JavaSound mixer with both Port(s) and DataLine(s)?

Question

The diagrms in the JavaSound API Programmer's Guide appear to imply (pp. 19-20) that a Mixer can in principle have both DataLines and Ports. However, I was wondering if anyone had actually seen this configuration? What I witness is that where relevant, Mixers come in pairs, one with a source/target data line, and then the other with the corresponding Port.

Has anyone witnessed a configuration as implied in the Guide, with a mixer having both port and data line (or am I misinterpreting the guide)?

Answer 1

It would appear that the intention of the JavaSound API was to allow a Mixer to handle both DataLines and Ports. However the Sun implementation of the API that's included in the JRE has four concrete classes (DirectAudioDevice, SimpleInputDevice, HeadspaceMixer and PortMixer) that each only handle one or the other. They have native methods that map to the way the OS handles audio and it makes sense to keep the logic separate (the classes aren't small). There's not a 1:1 of DataLines to Ports (I for example have 5x DirectAudioDevice and 3x PortMixer) so it's up the programmer to determine what to use for what (or expose to the user for control). Perhaps there are 3rd party implementations of the API for specific devices which combine the two into one Mixer implementation, however I haven't seen one.

Answer 2

I am developing this for my site at pscode.org, but have not quite finished it yet. In any case, it gives a good overview of the sound system as either an applet or application.

/*
<applet
    code='MediaTypes'
    width='800'
    height='600'>
<param name='show' value='Sound|Sampled|Mixers|Primary Sound Driver'>
</applet>
*/
import javax.imageio.ImageIO;
import javax.sound.sampled.*;
import javax.sound.midi.*;
import java.awt.*;
import java.util.Arrays;
import java.util.ArrayList;
import javax.swing.*;
import javax.swing.table.DefaultTableModel;
import javax.swing.tree.*;
import javax.swing.event.*;
import javax.swing.text.Position;

public class MediaTypes extends JApplet {

    JTable table;
    boolean sortable = false;
    JTree tree;

    public void init() {
        Runnable r = new Runnable() {
            public void run() {
                MediaTypes mediaTypes = new MediaTypes();

                String show = "";
                if (getParameter("show")!=null) {
                    show = getParameter("show");
                }

                JPanel p = new JPanel();
                mediaTypes.createGui(p, show);
                add(p);
                validate();
            }
        };
        SwingUtilities.invokeLater(r);
    }

    public static void main(String[] args) {
        Runnable r = new Runnable() {
            public void run() {
                MediaTypes mediaTypes = new MediaTypes();

                JPanel p = new JPanel();
                mediaTypes.createGui(p);
                JOptionPane.showMessageDialog(null,p);
            }
        };
        SwingUtilities.invokeLater(r);
    }

    public Object[][] mergeArrays(String name1, Object[] data1, String name2, Object[] data2) {
        Object[][] data = new Object[data1.length+data2.length][2];
        for (int ii=0; ii<data1.length; ii++) {
            data[ii][0] = name1;
            data[ii][1] = data1[ii];
        }
        int offset = data1.length;
        for (int ii=offset; ii<data.length; ii++) {
            data[ii][0] = name2;
            data[ii][1] = data2[ii-offset];
        }
        return data;
    }

    public void createGui(JPanel panel) {
        createGui(panel, "");
    }

    public String getShortLineName(String name) {
        String[] lineTypes = {
            "Clip",
            "SourceDataLine",
            "TargetDataLine",
            "Speaker",
            "Microphone",
            "Master Volume",
            "Line In"
        };
        for (String shortName : lineTypes) {
            if ( name.toLowerCase().replaceAll("_", " ").contains(shortName.toLowerCase() )) {
                return shortName;
            }
        }
        return name;
    }

    public void createGui(JPanel panel, String path) {

        //DefaultMutableTreeNode selected = null;

        panel.setLayout( new BorderLayout(5,5) );
        final JLabel output = new JLabel("Select a tree leaf to see the details.");
        panel.add(output, BorderLayout.SOUTH);

        table = new JTable();
        try {
            table.setAutoCreateRowSorter(true);
            sortable = true;
        } catch (Throwable ignore) {
            // 1.6+ functionality - not vital
        }
        JScrollPane tableScroll = new JScrollPane(table);
        Dimension d = tableScroll.getPreferredSize();
        d = new Dimension(450,d.height);
        tableScroll.setPreferredSize(d);
        panel.add( tableScroll, BorderLayout.CENTER );

        DefaultMutableTreeNode rootNode = new DefaultMutableTreeNode("Media");
        DefaultTreeModel treeModel = new DefaultTreeModel(rootNode);

        DefaultMutableTreeNode imageNode = new DefaultMutableTreeNode("Image");
        rootNode.add(imageNode);

        Object[][] data;
        int offset;
        String[] columnNames;

        data = mergeArrays(
            "Reader",
            ImageIO.getReaderFileSuffixes(),
            "Writer",
            ImageIO.getWriterFileSuffixes() );
        columnNames = new String[]{"Input/Output", "Image File Suffixes"};
        MediaData md = new MediaData( "Suffixes", columnNames, data);
        imageNode.add(new DefaultMutableTreeNode(md));

        data = mergeArrays(
            "Reader",
            ImageIO.getReaderMIMETypes(),
            "Writer",
            ImageIO.getWriterMIMETypes() );
        columnNames = new String[]{"Input/Output", "Image MIME Types"};
        md = new MediaData( "MIME", columnNames, data);
        imageNode.add(new DefaultMutableTreeNode(md));

        DefaultMutableTreeNode soundNode = new DefaultMutableTreeNode("Sound");
        rootNode.add(soundNode);

        DefaultMutableTreeNode soundSampledNode = new DefaultMutableTreeNode("Sampled");
        soundNode.add(soundSampledNode);

        md = new MediaData("Suffixes", "Sound File Suffixes", AudioSystem.getAudioFileTypes());
        soundSampledNode.add(new DefaultMutableTreeNode(md));

        Mixer.Info[] mixerInfo = AudioSystem.getMixerInfo();
        String[][] mixerData = new String[mixerInfo.length][4];
        for (int ii=0; ii<mixerData.length; ii++) {
            mixerData[ii][0] = mixerInfo[ii].getName();
            mixerData[ii][1] = mixerInfo[ii].getVendor();
            mixerData[ii][2] = mixerInfo[ii].getVersion();
            mixerData[ii][3] = mixerInfo[ii].getDescription();
        }
        columnNames = new String[]{"Name", "Vendor", "Version", "Description"};
        md = new MediaData("Mixers", columnNames, mixerData);
        DefaultMutableTreeNode soundSampledMixersNode = new DefaultMutableTreeNode(md);
        soundSampledNode.add(soundSampledMixersNode);

        for (int ii=0; ii<mixerInfo.length; ii++) {
            Mixer mixer = AudioSystem.getMixer(mixerInfo[ii]);
            data = mergeArrays(
                "Source",
                mixer.getSourceLineInfo(),
                "Target",
                mixer.getTargetLineInfo() );
            columnNames = new String[]{ "Input/Output", "Line Info" };
            md = new MediaData(mixerInfo[ii].getName(), columnNames, data);
            DefaultMutableTreeNode soundSampledMixerNode = new DefaultMutableTreeNode(md);
            soundSampledMixersNode.add( soundSampledMixerNode );

            //Mixer mixer = AudioSystem.getMixer(mixerInfo[ii]);
            Line.Info[] source = mixer.getSourceLineInfo();
            Line.Info[] target = mixer.getTargetLineInfo();
            Line[] all = new Line[source.length + target.length];
            try {
                for (int jj=0; jj<source.length; jj++) {
                    all[jj] = AudioSystem.getLine(source[jj]);
                }
                for (int jj=source.length; jj<all.length; jj++) {
                    all[jj] = AudioSystem.getLine(target[jj-source.length]);
                }
                columnNames = new String[]{"Attribute", "Value"};
                for (Line line : all) {
                    Control[] controls = line.getControls();
                    if (line instanceof DataLine) {
                        DataLine dataLine = (DataLine)line;
                        AudioFormat audioFormat = dataLine.getFormat();
                        data = new Object[7+controls.length][2];

                        data[0][0] = "Channels";
                        data[0][1] = new Integer(audioFormat.getChannels());

                        data[1][0] = "Encoding";
                        data[1][1] = audioFormat.getEncoding();

                        data[2][0] = "Frame Rate";
                        data[2][1] = new Float(audioFormat.getFrameRate());

                        data[3][0] = "Sample Rate";
                        data[3][1] = new Float(audioFormat.getSampleRate());

                        data[4][0] = "Sample Size (bits)";
                        data[4][1] = new Integer(audioFormat.getSampleSizeInBits());

                        data[5][0] = "Big Endian";
                        data[5][1] = new Boolean(audioFormat.isBigEndian());

                        data[6][0] = "Level";
                        data[6][1] = new Float(dataLine.getLevel());

                    } else if (line instanceof Port) {
                        Port port = (Port)line;
                        Port.Info portInfo = (Port.Info)port.getLineInfo();
                        data = new Object[2+controls.length][2];

                        data[0][0] = "Name";
                        data[0][1] = portInfo.getName();

                        data[1][0] = "Source";
                        data[1][1] = new Boolean(portInfo.isSource());
                    } else {
                        System.out.println( "?? " + line );
                    }
                    int start = data.length-controls.length;
                    for (int kk=start; kk<data.length; kk++) {
                        data[kk][0] = "Control";
                        int index = kk-start;
                        data[kk][1] = controls[index];
                    }
                    md = new MediaData(getShortLineName(line.getLineInfo().toString()), columnNames, data);
                    soundSampledMixerNode.add(new DefaultMutableTreeNode(md));
                }
            } catch(Exception e) {
                e.printStackTrace();
            }
        }

        int[] midiTypes = MidiSystem.getMidiFileTypes();
        data = new Object[midiTypes.length][2];
        for (int ii=0; ii<midiTypes.length; ii++) {
            data[ii][0] = new Integer(midiTypes[ii]);
            String description = "Unknown";
            switch (midiTypes[ii]) {
                case 0:
                    description = "Single Track";
                    break;
                case 1:
                    description = "Multi Track";
                    break;
                case 2:
                    description = "Multi Song";
            }
            data[ii][1] = description;
        }
        columnNames = new String[]{"Type", "Description"};
        md = new MediaData("MIDI", columnNames, data);
        DefaultMutableTreeNode soundMIDINode = new DefaultMutableTreeNode(md);
        soundNode.add(soundMIDINode);

        columnNames = new String[]{
            "Attribute",
            "Value"};
        MidiDevice.Info[] midiDeviceInfo = MidiSystem.getMidiDeviceInfo() ;
        for (int ii=0; ii<midiDeviceInfo.length; ii++) {
            data = new Object[6][2];
            data[0][0] = "Name";
            data[0][1] = midiDeviceInfo[ii].getName();

            data[1][0] = "Vendor";
            data[1][1] = midiDeviceInfo[ii].getVendor();

            data[2][0] = "Version";
            String version = midiDeviceInfo[ii].getVersion();
            data[2][1] = version.replaceAll("Version ", "");

            data[3][0] = "Description";
            data[3][1] = midiDeviceInfo[ii].getDescription();

            data[4][0] = "Maximum Transmitters";
            data[5][0] = "Maximum Receivers";
            try {
                MidiDevice midiDevice = MidiSystem.getMidiDevice(midiDeviceInfo[ii]);
                Object valueTransmitter;
                if (midiDevice.getMaxTransmitters()==AudioSystem.NOT_SPECIFIED) {
                    valueTransmitter = "Not specified";
                } else {
                    valueTransmitter = new Integer(midiDevice.getMaxTransmitters());
                }

                Object valueReceiver;
                if (midiDevice.getMaxReceivers()==AudioSystem.NOT_SPECIFIED) {
                    valueReceiver = "Not specified";
                } else {
                    valueReceiver = new Integer(midiDevice.getMaxReceivers());
                }

                data[4][1] = valueTransmitter;
                data[5][1] = valueReceiver;
            } catch(MidiUnavailableException mue) {
                data[4][1] = "Unknown";
                data[5][1] = "Unknown";
            }
            md = new MediaData(midiDeviceInfo[ii].getName(), columnNames, data);
            soundMIDINode.add( new DefaultMutableTreeNode(md) );
        }

        tree = new JTree(treeModel);
        tree.setRootVisible(false);
        tree.getSelectionModel().setSelectionMode
            (TreeSelectionModel.SINGLE_TREE_SELECTION);
        tree.addTreeSelectionListener( new TreeSelectionListener() {
            public void valueChanged(TreeSelectionEvent tse) {
                if (sortable) {
                    output.setText("Click table column headers to sort.");
                }

                DefaultMutableTreeNode node = (DefaultMutableTreeNode)
                    tree.getLastSelectedPathComponent();

                if (node == null) return;

                Object nodeInfo = node.getUserObject();
                if (nodeInfo instanceof MediaData) {
                    MediaData mediaData = (MediaData)nodeInfo;
                    table.setModel( new DefaultTableModel(
                        mediaData.getData(),
                        mediaData.getColumnNames()) );
                }
            }
        } );

        for (int ii=0; ii<tree.getRowCount(); ii++) {
            tree.expandRow(ii);
        }

        String[] paths = path.split("\\|");
        int row = 0;
        TreePath treePath = null;
        for (String prefix : paths) {
            treePath = tree.getNextMatch( prefix, row, Position.Bias.Forward );
            row = tree.getRowForPath(treePath);
        }

        panel.add(new JScrollPane(tree),BorderLayout.WEST);

        tree.setSelectionPath(treePath);
        tree.scrollRowToVisible(row);
    }
}

class MediaData {

    String name;
    String[] columnNames;
    Object[][] data;

    MediaData(String name, String columnName, Object[] data) {
        this.name = name;

        columnNames = new String[1];
        columnNames[0] = columnName;

        this.data = new Object[data.length][1];
        for (int ii=0; ii<data.length; ii++) {
            this.data[ii][0] = data[ii];
        }
    }

    MediaData(String name, String[] columnNames, Object[][] data) {
        this.name = name;
        this.columnNames = columnNames;
        this.data = data;
    }

    public String toString() {
        return name;
    }

    public String[] getColumnNames() {
        return columnNames;
    }

    public Object[][] getData() {
        return data;
    }
}

Screenshot