nnmnkwii.preprocessing.modspec¶
-
nnmnkwii.preprocessing.
modspec
(x, n=4096, norm=None, return_phase=False)[source]¶ Modulation spectrum (MS) computation
Given a parameter trajectory, it computes modulation spectrum. In the library, we define modulation spectrum as power of discrete Fourier transform of parameter trajectory across time-axis. See [1] for example application.
[1] Takamichi, Shinnosuke, et al. “A postfilter to modify the modulation spectrum in HMM-based speech synthesis.” Acoustics, Speech and Signal Processing (ICASSP), 2014 IEEE International Conference on. IEEE, 2014. Warning
This may move in different module in future.
Parameters: - y (numpy.ndarray) – Parameter trajectory, shape (
T x D
). - n (int) – DFT length
- norm (str) – Normalization mode. See
numpy.fft.fft()
. - return_phase (bool) – If True, return phase of MS.
Returns: Modulation spectrum (
n//2 + 1 x D
) and phase (ifreturn_phase
is True).Return type: Examples
>>> import numpy as np >>> from nnmnkwii import preprocessing as P >>> generated = np.random.rand(10, 2) >>> ms = P.modspec(generated, n=16) >>> ms.shape (9, 2)
- y (numpy.ndarray) – Parameter trajectory, shape (