Android - Getting audio to play through earpiece

Question

I currently have code that reads a recording in from the devices mic using the AudioRecord class and then playing it back out using the AudioTrack class.

My problem is that when I play it out it plays vis the speaker phone.

I want it to play out via the ear piece on the device.

Here is my code:

public class LoopProg extends Activity {


 boolean isRecording; //currently not used
 AudioManager am;
 int count = 0;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
        am.setMicrophoneMute(true);
        while(count <= 1000000){
        Record record = new Record();  
        record.run();
        count ++;
        Log.d("COUNT", "Count is : " + count);
        }
    } 

   public class Record extends Thread
   {

           static final int bufferSize = 200000;
           final short[] buffer = new short[bufferSize];
           short[] readBuffer = new short[bufferSize];

           public void run() {  
            isRecording = true;
            android.os.Process.setThreadPriority
            (android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);

            int buffersize = AudioRecord.getMinBufferSize(11025,
            AudioFormat.CHANNEL_CONFIGURATION_MONO,
            AudioFormat.ENCODING_PCM_16BIT);

                           AudioRecord arec = new AudioRecord(MediaRecorder.AudioSource.MIC,
                                           11025,
                                           AudioFormat.CHANNEL_CONFIGURATION_MONO,
                                           AudioFormat.ENCODING_PCM_16BIT,
                                           buffersize);

                           AudioTrack atrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                                           11025,
                                           AudioFormat.CHANNEL_CONFIGURATION_MONO,
                                           AudioFormat.ENCODING_PCM_16BIT,
                                           buffersize,
                                           AudioTrack.MODE_STREAM);


        am.setRouting(AudioManager.MODE_NORMAL,1,
                             AudioManager.STREAM_MUSIC);


                           int ok = am.getRouting(AudioManager.ROUTE_EARPIECE);
                           Log.d("ROUTING", "getRouting = " + ok);
                           setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);
                           //am.setSpeakerphoneOn(true);
                           Log.d("SPEAKERPHONE", "Is speakerphone on? : " + am.isSpeakerphoneOn());
                           am.setSpeakerphoneOn(false);
                           Log.d("SPEAKERPHONE", "Is speakerphone on? : " + am.isSpeakerphoneOn());
                           atrack.setPlaybackRate(11025);

                           byte[] buffer = new byte[buffersize];
                           arec.startRecording();
                           atrack.play();

                           while(isRecording) {
                                   arec.read(buffer, 0, buffersize);
                                   atrack.write(buffer, 0, buffer.length);
                           }

                           arec.stop();
                           atrack.stop();
                           isRecording = false;
           }
   } 
}

As you can see if the code I have tried using the AudioManager class and its methods including the deprecated setRouting method and nothing works, the setSpeatPoneOn method seems to have no effect at all, neither does the routing method.

Has anyone got any ideas on how to get it to play via the earpiece instead of the spaker phone?

Answer 1

There was some related discussion in this recent question:
http://stackoverflow.com/questions/1993471/android-can-i-mute-currently-playing-audio-applications

Based on the AudioManager source code, it seems that you must be in "call mode" before the setSpeakerphoneOn method has any effect.

However, I recently saw an application that could seamlessly switch between earpiece and speakerphone while still showing the current stream as the "media" stream, so I would be interested in any further answers.

Answer 2

If the ear piece is connected to the phone with bluetooth (which I assume it is), have you tried calling AudioManager.setBluetoothScoOn(true)?

I've been through the Android reference and this is the only thing I could find that you didn't mention trying.

Answer 3

I appear to have got it working on 1.6.

So I said I'd post here how I done it.

To get it working in 1.6 I:

Used the AudioManager class to use the setSpeakerPhoneOn() to false, I then used the Voice_Call_Stream and add volueme control to the Voice_Call_Stream.

The setSpeakerPhoneOn(false) method is used in onCreate() of the activity and this appears to route to the headset, I then used a button and used the setSpeakerPhoneOn(true) method and the audio gets routed to the speaker.

The method only appears to work when it is used in onCreate() for me and I haven't tested it extensively but for the moment it allows me to switch between headset and speaker on a 1.6 device

Answer 4

public MediaPlayer m_mpSpeakerPlayer;

private AudioManager m_amAudioManager;

m_amAudioManager = (AudioManager)getSystemService(Context.AUDIO_SERVICE);

// 從Receiver Earpiece發音

m_amAudioManager.setSpeakerphoneOn(false);

m_amAudioManager.setRouting(AudioManager.MODE_NORMAL, AudioManager.ROUTE_EARPIECE, AudioManager.ROUTE_ALL); 

Log.i(TAG, String.valueOf(m_amAudioManager.getRouting(AudioManager.ROUTE_EARPIECE))); 

setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);

// 把聲音設定成從Earpiece出來
// 重點在這行，要把它設定為正在通話中
m_amAudioManager.setMode(AudioManager.MODE_IN_CALL);

// 開始放音樂
m_mpSpeakerPlayer.reset();

m_mpSpeakerPlayer.setDataSource("sdcard/receiver.mp3");

m_mpSpeakerPlayer.prepare();

m_mpSpeakerPlayer.start();

//最後再把它設定從Speaker放音，達成！

m_amAudioManager.setMode(AudioManager.MODE_NORMAL);