Class: Musikov::MidiWriter

Inherits:
Object
  • Object
show all
Defined in:
lib/musikov/midi_writer.rb

Overview

This class is responsible for interacting with MidiLib in order to write the output midi files.

Instance Method Summary collapse

Constructor Details

#initialize(output_path = ".") ⇒ MidiWriter

Initializes the parser using the output path parameter

  • Parameter need to be a folder folder



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# File 'lib/musikov/midi_writer.rb', line 17

def initialize(output_path = ".")
  @path = output_path
end

Instance Method Details

#write(sequence_hash) ⇒ Object

Writes the output midi file from the generated sequence hash



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# File 'lib/musikov/midi_writer.rb', line 22

def write(sequence_hash)
  # Create a new, empty sequence.
  seq = MIDI::Sequence.new()
  
  track = MIDI::Track.new(seq)
  seq.tracks << track
  track.events << MIDI::Tempo.new(MIDI::Tempo.bpm_to_mpq(120))
  i = 0
  
  # Create a track to hold the notes. Add it to the sequence.
  sequence_hash.each { |program_change, midi_elements|
    track = MIDI::Track.new(seq)
    seq.tracks << track
    
    instrument = MIDI::GM_PATCH_NAMES[program_change]
  
    # Give the track a name and an instrument name (optional).
    track.instrument = instrument
  
    # Add a volume controller event (optional).
    track.events << MIDI::Controller.new(i, MIDI::CC_VOLUME, 127)
    track.events << MIDI::ProgramChange.new(i, program_change, 0)
    midi_elements.each { |midi_element|
      track.events << MIDI::NoteOn.new(i, midi_element.note ,127,0)
      track.events << MIDI::NoteOff.new(i, midi_element.note ,127, seq.note_to_delta(midi_element.duration))
    }

    i += 1
  }
  
  write_midi(seq)
end