def energy_envelope(args):
sig = get_sig(args)
nfft = unroll_args(args, ['nfft'])
sig = np.abs(sig)
hann_window = _cached_get_window('hanning', nfft)
envelope = np.convolve(sig, hann_window, 'same')
return envelope.reshape((len(envelope), 1))
def lp_coefficients(args):
sig = get_sig(args)
nfft, fs, noverlap, win_length, order = unroll_args(
args, ['nfft', 'fs', 'noverlap', 'win_length', 'order'])
hann_window = _cached_get_window('hanning', nfft)
window = unroll_args(args, [('window', hann_window)])
siglen = len(sig)
nsegs, segs = split_segments(siglen, win_length, noverlap, incltail=False)
lp_coeffs = np.zeros((order, nsegs), dtype=np.float32)
for i in range(nsegs):
seg_beg, seg_end = segs[i]
frame = sig[seg_beg:seg_end]
lp_coeffs[:, i] = lp_coefficients_frame(frame * window, order)
return lp_coeffs
def lpc_spectrum(args):
sig = get_sig(args)
nfft, fs, noverlap, win_length, order = unroll_args(
args, ['nfft', 'fs', 'noverlap', 'win_length', 'order'])
hann_window = _cached_get_window('hanning', nfft)
window = unroll_args(args, [('window', hann_window)])
siglen = len(sig)
nsegs, segs = split_segments(siglen, win_length, noverlap, incltail=False)
lpcs = np.zeros((nfft, nsegs), dtype=np.complex64)
for i in range(nsegs):
seg_beg, seg_end = segs[i]
frame = sig[seg_beg:seg_end]
lpcs[:, i] = lpc_spectrum_frame(frame * window, order, nfft)
return np.log10(abs(lpcs))