Streaming voice between Android Phones over WiFi

Alabhya picture Alabhya · Feb 11, 2012 · Viewed 41k times · Source

I'm trying to stream audio from the mic from 1 Android to another over WiFi. After looking at some examples I made 2 applications with a single activity in each, 1 to capture and send audio and the other to receive.

I've used the Audiorecord and Audiotrack classes to capture and play. However, i just hear some crackling sound (which has now stopped after i made some changes though i reverted back)

The activity to send voice.

public class VoiceSenderActivity extends Activity {

private EditText target;
private TextView streamingLabel;
private Button startButton,stopButton;

public byte[] buffer;
public static DatagramSocket socket;
private int port=50005;         //which port??
AudioRecord recorder;

//Audio Configuration. 
private int sampleRate = 8000;      //How much will be ideal?
private int channelConfig = AudioFormat.CHANNEL_CONFIGURATION_MONO;    
private int audioFormat = AudioFormat.ENCODING_PCM_16BIT;       

private boolean status = true;




@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    target = (EditText) findViewById (R.id.target_IP);
    streamingLabel = (TextView) findViewById(R.id.streaming_label);
    startButton = (Button) findViewById (R.id.start_button);
    stopButton = (Button) findViewById (R.id.stop_button);

    streamingLabel.setText("Press Start! to begin");

    startButton.setOnClickListener (startListener);
    stopButton.setOnClickListener (stopListener);
}

private final OnClickListener stopListener = new OnClickListener() {

    @Override
    public void onClick(View arg0) {
                status = false;
                recorder.release();
                Log.d("VS","Recorder released");
    }

};

private final OnClickListener startListener = new OnClickListener() {

    @Override
    public void onClick(View arg0) {
                status = true;
                startStreaming();           
    }

};

public void startStreaming() {


    Thread streamThread = new Thread(new Runnable() {

        @Override
        public void run() {
            try {


                int minBufSize = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat);
                DatagramSocket socket = new DatagramSocket();
                Log.d("VS", "Socket Created");

                byte[] buffer = new byte[minBufSize];

                Log.d("VS","Buffer created of size " + minBufSize);
                DatagramPacket packet;

                final InetAddress destination = InetAddress.getByName(target.getText().toString());
                Log.d("VS", "Address retrieved");


                recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,sampleRate,channelConfig,audioFormat,minBufSize);
                Log.d("VS", "Recorder initialized");

                recorder.startRecording();


                while(status == true) {


                    //reading data from MIC into buffer
                    minBufSize = recorder.read(buffer, 0, buffer.length);

                    //putting buffer in the packet
                    packet = new DatagramPacket (buffer,buffer.length,destination,port);

                    socket.send(packet);


                }



            } catch(UnknownHostException e) {
                Log.e("VS", "UnknownHostException");
            } catch (IOException e) {
                Log.e("VS", "IOException");
            } 


        }

    });
    streamThread.start();
 }
 }

The activity to receive voice

public class VoiceReceiverActivity extends Activity {


private Button receiveButton,stopButton;

public static DatagramSocket socket;
private AudioTrack speaker;

//Audio Configuration. 
private int sampleRate = 8000;      //How much will be ideal?
private int channelConfig = AudioFormat.CHANNEL_CONFIGURATION_MONO;    
private int audioFormat = AudioFormat.ENCODING_PCM_16BIT;       

private boolean status = true;


@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    receiveButton = (Button) findViewById (R.id.receive_button);
    stopButton = (Button) findViewById (R.id.stop_button);
    findViewById(R.id.receive_label);

    receiveButton.setOnClickListener(receiveListener);
    stopButton.setOnClickListener(stopListener);

}


private final OnClickListener stopListener = new OnClickListener() {

    @Override
    public void onClick(View v) {
        status = false;
        speaker.release();
        Log.d("VR","Speaker released");

    }

};


private final OnClickListener receiveListener = new OnClickListener() {

    @Override
    public void onClick(View arg0) {
        status = true;
        startReceiving();

    }

};

public void startReceiving() {

    Thread receiveThread = new Thread (new Runnable() {

        @Override
        public void run() {

            try {

                DatagramSocket socket = new DatagramSocket(50005);
                Log.d("VR", "Socket Created");


                byte[] buffer = new byte[256];


                //minimum buffer size. need to be careful. might cause problems. try setting manually if any problems faced
                int minBufSize = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat);

                speaker = new AudioTrack(AudioManager.STREAM_MUSIC,sampleRate,channelConfig,audioFormat,minBufSize,AudioTrack.MODE_STREAM);

                speaker.play();

                while(status == true) {
                    try {


                        DatagramPacket packet = new DatagramPacket(buffer,buffer.length);
                        socket.receive(packet);
                        Log.d("VR", "Packet Received");

                        //reading content from packet
                        buffer=packet.getData();
                        Log.d("VR", "Packet data read into buffer");

                        //sending data to the Audiotrack obj i.e. speaker
                        speaker.write(buffer, 0, minBufSize);
                        Log.d("VR", "Writing buffer content to speaker");

                    } catch(IOException e) {
                        Log.e("VR","IOException");
                    }
                }


            } catch (SocketException e) {
                Log.e("VR", "SocketException");
            }


        }

    });
    receiveThread.start();
}

}

I used wireshark to check if the packets are being sent and i can see the packets. The source however, is the MAC address of the sending device and destination too something like a physical address. Not sure if this is relevant though.

So what's the problem with?

Answer

user3482497 picture user3482497 · Dec 3, 2014

Hey there is an Open Source library called "Libstreaming" that is used for streaming voice/video over the network using WIFI. Just Have a look at it:

https://github.com/fyhertz/libstreaming

There are also some examples provided, kindly have a look at it:

https://github.com/fyhertz/libstreaming-examples

I have used the library to Stream RTSP Audio over the network,hope it may be useful.