code: def encode_mu_law(x, mu=256):
      """Perform mu-law encoding.
  
      Args:
          x (ndarray): Audio signal with the range from -1 to 1.
          mu (int): Quantized level.
  
      Returns:
          ndarray: Quantized audio signal with the range from 0 to mu - 1.
  
      """
      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.int64)
  
imports: import logging
  import sys
  import time
  import numpy
  import torch
  import torch.nn.functional
  from torch import nn
label_desc: Use image node_id 1 for calling a global function with example usage: encode_mu_law(x, mu) and returns: np