Java - recording from mixer

Question

I have a problem connected with my previous question. I want to record audio from mixer (speakers), I'm using javax.sound. I have to set up audioFormat and I don't know what to type there :/ Using class ListMixer (which I found here -> http://forums.oracle.com/forums/thread.jspa?threadID=2198477&tstart=2), I write something like this: http://forums.oracle.com/forums/thread.jspa?threadID=2198477&tstart=2 but I don't have any info about sample rate (unknown sample rate). Program is throwing this exception:

java.lang.IllegalArgumentException: Line unsupported: interface TargetDataLine supporting format PCM_UNSIGNED 44100.0 Hz, 8 bit, mono, 4 bytes/frame,

Code:

package sound;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.io.*;
import javax.sound.sampled.*;

public class AudioCapture02 extends JFrame{

  boolean stopCapture = false;
  ByteArrayOutputStream byteArrayOutputStream;
  AudioFormat audioFormat;
  TargetDataLine targetDataLine;
  AudioInputStream audioInputStream;
  SourceDataLine sourceDataLine;

  public AudioCapture02(){//constructor
    final JButton captureBtn =
                          new JButton("Capture");
    final JButton stopBtn = new JButton("Stop");
    final JButton playBtn =
                         new JButton("Playback");

    captureBtn.setEnabled(true);
    stopBtn.setEnabled(false);
    playBtn.setEnabled(false);

    //Register anonymous listeners
    captureBtn.addActionListener(
      new ActionListener(){
        public void actionPerformed(
                                 ActionEvent e){
          captureBtn.setEnabled(false);
          stopBtn.setEnabled(true);
          playBtn.setEnabled(false);
          //Capture input data from the
          // microphone until the Stop button is
          // clicked.
          captureAudio();
        }//end actionPerformed
      }//end ActionListener
    );//end addActionListener()
    getContentPane().add(captureBtn);

    stopBtn.addActionListener(
      new ActionListener(){
        public void actionPerformed(
                                 ActionEvent e){
          captureBtn.setEnabled(true);
          stopBtn.setEnabled(false);
          playBtn.setEnabled(true);
          //Terminate the capturing of input data
          // from the microphone.
          stopCapture = true;
        }//end actionPerformed
      }//end ActionListener
    );//end addActionListener()
    getContentPane().add(stopBtn);

    playBtn.addActionListener(
      new ActionListener(){
        public void actionPerformed(
                                 ActionEvent e){
          //Play back all of the data that was
          // saved during capture.
          playAudio();
        }//end actionPerformed
      }//end ActionListener
    );//end addActionListener()
    getContentPane().add(playBtn);

    getContentPane().setLayout(new FlowLayout());
    setTitle("Capture/Playback Demo");
    setDefaultCloseOperation(EXIT_ON_CLOSE);
    setSize(250,70);
    setVisible(true);
  }//end constructor

  //This method captures audio input from a
  // microphone and saves it in a
  // ByteArrayOutputStream object.
  private void captureAudio(){
    try{
      //Get and display a list of
      // available mixers.
      Mixer.Info[] mixerInfo = AudioSystem.getMixerInfo();
      System.out.println("Available mixers:");
      for(int cnt = 0; cnt < mixerInfo.length;
                                          cnt++){
        System.out.println(mixerInfo[cnt].
                                      getName());
      }//end for loop

      //Get everything set up for capture
      audioFormat = new AudioFormat(AudioFormat.Encoding.PCM_UNSIGNED, 44100.0F, 8, 1, 4, 44100.0F,
                        false);


      DataLine.Info dataLineInfo =
                            new DataLine.Info(
                            TargetDataLine.class,
                            audioFormat);
      ListMixers lm = new ListMixers();
      lm.listAll(new PrintWriter(System.out));

      System.out.println(" AKTUALNY => "+mixerInfo[0].getName());
      Mixer mixer = AudioSystem.getMixer(mixerInfo[0]);

      //Get a TargetDataLine on the selected
      // mixer.
      targetDataLine = (TargetDataLine)
                     mixer.getLine(dataLineInfo);
      //Prepare the line for use.
      targetDataLine.open(audioFormat);
      targetDataLine.start();

      //Create a thread to capture the microphone
      // data and start it running.  It will run
      // until the Stop button is clicked.
      Thread captureThread = new CaptureThread();
      captureThread.start();
    } catch (Exception e) {
      System.out.println(e);
      System.exit(0);
    }//end catch
  }//end captureAudio method

  //This method plays back the audio data that
  // has been saved in the ByteArrayOutputStream
  private void playAudio() {
    try{
      //Get everything set up for playback.
      //Get the previously-saved data into a byte
      // array object.
      byte audioData[] = byteArrayOutputStream.
                                   toByteArray();
      //Get an input stream on the byte array
      // containing the data
      InputStream byteArrayInputStream =
             new ByteArrayInputStream(audioData);
      AudioFormat audioFormat = getAudioFormat();
      audioInputStream = new AudioInputStream(
                    byteArrayInputStream,
                    audioFormat,
                    audioData.length/audioFormat.
                                 getFrameSize());
      DataLine.Info dataLineInfo =
                            new DataLine.Info(
                            SourceDataLine.class,
                            audioFormat);
      sourceDataLine = (SourceDataLine)
               AudioSystem.getLine(dataLineInfo);
      sourceDataLine.open(audioFormat);
      sourceDataLine.start();

      //Create a thread to play back the data and
      // start it  running.  It will run until
      // all the data has been played back.
      Thread playThread = new PlayThread();
      playThread.start();
    } catch (Exception e) {
      System.out.println(e);
      System.exit(0);
    }//end catch
  }//end playAudio

  //This method creates and returns an
  // AudioFormat object for a given set of format
  // parameters.  If these parameters don't work
  // well for you, try some of the other
  // allowable parameter values, which are shown
  // in comments following the declartions.
  private 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);
  }//end getAudioFormat
//=============================================//

//Inner class to capture data from microphone
class CaptureThread extends Thread{
  //An arbitrary-size temporary holding buffer
  byte tempBuffer[] = new byte[10000];
  public void run(){
    byteArrayOutputStream =
                     new ByteArrayOutputStream();
    stopCapture = false;
    try{//Loop until stopCapture is set by
        // another thread that services the Stop
        // button.
      while(!stopCapture){
        //Read data from the internal buffer of
        // the data line.
        int cnt = targetDataLine.read(tempBuffer,
                              0,
                              tempBuffer.length);
        if(cnt > 0){
          //Save data in output stream object.
          byteArrayOutputStream.write(tempBuffer,
                                      0,
                                      cnt);
        }//end if
      }//end while
      byteArrayOutputStream.close();
    }catch (Exception e) {
      System.out.println(e);
      System.exit(0);
    }//end catch
  }//end run
}//end inner class CaptureThread
//===================================//
//Inner class to play back the data
// that was saved.
class PlayThread extends Thread{
  byte tempBuffer[] = new byte[10000];

  public void run(){
    try{
      int cnt;
      //Keep looping until the input read method
      // returns -1 for empty stream.
      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
      }//end while
      //Block and wait for internal buffer of the
      // data line to empty.
      sourceDataLine.drain();
      sourceDataLine.close();
    }catch (Exception e) {
      System.out.println(e);
      System.exit(0);
    }//end catch
  }//end run
}//end inner class PlayThread
//=============================================//
class ListMixers {
    PrintWriter out;

     void listAll(final PrintWriter out) {
        this.out = out;
        Mixer.Info[] aInfos = AudioSystem.getMixerInfo();
        for (int i = 0; i < aInfos.length; i++) {
            try {
                Mixer mixer = AudioSystem.getMixer(aInfos[i]);
                out.println(""+i+": "+aInfos[i].getName()+", "
                        +aInfos[i].getVendor()+", "
                        +aInfos[i].getVersion()+", "
                        +aInfos[i].getDescription());

                printLines(mixer, mixer.getSourceLineInfo());
                printLines(mixer, mixer.getTargetLineInfo());
            } catch (Exception e) {
                out.println("Exception: "+e);
            }
            out.println();
        }
        if (aInfos.length == 0) {
            out.println("[No mixers available]");
        }
    }

    void printLines(Mixer mixer, Line.Info[] infos) {
        for (int i = 0; i < infos.length; i++) {
            try {
                if (infos[i] instanceof Port.Info) {
                    Port.Info info = (Port.Info) infos[i];

                    out.println("  Port " + info);
                }
                if (infos[i] instanceof DataLine.Info) {
                    DataLine.Info info = (DataLine.Info) infos[i];

                    out.println("  Line " + info + " (max. " +
                                mixer.getMaxLines(info) + " simultaneously): ");
                    printFormats(info);
                }
                Line line = mixer.getLine(infos[i]);

                if (!(line instanceof Clip)) {
                    try {
                        line.open();
                    }
                    catch (LineUnavailableException e) {
                        out.println("LineUnavailableException when trying to open this line");
                    }
                }
                try {
                    printControls(line.getControls());
                }
                finally {
                    if (!(line instanceof Clip)) {
                        line.close();
                    }
                }
            }
            catch (Exception e) {
                out.println("Exception: " + e);
            }
            out.println();
        }
    }

    void printFormats(DataLine.Info info) {
        AudioFormat[] formats = info.getFormats();
        for (int i = 0; i < formats.length; i++) {
            out.println("  "+i+": "+formats[i]
                    +" ("+formats[i].getChannels()+" channels, "
                    +"frameSize="+formats[i].getFrameSize()+", "
                    +(formats[i].isBigEndian()?"big endian":"little endian")
                    +")");
        }
        if (formats.length == 0) {
            out.println("  [no formats]");
        }
        out.println();
    }

    void printControls(Control[] controls) {
        for (int i = 0; i<controls.length; i++) {
            printControl("    ", "Controls["+i+"]: ", controls[i]);
        }
        if (controls.length == 0) {
            out.println("    [no controls]");
        }
        out.println();
    }

    void printControl(String indent, String id, Control control) {
        if (control instanceof BooleanControl) {
            BooleanControl ctrl = (BooleanControl) control;
            out.println(indent+id+"BooleanControl: "+ctrl);
        } else if (control instanceof CompoundControl) {
            CompoundControl ctrl = (CompoundControl) control;
            Control[] ctrls = ctrl.getMemberControls();
            out.println(indent+id+"CompoundControl: "+control);
            for (int i=0; i<ctrls.length; i++) {
                printControl(indent+"  ", "MemberControls["+i+"]: ", ctrls[i]);
            }
        } else if (control instanceof EnumControl) {
            EnumControl ctrl = (EnumControl) control;
            Object[] values = ctrl.getValues();
            Object value = ctrl.getValue();
            out.println(indent+id+"EnumControl: "+control);
            for (int i=0; i<values.length; i++) {
                if (values[i] instanceof Control) {
                    printControl(indent+"  ", "Values["+i+"]: "+((values[i]==value)?"*":""), (Control) values[i]);
                } else {
                    out.println(indent+"  Values["+i+"]: "+((values[i]==value)?"*":"")+values[i]);
                }
            }
        } else if (control instanceof FloatControl) {
            FloatControl ctrl = (FloatControl) control;
            out.println(indent+id+"FloatControl: "+ctrl);
        } else {
            out.println(indent+id+"Control: "+control);
        }
    }
}
}//end outer class AudioCapture02.java

Answer 1

You're getting a TargetDataLine using an AudioFormat you've created. This isn't guaranteed to work. You must first query the Mixer to check if it supports your desired AudioFormat using the AudioSystem.isLineSupported(Info info) method.

Personally, I find this quite cumbersome. You need to query the Mixers on the system to determine if they support the AudioFormat you want.

The function below will get a Vector of supported formats for a data line class. Call it using

Vector<AudioFormat> formats = getSupportedFormats(TargetDataLine.class);

or

Vector<AudioFormat> formats = getSupportedFormats(SourceDataLine.class);

This code might need a bit of debugging; I had to remove some of my app-specific stuff to make it self contained...

public Vector<AudioFormat> getSupportedFormats(Class<?> dataLineClass) {
    /*
     * These define our criteria when searching for formats supported
     * by Mixers on the system.
     */
    float sampleRates[] = { (float) 8000.0, (float) 16000.0, (float) 44100.0 };
    int channels[] = { 1, 2 };
    int bytesPerSample[] = { 2 };

    AudioFormat format;
    DataLine.Info lineInfo;

    SystemAudioProfile profile = new SystemAudioProfile(); // Used for allocating MixerDetails below.
    Vector<AudioFormat> formats = new Vector<AudioFormat>();

    for (Mixer.Info mixerInfo : AudioSystem.getMixerInfo()) {
        for (int a = 0; a < sampleRates.length; a++) {
            for (int b = 0; b < channels.length; b++) {
                for (int c = 0; c < bytesPerSample.length; c++) {
                    format = new AudioFormat(AudioFormat.Encoding.PCM_SIGNED,
                            sampleRates[a], 8 * bytesPerSample[c], channels[b], bytesPerSample[c],
                            sampleRates[a], false);
                    lineInfo = new DataLine.Info(dataLineClass, format);
                    if (AudioSystem.isLineSupported(lineInfo)) {
                        /*
                         * TODO: To perform an exhaustive search on supported lines, we should open
                         * TODO: each Mixer and get the supported lines. Do this if this approach
                         * TODO: doesn't give decent results. For the moment, we just work with whatever
                         * TODO: the unopened mixers tell us.
                         */
                        if (AudioSystem.getMixer(mixerInfo).isLineSupported(lineInfo)) {
                            formats.add(format);
                        }
                    }
                }
            }
        }
    }
    return formats;
}