def main():
""" main function """
sgen = sig.SigGen()
waves = [dsp.tube(sgen.sin(), x) for x in range(1, 17)]
wtab = wavetable.WaveTable(waves)
visualize.plot_wavetable(wtab, title='tube')
waves = [dsp.clip(sgen.sin(), x) for x in range(1, 17)]
wtab = wavetable.WaveTable(waves)
visualize.plot_wavetable(wtab, title='clip')
waves = [dsp.fold(sgen.sin(), x) for x in range(1, 17)]
wtab = wavetable.WaveTable(waves)
visualize.plot_wavetable(wtab, title='fold')
waves = [dsp.shape(sgen.sin(), x) for x in range(1, 17)]
wtab = wavetable.WaveTable(waves)
visualize.plot_wavetable(wtab, title='shape')
waves = [dsp.slew(sgen.sqr(), 1 / x) for x in range(1, 9)]
waves += [dsp.slew(sgen.sqr(), 1 / x) for x in range(-8, 0)]
wtab = wavetable.WaveTable(waves)
visualize.plot_wavetable(wtab, title='slew')
waves = [dsp.downsample(sgen.sin(), x) for x in range(1, 17)]
wtab = wavetable.WaveTable(waves)
visualize.plot_wavetable(wtab, title='downsample')
waves = [dsp.quantize(sgen.sin(), x) for x in range(1, 17)]
wtab = wavetable.WaveTable(waves)
visualize.plot_wavetable(wtab, title='quantize')
def test_resynthesize():
""" test resynthesize """
a = np.array([-1.0, 1.0, 1.0, -1.0])
e = a
a = np.tile(a, 1024)
s = sig.SigGen()
s.num_points = 4
o = dsp.resynthesize(a, s)
assert np.allclose(o, e)
def from_wav(self, filename, sig_gen=None, resynthesize=False):
"""
Populate the wavetable from a wav file by filling all slots with
cycles from a wav file.
@param filename str : Wav file name.
@param sig_gen SigGen : SigGen to use for regenerating the signal.
@param resynthesize : If True, the signal is resynthesised using the
harmonic series of the original signal - works best on signals with
a low findamental frequency (< 200 Hz). If False, n evenly spaced
single cycles are extracted from the input (default False).
@returns WaveTable : self, populated by content from the wav file
settings as this one
"""
data, fs = wavfile.read(filename, with_sample_rate=True)
if sig_gen is None:
sig_gen = sig.SigGen()
if resynthesize:
num_sections = self.num_waves
while True:
data = data[:data.size - (data.size % num_sections)]
sections = np.split(data, num_sections)
try:
self.waves = [
dsp.resynthesize(s, sig_gen) for s in sections
]
break
except dsp.NotEnoughSamplesError as exc:
num_sections -= 1
if num_sections <= 0:
raise exc
if num_sections < self.num_waves:
self.waves = sig.morph(self.waves, self.num_waves)
else:
cycles = dsp.slice_cycles(data, self.num_waves, fs)
self.waves = [sig_gen.arb(c) for c in cycles]
return self
def main():
""" main """
# create a signal generator
sig_gen = sig.SigGen()
# create a wave table to store the waves
zwt = wavetable.WaveTable(num_waves=16)
# example 1: generate and save a simple saw wave
# generate a saw using our signal generator and store it in a new Wave
# object.
saw_wave = sig_gen.saw()
# put the saw wave into our wave table.
zwt.waves = [saw_wave]
# as we're only adding one wave to the wave table, only the first slot of
# the resulting oscillator in zebra will contain the saw. the remaining
# slots will be empty, because we haven't added anything to those yet.
render(zwt, 'osc_gen_saw')
# you could fill all 16 slots with the same saw, by repeating it 16 times
zwt.waves = [saw_wave for _ in range(16)]
render(zwt, 'osc_gen_saw_16')
# example 2: morphing between two waveforms we can use up all 16 slots in
# the zebra oscillator, even with fewer than 16 starting waveforms, if we
# use morph() to morph from one waveform to the other, to fill in the
# in-between slots.
# morph from sine to triangle over 16 slots
zwt.waves = sig.morph((sig_gen.sin(), sig_gen.tri()), 16)
render(zwt, 'osc_gen_sin_tri')
# of course, we don't have to use all 16 slots. we could use only the first
# 5, for example.
# morph from sine to triangle over 5 slots
zwt.waves = sig.morph((sig_gen.sin(), sig_gen.tri()), 5)
render(zwt, 'osc_gen_sin_tri_5')
# example 3: morphing between many waveforms
# it is possible to morph between any number of waveforms, to produce
# interpolated waves between the given waves.
# morph between sine, triangle, saw and square over 16 slots
zwt.waves = sig.morph(
(sig_gen.sin(), sig_gen.tri(), sig_gen.saw(), sig_gen.sqr()), 16)
render(zwt, 'osc_gen_sin_tri_saw_sqr')
# example 4: generting arbitrary waves
# a custom signal can be used as an oscillator.
# in this example, one slot is filled with random data, but any data,
# generated or, say, read in from a wav file, can be used.
# the custom signal generator function automatically normaises and scales
# any data you throw at it to the right ranges, which is useful.
zwt.waves = [
sig_gen.arb(np.random.uniform(low=-1, high=1, size=128))
for _ in range(16)
]
render(zwt, 'osc_gen_random')
# example 5: pulse-width modulation
# SigGen has a pulse wave generator too.
# let's use that to make a pwm wavetable.
# pulse widths are between 0 and 1 (0 to 100%). 0 and 1 are silent as the
# pulse is a flat line. so, we want to have 16 different, equally spaced
# pulse widths, increasing in duration, but also avoid any silence:
pws = (i / 17. for i in range(1, 17))
# generate the 16 pulse waves
zwt.waves = [sig_gen.pls(p) for p in pws]
render(zwt, 'osc_gen_pwm')
# example 6: processing wave forms
# the dsp module can be used to process waves in various ways
# let's try downsampling a sine
downsampled = dsp.downsample(sig_gen.sin(), 16)
# that downsampled sine from probably sounds pretty edgy
# let's try that again with some slew this time, to smooth it out a bit
slewed = dsp.slew(dsp.downsample(sig_gen.sin(), 16), 0.8)
# generate a triangle wave and quantize (bit crush) it
quantized = dsp.quantize(sig_gen.tri(), 3)
# applying inverse slew, or overshoot, to a square wave
slewed_square = dsp.slew(sig_gen.sqr(), 0.8, inv=True)
# overshoot might make the wave quieter, so let's normalize it
dsp.normalize(slewed_square)
# morph between the waves over 16 slots
zwt.waves = sig.morph((downsampled, slewed, quantized, slewed_square), 16)
render(zwt, 'osc_gen_dsp')
# example 7: longer wavetables, more processing and writing a wav file
# wavetables can have any number of slots, this one has 120 slots
lwt = wavetable.WaveTable(num_waves=120)
# similarly, a signal generator can generate any number of samples
# a waveform coresponding to the frequency of C3 at 44.1 kHz would
# have approx. 337 samples.
mc_sig_gen = sig.SigGen()
mc_sig_gen.num_points = 337
# create ever-decreasing wave folding distortion over the wavetable
lwt.waves = [
dsp.fold(mc_sig_gen.sin(), (lwt.num_waves - i) / 50.)
for i in range(lwt.num_waves)
]
wavfile.write_wavetable(lwt, os.path.join(make_osc_path(), 'folding.wav'))
# create ever-increasing wave shaping distortion over the wavetable
lwt.waves = [
dsp.shape(mc_sig_gen.sin(), power=i + 1) for i in range(lwt.num_waves)
]
wavfile.write_wavetable(lwt, os.path.join(make_osc_path(), 'shaping.wav'))
from osc_gen import wavetable, dsp, sig, visualize import numpy as np from scipy import fftpack from scipy.io.wavfile import write import matplotlib.pyplot as plt # Create a signal generator. sample_length = 2048 sg = sig.SigGen(num_points=sample_length) Fs = 44100 # Create a wave table with 1024 slots to store the waves. wt = wavetable.WaveTable(1, wave_len=1024) #m = sg.saw() m = sg.tri() wt.waves = [m] #visualize.plot_wavetable(wt) timestep = 1.0 / Fs rFFT_values = fftpack.rfft(m) freq = fftpack.rfftfreq(rFFT_values.size, d=timestep) # Make array uniform with C input data X = rFFT_values X = np.insert(X, 0, 0) freq = np.insert(freq, 0, 0) X = np.delete(X, -1) freq = np.delete(freq, -1) outfile = "./waves/tri_%d.cgw" % sample_length
