A Processing Music Visualizer

visualizer.rb

# Visualizer

class Visualizer < Processing::App

  load_library "minim" #Java sound library included with processing. load_library is provided by ruby-processing
  import "ddf.minim"
  import "ddf.minim.analysis"

  def setup
    smooth
    size(1280, 100)
    background 10    
    setup_sound
  end
  
  def draw
    update_sound
    animate_sound
  end
  
  def setup_sound
    @minim = Minim.new(self)
    @input = @minim.get_line_in
    @fft = FFT.new(@input.left.size, 44100)
    @beat = BeatDetect.new

    @frequencies = [60,170,310,600,600,1000,3000,6000,12000,14000,16000]

    @current_ffts = Array.new(@frequencies.size, 0.001)
    @previous_ffts = Array.new(@frequencies.size, 0.001)
    @max_ffts = Array.new(@frequencies.size, 0.001)
    @scaled_ffts = Array.new(@frequencies.size, 0.001)

    @fft_smoothing = 0.8
  end

  def update_sound
    @fft.forward(@input.left)
    @previous_ffts = @current_ffts

    @frequencies.each_with_index do |frequency, i|
      new_fft = @fft.get_freq(frequency)
      @max_ffts[i] = new_fft if new_fft > @max_ffts[i]
      @current_ffts[i] = ((1-@fft_smoothing ) * new_fft) + (@fft_smoothing * @previous_ffts[i])
      @scaled_ffts[i] = (@current_ffts[i]/@max_ffts[i])
    end
    @beat.detect(@input.left)
  end

  def animate_sound
    @size = @scaled_ffts[1] * height
    @size *= 4 if @beat.is_onset

    @x1 = @scaled_ffts[0]*width + width/2
    @y1 = @scaled_ffts[1]*height + height/2
    @red1 = @scaled_ffts[2]*255
    @green1 = @scaled_ffts[3]*255
    @blue1 = @scaled_ffts[4]*255

    fill @red1, @green1, @blue1
    stroke @red1+20, @green1+20, @blue1+20
    ellipse(@x1, @y1, @size, @size)
  end

end

Visualizer.new :title => "Visualizer"