def noise(params, amplitude=1, offset=0):
'''
Generate a noise signal
:param params: buffer parameters, controls length of signal created
:param amplitude: wave amplitude (array or value)
:param offset: offset of wave mean from zero (array or value)
:return: array of resulting signal
'''
amplitude = create_buffer(params, amplitude)
offset = create_buffer(params, offset)
output = offset + amplitude * (np.random.random(params.length) * 2 - 1)
return output
def square_wave(params, frequency=400, amplitude=1, offset=0, ratio=0.5):
'''
Generate a square wave
:param params: buffer parameters, controls length of signal created
:param frequency: wave frequency (array or value)
:param amplitude: wave amplitude (array or value)
:param offset: offset of wave mean from zero (array or value)
:param ratio: ratio of high to low time (array or value)
:return: array of resulting signal
'''
frequency = create_buffer(params, frequency)
amplitude = create_buffer(params, amplitude)
offset = create_buffer(params, offset)
ratio = create_buffer(params, ratio)
phase = np.add.accumulate(frequency / params.sample_rate) % 1
output = offset + amplitude * np.where(phase < ratio, 1, -1)
return output
def echo(params, source, delay, strength):
'''
Create an echo
:param params:
:param source:
:param delay:
:param strength:
:return:
'''
source = create_buffer(params, source)
delay = create_buffer(params, delay)
strength = create_buffer(params, strength)
output = source[:]
for i in range(params.length):
d = int(i - delay[i])
if 0 <= d < params.length:
output[i] += source[d]*strength[i]
return output
def saw_wave(params, frequency=400, amplitude=1, offset=0, ratio=0.5):
'''
Generate a saw wave
:param params: buffer parameters, controls length of signal created
:param frequency: wave frequency (array or value)
:param amplitude: wave amplitude (array or value)
:param offset: offset of wave mean from zero (array or value)
:param ratio: ratio of rise to fall time (array or value)
:return: array of resulting signal
'''
frequency = create_buffer(params, frequency)
amplitude = create_buffer(params, amplitude)
offset = create_buffer(params, offset)
ratio = np.clip(create_buffer(params, ratio), 0.000001, 0.999999)
phase = np.add.accumulate(frequency / params.sample_rate) % 1
output = offset + amplitude * np.where(
phase < ratio, -1 + 2 * phase / ratio, 1 - 2 * (phase - ratio) /
(1 - ratio))
return output
def table_wave(params, frequency=400, amplitude=1, offset=0, table=None):
'''
Generate a wave from a wavetable
:param params: buffer parameters, controls length of signal created
:param frequency: wave frequency (array or value)
:param amplitude: wave amplitude (array or value)
:param offset: offset of wave mean from zero (array or value)
:param table: table of values representing one full cycle of the waveform. Nominally the values
should be between +/-1 (array). The array can be any size.
:return: array of resulting signal
'''
if not table:
table = create_sine_table(65536)
size = table.size
frequency = create_buffer(params, frequency)
amplitude = create_buffer(params, amplitude)
offset = create_buffer(params, offset)
index = np.floor((np.add.accumulate(frequency / params.sample_rate) % 1) *
size).astype(int)
output = offset + amplitude * table[index]
return output
def __init__(self, params, instrument, step):
self.params = params
self.instrument = instrument
self.step = step
self.buffer = buffer.create_buffer(params, 0)
self.pos = 0