utils.py

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"""
Module: utility module for WaveNet
"""
import numpy as np

# pylint: disable=invalid-name, too-many-arguments
def encode_mu_law(x, mu=256):
    """
    Description : generation encoding
    """
    mu = mu-1
    fx = np.sign(x)*np.log(1+mu*np.abs(x))/np.log(1+mu)
    return np.floor((fx+1)/2*mu+0.5).astype(np.long)

def decode_mu_law(y, mu=256):
    """
    Description : generation decoding
    """
    mu = mu-1
    fx = (y-0.5)/mu*2-1
    x = np.sign(fx)/mu*((1+mu)**np.abs(fx)-1)
    return x