-
Notifications
You must be signed in to change notification settings - Fork 0
/
stride.py
57 lines (50 loc) · 2.01 KB
/
stride.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
#!/usr/bin/python
import mido, time
max_notes = 3 # chords are considered complete after this many notes
max_latency = 0.03 # seconds to wait before a chord is considered complete
events = []
turn_off_map = {}
def chord_ready():
return ((len(events) > 0 and time.time() - events[-1].time > max_latency)
or len(events) >= max_notes)
def get_voicing(chord):
if len(chord) == 0: # 1 note
# bass note alone is 1 octave down
return [-12, 0]
if len(chord) == 1: # 2 notes
if chord[0] in [3, 4]:
# Thirds signify the corresponding major/minor triad (same root)
return [0, 7, chord[0] + 12]
if chord[0] in [8, 9]:
# Sixths signify the cooresponding major/minor triad (6 inversion)
return [0, chord[0], chord[0] + 7]
if chord[0] in [10, 11]:
# Sevenths specify the corresponding seventh chord
return [0, chord[0], 16, 19]
# Default: keep it the same
return [0] + chord
piano = mido.open_ioport('CASIO USB-MIDI:CASIO USB-MIDI MIDI 1')
while True:
event = piano.poll()
if event:
if event.type == 'note_on' and event.note < 60:
event.time = time.time()
events.append(event)
elif event.type == 'note_off' and event.note < 60:
for note in turn_off_map:
if turn_off_map[note] == event.note:
piano.send(event.copy(note=note))
turn_off_map[note] = None
else:
piano.send(event)
if chord_ready():
velocity = int(sum([event.velocity for event in events]) / len(events))
notes = [event.note for event in events]
notes.sort()
chord = [n - notes[0] for n in notes[1:]]
print('root {}, chord {}'.format(notes[0], chord))
voicing = [n + notes[0] for n in get_voicing(chord)]
for note in voicing:
turn_off_map[note] = notes[0]
piano.send(events[-1].copy(note=note, velocity=velocity))
events = []