Class: AudioStream::Buffer

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

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(stream0, stream1 = nil) ⇒ Buffer

Returns a new instance of Buffer.



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# File 'lib/audio_stream/buffer.rb', line 8

def initialize(stream0, stream1=nil)
  if Array===stream0
    stream0 = Vdsp::DoubleArray.create(stream0)
  end
  if Array===stream1
    stream1 = Vdsp::DoubleArray.create(stream1)
  end

  @stream0 = stream0
  @stream1 = stream1

  if !stream1
    @streams = [stream0]
    @channels = 1
    @window_size = stream0.size
  else
    @streams = [stream0, stream1]
    @channels = 2
    @window_size = stream0.size

    if stream0.size!=stream1.size
      raise Error, "stream size is not match: stream0.size=#{stream0.size}, stream1.size=#{stream1.size}"
    end
  end
end

Instance Attribute Details

#channels ⇒ Object (readonly)

Returns the value of attribute channels.



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# File 'lib/audio_stream/buffer.rb', line 5

def channels
  @channels
end

#streams ⇒ Object (readonly)

Returns the value of attribute streams.



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# File 'lib/audio_stream/buffer.rb', line 4

def streams
  @streams
end

#window_size ⇒ Object (readonly)

Returns the value of attribute window_size.



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# File 'lib/audio_stream/buffer.rb', line 6

def window_size
  @window_size
end

Class Method Details

.create(window_size, channels) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 212

def self.create(window_size, channels)
  case channels
  when 1
    create_mono(window_size)
  when 2
    create_stereo(window_size)
  end
end

.create_mono(window_size) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 221

def self.create_mono(window_size)
  stream0 = Vdsp::DoubleArray.new(window_size)
  new(stream0)
end

.create_stereo(window_size) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 226

def self.create_stereo(window_size)
  stream0 = Vdsp::DoubleArray.new(window_size)
  stream1 = Vdsp::DoubleArray.new(window_size)
  new(stream0, stream1)
end

.from_na(na) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 232

def self.from_na(na)
  channels = na.shape[0]
  window_size = na.size / channels

  case na.typecode
  when NArray::SINT
    max = 0x7FFF.to_f
  when NArray::FLOAT
    max = 1.0
  when NArray::DCOMPLEX
    max = 1.0
  end

  case channels
  when 1
    stream0 = []
    window_size.times {|i|
      stream0 << na[i].real / max
    }
    self.new(stream0)
  when 2
    stream0 = []
    stream1 = []
    window_size.times {|i|
      stream0 << na[i*2].real / max
      stream1 << na[(i*2)+1].real / max
    }
    self.new(stream0, stream1)
  end
end

.from_rabuffer(rabuf) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 263

def self.from_rabuffer(rabuf)
  channels = rabuf.channels
  window_size = rabuf.size

  case channels
  when 1
    stream0 = rabuf.to_a
    while stream0.size<window_size
      stream0 << 0.0
    end
    self.new(stream0)
  when 2
    stream0 = Array.new(window_size, 0.0)
    stream1 = Array.new(window_size, 0.0)
    rabuf.each_with_index {|fa, i|
      stream0[i] = fa[0]
      stream1[i] = fa[1]
    }
    self.new(stream0, stream1)
  end
end

.merge(buffers, average: false) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 107

def self.merge(buffers, average: false)
  buffers.each {|buf|
    unless Buffer===buf
      raise Error, "argument is not Buffer: #{buf}"
    end
  }

  if buffers.length==0
    raise Error, "argument is empty"
  elsif buffers.length==1
    return buffers[0]
  end

  dst = buffers.inject(:+)

  if average
    gain = AGain.new(level: Decibel.mag(1.0/buffers.length))
    dst = gain.process(dst)
  end

  dst
end

Instance Method Details

#+(other) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 67

def +(other)
  if self.window_size!=other.window_size
    raise Error, "Buffer.window_size is not match: self.window_size=#{self.window_size} other.window_size=#{other.window_size}"
  end

  channels = [self.channels, other.channels].max
  case channels
  when 1
    stream0 = self.streams[0] + other.streams[0]
    self.class.new(stream0)
  when 2
    st_self = self.stereo
    st_other = other.stereo

    stream0 = st_self.streams[0] + st_other.streams[0]
    stream1 = st_self.streams[1] + st_other.streams[1]
    self.class.new(stream0, stream1)
  end
end

#-(other) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 87

def -(other)
  if self.window_size!=other.window_size
    raise Error, "Buffer.window_size is not match: self.window_size=#{self.window_size} other.window_size=#{other.window_size}"
  end

  channels = [self.channels, other.channels].max
  case channels
  when 1
    stream0 = self.streams[0] + other.streams[0]
    self.class.new(stream0)
  when 2
    st_self = self.stereo
    st_other = other.stereo

    stream0 = st_self.streams[0] - st_other.streams[0]
    stream1 = st_self.streams[1] - st_other.streams[1]
    self.class.new(stream0, stream1)
  end
end

#fft_plot(samplerate = 44100, window = nil) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 139

def fft_plot(samplerate=44100, window=nil)
  window ||= HanningWindow.instance

  na = window.process(self).to_float_na
  fft = FFTW3.fft(na, FFTW3::FORWARD) / na.length
  buf = Buffer.from_na(fft)

  xs = window_size.times.map{|i| i.to_f * samplerate / window_size}
  traces = buf.streams.map {|stream|
    {x: xs, y: stream}
  }

  Plotly::Plot.new(
    data: traces,
    xaxis: {title: 'Frequency (Hz)', type: 'log'}
  )
end

#mono(deep_copy: false) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 51

def mono(deep_copy: false)
  case self.channels
  when 1
    if deep_copy
      self.class.new(@stream0.clone)
    else
      self
    end
  when 2
    mono_stream = window_size.times.map {|i|
      (@stream0[i] + @stream1[i]) * 0.5
    }
    self.class.new(mono_stream)
  end
end

#plot ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 130

def plot
  xs = window_size.times.to_a
  traces = @streams.map {|stream|
    {x: xs, y: stream}
  }

  Plotly::Plot.new(data: traces)
end

#stereo(deep_copy: false) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 34

def stereo(deep_copy: false)
  case self.channels
  when 1
    if deep_copy
      self.class.new(@stream0.clone, @stream0.clone)
    else
      self.class.new(@stream0, @stream0)
    end
  when 2
    if deep_copy
      self.class.new(@stream0.clone, @stream1.clone)
    else
      self
    end
  end
end

#to_float_na(dst = nil, offset = 0) ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 157

def to_float_na(dst=nil, offset=0)
  if dst
    if channels!=dst.shape[0]
      raise Error, "channels is not match: buffer.channels=#{channels} na.shape[0]=#{dst.shape[0]}"
    end
    if dst.typecode!=NArray::FLOAT
      raise Error, "typecode is not match: na.typecode=#{dst.typecode}"
    end
  end
  na = dst || NArray.float(channels, window_size)

  case channels
  when 1
    na[(0+offset)...(window_size+offset)] = @stream0.to_a
  when 2
    na[window_size.times.map{|i| i*2+offset}] = @stream0.to_a
    na[window_size.times.map{|i| i*2+1+offset}] = @stream1.to_a
  end

  na
end

#to_rabuffer ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 193

def to_rabuffer
  rabuf = RubyAudio::Buffer.float(window_size, channels)

  case channels
  when 1
    @stream0.each_with_index {|v, i|
      rabuf[i] = v
    }
  when 2
    stream0 = @stream0.to_a
    stream1 = @stream1.to_a
    window_size.times {|i|
      rabuf[i] = [stream0[i], stream1[i]]
    }
  end

  rabuf
end

#to_sint_na ⇒ Object 



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# File 'lib/audio_stream/buffer.rb', line 179

def to_sint_na
  na = NArray.sint(channels, window_size)

  case channels
  when 1
    na[0...window_size] = @stream0.map {|f| (f * 0x7FFF).round}
  when 2
    na[window_size.times.map{|i| i*2}] = @stream0.map {|f| (f * 0x7FFF).round}
    na[window_size.times.map{|i| i*2+1}] = @stream1.map {|f| (f * 0x7FFF).round}
  end

  na
end