Function mu_law_decode

wavenet/ops.py:78–86

Recovers waveform from quantized values.

(output, quantization_channels)

def mu_law_decode(output, quantization_channels):
    '''Recovers waveform from quantized values.'''
    with tf.name_scope('decode'):
        mu = quantization_channels - 1
        # Map values back to [-1, 1].
        signal = 2 * (tf.to_float(output) / mu) - 1
        # Perform inverse of mu-law transformation.
        magnitude = (1 / mu) * ((1 + mu)**abs(signal) - 1)
        return tf.sign(signal) * magnitude