Class: AudioStream::Fx::Chorus

Inherits:
Object
  • Object
show all
Defined in:
lib/audio_stream/fx/chorus.rb

Instance Method Summary collapse

Constructor Details

#initialize(soundinfo, depth: 100, rate: 0.25) ⇒ Chorus

Returns a new instance of Chorus.



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# File 'lib/audio_stream/fx/chorus.rb', line 4

def initialize(soundinfo, depth: 100, rate: 0.25)
  @soundinfo = soundinfo

  @depth = depth
  @rate = rate

  @delaybufs = [
    RingBuffer.new(@depth * 3, 0.0),
    RingBuffer.new(@depth * 3, 0.0)
  ]

  @phase = 0
  @speed = (2.0 * Math::PI * @rate) / @soundinfo.samplerate
end

Instance Method Details

#lerp(start, stop, step) ⇒ Object 



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# File 'lib/audio_stream/fx/chorus.rb', line 46

def lerp(start, stop, step)
  (stop * step) + (start * (1.0 - step))
end

#process(input) ⇒ Object 



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# File 'lib/audio_stream/fx/chorus.rb', line 19

def process(input)
  window_size = input.window_size
  channels = input.channels

  streams = channels.times.map {|ch|
    delaybuf = @delaybufs[ch]
    input.streams[ch].map.with_index {|f, i|
      tau = @depth * (Math.sin(@speed * (@phase + i)) + 1)
      t = i - tau

      m = t.floor
      delta = t - m

      wet = delta * delaybuf[i-m+1] + (1.0 - delta) * delaybuf[i-m]
      f = (f + wet) * 0.5

      delaybuf.current = f
      delaybuf.rotate

      f
    }
  }
  @phase = (@phase + window_size) % (window_size / @speed)

  Buffer.new(*streams)
end