Microphone Streaming is Not Clear

Question

I'm trying to stream microphone over UDP but my output is so noisy, it's not able to understand the input audio. Here is my code:

Server Side:

import java.io.DataOutputStream;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.Mixer;
import javax.sound.sampled.Port;
import javax.sound.sampled.TargetDataLine;

public class MicPlayer {

    private static final String IP_TO_STREAM_TO   = "localhost" ;
    private static final int PORT_TO_STREAM_TO     = 8888 ;

    /** Creates a new instance of MicPlayer */
    public MicPlayer() {

    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
    Mixer.Info minfo[] = AudioSystem.getMixerInfo() ;
    for( int i = 0 ; i < minfo.length ; i++ )
    {
     System.out.println( minfo[i] ) ;    
    }


    if (AudioSystem.isLineSupported(Port.Info.MICROPHONE)) {
    try {


      DataLine.Info dataLineInfo = new DataLine.Info(
              TargetDataLine.class , getAudioFormat() ) ;
     final TargetDataLine targetDataLine = (TargetDataLine)AudioSystem.getLine( dataLineInfo  ) ;
      targetDataLine.open( getAudioFormat() );
      targetDataLine.start();
      byte tempBuffer[] = new byte[targetDataLine.getBufferSize() / 5] ;
      int cnt = 0 ;
      while( true )
      {
      targetDataLine.read( tempBuffer , 0 , tempBuffer.length );
      sendThruUDP( tempBuffer ) ;
      }

    }
    catch(Exception e )
    {
    System.out.println(" not correct " ) ;
    System.exit(0) ;
    }
    }



    }


    public static AudioFormat getAudioFormat(){
    float sampleRate = 8000.0F;
    //8000,11025,16000,22050,44100
    int sampleSizeInBits = 16;
    //8,16
    int channels = 1;
    //1,2
    boolean signed = true;
    //true,false
    boolean bigEndian = false;
    //true,false
    return new AudioFormat( sampleRate, sampleSizeInBits, channels, signed, bigEndian );
    }


    public static void sendThruUDP( byte soundpacket[] )
    {
       try
       {
       DatagramSocket sock = new DatagramSocket() ; 
       sock.send( new DatagramPacket( soundpacket , soundpacket.length , InetAddress.getByName( IP_TO_STREAM_TO ) , PORT_TO_STREAM_TO ) ) ; 
       sock.close() ;
       }
       catch( Exception e )
       {
       e.printStackTrace() ;
       System.out.println(" Unable to send soundpacket using UDP " ) ;   
       }

    }

    }

I don't think client-side has problems but here is the code;

Client Side:

import java.io.DataInputStream;
import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.SourceDataLine;

public class RadioReceiver extends Thread {
    private static final String IP_TO_STREAM_TO   = "localhost" ;
    private static final int PORT_TO_STREAM_TO     = 8888 ;

    /** Creates a new instance of RadioReceiver */
    public RadioReceiver() {
    }

    public void run()
    {
        byte b[] = null ;
        while( true )
        {
           b = receiveThruUDP() ; 
           toSpeaker( b ) ;
        }        
    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {

    RadioReceiver r = new RadioReceiver() ;
    r.start() ;

    }

    public static byte[] receiveThruUDP()
    {
       try
       {
       DatagramSocket sock = new DatagramSocket(PORT_TO_STREAM_TO) ; 
       byte soundpacket[] = new byte[1230] ;
       DatagramPacket datagram = new DatagramPacket( soundpacket , soundpacket.length , InetAddress.getByName( IP_TO_STREAM_TO ) , PORT_TO_STREAM_TO ) ;
       sock.receive( datagram ) ; 
       sock.close() ;       return datagram.getData() ; // soundpacket ;
       }
       catch( Exception e )
       {
       System.out.println(" Unable to send soundpacket using UDP " ) ;   
       return null ;
       } 

    }


     public static void toSpeaker( byte soundbytes[] )
     {

      try{  
      DataLine.Info dataLineInfo = new DataLine.Info( SourceDataLine.class , getAudioFormat() ) ;
      SourceDataLine sourceDataLine = (SourceDataLine)AudioSystem.getLine( dataLineInfo );
      sourceDataLine.open( getAudioFormat() ) ;
      sourceDataLine.start();

      int cnt = 0;
      sourceDataLine.write( soundbytes , 0, soundbytes.length );
      sourceDataLine.drain() ;
      sourceDataLine.close() ;
      }
      catch(Exception e )
      {
      System.out.println("not working in speakers " ) ;
      }

    }


    public static AudioFormat getAudioFormat()
    {
    float sampleRate = 8000.0F;
    //8000,11025,16000,22050,44100
    int sampleSizeInBits = 16;
    //8,16
    int channels = 1;
    //1,2
    boolean signed = true;
    //true,false
    boolean bigEndian = false;
    //true,false
    return new AudioFormat( sampleRate, sampleSizeInBits, channels, signed, bigEndian );
    }


}

I'm sure that my connection is OK but i don't have any idea why my output is so noisy. It's getting me crazy i'm working on it till 1 week, please help me. Thank You.

Answer 1

The reason is probably that your datagram packets are too small, which causes you to send a whole bunch of packages that creates a lot of overhead. This might result in a huge packet loss rate and make them arrive in the wrong order.

So, make your buffer size bigger:

byte tempBuffer[] = new byte[8192] ;

And this comes from the DatagramSocket.receive() JavaDoc:

This method blocks until a datagram is received. The length field of the datagram packet object contains the length of the received message. If the message is longer than the packet's length, the message is truncated.

This might be a problem as well. Try to use the same size for both sending and receiving packets.

byte soundpacket[] = new byte[8192];

Also, do not continiously open and close the AudioLine to the speakers. Do also not continuously create DatagramSockets. Create one, and keep it.