def occupation_polyphony_rate(pm: PrettyMIDI) -> Tuple[ndarray, ndarray]:
occupation_rate = []
polyphony_rate = []
total_roll = pm.get_piano_roll()
for instrument in pm.instruments:
piano_roll = instrument.get_piano_roll()
if piano_roll.shape[1] == 0:
occupation_rate.append(0)
else:
occupation_rate.append(
np.count_nonzero(np.any(piano_roll, 0)) / total_roll.shape[1])
if np.count_nonzero(np.any(piano_roll, 0)) == 0:
polyphony_rate.append(0)
else:
polyphony_rate.append(
np.count_nonzero(np.count_nonzero(piano_roll, 0) > 1) /
np.count_nonzero(np.any(piano_roll, 0)))
occupation_rate = np.array(occupation_rate)
zero_idx = np.where(occupation_rate < 0.01)[0]
if len(zero_idx) > 0:
occupation_rate[zero_idx] = 0
occupation_rate = occupation_rate[:, np.newaxis]
polyphony_rate = np.array(polyphony_rate)
zero_idx = np.where(polyphony_rate < 0.01)[0]
if len(zero_idx) > 0:
polyphony_rate[zero_idx] = 0
polyphony_rate = polyphony_rate[:, np.newaxis]
return occupation_rate, polyphony_rate
def load_melody_roll(self, midi_path, melody_track):
"""
TODO: for each midi file, label which track index is the melody
For now, assume that we somehow know which track is the melody
"""
self.midi_path = midi_path
self.midi_name = midi_path.split(sep='/')[-1]
mid = MidiFile(midi_path)
# for i, track in enumerate(mid.tracks):
# print("Track {}: {}".format(i, track.name))
melody = mid.tracks[melody_track]
# drop all tracks except for melody
mid.tracks = [melody]
mid.save(PREPROCESS_MIDI_DIR + self.midi_name)
# now we have a midi file with only the melody track
# use Pretty Midi to extract the piano roll into a 2d numpy array
# roll = (PITCH_SPACE x ROLL_LENGTH)
midi_data = PrettyMIDI(PREPROCESS_MIDI_DIR + self.midi_name)
# get the instrument of the midi, should only be one melody track!
assert len(midi_data.instruments) == 1
print("instrument", midi_data.instruments)
self.program = midi_data.instruments[0].program
self.roll = midi_data.get_piano_roll(fs=400)
def get_piano_roll(pm: PrettyMIDI, beat_times: ndarray) -> PianoRoll:
piano_roll = pm.get_piano_roll(times=beat_times)
np.nan_to_num(piano_roll, copy=False)
piano_roll = piano_roll > 0
piano_roll = piano_roll.astype(int)
return piano_roll