Class: Ruck::Generators::WavIn

Inherits:
Object
  • Object
show all
Includes:
MultiChannelSource, UGen
Defined in:
lib/ruck/ugen/wav.rb

Overview

plays sound stored in a RIFF WAV file

Instance Attribute Summary collapse

Attributes included from UGen

#name

Instance Method Summary collapse

Methods included from MultiChannelSource

#<<, #>>, #last, #out, #out_channels

Methods included from UGen

#to_s

Constructor Details

#initialize(attrs = {}) ⇒ WavIn

Returns a new instance of WavIn.



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# File 'lib/ruck/ugen/wav.rb', line 102

def initialize(attrs = {})
  require_attrs attrs, [:filename]
  @rate = 1.0
  @gain = 1.0
  @filename = attrs.delete(:filename)
  parse_attrs attrs

  @loaded = false
  @playing = true

  init_wav
end

Instance Attribute Details

#filename ⇒ Object (readonly)

Returns the value of attribute filename.



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# File 'lib/ruck/ugen/wav.rb', line 100

def filename
  @filename
end

Instance Method Details

#attr_names ⇒ Object 



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# File 'lib/ruck/ugen/wav.rb', line 152

def attr_names
  [:filename, :rate]
end

#duration ⇒ Object 



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# File 'lib/ruck/ugen/wav.rb', line 148

def duration
  @loaded ? @wav.size / @block_align / @rate_adjust : 0
end

#init_wav ⇒ Object 



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# File 'lib/ruck/ugen/wav.rb', line 115

def init_wav
  riff = Riff::RiffReader.new(@filename).chunks.first
  unless riff.type == "RIFF"
    LOG.error "#{@filename}: Not RIFF!"
    return
  end
  unless riff[0..3] == "WAVE"
    LOG.error "#{@filename}: Not WAVE!"
    return
  end

  riff.data_skip = 4 # skip "WAVE"
  fmt = riff.chunks.first
  @wav = riff.chunks.find { |c| c.type == "data" }
  unless fmt[0..1].unpack("s1").first == 1
    LOG.error "#{@filename}: Not PCM!"
    return
  end

  @num_channels, @sample_rate, @byte_rate,
    @block_align, @bits_per_sample =
    fmt[2..15].unpack("s1i1i1s1s1")
  @range = (2 ** (@bits_per_sample - 1)).to_f

  @out_channels = (0..@num_channels-1).map { |chan| OutChannel.new self, chan }
  @sample = [0.0] * @num_channels
  @last = [0.0] * @num_channels
  @now = [nil] * @num_channels
  @rate_adjust = @sample_rate / SAMPLE_RATE

  @loaded = true
end

#next(now, chan = 0) ⇒ Object 



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# File 'lib/ruck/ugen/wav.rb', line 156

def next(now, chan = 0)
  return @last[chan] if @now[chan] == now
  @now[chan] = now

  return @last[chan] unless @loaded && @playing

  offset = @sample[chan].to_i * @block_align
  chan_offset = (chan * @bits_per_sample) / 8

  if offset + @block_align > @wav.size
    @playing = false
    return @last[chan]
  end

  @last[chan] = @wav[offset + chan_offset, @bits_per_sample].unpack("s1").first / @range * gain
  @sample[chan] += rate * @rate_adjust
  @last[chan]
end

#play ⇒ Object 



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# File 'lib/ruck/ugen/wav.rb', line 175

def play; @playing = true; end

#reset ⇒ Object 



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# File 'lib/ruck/ugen/wav.rb', line 178

def reset
  @offset = 0
end

#stop ⇒ Object 



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# File 'lib/ruck/ugen/wav.rb', line 176

def stop; @playing = false; end