Java example source code file (DirectAudioDeviceProvider.java)

This example Java source code file (DirectAudioDeviceProvider.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

directaudiodeviceinfo, directaudiodeviceprovider, illegalargumentexception, mixer, mixerprovider, string

The DirectAudioDeviceProvider.java Java example source code

/*
 * Copyright (c) 2002, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

package com.sun.media.sound;

import javax.sound.sampled.Mixer;
import javax.sound.sampled.spi.MixerProvider;


/**
 * DirectAudioDevice provider.
 *
 * @author Florian Bomers
 */
public final class DirectAudioDeviceProvider extends MixerProvider {

    // STATIC VARIABLES

    /**
     * Set of info objects for all port input devices on the system.
     */
    private static DirectAudioDeviceInfo[] infos;

    /**
     * Set of all port input devices on the system.
     */
    private static DirectAudioDevice[] devices;


    // STATIC

    static {
        // initialize
        Platform.initialize();
    }


    // CONSTRUCTOR


    /**
     * Required public no-arg constructor.
     */
    public DirectAudioDeviceProvider() {
        synchronized (DirectAudioDeviceProvider.class) {
            if (Platform.isDirectAudioEnabled()) {
                init();
            } else {
                infos = new DirectAudioDeviceInfo[0];
                devices = new DirectAudioDevice[0];
            }
        }
    }

    private static void init() {
        // get the number of input devices
        int numDevices = nGetNumDevices();

        if (infos == null || infos.length != numDevices) {
            if (Printer.trace) Printer.trace("DirectAudioDeviceProvider: init()");
            // initialize the arrays
            infos = new DirectAudioDeviceInfo[numDevices];
            devices = new DirectAudioDevice[numDevices];

            // fill in the info objects now.
            for (int i = 0; i < infos.length; i++) {
                infos[i] = nNewDirectAudioDeviceInfo(i);
            }
            if (Printer.trace) Printer.trace("DirectAudioDeviceProvider: init(): found numDevices: " + numDevices);
        }
    }

    public Mixer.Info[] getMixerInfo() {
        synchronized (DirectAudioDeviceProvider.class) {
            Mixer.Info[] localArray = new Mixer.Info[infos.length];
            System.arraycopy(infos, 0, localArray, 0, infos.length);
            return localArray;
        }
    }


    public Mixer getMixer(Mixer.Info info) {
        synchronized (DirectAudioDeviceProvider.class) {
            // if the default device is asked, we provide the mixer
            // with SourceDataLine's
            if (info == null) {
                for (int i = 0; i < infos.length; i++) {
                    Mixer mixer = getDevice(infos[i]);
                    if (mixer.getSourceLineInfo().length > 0) {
                        return mixer;
                    }
                }
            }
            // otherwise get the first mixer that matches
            // the requested info object
            for (int i = 0; i < infos.length; i++) {
                if (infos[i].equals(info)) {
                    return getDevice(infos[i]);
                }
            }
        }
        throw new IllegalArgumentException("Mixer " + info.toString() + " not supported by this provider.");
    }


    private static Mixer getDevice(DirectAudioDeviceInfo info) {
        int index = info.getIndex();
        if (devices[index] == null) {
            devices[index] = new DirectAudioDevice(info);
        }
        return devices[index];
    }

    // INNER CLASSES


    /**
     * Info class for DirectAudioDevices.  Adds an index value and a string for
     * making native references to a particular device.
     * This constructor is called from native.
     */
    static final class DirectAudioDeviceInfo extends Mixer.Info {
        private final int index;
        private final int maxSimulLines;

        // For ALSA, the deviceID contains the encoded card index, device index, and sub-device-index
        private final int deviceID;

        private DirectAudioDeviceInfo(int index, int deviceID, int maxSimulLines,
                                      String name, String vendor,
                                      String description, String version) {
            super(name, vendor, "Direct Audio Device: "+description, version);
            this.index = index;
            this.maxSimulLines = maxSimulLines;
            this.deviceID = deviceID;
        }

        int getIndex() {
            return index;
        }

        int getMaxSimulLines() {
            return maxSimulLines;
        }

        int getDeviceID() {
            return deviceID;
        }
    } // class DirectAudioDeviceInfo

    // NATIVE METHODS
    private static native int nGetNumDevices();
    // index: [0..nGetNumDevices()-1]
    private static native DirectAudioDeviceInfo nNewDirectAudioDeviceInfo(int deviceIndex);
}