attempt 3 on fps issue

app.py

@@ -12,7 +12,7 @@ def extract_waveform_animation(audio_file, window_seconds=5):
     FPS = 30
     fig, ax = plt.subplots()
     line, = ax.plot([], [], lw=2)
-    window_length = int(window_seconds * sr)
+    window_length = int(window_seconds * sr / FPS)
     
     # Initialize with first window
     first_window = y[:window_length]
@@ -27,7 +27,7 @@ def extract_waveform_animation(audio_file, window_seconds=5):
 
     def update(frame):
         # Get current window
-        start = frame * (sr // FPS)
+        start = frame * sr
         end = start + window_length
         window = y[start:end]