def __test(order):
a1 = pysptk.lpc(x, order, use_scipy=False)
a2 = pysptk.lpc(x, order, use_scipy=True)
a3 = pysptk.levdur(pysptk.acorr(x, order), use_scipy=False)
a4 = pysptk.levdur(pysptk.acorr(x, order), use_scipy=True)
assert np.all(np.isfinite(a1))
assert np.allclose(a1, a2)
assert np.allclose(a1, a3)
assert np.allclose(a1, a4)
def test_lpc(order):
x = windowed_dummy_data(1024)
a1 = pysptk.lpc(x, order, use_scipy=False)
a2 = pysptk.lpc(x, order, use_scipy=True)
a3 = pysptk.levdur(pysptk.acorr(x, order), use_scipy=False)
a4 = pysptk.levdur(pysptk.acorr(x, order), use_scipy=True)
assert np.all(np.isfinite(a1))
assert np.allclose(a1, a2)
assert np.allclose(a1, a3)
assert np.allclose(a1, a4)
def __test_synthesis_levdur(filt):
# dummy source excitation
source = __dummy_source()
hopsize = 80
# dummy filter coef.
windowed = __dummy_windowed_frames(source,
frame_len=512,
hopsize=hopsize)
c = pysptk.mcep(windowed, filt.order)
a = pysptk.c2acr(c)
lpc = pysptk.levdur(a)
lpc2 = pysptk.levdur(a, use_scipy=True)
assert np.allclose(lpc, lpc2)
# make sure lpc has loggain
lpc[:, 0] = np.log(lpc[:, 0])
# synthesis
synthesizer = Synthesizer(filt, hopsize)
y = synthesizer.synthesis(source, lpc)
assert np.all(np.isfinite(y))
def pitch_shift_on_lpc_residual(
wav,
sr,
shift_in_cent,
frame_length=4096,
hop_length=240,
mgc_order=59,
):
assert wav.dtype == np.int16
frames = (librosa.util.frame(wav,
frame_length=frame_length,
hop_length=hop_length).astype(np.float64).T)
frames *= pysptk.blackman(frame_length)
alpha = pysptk.util.mcepalpha(sr)
mgc = pysptk.mcep(frames, mgc_order, alpha, eps=1e-5, etype=1)
c = pysptk.freqt(mgc, mgc_order, -alpha)
lpc = pysptk.levdur(pysptk.c2acr(c, mgc_order, frame_length))
# remove gain
lpc[:, 0] = 0
# Compute LPC residual
synth = Synthesizer(AllZeroDF(mgc_order), hop_length)
wav_lpc = synth.synthesis(wav.astype(np.float64), -lpc)
residual = wav - wav_lpc
# Pitch-shift on LPC residual
residual_shifted = librosa.effects.pitch_shift(residual,
sr=sr,
n_steps=shift_in_cent,
bins_per_octave=1200)
# Filtering by LPC
synth = Synthesizer(AllPoleDF(mgc_order), hop_length)
wav_shifted = synth.synthesis(residual_shifted, lpc)
return wav_shifted.astype(np.int16)