Class: Music::Performance::MidiUtil

Inherits:
Object
  • Object
show all
Defined in:
lib/music-performance/arrangement/midi/midi_util.rb

Constant Summary collapse

QUARTER = 
Rational(1,4)
MIDI_NOTENUMS = 
Hash[
    (0..127).map do |note_num|
[ p0.transpose(note_num), note_num ]

Class Method Summary collapse

Class Method Details

.delta(duration, ppqn) ⇒ Object 



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# File 'lib/music-performance/arrangement/midi/midi_util.rb', line 6

def self.delta duration, ppqn
  pulses = (duration / QUARTER) * ppqn
  return pulses.round
end

.dynamic_to_volume(dynamic) ⇒ Object 



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# File 'lib/music-performance/arrangement/midi/midi_util.rb', line 28

def self.dynamic_to_volume dynamic
  (dynamic * 127).round
end

.note_velocity(accented) ⇒ Object 



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# File 'lib/music-performance/arrangement/midi/midi_util.rb', line 32

def self.note_velocity(accented)
  accented ? 112 : 70
end

.pitch_to_notenum(pitch) ⇒ Object 



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# File 'lib/music-performance/arrangement/midi/midi_util.rb', line 24

def self.pitch_to_notenum pitch
  MIDI_NOTENUMS[pitch.round]
end

.usec_per_qnote(notes_per_sec) ⇒ Object 



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# File 'lib/music-performance/arrangement/midi/midi_util.rb', line 11

def self.usec_per_qnote notes_per_sec
  spn = 1.0 / notes_per_sec
  spqn = spn / 4.0
  return (spqn * 1_000_000).to_i
end