def sinusoid_analysis(X, input_sample_rate, resample_block=128, copy=True):
"""
Contruct a sinusoidal model for the input signal.
Parameters
----------
X : ndarray
Input signal to model
input_sample_rate : int
The sample rate of the input signal
resample_block : int, optional (default=128)
Controls the step size of the sinusoidal model
Returns
-------
frequencies_hz : ndarray
Frequencies for the sinusoids, in Hz.
magnitudes : ndarray
Magnitudes of sinusoids returned in ``frequencies``
References
----------
D. P. W. Ellis (2004), "Sinewave Speech Analysis/Synthesis in Matlab",
Web resource, available: http://www.ee.columbia.edu/ln/labrosa/matlab/sws/
"""
X = np.array(X, copy=copy)
resample_to = 8000
if input_sample_rate != resample_to:
if input_sample_rate % resample_to != 0:
raise ValueError("Input sample rate must be a multiple of 8k!")
# Should be able to use resample... ?
# resampled_count = round(len(X) * resample_to / input_sample_rate)
# X = sg.resample(X, resampled_count, window=sg.hanning(len(X)))
X = sg.decimate(X, input_sample_rate // resample_to, zero_phase=True)
step_size = 2 * round(resample_block / input_sample_rate * resample_to / 2.)
a, g, e = lpc_analysis(X, order=8, window_step=step_size,
window_size=2 * step_size)
f, m = lpc_to_frequency(a, g)
f_hz = f * resample_to / (2 * np.pi)
return f_hz, m
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