Update app.py

app.py

@@ -18,6 +18,7 @@ def greet(audio):
     
     mel = librosa.feature.melspectrogram(y=y, sr=sr)   
      # #https://stackoverflow.com/questions/56719138/how-can-i-save-a-librosa-spectrogram-plot-as-a-specific-sized-image/57204349#57204349
+    mel = np.log(mel + 1e-9)  
     img = scale_minmax(mel, 0, 255).astype(np.uint8)
     img = 255-img 
     return img