def predlin(s,p,w):
"""
Function that computes de linear prediction using lpc for a given signal
"""
x = s*w
lpc,e = spectrum.lpc(x,N = p)
#E = np.sqrt(np.sum(x**2))
ar,sigma,lt = spectrum.aryule(x,p)
plt.subplot(3,1,1)
plt.plot(s)
plt.title("Speech signal")
xx = np.arange(0,len(w))
plt.plot(xx,w*np.max(s))
plt.subplot(312)
plt.plot(x)
plt.title("Windowed signal")
plt.subplot(313)
S_x = 20*np.log10(np.abs(np.fft.fft(x,2*len(w))))
plt.plot(S_x[0:len(w)])
ff,h = scipy.signal.freqz(1,ar,len(w),whole=False)
h2 = spectrum.arma2psd(ar,NFFT=len(w)*2)
plt.plot(20*np.log10(np.abs(h2[0:len(w)])))
def func(n_frames, n_freqs, data_frames):
#win=np.hanning(frame_length)
print("computing the weight factor...")
w_matrix = np.ones_like(data_frames)
for i in range(n_frames):
ak, _ = lpc(data_frames[i, :], 10)
a_numerator = np.insert(ak, 0, 1)
a_denominator = np.ones_like(a_numerator)
for ii in range(1, len(a_numerator)):
a_denominator[ii] = (0.8 ** ii) * a_numerator[ii]
_, H = signal.freqz(a_numerator, a_denominator, worN=n_freqs, whole=True)
w_matrix[i, :] = H.copy()
return 20*np.log10(abs(w_matrix[:, 0:n_freqs]))
def lpc_cepstrum_frame(sig, order=None):
"""
:param lpc: A sequence of lpc components. Need to be preprocessed by lpc()
:param g: Error term for lpc sequence
:param order: size of the array. Function returns order+1 length array. Default is len(seq)
:return:
"""
lp, g = spectrum.lpc(sig, order)
cepst = np.zeros((order, ), dtype=np.float32)
for i in range(0, order):
sum = 0
for j in range(0, i):
sum += (j - i) * lp[j] * cepst[i - j - 1]
cepst[i] = -lp[i] + sum / (i + 1)
return cepst
def predlin2(s,p,w):
x = s*w
lpc,e = spectrum.lpc(x,N = p)
return lpc
def lpc_spectrum_frame(sig, order, nfft):
lp, e = spectrum.lpc(sig, order)
# Need to add 1 to the lp coefficients to make it similar to result from Matlab
w, h = freqz(1, np.concatenate((np.array([1]), lp)), nfft)
return h
def lp_coefficients_frame(sig, order):
lp, e = spectrum.lpc(sig, order)
return lp.astype(np.float32)
def lpc_coeff(self, p):
#print "LPC coeff for: " + str(self)
sc_data = self.data - np.mean(self.data)
sc_data = sc_data/np.max(sc_data)
(coeff, err) = lpc(sc_data, p);
return coeff
def lpc_coeff(self, p):
# print "LPC coeff for: " + str(self)
sc_data = self.data - np.mean(self.data)
sc_data = sc_data / np.max(sc_data)
(coeff, err) = lpc(sc_data, p)
return coeff
import voice_sample
def frame(x, framesize, framehop):
w = scipy.hamming(framesize)
return scipy.array([w*x[i:i+framesize]
for i in range(0, len(x)-framesize, framehop)])
if __name__ == '__main__':
import scipy.io.wavfile as wf
names = voice_sample.get_names()
for num, name in zip(range(1, len(names) + 1), names):
pylab.subplot(2,3, num)
for it in range(0, 9):
(fs, sd) = wf.read(voice_sample.SAMPLES_DIR + '/%s/imie/%02d.wav' % (name, it+1) )
sd = sd - scipy.mean(sd)
sd = sd / scipy.amax(sd)
#sf = frame(sd, int(fs*0.03), int(fs*0.02))
#lpcc = scipy.array([ lpc(f, 10) for f in sf ]);
#lpcc_mean = scipy.mean(lpcc, 0)
#pylab.figure();
#pylab.plot(sd);
lpcc, e = spectrum.lpc(sd, 12)
pylab.plot(lpcc, label="Zapis {:02d}".format(it+1) );
pylab.title(name)
pylab.ylim(-5, 5)
pylab.show();