98 lines
2.4 KiB
Python
98 lines
2.4 KiB
Python
|
import wave
|
|||
|
|
import numpy as np
|
|||
|
|
import scipy.signal as sig
|
|||
|
|
import math
|
|||
|
|
|
|||
|
|
# Nombre d’octets par échantillon
|
|||
|
|
samp_width = 2
|
|||
|
|
|
|||
|
|
# Valeur maximale d’un échantillon
|
|||
|
|
max_val = 2 ** (8 * samp_width - 1) - 1
|
|||
|
|
|
|||
|
|
# Fréquence d’échantillonnage (Hertz)
|
|||
|
|
samp_rate = 44100
|
|||
|
|
|
|||
|
|
|
|||
|
|
def add_signal(dest, start, source):
|
|||
|
|
dest[int(samp_rate * start):int(samp_rate * start) + len(source)] += source
|
|||
|
|
|
|||
|
|
|
|||
|
|
def silence(dur):
|
|||
|
|
return np.zeros((int(samp_rate * dur),))
|
|||
|
|
|
|||
|
|
|
|||
|
|
def sine(dur, freq, value=1):
|
|||
|
|
x = np.arange(int(samp_rate * dur))
|
|||
|
|
return value * max_val * np.sin(2 * np.pi * freq * x / samp_rate)
|
|||
|
|
|
|||
|
|
|
|||
|
|
def square(dur, freq, value=1):
|
|||
|
|
x = np.arange(int(samp_rate * dur))
|
|||
|
|
return value * max_val * sig.square(2 * np.pi * freq * x / samp_rate)
|
|||
|
|
|
|||
|
|
|
|||
|
|
def envelope(attack, decay, release, signal):
|
|||
|
|
total = len(signal)
|
|||
|
|
attack = int(attack * total)
|
|||
|
|
decay = int(decay * total)
|
|||
|
|
release = int(release * total)
|
|||
|
|
sustain = total - attack - decay - release
|
|||
|
|
|
|||
|
|
return signal * np.concatenate((
|
|||
|
|
np.linspace(start=0, stop=1, num=attack, endpoint=False),
|
|||
|
|
np.linspace(start=1, stop=2/3, num=decay, endpoint=False),
|
|||
|
|
np.linspace(start=2/3, stop=2/3, num=sustain, endpoint=False),
|
|||
|
|
np.linspace(start=2/3, stop=0, num=release, endpoint=True),
|
|||
|
|
))
|
|||
|
|
|
|||
|
|
notes = {
|
|||
|
|
'do': 0, 'si#': 0,
|
|||
|
|
'do#': 1, 'reb': 1,
|
|||
|
|
're': 2,
|
|||
|
|
're#': 3, 'mib': 3,
|
|||
|
|
'mi': 4, 'fab': 4,
|
|||
|
|
'fa': 5, 'mi#': 5,
|
|||
|
|
'fa#': 6, 'solb': 6,
|
|||
|
|
'sol': 7,
|
|||
|
|
'sol#': 8, 'lab': 8,
|
|||
|
|
'la': 9,
|
|||
|
|
'la#': 10, 'sib': 10,
|
|||
|
|
'si': 11, 'dob': 11,
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
|
|||
|
|
def note_freq(note, octave):
|
|||
|
|
return (440
|
|||
|
|
* (2 ** (octave - 3))
|
|||
|
|
* math.pow(2, (notes[note] - 9) / 12))
|
|||
|
|
|
|||
|
|
|
|||
|
|
def note_freqs(notes):
|
|||
|
|
return list(map(lambda info: note_freq(*info), notes))
|
|||
|
|
|
|||
|
|
|
|||
|
|
def chord(instr, dur, freqs, value=1):
|
|||
|
|
signal = np.zeros((int(samp_rate * dur),))
|
|||
|
|
|
|||
|
|
for freq in freqs:
|
|||
|
|
signal += instr(dur, freq, value / len(freqs))
|
|||
|
|
|
|||
|
|
return signal
|
|||
|
|
|
|||
|
|
|
|||
|
|
def save_signal(out_name, signal):
|
|||
|
|
with wave.open(out_name, 'w') as file:
|
|||
|
|
file.setnchannels(1)
|
|||
|
|
file.setsampwidth(samp_width)
|
|||
|
|
file.setframerate(samp_rate)
|
|||
|
|
file.writeframesraw(signal.astype('<h').tostring())
|
|||
|
|
|
|||
|
|
|
|||
|
|
def load_signal(in_name):
|
|||
|
|
with wave.open(in_name, 'r') as file:
|
|||
|
|
assert file.getnchannels() == 1
|
|||
|
|
assert file.getsampwidth() == samp_width
|
|||
|
|
assert file.getframerate() == samp_rate
|
|||
|
|
size = file.getnframes()
|
|||
|
|
return np.ndarray((size,), '<h', file.readframes(size))
|