def save_midi(path, pitches, intervals, velocities):
"""
Save extracted notes as a MIDI file
Parameters
----------
path: the path to save the MIDI file
pitches: np.ndarray of bin_indices
intervals: list of (onset_index, offset_index)
velocities: list of velocity values
"""
file = MidiFile()
track = MidiTrack()
file.tracks.append(track)
ticks_per_second = file.ticks_per_beat * 2.0
events = []
for i in range(len(pitches)):
events.append(dict(type='on', pitch=pitches[i], time=intervals[i][0], velocity=velocities[i]))
events.append(dict(type='off', pitch=pitches[i], time=intervals[i][1], velocity=velocities[i]))
events.sort(key=lambda row: row['time'])
last_tick = 0
for event in events:
current_tick = int(event['time'] * ticks_per_second)
velocity = int(event['velocity'] * 127)
if velocity > 127:
velocity = 127
pitch = int(round(hz_to_midi(event['pitch'])))
track.append(Message('note_' + event['type'], note=pitch, velocity=velocity, time=current_tick - last_tick))
last_tick = current_tick
file.save(path)
def _intervals_to_annotated_roll(pitch_list, interval_list,
matched_index_list, shape):
roll = np.zeros(shape)
for n, (pitch, (onset,
offset)) in enumerate(zip(pitch_list, interval_list)):
hit = True if n in matched_index_list else False
pitch = int(round(hz_to_midi(pitch) - 21))
onset = int(round(16000 / 512 * onset))
offset = int(round(16000 / 512 * offset))
roll[onset:offset, pitch] = 1 if hit else 4
roll[onset, pitch] = 2
return roll
def save_midi(path, pitches, intervals, velocities):
"""
Save extracted notes as a MIDI file
Parameters
----------
path: the path to save the MIDI file
pitches: np.ndarray of bin_indices
intervals: list of (onset_index, offset_index)
velocities: list of velocity values
"""
file = pretty_midi.PrettyMIDI()
piano_program = pretty_midi.instrument_name_to_program('Acoustic Grand Piano')
piano = pretty_midi.Instrument(program=piano_program)
# Remove overlapping intervals (end time should be smaller of equal start time of next note on the same pitch)
intervals_dict = collections.defaultdict(list)
for i in range(len(pitches)):
pitch = int(round(hz_to_midi(pitches[i])))
intervals_dict[pitch].append((intervals[i], i))
for pitch in intervals_dict:
interval_list = intervals_dict[pitch]
interval_list.sort(key=lambda x: x[0][0])
for i in range(len(interval_list) - 1):
# assert interval_list[i][1] <= interval_list[i+1][0], f'End time should be smaller of equal start time of next note on the same pitch. It was {interval_list[i][1]}, {interval_list[i+1][0]} for pitch {key}'
interval_list[i][0][1] = min(interval_list[i][0][1], interval_list[i+1][0][0])
for pitch in intervals_dict:
interval_list = intervals_dict[pitch]
for interval,i in interval_list:
pitch = int(round(hz_to_midi(pitches[i])))
velocity = int(127*min(velocities[i], 1))
note = pretty_midi.Note(velocity=velocity, pitch=pitch, start=interval[0], end=interval[1])
piano.notes.append(note)
file.instruments.append(piano)
file.write(path)