!7

sS lib = "JavaSound"; // "JavaSound" or "JACK"

lib 1009653 lib 1009652 lib 1009650 // JACK
lib 1009654 // JavaSound
lib 1009055 lib 1009056 // JNA

import java.nio.FloatBuffer;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jaudiolibs.audioservers.AudioClient;
import org.jaudiolibs.audioservers.AudioConfiguration;
import org.jaudiolibs.audioservers.AudioServer;
import org.jaudiolibs.audioservers.AudioServerProvider;
import org.jaudiolibs.audioservers.ext.ClientID;
import org.jaudiolibs.audioservers.ext.Connections;

p { SineAudioClient.main(args); }

/**
 * Basic example for processing audio using the AudioServer API.
 * 
 * A simple AudioClient that outputs a sine wave.
 * 
 * Run main() - if not using NetBeans, make sure to configure JVM arguments.
 * -Xincgc is recommended.
 * -Djna.nosys=true may be required if using the JACK AudioServer and 
 * an older version of JNA is installed on your system.
 * 
 * @author Neil C Smith
 */
sclass SineAudioClient implements AudioClient {

    
    public static void main(String[] args) throws Exception {
      fixContextClassLoader();
      
        
        /* Search for an AudioServerProvider that matches the required library name
         * using the ServiceLoader mechanism. This removes the need for a direct
         * dependency on any particular server implementation.
         * 
         * It is also possible to create particular AudioServerProvider's 
         * directly. 
         */

        AudioServerProvider provider = null;
        for (AudioServerProvider p : ServiceLoader.load(AudioServerProvider.class)) {
            if (lib.equals(p.getLibraryName())) {
                provider = p;
                break;
            }
        }
        if (provider == null) {
            throw new NullPointerException("No AudioServer found that matches : " + lib);
        }
        
        /* Create an instance of our client - see methods in the implementation 
         * below for more information.
         */
        AudioClient client = new SineAudioClient();
        
        /* Create an audio configuration.
         * 
         * The configuration is a hint to the AudioServer. Some servers (eg. JACK)
         * will ignore the sample rate and buffersize here.
         * The correct values will be passed to the client during configuration.
         * 
         * Various extension objects can be added to the AudioConfiguration.
         * The ClientID and Connections parameters here will be used by the JACK server.
         * 
         */
        AudioConfiguration config = new AudioConfiguration(
                44100.0f, //sample rate
                0, // input channels
                2, // output channels
                256, //buffer size
                // extensions
                new ClientID("Sine"),
                Connections.OUTPUT);
        
        
        /* Use the AudioServerProvider to create an AudioServer for the client. 
         */
        final AudioServer server = provider.createServer(config, client);
        
        /* Create a Thread to run our server. All servers require a Thread to run in.
         */   
        Thread runner = new Thread(new Runnable() {
            public void run() {
                // The server's run method can throw an Exception so we need to wrap it
                try {
                    server.run();
                } catch (Exception ex) {
                    Logger.getLogger(SineAudioClient.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        });
        // set the Thread priority as high as possible.
        runner.setPriority(Thread.MAX_PRIORITY);
        // and start processing audio - you'll have to kill the program manually!
        runner.start();

    }

    // AudioClient implementation
    
    private final static float FREQ = 440.0f;
    private float[] data;
    private int idx;

    public void configure(AudioConfiguration context) throws Exception {
        /* Check the configuration of the passed in context, and set up any
         * necessary resources. Throw an Exception if the sample rate, buffer
         * size, etc. cannot be handled. DO NOT assume that the context matches
         * the configuration you passed in to create the server - it will
         * be a best match.
         */
        if (context.getOutputChannelCount() != 2) {
            throw new IllegalArgumentException("SineAudioClient can only work with stereo output");
        }
        
        int size = (int) (context.getSampleRate() / FREQ);
        data = new float[size];
        for (int i = 0; i < size; i++) {
            data[i] = (float) (0.2 * Math.sin(((double) i / (double) size) * Math.PI * 2.0));
        }
    }

    public boolean process(long time, List<FloatBuffer> inputs, List<FloatBuffer> outputs, int nframes) {
        // get left and right channels from array list
        FloatBuffer left = outputs.get(0);
        FloatBuffer right = outputs.get(1);
        
        // always use nframes as the number of samples to process
        for (int i = 0; i < nframes; i++) {
            left.put(data[idx]);
            right.put(data[idx]);
            idx++;
            if (idx == data.length) {
                idx = 0;
            }

        }
        return true;
    }

    public void shutdown() {
        //dispose resources.
        data = null;
    }

}

Began life as a copy of #1009651