Waveform

examples/Analysis/AudioWaveform/AudioWaveform.pde

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+/**
+ * This sketch shows how to use the Waveform class to analyze a stream
+ * of sound. Change the number of samples to get a longer/shorter part of the waveform.
+ */
+
+import processing.sound.*;
+
+// Declare the sound source and Waveform analyzer variables
+SoundFile sample;
+Waveform waveform;
+
+// Define how many samples of the Waveform you want to use (must be a power of two)
+int samples = 128;
+
+public void setup() {
+  size(640, 360);
+  background(255);
+
+  // Load and play a soundfile and loop it.
+  sample = new SoundFile(this, "beat.aiff");
+  sample.loop();
+
+  // Create the Waveform analyzer and connect the playing soundfile to it.
+  waveform = new Waveform(this, samples);
+  waveform.input(sample);
+}
+
+public void draw() {
+  // Set background color, noFill and stroke style
+  background(0);
+  stroke(255);
+  strokeWeight(2);
+  noFill();
+
+  // Perform the analysis
+  waveform.analyze();
+
+  beginShape();
+  for(int i = 0; i < samples; i++){
+    // Draw current data of the waveform
+    // Each sample in the data array is between -1 and +1 
+    vertex(
+      map(i, 0, samples, 0, width),
+      map(waveform.data[i], -1, 1, 0, height)
+    );
+  }
+  endShape();
+}

src/processing/sound/JSynWaveform.java

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+package processing.sound;
+
+import java.util.Arrays;
+
+import com.jsyn.data.FloatSample;
+import com.jsyn.unitgen.FixedRateMonoWriter;
+
+/**
+ * This class copies all input to an audio buffer of the given size and returns it.
+ * 
+ * @author icalvin102
+ */
+class JSynWaveform extends FixedRateMonoWriter {
+
+	private FloatSample buffer;
+
+	protected JSynWaveform(int bufferSize) {
+		super();
+		this.buffer = new FloatSample(bufferSize);
+
+		// write any connected input into the output buffer ad infinitum
+		this.dataQueue.queueLoop(this.buffer);
+	}
+
+	protected void calculateWaveform(float[] target) {
+		// get position currently being written to
+		int pos = (int) this.dataQueue.getFrameCount() % this.buffer.getNumFrames();
+		for (int i = 0; i < this.buffer.getNumFrames(); i++) {
+			target[i] = (float)(2*this.buffer.readDouble((pos + i) % this.buffer.getNumFrames()));
+		}
+	}
+}

src/processing/sound/Waveform.java

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+package processing.sound;
+
+import com.jsyn.ports.UnitOutputPort;
+
+import processing.core.PApplet;
+
+/**
+ * This is a Waveform analyzer. It returns the waveform of the 
+ * of an audio stream the moment it is queried with the analyze()
+ * method.
+ * 
+ * @author icalvin102
+ * 
+ * @webref sound
+ **/
+public class Waveform extends Analyzer {
+
+	public float[] data;
+
+	private JSynWaveform waveform;
+
+	public PApplet app;
+
+	public Waveform(PApplet parent) {
+		this(parent, 512);
+	}
+
+	/**
+	 * @param parent
+	 *            typically use "this"
+	 * @param samples
+	 *            number of waveform samples as an integer (default 512).
+	 *            This parameter needs to be a power of 2 (e.g. 16, 32, 64, 128,
+	 *            ...).
+	 * @webref sound
+	 */
+	public Waveform(PApplet parent, int samples) {
+		super(parent);
+		app = parent;
+		if (samples < 0 || Integer.bitCount(samples) != 1) {
+			// TODO throw RuntimeException?
+			Engine.printError("number of waveform frames needs to be a power of 2");
+		} else {
+			// FFT buffer size is twice the number of frequency bands
+			this.waveform = new JSynWaveform(samples);
+			this.data = new float[samples];
+		}
+	}
+
+	protected void removeInput() {
+		this.waveform.input.disconnectAll();
+		this.input = null;
+	}
+
+	protected void setInput(UnitOutputPort input) {
+		// superclass makes sure that input unit is actually playing, just connect it
+		Engine.getEngine().add(this.waveform);
+		this.waveform.input.connect(input);
+		this.waveform.start();
+	}
+
+	/**
+	 * Gets the content of the current audiobuffer from the input source, writes it
+	 * into this Waveform's `data` array, and returns it.
+	 *
+	 * @return the current audiobuffer of the input source. The array has as
+	 *         many elements as this Waveform analyzer's number of samples
+	 */
+	public float[] analyze() {
+		return this.analyze(this.data);
+	}
+
+	/**
+	 * Gets the content of the current audiobuffer from the input source.
+	 *
+	 * @param value
+	 *            an array with as many elements as this Waveform analyzer's number of
+	 *            samples
+	 * @return the current audiobuffer of the input source. The array has as
+	 *         many elements as this Waveform analyzer's number of samples
+	 * @webref sound
+	 **/
+	public float[] analyze(float[] value) {
+		if (this.input == null) {
+			Engine.printWarning("this Waveform has no sound source connected to it, nothing to analyze");
+		}
+		this.waveform.calculateWaveform(value);
+		return value;
+	}
+
+	// Below are just duplicated methods from superclasses which are required
+	// for the online reference to build the corresponding pages.
+
+	/**
+	 * Define the audio input for the analyzer.
+	 * 
+	 * @param input
+	 *            the input sound source. Can be an oscillator, noise generator,
+	 *            SoundFile or AudioIn.
+	 * @webref sound
+	 **/
+	public void input(SoundObject input) {
+		super.input(input);
+	}
+}