convert float16 to float32 for plotting spectrograms

TTS/tts/utils/visual.py

@@ -1,6 +1,8 @@
-import torch
 import librosa
 import matplotlib
+import numpy as np
+import torch
+
 matplotlib.use('Agg')
 import matplotlib.pyplot as plt
 from TTS.tts.utils.text import phoneme_to_sequence, sequence_to_phoneme
@@ -43,6 +45,8 @@ def plot_spectrogram(spectrogram,
         spectrogram_ = spectrogram.detach().cpu().numpy().squeeze().T
     else:
         spectrogram_ = spectrogram.T
+    spectrogram_ = spectrogram_.astype(
+        np.float32) if spectrogram_.dtype == np.float16 else spectrogram_
     if ap is not None:
         spectrogram_ = ap._denormalize(spectrogram_)  # pylint: disable=protected-access
     fig = plt.figure(figsize=fig_size)