Basic Audio Tracking in Processing IDE

import ddf.minim.*;
import ddf.minim.analysis.*;

// Declare Minim and AudioInput objects
Minim minim;
AudioInput in;

// Declare FFT object
FFT fft;

// Variables for average volume and smoothed volume
float rms;
float smoothedRMS = 0;

// Variables for spectral centroid
float spectralCentroid;
float smoothedSpectralCentroid = 0;

void setup() {
  // Set up the canvas size
  size(800, 600);

  // Initialize Minim
  minim = new Minim(this);

  // Get a stereo audio input from the microphone
  in = minim.getLineIn(Minim.STEREO, 1024);

  // Create an FFT object for the audio input
  fft = new FFT(in.bufferSize(), in.sampleRate());

  // Set the analysis window to Hamming
  fft.window(FFT.HAMMING);
}

void draw() {
  // Clear the background
  background(0);

  // Perform the FFT on the audio input
  fft.forward(in.mix);

  // Draw the FFT spectrum
  stroke(255);
  for (int i = 0; i < fft.specSize(); i++) {
    // Calculate the height of the line for this frequency bin
    float amplitude = fft.getBand(i) * 4;

    // Draw a line for each frequency bin
    line(i * (width / fft.specSize()), height, i * (width / fft.specSize()), height - amplitude);
  }

  // Calculate RMS (average volume)
  rms = in.mix.level();

  // Smooth the RMS value using lerp
  smoothedRMS = lerp(smoothedRMS, rms, 0.1);

  // Display the smoothed RMS value
  fill(255);
  textSize(16);
  text("Smoothed RMS: " + nf(smoothedRMS, 1, 3), 10, height - 40);

  // Calculate spectral centroid
  float weightedSum = 0;
  float totalSum = 0;
  for (int i = 0; i < fft.specSize(); i++) {
    weightedSum += fft.getBand(i) * i;
    totalSum += fft.getBand(i);
  }
  if (totalSum > 0) {
    spectralCentroid = weightedSum / totalSum;
  } else {
    spectralCentroid = 0;
  }

  // Smooth the spectral centroid using lerp
  smoothedSpectralCentroid = lerp(smoothedSpectralCentroid, spectralCentroid, 0.1);

  // Display the smoothed spectral centroid
  text("Spectral Centroid: " + nf(smoothedSpectralCentroid, 1, 3), 10, height - 20);

  // Display a message on the canvas
  text("Audio FFT Spectrum", 10, 20);
}

void stop() {
  // Close the audio input when the sketch is stopped
  in.close();
  minim.stop();
  super.stop();
}