import random import audiocore import synthio from ulab import numpy as np import adafruit_wave as wave h = np.array( [ -0.001229734800309099, -0.008235561806605458, -0.015082497016061390, -0.020940136918319988, -0.024981800822463429, -0.026464233332370746, -0.024803890156806906, -0.019642276775473012, -0.010893620860173042, 0.001230341899766145, 0.016221637398855598, 0.033304135659230648, 0.051486665261155681, 0.069636961761409016, 0.086570197432542767, 0.101144354207918147, 0.112353938422488253, 0.119413577288191297, 0.121823886314051028, 0.119413577288191297, 0.112353938422488253, 0.101144354207918147, 0.086570197432542767, 0.069636961761409016, 0.051486665261155681, 0.033304135659230648, 0.016221637398855598, 0.001230341899766145, -0.010893620860173042, -0.019642276775473012, -0.024803890156806906, -0.026464233332370746, -0.024981800822463429, -0.020940136918319988, -0.015082497016061390, -0.008235561806605458, -0.001229734800309099, ] ) filter_coeffs = np.array(h[::-1] * 32768, dtype=np.int16) def randf(lo, hi): return random.random() * (hi - lo) + lo SAMPLE_SIZE = 1024 VOLUME = 14700 sine = np.array( np.sin(np.linspace(0, 2 * np.pi, SAMPLE_SIZE, endpoint=False)) * VOLUME, dtype=np.int16 ) square = np.array([24000] * (SAMPLE_SIZE // 2) + [-24000] * (SAMPLE_SIZE // 2), dtype=np.int16) noise = np.array( [random.randint(-32768, 32767) for i in range(SAMPLE_SIZE)], dtype=np.int16, ) envelope = synthio.Envelope( attack_time=0.1, decay_time=0.05, release_time=0.2, attack_level=1, sustain_level=0.8 ) instant = synthio.Envelope( attack_time=0, decay_time=0, release_time=0, attack_level=1, sustain_level=1 ) synth = synthio.Synthesizer( sample_rate=48000, envelope=None, filter=filter_coeffs, channel_count=2 ) def synthesize(synth): print( """you can use arbitrary waveforms, including ones calculated on the fly or read from wave files (up to 1024 points)""" ) waveform = np.zeros(SAMPLE_SIZE, dtype=np.int16) chord = [ synthio.Note(synthio.midi_to_hz(n), waveform=waveform, envelope=envelope) for n in (60, 64, 67, 70) ] synth.press(chord) for i in range(256): ctrl = i / 255 waveform[:] = np.array(square * (1 - ctrl) + sine * ctrl, dtype=np.int16) yield 4 def synthesize2(synth): print("""Envelope controls how notes fade in or out""") chord = [ synthio.Note(synthio.midi_to_hz(n), waveform=sine, envelope=instant) for n in (60, 64, 67, 70) ] for i in range(4): for c in chord: synth.release_all_then_press((c,)) yield 24 synth.release_all() chord = [ synthio.Note(synthio.midi_to_hz(n), waveform=sine, envelope=envelope) for n in (60, 64, 67, 70) ] for i in range(4): for c in chord: old = (c,) synth.release_all_then_press((c,)) yield 24 def synthesize3(synth): print("""A noise waveform creates percussive sounds""") env = synthio.Envelope( attack_time=0, decay_time=0.2, sustain_level=0, ) notes = [ synthio.Note( frequency=synthio.midi_to_hz(1 + i), waveform=noise, envelope=env, ) for i in range(12) ] random.seed(9) for _ in range(16): n = random.choice(notes) d = random.randint(30, 60) synth.press((n,)) yield d def synthesize4(synth): print("""Tremolo varies the note volume within a range at a low frequency""") chord = [ synthio.Note(synthio.midi_to_hz(n), waveform=sine, envelope=None) for n in (60, 64, 67, 70) ] synth.press(chord) for i in range(16): for c in chord: c.tremolo_depth = i / 50 c.tremolo_rate = (i + 1) / 4 yield 48 yield 36 def synthesize5(synth): print("""You can add vibrato or frequency sweep to notes""") chord = [synthio.Note(synthio.midi_to_hz(n), waveform=sine) for n in (60, 64, 67, 70)] synth.press(chord) for i in range(16): for c in chord: c.bend_depth = 1 / 24 c.bend_rate = (i + 1) / 2 yield 24 synth.release_all() yield 100 for c in chord: synth.release_all() c.bend_mode = synthio.BendMode.SWEEP_IN c.bend_depth = randf(-1, 1) c.bend_rate = 1 / 2 synth.press(chord) yield 320 def synthesize6(synth): print("""Ring modulation multiplies two waveforms together to create rich sounds""") chord = [ synthio.Note(synthio.midi_to_hz(n), waveform=square, ring_waveform=sine, envelope=envelope) for n in (60,) ] synth.press(chord) yield 200 random.seed(75) for _ in range(3): synth.release_all() yield 36 for note in chord: note.ring_frequency = note.frequency * (random.random() * 35 / 1200 + 8) synth.press(chord) yield 200 def synthesize7(synth): print("""FIR filtering can reproduce low, high, notch and band filters""") chord = [ synthio.Note(synthio.midi_to_hz(n), waveform=square, filter=False) for n in (60, 64, 67, 70) ] for i in range(4): for c in chord: synth.release_all_then_press((c,)) yield 24 synth.release_all() for note in chord: note.filter = True for i in range(4): for c in chord: synth.release_all_then_press((c,)) yield 24 def synthesize8(synth): print("""Notes can be panned between channels""") chord = [ synthio.Note(synthio.midi_to_hz(n), waveform=square, envelope=envelope) for n in (60, 64, 67, 70) ] synth.press(chord) for p in range(-10, 11, 1): for note in chord: note.panning = p / 10 yield 36 def delay(synth): synth.release_all() yield 200 def chain(*args): for a in args: yield from a # sox -r 48000 -e signed -b 16 -c 1 tune.raw tune.wav with wave.open("demo.wav", "w") as f: f.setnchannels(2) f.setsampwidth(2) f.setframerate(48000) import array for n in chain( synthesize(synth), delay(synth), synthesize2(synth), delay(synth), synthesize3(synth), delay(synth), synthesize4(synth), delay(synth), synthesize5(synth), delay(synth), synthesize6(synth), delay(synth), synthesize7(synth), delay(synth), synthesize8(synth), ): for i in range(n): result, data = audiocore.get_buffer(synth) f.writeframes(data)