非阻塞式播放pcm和mp3檔案類

/** * Plays a series of audio URIs, but does all the hard work on another thread * so that any slowness with preparing or loading doesn't block the calling thread. */public class Mp3OrPcmAsyncPlayer implements IPcmPlayCompleteListener, OnCompletionListener {    public static final int PLAY = 1;    public static final int STOP = 2;    private static final boolean mDebug = true;    // 獲得目前狀態    public int getState() {    return mState;    }    // 代表Mp3類型    public static final int TYPE_MP3 = 0x0101;    // 代表PCM類型    public static final int TYPE_PCM = 0x0102;    private static final class Command {        // 每次把播放或者停止請求封裝成一個對象        int code;        Context context;        String path;        int type;        boolean looping;        int stream;        long requestTime;        // 這個PcmInfo是代表一個pcm檔案的各種參數的類集合，比如什麼採樣率啊，什麼的        PcmInfo info;        public String toString() {            return "{ code=" + code + " looping=" + looping + " stream=" + stream                    + " path=" + path + " }";        }    }    private final LinkedList<Command> mCmdQueue = new LinkedList();    private void startSound(final Command cmd) {        // Preparing can be slow, so if there is something else        // is playing, let it continue until we're done, so there        // is less of a glitch.        try {            // 播放mp3類型檔案if (cmd.type == TYPE_MP3) {if (mDebug)Log.d(mTag, "Starting playback mp3 : " + cmd.path);MediaPlayer player = new MediaPlayer();player.setOnCompletionListener(PGAsyncPlayer.this);//player.setAudioStreamType(cmd.stream);player.setDataSource(cmd.path);//player.setLooping(cmd.looping);player.prepare();player.start();if (mPlayer != null) {mPlayer.release();}mPlayer = player;long delay = SystemClock.uptimeMillis() - cmd.requestTime;if (delay > 1000) {Log.w(mTag, "Notification sound delayed by " + delay + "msecs");}// 播放PCM類型檔案} else if (cmd.type == TYPE_PCM) {if (mDebug)Log.d(mTag, "Starting playback pcm : " + cmd.path);Thread pcm = new Thread() {@Overridepublic void run(){try {playPcmFile(cmd.path, cmd.info.getSampleRate(),cmd.info.getChannel(), cmd.info.getAudioFormat(), PGAsyncPlayer.this);} catch (InitializeException e) {e.printStackTrace();}}};pcm.start();} else {}        }        catch (Exception e) {            Log.w(mTag, "error loading sound for " + cmd.path, e);        }    }    private final class CmdQueueThread extends java.lang.Thread {    CmdQueueThread() {            super("AsyncPlayer-" + mTag);        }        public void run() {            while (true) {                Command cmd = null;                synchronized (mCmdQueue) {                    if (mDebug) Log.d(mTag, "RemoveFirst");                    // 取出第一個cmd來執行                    cmd = mCmdQueue.removeFirst();                }                switch (cmd.code) {                case PLAY:                    if (mDebug) Log.d(mTag, "PLAY");                    startSound(cmd);                    break;                case STOP:                    if (mDebug) Log.d(mTag, "STOP");if (mPlayer != null) {long delay = SystemClock.uptimeMillis() - cmd.requestTime;if (delay > 1000) {Log.w(mTag, "Notification stop delayed by " + delay + "msecs");}mPlayer.stop();mPlayer.release();mPlayer = null;} else {Log.w(mTag, "STOP command without a player");}stopPlayPcmFile();                    break;                }                synchronized (mCmdQueue) {                    if (mCmdQueue.size() == 0) {                        // nothing left to do, quit                        // doing this check after we're done prevents the case where they                        // added it during the operation from spawning two threads and                        // trying to do them in parallel.                        mThread = null;                        return;                    }                }            }        }    }    private String mTag;    private CmdQueueThread mThread;    private MediaPlayer mPlayer;    // The current state according to the caller.  Reality lags behind    // because of the asynchronous nature of this class.    private int mState = STOP;    /**     * Construct an AsyncPlayer object.     *     * @param tag a string to use for debugging     */    public PGAsyncPlayer(String tag) {        if (tag != null) {            mTag = tag;        } else {            mTag = "AsyncPlayer";        }    }    /**     * Start playing the sound.  It will actually start playing at some     * point in the future.  There are no guarantees about latency here.     * Calling this before another audio file is done playing will stop     * that one and start the new one.     *     * @param context Your application's context.     * @param uri The URI to play.  (see {@link MediaPlayer#setDataSource(Context, Uri)})     * @param looping Whether the audio should loop forever.       *          (see {@link MediaPlayer#setLooping(boolean)})     * @param stream the AudioStream to use.     *          (see {@link MediaPlayer#setAudioStreamType(int)})     */    public void play(Context context, String path, boolean looping, int stream, PcmInfo info) {        Command cmd = new Command();        cmd.requestTime = SystemClock.uptimeMillis();        cmd.code = PLAY;        cmd.context = context;        cmd.path = path;        cmd.looping = looping;        cmd.stream = stream;        // 外界使用的時候，如果info沒有傳如，就說明想播放mp3檔案，反之，想播放pcm檔案        if (info == null) {        cmd.type = TYPE_MP3;        } else {        cmd.type = TYPE_PCM;        cmd.info = info;        }        synchronized (mCmdQueue) {            enqueueLocked(cmd);            mState = PLAY;        }    }        /**     * Stop a previously played sound.  It can't be played again or unpaused     * at this point.  Calling this multiple times has no ill effects.     */    public void stop() {        synchronized (mCmdQueue) {            // This check allows stop to be called multiple times without starting            // a thread that ends up doing nothing.        Log.w(mTag, "current state : " + mState);            if (mState != STOP) {                Command cmd = new Command();                cmd.requestTime = SystemClock.uptimeMillis();                cmd.code = STOP;                enqueueLocked(cmd);                mState = STOP;            }                    }    }    // 加入一個請求到鏈表    private void enqueueLocked(Command cmd) {        mCmdQueue.add(cmd);        if (mThread == null) {            mThread = new CmdQueueThread();            mThread.start();        }    }        // 播放完的回調    public static interface OnSoundPlayCompletedListener{void onPlayCompleted();void onPlayError();}        private OnSoundPlayCompletedListener mListener;        public void setOnPlayCompletedListener(OnSoundPlayCompletedListener listener) {mListener = listener;}@Overridepublic void onPlayPcmAudioComplete() {if (mListener != null) {mListener.onPlayCompleted();}}@Overridepublic void onCompletion(MediaPlayer mp) {if (mListener != null) {mListener.onPlayCompleted();}}// 開啟播放外放public static void enableSpeaker(Activity context) {final AudioManager audioManager = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);if (!audioManager.isSpeakerphoneOn()) {audioManager.setMicrophoneMute(false);audioManager.setSpeakerphoneOn(true);// 使用擴音器外放，即使已經插入耳機context.setVolumeControlStream(AudioManager.STREAM_MUSIC);// 控制聲音的大小audioManager.setMode(AudioManager.STREAM_MUSIC);}}/** * 播放pcm檔案資源 * @param pcmFilePath 檔案路徑 * @param sampleRate 採樣率 * @param channel 聲道 * @param audioFormat 格式 * @param listener 回調監聽 * @throws InitializeException */AudioTrack mAudioTrack = null;    public void playPcmFile(String pcmFilePath, int sampleRate, int channel, int audioFormat,            IPcmPlayCompleteListener listener) throws InitializeException {        Log.e("test ","playPcmFile pcmFilePath =  " + pcmFilePath + " sampleRate = " + sampleRate                + " channel = " + channel + " audioFormat = " + audioFormat);        if (TextUtils.isEmpty(pcmFilePath) || !pcmFilePath.endsWith(".pcm")) return;        IPcmPlayCompleteListener pcmListener = listener;                // 轉換音頻聲道        if (channel == AudioFormat.CHANNEL_IN_MONO) {            channel = AudioFormat.CHANNEL_OUT_MONO;        } else if (channel == AudioFormat.CHANNEL_IN_STEREO) {            channel = AudioFormat.CHANNEL_OUT_STEREO;        }        // 根據檔案路徑組建檔案        File file = new File(pcmFilePath);        FileInputStream in = null;        try {            in = new FileInputStream(file);        } catch (FileNotFoundException e) {            Log.e("test","create the file failed when we want to play pcm file !");            e.printStackTrace();            return;        }        // 獲得滿足條件的最小緩衝區大小        int bufferSizeInBytes = AudioTrack.getMinBufferSize(sampleRate, channel, audioFormat);        // 2倍緩衝區        byte[] buffer = new byte[bufferSizeInBytes * 2];        try {            // 雖然每次都new出來一個新的AudioTrack對象，比較耗效能，但是為了安全考慮，比如使用者            // 重新開啟錄音功能，假如此時的採樣率22050初始化AudioRecord對象不成功,            // 就會改變當前的採樣率。所以錄製的音頻採樣率有可能與前幾次的不一樣，所以我們不能            // 緩衝一個AudioTrack引用來重複使用,這是我的理解            mAudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, sampleRate, channel,                    audioFormat, buffer.length, AudioTrack.MODE_STREAM);        } catch (IllegalArgumentException e) {            throw new InitializeException(                    "Can't initialize the AudioTrack instance," +                        "maybe be your parameters not right!");        }        // 開始放音，其實此時還在準備等待資料        mAudioTrack.setStereoVolume(1.0f, 1.0f);        mAudioTrack.play();        try {            while ((in.read(buffer)) != -1) {                mAudioTrack.write(buffer, 0, buffer.length);            }        } catch (Exception e) {            Log.e("AudioTrack", "Playback Failed");        }        // 播放結束，回調介面方法        if (pcmListener != null) {            pcmListener.onPlayPcmAudioComplete();        }        // 播放結束，釋放資源        if (mAudioTrack != null) {            // 釋放資源            mAudioTrack.release();            mAudioTrack = null;        }    }        /**     * 停止播放pcm音頻檔案     */    public void stopPlayPcmFile() {        Log.e("test","Stop play pcm !");        if (mAudioTrack == null) return;        int state = mAudioTrack.getState();        if (state == AudioTrack.STATE_INITIALIZED) {            try {                if (mAudioTrack != null) {                    mAudioTrack.stop();                }            } catch (IllegalStateException e) {                Log.e("test","AudioTrack.stop() exception and state = " + mAudioTrack.getState());            }        }    }}