fix

app.py

@@ -19,6 +19,7 @@ with gr.Blocks() as demo:
                 input_video.render()
                 input_video.clear(clear_duration, outputs=[
                     start_time, end_time])
+                input_video_button.render()
                 input_video_button.click(get_duration, input_video, [
                     start_time, end_time])
             with gr.Column():