Java Record Mic to Byte Array and Play sound

Question

I want to make a live voice chatting program in Java, but I know nothing about recording/playing sound in Java, so with the help of Google, I think I have been able to record from my mic to a byte array with the following:

AudioFormat format = new AudioFormat(8000.0f, 16, 1, true, true);
TargetDataLine microphone;
try{
    microphone = AudioSystem.getTargetDataLine(format);

    DataLine.Info info = new DataLine.Info(TargetDataLine.class, format);
    microphone = (TargetDataLine)AudioSystem.getLine(info);
    microphone.open(format);

    ByteArrayOutputStream out = new ByteArrayOutputStream();
    int numBytesRead;
    byte[] data = new byte[microphone.getBufferSize()/5];
    microphone.start();

    int bytesRead =0;

    try{
        while(bytesRead<100000){ //Just so I can test if recording my mic works...
            numBytesRead = microphone.read(data, 0, data.length);
            bytesRead = bytesRead + numBytesRead;
        //    System.out.println(bytesRead);
            out.write(data, 0, numBytesRead);
        }
    catch(Exception e){
        e.printStackTrace();
    }
    microphone.close();

catch(LineUnavailibleException e){
    e.printStackTrace();
}

So now, to my understanding, if I call out.toByteArray();, I should have gotten a byte array of the sound I just recorded from my microphone. (I got no errors running the above, but have no way to prove if it actually recorded because I do not wish to output it to a file and didn't do so)

Now, if the above is correct, then below is where I run into my problem: I want to now play the byte array I just created... (In my real program, I would've sent the bytes over to my "receiving program" through a Java socket which I have already been able to do, but right now I just want to make a small program that records the mic and plays it back). In order to play the sound information from the byte array I followed this: http://www.wikijava.org/wiki/Play_a_wave_sound_in_Java And came up with the following: (this is located right after microphone.close() from the above)

try{
    DataLine.Info info2 = DataLine.Info(SourceDataLine.class, format);
    SourceDataLine dataLine = (SourceDataLine)AudioSystem.getLine(info2);
    int bufferSize = 2200;
    soundLine.open(format, bufferSize);
    soundLine.start();
    AudioInputStream audioInputStream = null;

    InputStream input = new ByteArrayInputStream(out.toByteArray());
    audioInputStream = AudioSystem.getAudioInputStream(input);

    ...

The rest is pretty much copy pasted from the playSound.java from this link: http://www.wikijava.org/wiki/Play_a_wave_sound_in_Java

When I run the above code... The recording seems to work all right, but I get the following error:

javax.sound.sampled.UnsupportedAudioFileException: could not get audio input stream from input stream

for this line audioInputStream = AudioSystem.getAudioInputStream(input);

From my limited knowledge, I'm assuming it's because I somehow messed up the recording method, I need some sort of "Audio Format Header?" https://ccrma.stanford.edu/courses/422/projects/WaveFormat/ (I assumed I wouldn't need something like that because I never saved to a file and just kept it all as a byte array), or I just completely misunderstood how java's AudioInputStream reads and parses data...

This is my first time working with any sound related things in Java, so I apologize if I am completely misunderstanding and butchering this code (yeah I know the code looks pretty bad and unorganized but I just want to get it to work)... I tried multiple searches on Google/StackOverflow, and was able to find a very similar question:

java byte array play sound

but it was also unanswered (the only answer was to save it to a file, but what we both want is to stream it directly as a byte array without it ever becoming a file)

What I do know:

Audio can be recorded using a TargetDataLine, and recording the microphone, which can be outputted to a Byte Array using a ByteArrayOutputStream

Audio can be saved to a file and played by using a AudioInputStream to read the file and a SourceDataLine to play the data.

If I wanted to write a file, I could use AudioSystem.write(new AudioInputStream(microphone), AudioFileFormat.Type.WAVE, new File("recording.wav"); //I have tested this by replacing the while loop with this line and it recorded fine (except it would never stop so I had to manually terminate it), but I don't want that, because outputting to a file means it will be impossible to send it over a socket to another side in real time.

What I don't know / My Question:

How to record and stream audio recorded from a mic to another computer that can be played with as little delay as possible (pretty much like a voice chat similar to Skype) with Java.

Thanks in advance for any help or someone who can point me in the correct direction. Also if someone knows a simpler method then please tell me that as well.

Answer 1

EDIT: Here's a slightly better version of the same idea as below that will playback directly as you record

AudioFormat format = new AudioFormat(8000.0f, 16, 1, true, true);
    TargetDataLine microphone;
    SourceDataLine speakers;
    try {
        microphone = AudioSystem.getTargetDataLine(format);

        DataLine.Info info = new DataLine.Info(TargetDataLine.class, format);
        microphone = (TargetDataLine) AudioSystem.getLine(info);
        microphone.open(format);

        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int numBytesRead;
        int CHUNK_SIZE = 1024;
        byte[] data = new byte[microphone.getBufferSize() / 5];
        microphone.start();

        int bytesRead = 0;
        DataLine.Info dataLineInfo = new DataLine.Info(SourceDataLine.class, format);
        speakers = (SourceDataLine) AudioSystem.getLine(dataLineInfo);
        speakers.open(format);
        speakers.start();
        while (bytesRead < 100000) {
            numBytesRead = microphone.read(data, 0, CHUNK_SIZE);
            bytesRead += numBytesRead;
            // write the mic data to a stream for use later
            out.write(data, 0, numBytesRead); 
            // write mic data to stream for immediate playback
            speakers.write(data, 0, numBytesRead);
        }
        speakers.drain();
        speakers.close();
        microphone.close();
    } catch (LineUnavailableException e) {
        e.printStackTrace();
    } 

Bear with me because this is really rough, but it gets the recorded audio playing through speakers;

In order to make it sound better, you will need to add threads, and optimize the input/output streams.

http://www.developer.com/java/other/article.php/1579071/Java-Sound-Getting-Started-Part-2-Capture-Using-Specified-Mixer.htm

package audio;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

import javax.sound.sampled.AudioFormat;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.DataLine;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.SourceDataLine;
import javax.sound.sampled.TargetDataLine;

public class AudioTest {

    public static void main(String[] args) {

        AudioFormat format = new AudioFormat(8000.0f, 16, 1, true, true);
        TargetDataLine microphone;
        AudioInputStream audioInputStream;
        SourceDataLine sourceDataLine;
        try {
            microphone = AudioSystem.getTargetDataLine(format);

            DataLine.Info info = new DataLine.Info(TargetDataLine.class, format);
            microphone = (TargetDataLine) AudioSystem.getLine(info);
            microphone.open(format);

            ByteArrayOutputStream out = new ByteArrayOutputStream();
            int numBytesRead;
            int CHUNK_SIZE = 1024;
            byte[] data = new byte[microphone.getBufferSize() / 5];
            microphone.start();

            int bytesRead = 0;

            try {
                while (bytesRead < 100000) { // Just so I can test if recording
                                                // my mic works...
                    numBytesRead = microphone.read(data, 0, CHUNK_SIZE);
                    bytesRead = bytesRead + numBytesRead;
                    System.out.println(bytesRead);
                    out.write(data, 0, numBytesRead);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            byte audioData[] = out.toByteArray();
            // Get an input stream on the byte array
            // containing the data
            InputStream byteArrayInputStream = new ByteArrayInputStream(
                    audioData);
            audioInputStream = new AudioInputStream(byteArrayInputStream,format, audioData.length / format.getFrameSize());
            DataLine.Info dataLineInfo = new DataLine.Info(SourceDataLine.class, format);
            sourceDataLine = (SourceDataLine) AudioSystem.getLine(dataLineInfo);
            sourceDataLine.open(format);
            sourceDataLine.start();
            int cnt = 0;
            byte tempBuffer[] = new byte[10000];
            try {
                while ((cnt = audioInputStream.read(tempBuffer, 0,tempBuffer.length)) != -1) {
                    if (cnt > 0) {
                        // Write data to the internal buffer of
                        // the data line where it will be
                        // delivered to the speaker.
                        sourceDataLine.write(tempBuffer, 0, cnt);
                    }// end if
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
            // Block and wait for internal buffer of the
            // data line to empty.
            sourceDataLine.drain();
            sourceDataLine.close();
            microphone.close();
        } catch (LineUnavailableException e) {
            e.printStackTrace();
        }
    }
}