Update app.py

app.py

@@ -26,6 +26,7 @@ def extract_waveform_animation(audio_file):
     def update(frame):
         start = frame * sr
         end = min(start + sr, len(y))
+        line.set_xlim(start, end)
         line.set_data(np.linspace(start, end, num=len(y[:end])), y[:end])
         return line,