Grains

Author: Kees van den Doel

This applet loads a wav file and divides it into segments. A transition matrix is generated which governs which segment follows which on playback. With the slider you can bias the probabilities to favour linear playback (1) or very randomized (0). The hard part, not addressed here, is to find interesting segmentation and transition probability matrices.

Source code:

import jass.render.*;
import jass.engine.*;
import jass.generators.*;
import java.net.*;
/**
   @author Kees van den Doel (kvdoel@cs.ubc.ca)
*/
public class GrainsApplet extends AppletController {
    GranularConstantLoopBuffer grainBuffer;
    SourcePlayer player;
    boolean isOn = false;
    String wavfile;
    int nGrains = 10;
    float fadeTime = .03f; // will smooth transitions here
    float linearBias = 0;
    
    public void setNSliders() {
        nsliders = 1;
    }
   
    public void setNButtons() {
        nbuttons = 1;
    }
    
    public void init() {
        super.init();
        wavfile = getParameter("wavfile");
        nGrains = Integer.parseInt(getParameter("ngrains"));
        fadeTime = new Float(getParameter("fadetime")).floatValue();
        linearBias = new Float(getParameter("linearbias")).floatValue();
    }
   
    public void start() {
        float srate = 44100.f;
        int bufferSize = 128;
        int bufferSizeJavaSound = 8*1024;
        URL codebase = getCodeBase();
        URL wavurl = null;
        try {
            wavurl = new URL(codebase,wavfile);
        } catch(MalformedURLException e) {
            System.out.println(e+" Malformed URL: " +codebase+" "+ wavfile);
        }
        grainBuffer = new GranularConstantLoopBuffer(srate,bufferSize, wavurl);
        grainBuffer.setFadeTime(fadeTime);
        grainBuffer.initRandom(nGrains,linearBias);
        player = new SourcePlayer(bufferSize,bufferSizeJavaSound,srate);
        try {
            player.addSource(grainBuffer);
        } catch(SinkIsFullException e) {
        }

        String[] names = {"Linearity "};
        double[] val =   {linearBias  };
        double[] min =   {0           };
        double[] max =   {1           };
        setValues(val,min,max,names);
        jButton[0].setText ("Stop");
        
        player.start();
        isOn = true;
    }

    protected void jButtonMousePressed (int k, java.awt.event.MouseEvent evt) {
        switch(k) {
        case 0:
            if(isOn) {
                jButton[0].setText ("Start");
                isOn = false;
                grainBuffer.setVolume(0);
            } else {
                jButton[0].setText ("Stop");
                isOn = true;
                grainBuffer.setVolume(1f);
                //player.resetAGC();
            }
            break;
        }

    }
    
    protected void onSlider(int k) {
        switch(k) {
        case 0:
            grainBuffer.setLinearBias((float)this.val[0]);
            grainBuffer.setTransitionMatrix();
            break;
        }
    }
    
}