code: def melspectrogram(self, wav):
      mel = librosa.feature.melspectrogram(
          wav,
          sr=self.sampling_rate,
          n_fft=self.n_fft,
          hop_length=self.hop_length,
          n_mels=self.n_mels,
      )
      mel = mel.astype(np.float32).T
      return mel
  
file_path: PaddleHub/modules/audio/voice_cloning/lstm_tacotron2/audio_processor.py
imports: from pathlib import Path
  from warnings import warn
  import struct
  from scipy.ndimage.morphology import binary_dilation
  import numpy
  import librosa
label_desc: Use image node_id 3 for calling the SpeakerVerificationPreprocessor obj's underlying member method code with example usage: obj.melspectrogram(wav) and returns: mel