

设置循环（true）

：

创建两个MediaPlayer并使用

setOnCompletionListener

same未能无间隙循环

使用

setNextMediaPlayer（nextmp）

。在完成前两个循环后，我们必须准备并重新开始

mp1.start();
mp1.setNextMediaPlayer(mp2);

更新： @Jeff Mixon回答的结果： . Jeff Mixon工作正常，但此后只有10或20个循环，由于一些垃圾收集问题，MediaPlayer立即停止，留下如下所示的日志。我真的被困在这里两年了。提前谢谢

E/MediaPlayer(24311): error (1, -38)
E/MediaPlayer(23256): Error(1,-1007)
E/MediaPlayer(23546): Error (1,-2147483648)

难看的概念验证代码，但你会明白：

// Will need this in the callbacks
final AssetFileDescriptor afd = getResources().openRawResourceFd(R.raw.sample);

// Build and start first player
final MediaPlayer player1 = MediaPlayer.create(this, R.raw.sample);
player1.start();

// Ready second player
final MediaPlayer player2 = MediaPlayer.create(this, R.raw.sample);
player1.setNextMediaPlayer(player2);

player1.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
    @Override
    public void onCompletion(MediaPlayer mediaPlayer) {

        // When player1 completes, we reset it, and set up player2 to go back to player1 when it's done
        mediaPlayer.reset();
        try {
            mediaPlayer.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
            mediaPlayer.prepare();
        } catch (Exception e) {
            e.printStackTrace();
        }

        player2.setNextMediaPlayer(player1);
    }
});
player2.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
    @Override
    public void onCompletion(MediaPlayer mediaPlayer) {
        // Likewise, when player2 completes, we reset it and tell it player1 to user player2 after it's finished again
        mediaPlayer.reset();
        try {
            mediaPlayer.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
            mediaPlayer.prepare();
        } catch (Exception e) {
            e.printStackTrace();
        }

        player1.setNextMediaPlayer(player2);
    }
});

// This loop repeats itself endlessly in this fashion without gaps

这在API 19设备和5秒128Kbps MP3上对我很有效。循环中没有间隙。

类似的方法应该可以工作。在res.raw目录中保留同一文件的两个副本。请注意，这只是一个POC，而不是一个优化的代码。我刚刚测试了这个，它正在按预期工作。让我知道你的想法

public class MainActivity extends Activity {
MediaPlayer mp1;
MediaPlayer mp2;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mp1 = MediaPlayer.create(MainActivity.this, R.raw.demo);
    mp2 = MediaPlayer.create(MainActivity.this, R.raw.demo2);

    mp1.start();

    Thread thread = new Thread(new Runnable() {

        @Override
        public void run() {
            int duration = mp1.getDuration();
            while (mp1.isPlaying() || mp2.isPlaying()) {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                duration = duration - 100;
                if (duration < 1000) {
                    if (mp1.isPlaying()) {
                        mp2.start();
                        mp1.reset();
                        mp1 = MediaPlayer.create(MainActivity.this,
                                R.raw.demo);
                        duration = mp2.getDuration();

                    } else {
                        mp1.start();
                        mp2.reset();
                        mp2 = MediaPlayer.create(MainActivity.this,
                                R.raw.demo2);
                        duration = mp1.getDuration();
                    }
                }
            }
        }

    });

    thread.start();
}
}

公共类MainActivity扩展活动{
MediaPlayer mp1；
MediaPlayer mp2；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
mp1=MediaPlayer.create（MainActivity.this，R.raw.demo）；
mp2=MediaPlayer.create（MainActivity.this，R.raw.demo2）；
mp1.start（）；
Thread Thread=新线程（new Runnable（）{
@凌驾
公开募捐{
int duration=mp1.getDuration（）；
而（mp1.isplay（）| | mp2.isplay（））{
试一试{
睡眠（100）；
}捕捉（中断异常e）{
e、 printStackTrace（）；
}
持续时间=持续时间-100；
如果（持续时间<1000）{
if（mp1.isPlaying（））{
mp2.start（）；
mp1.reset（）；
mp1=MediaPlayer.create（MainActivity.this，
R.raw.demo）；
duration=mp2.getDuration（）；
}否则{
mp1.start（）；
mp2.reset（）；
mp2=MediaPlayer.create（MainActivity.this，
R.raw.demo2）；
duration=mp1.getDuration（）；
}
}
}
}
});
thread.start（）；
}
}

我建议您使用API而不是

MediaPlayer

从官方文件：

SoundPool类管理和播放音频资源应用程序

可以通过设置非零循环来循环声音价值值-1会导致声音永远循环。在这种情况下,，应用程序必须显式调用stop（）函数来停止声音。任何其他非零值都会导致声音重复指定的次数，例如，值为3会使声音播放总共4次

通过我所做的测试，查看如何使用

声音池的实际示例，此解决方案运行良好，超过150个循环，13秒160 kbps MP3，没有任何问题：
public class LoopMediaPlayer {

    public static final String TAG = LoopMediaPlayer.class.getSimpleName();

    private Context mContext = null;
    private int mResId = 0;
    private int mCounter = 1;

    private MediaPlayer mCurrentPlayer = null;
    private MediaPlayer mNextPlayer = null;

    public static LoopMediaPlayer create(Context context, int resId) {
        return new LoopMediaPlayer(context, resId);
    }

    private LoopMediaPlayer(Context context, int resId) {
        mContext = context;
        mResId = resId;

        mCurrentPlayer = MediaPlayer.create(mContext, mResId);
        mCurrentPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
            @Override
            public void onPrepared(MediaPlayer mediaPlayer) {
                mCurrentPlayer.start();
            }
        });

        createNextMediaPlayer();
    }

    private void createNextMediaPlayer() {
        mNextPlayer = MediaPlayer.create(mContext, mResId);
        mCurrentPlayer.setNextMediaPlayer(mNextPlayer);
        mCurrentPlayer.setOnCompletionListener(onCompletionListener);
    }

    private MediaPlayer.OnCompletionListener onCompletionListener = new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
            mediaPlayer.release();
            mCurrentPlayer = mNextPlayer;

            createNextMediaPlayer();

            Log.d(TAG, String.format("Loop #%d", ++mCounter));
        }
    };
}

要使用LoopMediaPlayer，只需调用：
LoopMediaPlayer.create(context, R.raw.sample);

至少到了KitKat，（对于这个问题）是我发现的唯一一个允许大（>1Mb未压缩）音频样本无间隙循环的解决方案。我试过：

.setLooping（true）：即使使用经过完美修剪的.WAV示例（），也会产生交替循环噪声或暂停
：无帧格式，因此比MP3更好，但MediaPlayer仍会发出交替播放的效果；及
：可能适用于小的声音样本，但是

只需在我的项目中包含Maestrini的LoopMediaPlayer
类，然后将我的MediaPlayer.create（）
调用替换为LoopMediaPlayer.create（）
调用，我就可以确保.OGG示例无缝循环<因此，code>LoopMediaPlayer

是一个非常实用和透明的解决方案

但这种透明性回避了一个问题：一旦我将我的

MediaPlayer

调用交换为

LoopMediaPlayer

调用，我的实例如何调用

MediaPlayer

方法，例如。

isPlaying

、

.pause

或

setVolume

下面是我对此问题的解决方案。也许比我更精通Java的人可以改进它（我欢迎他们的意见），但到目前为止，我发现这是一个可靠的解决方案

我对Maestrini的类所做的唯一更改（除了Lint建议的一些调整）如下代码末尾所示；其余的我都包含在上下文中。我的新增功能是在

LoopMediaPlayer

中通过调用

mCurrentPlayer

实现

MediaPlayer

的几种方法

警告：虽然我实现了下面的

MediaPlayer

的几种有用方法，但我并没有实现所有这些方法。因此，如果您希望调用

。attachauxeeffect

，您需要按照我添加的内容，自己将其作为方法添加到

LoopMediaPlayer

。确保复制这些方法的原始接口（即参数、抛出和返回）：

出于某种原因，我发现我的“OnCompletion”事件在尝试循环8秒时总是在晚些时候触发一小部分秒

LoopMediaPlayer.create(context, R.raw.sample);

public class LoopMediaPlayer {

    private static final String TAG = LoopMediaPlayer.class.getSimpleName();

    private Context mContext = null;
    private int mResId   = 0;
    private int mCounter = 1;

    private MediaPlayer mCurrentPlayer = null;
    private MediaPlayer mNextPlayer    = null;

    public static LoopMediaPlayer create(Context context, int resId) {
        return new LoopMediaPlayer(context, resId);
    }

    private LoopMediaPlayer(Context context, int resId) {
        mContext = context;
        mResId   = resId;

        mCurrentPlayer = MediaPlayer.create(mContext, mResId);
        mCurrentPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
            @Override
            public void onPrepared(MediaPlayer mediaPlayer) {
                mCurrentPlayer.start();
            }
        });
        createNextMediaPlayer();
    }

    private void createNextMediaPlayer() {
        mNextPlayer = MediaPlayer.create(mContext, mResId);
        mCurrentPlayer.setNextMediaPlayer(mNextPlayer);
        mCurrentPlayer.setOnCompletionListener(onCompletionListener);
    }

    private final MediaPlayer.OnCompletionListener onCompletionListener = new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
            mediaPlayer.release();
            mCurrentPlayer = mNextPlayer;
            createNextMediaPlayer();
            Log.d(TAG, String.format("Loop #%d", ++mCounter));
        }
    };
    // code-read additions:
    public boolean isPlaying() throws IllegalStateException {
        return mCurrentPlayer.isPlaying();
    }

    public void setVolume(float leftVolume, float rightVolume) {
        mCurrentPlayer.setVolume(leftVolume, rightVolume);
    }

    public void start() throws IllegalStateException {
        mCurrentPlayer.start();
    }

    public void stop() throws IllegalStateException {
        mCurrentPlayer.stop();
    }

    public void pause() throws IllegalStateException {
        mCurrentPlayer.pause();
    }

    public void release() {
        mCurrentPlayer.release();
        mNextPlayer.release();
    }

    public void reset() {
        mCurrentPlayer.reset();
    }
}

private HandlerThread SongLooperThread = new HandlerThread("SongLooperThread");
private Handler SongLooperHandler;

public void startSongLooperThread(){
    SongLooperThread.start();
    Looper looper = SongLooperThread.getLooper();
    SongLooperHandler = new Handler(looper){
        @Override
        public void handleMessage(Message msg){
            //do whatever...
        }
    }
}

public void stopSongLooperThread(){
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN_MR2){
        SongLooperThread.quit();
    } else {
        SongLooperThread.quitSafely();
    }
}`

@Override
public void onCreate() {
    // TODO Auto-generated method stub
    super.onCreate();

    startSongLooperThread();

    activeSongResID = R.raw.some_loop;
    activeMP = MediaPlayer.create(getApplicationContext(), activeSongResID);
    activeSongMilliseconds = activeMP.getDuration();

    queuedMP = MediaPlayer.create(getApplicationContext(),activeSongResID);
}

@Override
public void onDestroy() {
    // TODO Auto-generated method stub
    super.onDestroy();
    stopSongLooperThread();

    activeMP.release();
    queuedMP.release();
    activeMP = null;
    queuedMP = null;
}

private void swapActivePlayers(){
    Log.v("SongLooperService","MediaPlayer swap started....");
    queuedMP.start();

    //Immediately get the Duration of the current track, then queue the next swap.
    activeSongMilliseconds = queuedMP.getDuration();
    SongLooperHandler.postDelayed(timedQueue,activeSongMilliseconds);
    Log.v("SongLooperService","Next call queued...");

    activeMP.release();

    //Swap your active and queued MPs...
    Log.v("SongLooperService","MediaPlayers swapping....");
    MediaPlayer temp = activeMP;
    activeMP = queuedMP;
    queuedMP = temp;

    //Prepare your now invalid queuedMP...
    queuedMP = MediaPlayer.create(getApplicationContext(),activeSongResID);
    Log.v("SongLooperService","MediaPlayer swapped.");
}

private Runnable startMP = new Runnable(){
    public void run(){
        activeMP.start();
        SongLooperHandler.postDelayed(timedQueue,activeSongMilliseconds);
    }
};

private Runnable timedQueue = new Runnable(){
    public void run(){
        swapActivePlayers();
    }
};

...
SongLooperHandler.post(startMP);
...

Uri.parse("file:///android_asset/" + path)

public class LoopMediaPlayer {

    private static final String TAG = LoopMediaPlayer.class.getSimpleName();

    private Context mContext = null;
    private int mResId   = 0;
    private int mCounter = 1;
    private AssetFileDescriptor mAfd = null;
    private File mFile = null;

    private MediaPlayer mCurrentPlayer = null;
    private MediaPlayer mNextPlayer    = null;

    public static LoopMediaPlayer create(Context context, int resId) {
        return new LoopMediaPlayer(context, resId);
    }

    public LoopMediaPlayer(Context context, File file){
        mContext = context;
        mFile = file;

        try {
            mCurrentPlayer = new MediaPlayer();
            mCurrentPlayer.setLooping(false);
            mCurrentPlayer.setDataSource(file.getAbsolutePath());
            mCurrentPlayer.prepareAsync();
            mCurrentPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                @Override
                public void onPrepared(MediaPlayer mediaPlayer) {
                    mCurrentPlayer.start();
                    mCurrentPlayer.setOnCompletionListener(onCompletionListener);
                    createNextMediaPlayer();
                }
            });
        } catch (Exception e) {
            Log.e("media", e.getLocalizedMessage());
        }
    }

    public LoopMediaPlayer(Context context, AssetFileDescriptor afd){
        mAfd =  afd;
        mContext = context;

        try {
            mCurrentPlayer = new MediaPlayer();
            mCurrentPlayer.setLooping(false);
            mCurrentPlayer.setDataSource(afd.getFileDescriptor(), afd.getStartOffset(), afd.getLength());
            mCurrentPlayer.prepareAsync();
            mCurrentPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                @Override
                public void onPrepared(MediaPlayer mediaPlayer) {
                    mCurrentPlayer.start();
                    mCurrentPlayer.setOnCompletionListener(onCompletionListener);
                    createNextMediaPlayer();
                }
            });

        } catch (Exception e) {
            Log.e("media", e.getLocalizedMessage());
        }
    }

    private LoopMediaPlayer(Context context, int resId) {
        mContext = context;
        mResId   = resId;

        mCurrentPlayer = MediaPlayer.create(mContext, mResId);
        mCurrentPlayer.setLooping(false);
        mCurrentPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
            @Override
            public void onPrepared(MediaPlayer mediaPlayer) {
                mCurrentPlayer.start();
                mCurrentPlayer.setOnCompletionListener(onCompletionListener);
                createNextMediaPlayer();
            }
        });
        mCurrentPlayer.prepareAsync();
    }

    private void createNextMediaPlayer() {
        try{
            if(mAfd != null){
                mNextPlayer = new MediaPlayer();
                mNextPlayer.setDataSource(mAfd.getFileDescriptor(), mAfd.getStartOffset(), mAfd.getLength());
                mNextPlayer.prepareAsync();
                mNextPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mp) {
                        mCurrentPlayer.setNextMediaPlayer(mNextPlayer);
                    }
                });
            }
            else if(mFile!=null){
                mNextPlayer = new MediaPlayer();
                mNextPlayer.setDataSource(mFile.getAbsolutePath());
                mNextPlayer.prepareAsync();
                mNextPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mp) {
                        mCurrentPlayer.setNextMediaPlayer(mNextPlayer);
                    }
                });
            }
            else {
                mNextPlayer = MediaPlayer.create(mContext, mResId);
                mNextPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
                    @Override
                    public void onPrepared(MediaPlayer mp) {
                        mCurrentPlayer.setNextMediaPlayer(mNextPlayer);
                    }
                });
            }
        } catch (Exception e) {

        }
    }

    private final MediaPlayer.OnCompletionListener onCompletionListener = new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
            mediaPlayer.release();
            mCurrentPlayer = mNextPlayer;
            mCurrentPlayer.setOnCompletionListener(onCompletionListener);
            createNextMediaPlayer();
            Log.d("LoopMediaPlayer", String.format("Loop #%d", ++mCounter));
        }
    };
    // code-read additions:
    public boolean isPlaying() throws IllegalStateException {
        return mCurrentPlayer.isPlaying();
    }

    public void setVolume(float leftVolume, float rightVolume) {
        mCurrentPlayer.setVolume(leftVolume, rightVolume);
    }

    public void start() throws IllegalStateException {
        mCurrentPlayer.start();
    }

    public void stop() throws IllegalStateException {
        mCurrentPlayer.stop();
    }

    public void pause() throws IllegalStateException {
        mCurrentPlayer.pause();
    }

    public void release() {
        mCurrentPlayer.release();
        mNextPlayer.release();
    }

    public void reset() {
        mCurrentPlayer.reset();
    }
}

public class LoopMediaPlayer extends MediaPlayer {
    private static final String TAG = LoopMediaPlayer.class.getSimpleName();

    private Context mContext = null;
    private Uri mMediaUri = null;
    private int mCounter = 1;

    private MediaPlayer mCurrentPlayer = null;
    private MediaPlayer mNextPlayer = null;

    private Float mLeftVolume;
    private Float mRightVolume;

    public static LoopMediaPlayer create(Context context, Uri mediaUri) {
        try {
            return new LoopMediaPlayer(context, mediaUri);
        }
        catch (Exception e) {
            throw new RuntimeException("Unable to create media player", e);
        }
    }

    private LoopMediaPlayer(Context context, Uri mediaUri) throws IOException {
        mContext = context;
        mMediaUri = mediaUri;

        mCurrentPlayer = new MediaPlayer();
        mCurrentPlayer.setDataSource(mContext, mMediaUri);
        mCurrentPlayer.prepare();

        createNextMediaPlayer();
    }

    private void createNextMediaPlayer() {
        try {
            mNextPlayer = new MediaPlayer();
            mNextPlayer.setDataSource(mContext, mMediaUri);
            if (mLeftVolume != null && mRightVolume != null) {
                mNextPlayer.setVolume(mLeftVolume, mRightVolume);
            }
            mNextPlayer.prepare();

            mCurrentPlayer.setNextMediaPlayer(mNextPlayer);
            mCurrentPlayer.setOnCompletionListener(onCompletionListener);
        }
        catch (Exception e) {
            Log.e(TAG, "Problem creating next media player", e);
        }
    }

    private MediaPlayer.OnCompletionListener onCompletionListener = new MediaPlayer.OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mediaPlayer) {
            mediaPlayer.release();
            mCurrentPlayer = mNextPlayer;

            createNextMediaPlayer();

            Log.d(TAG, String.format("Loop #%d", ++mCounter));
        }
    };

    @Override
    public void prepare() throws IllegalStateException {
        // no-op, internal media-players are prepared when they are created.
    }

    @Override
    public boolean isPlaying() throws IllegalStateException {
        return mCurrentPlayer.isPlaying();
    }

    @Override
    public void setVolume(float leftVolume, float rightVolume) {
        mCurrentPlayer.setVolume(leftVolume, rightVolume);
        mNextPlayer.setVolume(leftVolume, rightVolume);
        mLeftVolume = leftVolume;
        mRightVolume = rightVolume;
    }

    @Override
    public void start() throws IllegalStateException {
        mCurrentPlayer.start();
    }

    @Override
    public void stop() throws IllegalStateException {
        mCurrentPlayer.stop();
    }

    @Override
    public void pause() throws IllegalStateException {
        mCurrentPlayer.pause();
    }

    @Override
    public void release() {
        mCurrentPlayer.release();
        mNextPlayer.release();
    }

    @Override
    public void reset() {
        mCurrentPlayer.reset();
    }
}