class AudioStream::Fx::Panning

Public Class Methods

new(pan: 0.0) click to toggle source
# File lib/audio_stream/fx/panning.rb, line 4
def initialize(pan: 0.0)
  @pan = pan

  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

Public Instance Methods

process(input) click to toggle source
# File lib/audio_stream/fx/panning.rb, line 29
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