如何在setdatasource中使用getfiledescriptor

Question

我应该如何传递setSourceFile才能正常工作。 基本上我想同时录制和播放音频。

这是我的代码：

public class MainActivity extends ActionBarActivity {

String outputfile;
MediaRecorder recorder;
MediaPlayer player;
ParcelFileDescriptor[] pfd;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    recorder = new MediaRecorder();
    pfd = new ParcelFileDescriptor[0];
    try {
        pfd=ParcelFileDescriptor.createPipe();
    } catch (IOException e) {
        e.printStackTrace();
    }


}


public void start(View v) throws IOException {

   recorder.setOutputFile(pfd[1].getFileDescriptor());//THIS IS WORKING 
   recorder.setAudioSource(MediaRecorder.AudioSource.MIC);
   recorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
   recorder.setAudioEncoder(MediaRecorder.OutputFormat.AMR_NB);
    try {
         recorder.prepare();
        } catch (IOException e) {
                                  e.printStackTrace();
                                }
   recorder.start();
   MediaPlayer   player = new MediaPlayer();
   try {
        player.setDataSource(pfd[0].getFileDescriptor());// NOT WORKING 
       }catch (IOException e) {
                               e.printStackTrace();
                              }
 //THIS IS THE EXCEPTION:
 // java.io.IOException: setDataSourceFD failed.: status=0x80000000
        plater.prepare();
        player.start();     
}

还有其他方法可以将音频从录音机传输到扬声器吗？