流模式MODE_STREAMING的AudioTrack

问题描述

| 我需要流式传输在运行时生成的PCM数据。所以我有一个带有循环的线程

public void run() {
  while(...) {
    mAudioTrack.write(getPCM(),...);
  }
}

不幸的是，这行不通。似乎并不取决于AudioTrack缓冲区的大小。我希望它很小以模拟某种低延迟行为（150毫秒），以便用户可以动态更改由getPCM（）选择的PCM

int bufferSize = 0.150 * sampleRate * channels * bitsPerSample / 8;

但是，我试图将缓冲区大小增加到100k，但没有结果     

解决方法

        这是对我有用的简短示例：

public class Internal extends Activity
{   
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);              
    }

    public void onPlayClicked(View v)
    {
        start();    
    }

    public void onStopClicked(View v)
    {
        stop();
    }

    boolean m_stop = false;
    AudioTrack m_audioTrack;
    Thread m_noiseThread;

    Runnable m_noiseGenerator = new Runnable()
    {       
        public void run()
        {
            Thread.currentThread().setPriority(Thread.MIN_PRIORITY);

            /* 8000 bytes per second,1000 bytes = 125 ms */
            byte [] noiseData = new byte[1000];
            Random rnd = new Random();

            while(!m_stop)
            {           
                rnd.nextBytes(noiseData);   
                m_audioTrack.write(noiseData,noiseData.length);                 
            }
        }
    };

    void start()
    {
        m_stop = false;

        /* 8000 bytes per second*/
        m_audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,8000,AudioFormat.CHANNEL_OUT_MONO,AudioFormat.ENCODING_PCM_8BIT,8000 /* 1 second buffer */,AudioTrack.MODE_STREAM);            

        m_audioTrack.play();        


        m_noiseThread = new Thread(m_noiseGenerator);
        m_noiseThread.start();
    }

    void stop()
    {
        m_stop = true;          
        m_audioTrack.stop();
    }   
}