def notes_from_file(filename: str) -> List[Note]:
midifile_rel = midi.read_midifile(filename)
midifile_abs = copy.deepcopy(midifile_rel)
midifile_abs.make_ticks_abs()
# Convert MIDI events to our music representation: a list of Note objects
notes = []
active_notes = {}
for ev_rel, ev_abs in zip(midifile_rel[-1], midifile_abs[-1]):
if isinstance(ev_rel, midi.NoteOnEvent) and ev_rel.data[1]:
n = Note()
n.resolution = midifile_rel.resolution
n.tick_abs = ev_abs.tick
n.pitch = ev_rel.data[0]
n.velocity = ev_rel.data[1]
if n.pitch not in active_notes:
active_notes[n.pitch] = {n}
else:
active_notes[n.pitch].add(n)
elif isinstance(ev_rel, midi.NoteOffEvent) or (isinstance(
ev_rel, midi.NoteOnEvent) and ev_rel.data[1] == 0):
n = active_notes[ev_rel.data[0]].pop()
n.duration = ev_abs.tick - n.tick_abs
notes.append(n)
assert not any(active_notes.values()), "Some notes were not released"
return sorted(notes, key=lambda note: note.tick_abs)
def notes_from_file(filename: str) -> List[Note]:
midifile_rel = midi.read_midifile(filename)
midifile_abs = copy.deepcopy(midifile_rel)
midifile_abs.make_ticks_abs()
# Convert MIDI events to our music representation: a list of Note objects
notes = []
active_notes = {}
for ev_rel, ev_abs in zip(midifile_rel[-1], midifile_abs[-1]):
if isinstance(ev_rel, midi.NoteOnEvent) and ev_rel.data[1]:
n = Note()
n.resolution = midifile_rel.resolution
n.tick_abs = ev_abs.tick
n.pitch = ev_rel.data[0]
n.velocity = ev_rel.data[1]
if n.pitch not in active_notes:
active_notes[n.pitch] = {n}
else:
active_notes[n.pitch].add(n)
elif isinstance(ev_rel, midi.NoteOffEvent) or (isinstance(ev_rel, midi.NoteOnEvent) and ev_rel.data[1] == 0):
n = active_notes[ev_rel.data[0]].pop()
n.duration = ev_abs.tick - n.tick_abs
notes.append(n)
assert not any(active_notes.values()), "Some notes were not released"
return sorted(notes, key=lambda note: note.tick_abs)
def convert_song(song: SongMetadata):
""" Combine the quantized and the unquantized MIDI files
into one that aligns to measures but attempts to retain the original phrasing """
from file_handlers import notes_to_file
from file_handlers import notes_from_file
Note.default_resolution = 960
quantized = notes_from_file('weimardb/midi_from_db_quant/{}.mid'.format(song.name))
original = notes_from_file('weimardb/midi_from_db/{}.mid'.format(song.name))
lilypond = notes_from_file('weimardb/midi_from_ly/{}.mid'.format(song.name))
d = {}
for n, m in zip(quantized, lilypond):
if m.measure - n.measure not in d:
d[m.measure - n.measure] = 1
else:
d[m.measure - n.measure] += 1
if len(d) == 2:
break
meas_start = min(d.keys()) # type: int
meas_size = Note.meter * Note.default_resolution
meas_no = 0
a, b, c = [], [], [] # quantized measure, original measure, combined output
lp = [] # lilypond measure: only needed for durations
for q, o, l in zip(quantized, original, lilypond):
if q.measure != meas_no:
if len(a) > 1:
r = (a[-1].tick_abs - a[0].tick_abs) / (b[-1].tick_abs - b[0].tick_abs) # stretch ratio
a_m = (meas_no + 0.5) * meas_size # middle of quantized measure
b_m = b[0].tick_abs + (a_m - a[0].tick_abs) / r # estimated middle of unquantized measure
for a_j, b_j, l_j in zip(a, b, lp):
n = Note()
n.pitch = b_j.pitch
n.resolution = b_j.resolution
n.velocity = b_j.velocity
n.tick_abs = int(a_m + r * (b_j.tick_abs - b_m)) + (meas_start * meas_size)
n.duration = int(r * b_j.duration) or a_j.duration or l_j.duration
c.append(n)
else:
c += a
meas_no = q.measure
a, b, lp = [], [], []
a.append(q)
b.append(o)
lp.append(l)
notes_to_file(sorted(c, key=lambda p: p.tick_abs), 'weimardb/midi_combined/{}.mid'.format(song.name))