So, I filled the microphone with a sine wave (or something which, in some vague sense, resembles a sine wave), and your program works fine.
My specific changes were thus:
package audioclient;
import java.io.*;
import java.net.*;
import java.nio.ByteBuffer;
import javax.sound.sampled.*;
public class Mic {
public byte[] buffer;
private int port;
static AudioInputStream ais;
public static void main(String[] args) {
TargetDataLine line;
DatagramPacket dgp;
AudioFormat.Encoding encoding = AudioFormat.Encoding.PCM_SIGNED;
float rate = 44100.0f;
int channels = 2;
int sampleSize = 16;
boolean bigEndian = true;
InetAddress addr;
AudioFormat format = new AudioFormat(encoding, rate, sampleSize, channels, (sampleSize / 8) * channels, rate, bigEndian);
DataLine.Info info = new DataLine.Info(TargetDataLine.class, format);
if (!AudioSystem.isLineSupported(info)) {
System.out.println("Line matching " + info + " not supported.");
return;
}
try {
line = (TargetDataLine) AudioSystem.getLine(info);
//TOTALLY missed this.
int buffsize = line.getBufferSize() / 5;
buffsize += 512;
line.open(format);
line.start();
int numBytesRead;
byte[] data = new byte[buffsize];
/*
* MICK's injection: We have a buffsize of 512; it is best if the frequency
* evenly fits into this (avoid skips, bumps, and pops). Additionally, 44100 Hz,
* with two channels and two bytes per sample. That's four bytes; divide
* 512 by it, you have 128.
*
* 128 samples, 44100 per second; that's a minimum of 344 samples, or 172 Hz.
* Well within hearing range; slight skip from the uneven division. Maybe
* bump it up to 689 Hz.
*
* That's a sine wave of shorts, repeated twice for two channels, with a
* wavelength of 32 samples.
*
* Note: Changed my mind, ignore specific numbers above.
*
*/
{
final int λ = 16;
ByteBuffer buffer = ByteBuffer.allocate(λ * 2 * 8);
for(int j = 0; j < 2; j++) {
for(double i = 0.0; i < λ; i++) {
System.out.println(j + " " + i);
//once for each sample
buffer.putShort((short)(Math.sin(Math.PI * (λ/i)) * Short.MAX_VALUE));
buffer.putShort((short)(Math.sin(Math.PI * (λ/i)) * Short.MAX_VALUE));
}
}
data = buffer.array();
}
addr = InetAddress.getByName("127.0.0.1");
try(DatagramSocket socket = new DatagramSocket()) {
while (true) {
for(byte b : data) System.out.print(b + " ");
// Read the next chunk of data from the TargetDataLine.
// numBytesRead = line.read(data, 0, data.length);
for(int i = 0; i < 64; i++) {
byte b = data[i];
System.out.print(b + " ");
}
System.out.println();
// Save this chunk of data.
dgp = new DatagramPacket(data, data.length, addr, 50005);
for(int i = 0; i < 64; i++) {
byte b = dgp.getData()[i];
System.out.print(b + " ");
}
System.out.println();
socket.send(dgp);
}
}
} catch (LineUnavailableException e) {
e.printStackTrace();
} catch (UnknownHostException e) {
// TODO: handle exception
} catch (SocketException e) {
// TODO: handle exception
} catch (IOException e2) {
// TODO: handle exception
}
}
}
Obviously I misinterpreted it as a 512-byte-long piece and botched the sine wave, but the thing is, it produced exactly the sound that it was meant to--a mind-numbing rattle at a specific pitch.
This in mind, I don't suspect that the problem is explicitly in your code. The first thing I would check is which line your system is tapping for audio. Do you have multiple microphones hooked up? A webcam mic, maybe? You might grab a utility like PulseAudio Volume Control to check. If you haven't already checked on the functionality of your microphone, you might do that too; they do have a lifespan on them.
It isn't uncommon at all to scramble the bits in an audio stream, nor is it difficult; but I don't see anywhere where you could be doing that.
One thought might be to modify your program to attempt to play the sound locally, before sending it over to the server. That way, you can at least determine if the problem is pre- or post-Mic.
