change gpu duration calculation to dynamically adapt to the number of inference steps

app.py

@@ -84,12 +84,10 @@ def get_duration(input_image, prompt, height, width,
                    guidance_scale, steps,
                    seed, randomize_seed, 
                    progress):
-    if steps > 4 and duration_seconds > 2:
-        return 90
-    elif steps > 4 or duration_seconds > 2:
-        return 75
+    if duration_seconds <= 2.5
+        return steps * 18
     else:
-        return 60
+        return steps * 25
 
 @spaces.GPU(duration=get_duration)
 def generate_video(input_image, prompt, height, width,