Update app.py

app.py

@@ -609,7 +609,7 @@ def on_highres_toggle(first_image, last_image, high_res):
 def get_gpu_duration(gpu_duration: float):
     return int(gpu_duration)
 
-@spaces.GPU(duration=gpu_duration)
+@spaces.GPU(duration=get_gpu_duration)
 @torch.inference_mode()
 def generate_video(
     first_image,