Android音频开发之AudioTrack实时播放

前言：

      其实在Android中录音可以用MediaRecord录音，操作比较简单。但是不能对音频进行处理。考虑到项目中做的是实时语音只能选择AudioRecord进行录音。然后实时播放也只能采用AudioTrack进行播放。

下文为具体实现：

public class AudioTrackManager {
    public static final String TAG = "AudioTrackManager";
    private AudioTrack audioTrack;
    private DataInputStream dis;
    private Thread recordThread;
    private boolean isStart = false;
    private static AudioTrackManager mInstance;
    private int bufferSize;

    public AudioTrackManager() {
        bufferSize = AudioTrack.getMinBufferSize(8000, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT);
        audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, 8000, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, bufferSize * 2, AudioTrack.MODE_STREAM);
    }

    /**
     * 获取单例引用
     *
     * @return
     */
    public static AudioTrackManager getInstance() {
        if (mInstance == null) {
            synchronized (AudioTrackManager.class) {
                if (mInstance == null) {
                    mInstance = new AudioTrackManager();
                }
            }
        }
        return mInstance;
    }

    /**
     * 销毁线程方法
     */
    private void destroyThread() {
        try {
            isStart = false;
            if (null != recordThread && Thread.State.RUNNABLE == recordThread.getState()) {
                try {
                    Thread.sleep(500);
                    recordThread.interrupt();
                } catch (Exception e) {
                    recordThread = null;
                }
            }
            recordThread = null;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            recordThread = null;
        }
    }

    /**
     * 启动播放线程
     */
    private void startThread() {
        destroyThread();
        isStart = true;
        if (recordThread == null) {
            recordThread = new Thread(recordRunnable);
            recordThread.start();
        }
    }

    /**
     * 播放线程
     */
    Runnable recordRunnable = new Runnable() {
        @Override
        public void run() {
            try {
                android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);
                byte[] tempBuffer = new byte[bufferSize];
                int readCount = 0;
                while (dis.available() > 0) {
                    readCount= dis.read(tempBuffer);
                    if (readCount == AudioTrack.ERROR_INVALID_OPERATION || readCount == AudioTrack.ERROR_BAD_VALUE) {
                        continue;
                    }
                    if (readCount != 0 && readCount != -1) {
                        audioTrack.play();
                        audioTrack.write(tempBuffer, 0, readCount);
                    }
                }
              stopPlay();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

    };

    /**
     * 播放文件
     *
     * @param path
     * @throws Exception
     */
    private void setPath(String path) throws Exception {
        File file = new File(path);
        dis = new DataInputStream(new FileInputStream(file));
    }

    /**
     * 启动播放
     *
     * @param path
     */
    public void startPlay(String path) {
        try {
            setPath(path);
            startThread();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    /**
     * 停止播放
     */
    public void stopPlay() {
        try {
            destroyThread();
            if (audioTrack != null) {
                if (audioTrack.getState() == AudioRecord.STATE_INITIALIZED) {
                    audioTrack.stop();
                }
                if (audioTrack != null) {
                    audioTrack.release();
                }
            }
            if (dis != null) {
                dis.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

使用前要添加如下权限：

<!-- 录音权限 -->
<uses-permission android:name="android.permission.RECORD_AUDIO" />

<!-- 往SDCard写入数据权限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<!-- 在SDCard中创建与删除文件权限 -->
<uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

相关音频知识链接：

   http://ticktick.blog.51cto.com/823160/1748506