Update app.py

app.py

@@ -58,7 +58,13 @@ def plot_features(y, sr, mfcc, delta, delta2):
     return fig
 
 def process(audio):
+    if audio is None:
+        return "No audio provided.", plt.figure()
+
     sr, y = audio
+    if y is None:
+        return "Audio data is empty.", plt.figure()
+
     y = y.astype(np.float32)
 
     # Lowpass filter