Using MediaPlayer to play AMR file created by MediaRecorder with Muri error

I am writing an application that records voice from a microphone in AMR format using MediaRecorder and then plays the data using MediaPlayer.

In any case, the goal.

I am sure that my side of MediaRecorder is working, I am creating a data file in the right place with the right data transfer speed. This is how I start and stop my MediaRecorder

public void OnStartRecord(View v )
{
    System.out.println( "StartRecord");

    try {
       audioFile = File.createTempFile("amrtmp", ".amr", getApplicationContext().getFilesDir());
    } catch (IOException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    System.out.println( "Recording to " + audioFile.getAbsolutePath());

    mRecorder = new MediaRecorder();
    mRecorder.setAudioSource(MediaRecorder.AudioSource.VOICE_COMMUNICATION);
    mRecorder.setOutputFormat(MediaRecorder.OutputFormat.AMR_NB);
    mRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
    mRecorder.setAudioEncodingBitRate(4750);
    mRecorder.setAudioSamplingRate(8000);      
    mRecorder.setOutputFile(audioFile.getAbsolutePath());

    try {
        mRecorder.prepare();
    } catch (IllegalStateException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }
    mRecorder.start();
}

public void OnStopRecord(View v )
{
    System.out.println( "StopRecord");
    mRecorder.stop();
    mRecorder.release();
}

It works like a charm. The typical conclusion is something like

StartRecord
Recording to /data/data/com.test.playback/files/amrtmp-235967797.amr

And when I start and then stop recording, I see that the file was created, and it has a certain amount of data that matches the settings correctly.

Side note: I find a weird buzz in my speaker while it works. Any idea what this is?

, . :

public void OnPlay(View v )
{
    MediaPlayer mPlayer = new MediaPlayer();
    mPlayer.setAudioStreamType(AudioManager.STREAM_VOICE_CALL);

    FileInputStream FIS = null;
    try {
        FIS = new FileInputStream(audioFile.getAbsolutePath());
        mPlayer.setDataSource(FIS.getFD());
        mPlayer.prepare();
    }
    catch( Exception e )        
    {
        e.printStackTrace();
    }
    mPlayer.start();
}

MediaPlayer:

start() mURI null

, mPlayer -:

mPlayer.setDataSource(audioFile.getAbsolutePath());

, prepare java.io.IOException status 0x1.

, - MediaPlayer, . ?