gistfile1.java

package pl.edu.pw.fizyka.pojava.sound_example;

import javax.sound.sampled.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.nio.ByteBuffer;


public class Example {

    /**
     * Beeps.  Currently half-assumes that the format the system expects is
     * "PCM_SIGNED unknown sample rate, 16 bit, stereo, 4 bytes/frame, big-endian"
     * I don't know what to do about the sample rate.  Using 11025, since that
     * seems to be right, by testing against A440.  I also can't figure out why
     * I had to *4 the duration.  Also, there's up to about a 100 ms delay before
     * the sound starts playing.
     * @param freq
     * @param millis
     */
    public static void beep(double freq, final double millis) throws InterruptedException, LineUnavailableException {

        final Clip clip = AudioSystem.getClip();
        /**
         * AudioFormat of the reclieved clip. Probably you can alter it
         * someway choosing proper Line.
         */
        AudioFormat af = clip.getFormat();

        /**
         * We assume that encoding uses signed shorts. Probably we could
         * make this code more generic but who cares.
         */
        if (af.getEncoding() != AudioFormat.Encoding.PCM_SIGNED){
            throw new UnsupportedOperationException("Unknown encoding");
        }

        if (af.getSampleSizeInBits() != 16) {
            System.err.println("Weird sample size.  Dunno what to do with it.");
            return;
        }

        /**
         * Number of bytes in a single frame
         */
        int bytesPerFrame = af.getFrameSize();
        /**
         * Number of frames per second
         */
        double fps = af.getFrameRate();
        /**
         * Number of frames during the clip .
         */
        int frames = (int)(fps * (millis / 1000));

        /**
         * Data
         */
        ByteBuffer data = ByteBuffer.allocate(frames * bytesPerFrame);

        /**
         * We will emit sinus, which needs to be scaled so it has proper
         * frequency --- here is the scaling factor.
         */
        double freqFactor = (Math.PI / 2) * freq / fps;
        /**
         * This sinus must also be scaled so it fills short.
         */
        double ampFactor = Short.MAX_VALUE;

        short sample;

        for (int frame = 0; frame < frames; frame++) {
            sample = (short) (ampFactor * Math.sin(frame * freqFactor));
            data.putShort(sample);
        }
        clip.open(af, data.array(), 0, data.position());

        // This is so Clip releases its data line when done.  Otherwise at 32 clips it breaks.
        clip.addLineListener(new LineListener() {
            @Override
            public void update(LineEvent event) {
                if (event.getType() == LineEvent.Type.START) {
                    Timer t = new Timer((int)millis + 1, new ActionListener() {
                        @Override
                        public void actionPerformed(ActionEvent e) {
                            clip.close();
                        }
                    });
                    t.setRepeats(false);
                    t.start();
                }
            }
        });
        clip.start();

        Thread.sleep((long)millis);



    }

    public static void main(String[] args) throws Exception {
        beep(750, 3000);
    }
}

nice

thanks

Cool!

Minor spelling corrections:
On line 27 "reclieved" should be "received".
On line 64 and 69 "sinus" should be "sines".

This crashed on line 25 clip = AudioSystem.getClip() for me with
java.lang.IllegalArgumentException: No line matching interface Clip supporting format PCM_SIGNED unknown sample rate, 16 bit, stereo, 4 bytes/frame, big-endian is supported.
So I added IllegalArgumentException to the list of exceptions on line 23