retry fps issue 2

app.py

@@ -40,7 +40,7 @@ def extract_waveform_animation(audio_file, window_seconds=5):
 
     total_frames = int(duration) * FPS
     ani = FuncAnimation(fig, update, frames=range(total_frames), 
-                       init_func=init, interval=window_seconds, blit=False)
+                       init_func=init, interval=window_seconds // FPS, blit=False)
     
     with tempfile.NamedTemporaryFile(delete=False, suffix='.mp4') as tmpfile:
         ani.save(tmpfile.name, writer='ffmpeg', fps=FPS)