Realtime FFT Analysis for Processing

realtime_fft.pde

// Processing realtime FFT analysis
import processing.sound.*;

AudioIn input;
FFT fft;

int bands=512;
float[] spectrum = new float[bands];

public void setup() {
  size(bands, 360);
  background(255);

  input = new AudioIn(this, 0);
  input.play();

  fft = new FFT(this);
  fft.input(input, bands);
}      

public void draw() {
  background(255);
  fft.analyze(spectrum);
  for (int i = 0; i < bands; i++) {
    line( i, height, i, height - spectrum[i]*height*5 );
  }
}