Class: Synthesizer::OscillatorSource::FormantVocoder

Inherits:
Object
  • Object
show all
Defined in:
lib/synthesizer/oscillator_source/formant_vocoder.rb

Defined Under Namespace

Classes: Context

Constant Summary collapse

@@f = 
{
  i: [110.0, 250.0, 2100.0, 2900.0, 3700.0],
  e: [160.0, 450.0, 1900.0, 2650.0, 3800.0],
  a: [110.0, 700.0, 1250.0, 2500.0, 3900.0],
  o: [110.0, 500.0, 1050.0, 2700.0, 3700.0],
  u: [110.0, 330.0, 1500.0, 2400.0, 3650.0],
  x: [110.0, 335.0, 1550.0, 2450.0, 3800.0],
}
@@gain = 
[50.0, 70.0, 110.0, 200.0, 200.0].map {|x| Math::PI * x}

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(vowels: [:i, :e, :a, :o, :u], pronunciation: 0) ⇒ FormantVocoder

Returns a new instance of FormantVocoder.



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# File 'lib/synthesizer/oscillator_source/formant_vocoder.rb', line 17

def initialize(vowels: [:i, :e, :a, :o, :u], pronunciation: 0)
  self.vowels = vowels
  self.pronunciation = pronunciation
  @pulse = Pulse.instance
end

Instance Attribute Details

#pronunciation ⇒ Object

Returns the value of attribute pronunciation.



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# File 'lib/synthesizer/oscillator_source/formant_vocoder.rb', line 5

def pronunciation
  @pronunciation
end

#vowels ⇒ Object

Returns the value of attribute vowels.



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# File 'lib/synthesizer/oscillator_source/formant_vocoder.rb', line 4

def vowels
  @vowels
end

Instance Method Details

#generate_context(soundinfo, note_perform, init_phase) ⇒ Object 



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# File 'lib/synthesizer/oscillator_source/formant_vocoder.rb', line 95

def generate_context(soundinfo, note_perform, init_phase)
  Context.new(soundinfo, note_perform, init_phase, @pronunciation)
end

#next(context, rate, sym, sync, l_gain, r_gain) ⇒ Object 



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# File 'lib/synthesizer/oscillator_source/formant_vocoder.rb', line 33

def next(context, rate, sym, sync, l_gain, r_gain)
  soundinfo = context.soundinfo
  channels = context.channels
  window_size = context.window_size
  samplerate = context.samplerate
  tmpbufs = context.tmpbufs
  pronunciation_mod = context.pronunciation_mod
  pulse_context = context.pulse_context

  pulse = Pulse.instance.next(pulse_context, rate, sym, sync, 0.5, 0.5).streams[0]

  notediff = Math.log2(rate.freq(soundinfo) / 440.0) * 12 + 69 - 36
  if notediff<0.0
    notediff = 0.0
  end
  notediff = Math.sqrt(notediff)
  vowels = @vowels.map {|vowel|
    vowel.map{|f| f * (ShapePos::SEMITONE_RATIO ** notediff)}
  }

  r_index = pronunciation_mod[]
  index = r_index.to_i

  dst = 5.times.map {|i|
  #dst = (1...5).each.map {|i|
    tmpbuf = tmpbufs[i]
    freq = vowels[index % @vowels_len][i]+(vowels[(index+1) % @vowels_len][i]-vowels[index % @vowels_len][i])*(r_index-index)
    w = Math::PI * 2 * freq
    resfil(pulse, tmpbufs[i], @@gain[i], w, 1.0/samplerate, window_size)
  }.inject(:+)

  case channels
  when 1
    Buffer.new(dst * l_gain)
  when 2
    Buffer.new(dst * l_gain, dst * r_gain)
  end
end

#resfil(x, v, a, w, dt, len) ⇒ Object 



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# File 'lib/synthesizer/oscillator_source/formant_vocoder.rb', line 72

def resfil(x, v, a, w, dt, len)
  b = 2.0 * (Math::E ** (-a*dt)) * Math.cos(w*dt)
  c = Math::E ** (-2.0 * a * dt)
  d = ((a*a+w*w)/w) * (Math::E ** (-a*dt)) * Math.sin(w*dt)

  #v[0] = v[len-2]
  #v[1] = v[len-1]
  #v[0] += 1.0

  #Vdsp::UnsafeDouble.vsmsma(v, 1, 1, b, v, 0, 1, -c, v, 2, 1, len)
  #v * (d / 25000.to_f)

  v[0] = v[len-2]
  v[1] = v[len-1]

  y = len.times.map {|i|
    v[i+2] = b * v[i+1] - c * v[i] + x[i]
    v[i+1] * (d / 25000.to_f)
  }

  Vdsp::DoubleArray.create(y)
end