Class: Musa::MIDIRecorder::MIDIRecorder

Inherits:
Object
  • Object
show all
Defined in:
lib/musa-dsl/midi/midi-recorder.rb

Instance Method Summary collapse

Constructor Details

#initialize(sequencer) ⇒ MIDIRecorder

Returns a new instance of MIDIRecorder.



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# File 'lib/musa-dsl/midi/midi-recorder.rb', line 6

def initialize(sequencer)
  @sequencer = sequencer
  @midi_parser = MIDIParser.new

  clear
end

Instance Method Details

#clear ⇒ Object 



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# File 'lib/musa-dsl/midi/midi-recorder.rb', line 13

def clear
  @messages = []
end

#raw ⇒ Object 



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# File 'lib/musa-dsl/midi/midi-recorder.rb', line 26

def raw
  @messages
end

#record(midi_bytes) ⇒ Object 



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# File 'lib/musa-dsl/midi/midi-recorder.rb', line 17

def record(midi_bytes)
  m = @midi_parser.parse midi_bytes
  m = [m] unless m.is_a? Array

  m.each do |mm|
    @messages << Message.new(@sequencer.position, mm)
  end
end

#transcription ⇒ Object 



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# File 'lib/musa-dsl/midi/midi-recorder.rb', line 30

def transcription
  note_on = {}
  last_note = {}

  notes = []

  @messages.each do |m|
    mm = m.message

    case mm
    when MIDIEvents::NoteOn
      if last_note[mm.channel]
        notes << { position: last_note[mm.channel], channel: mm.channel, pitch: :silence, duration: m.position - last_note[mm.channel] }
        last_note.delete mm.channel
      end

      note = { position: m.position, channel: mm.channel, pitch: mm.note, velocity: mm.velocity }

      note_on[mm.channel] ||= {}
      note_on[mm.channel][mm.note] = note

      notes << note

    when MIDIEvents::NoteOff
      note_on[mm.channel] ||= {}

      note = note_on[mm.channel][mm.note]

      if note
        note_on[mm.channel].delete mm.note

        note[:duration] = m.position - note[:position]
        note[:velocity_off] = mm.velocity
      end

      last_note[mm.channel] = m.position
    end
  end

  notes
end