Class: AudioStream::Fx::Panning

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

Instance Method Summary collapse

Constructor Details

#initialize(pan: 0.0) ⇒ Panning

Returns a new instance of Panning.

Parameters:

  • pan (Float) (defaults to: 0.0) —

    panning (-1.0~1.0) -1.0=left, 0.0=center, 1.0=right



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# File 'lib/audio_stream/fx/panning.rb', line 5

def initialize(pan: 0.0)
  @pan = pan.to_f

  l_gain = 1.0 - pan
  lr_gain = 0.0
  if 1.0<l_gain
    lr_gain = l_gain - 1.0
    l_gain = 1.0
  end

  r_gain = 1.0 + pan
  rl_gain = 0.0
  if 1.0<r_gain
    rl_gain = r_gain - 1.0
    r_gain = 1.0
  end

  normalize = [1.0 - pan, 1.0 + pan].max

  @r_gain = r_gain / normalize
  @rl_gain = rl_gain / normalize
  @l_gain = l_gain / normalize
  @lr_gain = lr_gain / normalize
end

Instance Method Details

#process(input) ⇒ Object 



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# File 'lib/audio_stream/fx/panning.rb', line 30

def process(input)
  return input if @pan==0.0

  src = input.stereo.streams
  src0 = src[0]
  src1 = src[1]

  dst0 = Vdsp::DoubleArray.new(src0.length)
  Vdsp::UnsafeDouble.vsmsma(src0, 0, 1, @l_gain, src1, 0, 1, @lr_gain, dst0, 0, 1, src0.length)

  dst1 = Vdsp::DoubleArray.new(src1.length)
  Vdsp::UnsafeDouble.vsmsma(src0, 0, 1, @rl_gain, src1, 0, 1, @r_gain, dst1, 0, 1, src1.length)

  Buffer.new(dst0, dst1)
end