order change again

app.py

@@ -39,7 +39,7 @@ with gr.Blocks() as demo:
             output_file.render()
             output_file.change(prepare_video_subtitle, inputs=[
                                input_video, start_time, end_time], outputs=output_video)
-            output_video.change(prepare_output, inputs=output_video, outputs=[
+            output_file.change(prepare_output, inputs=input_video, outputs=[
                 adjust_speaker, adjust_audio, prev_button, next_button, adjust_button])
 
         with gr.Column():

set_up.py

@@ -10,6 +10,15 @@ import utils
 
 
 def prepare_video_subtitle(input_file, start_time, end_time, progress=gr.Progress()):
+    if input_file is None or not os.path.exists(input_file):
+        gr.Warning(ui_lang["input_video_warning"])
+        return [None, None, [None, None]]
+    if validate_time_format(start_time) is False:
+        gr.Warning(ui_lang["start_time_warning"])
+        return [None, None, [None, None]]
+    if validate_time_format(end_time) is False:
+        gr.Warning(ui_lang["end_time_warning"])
+        return [None, None, [None, None]]
     # Add subtitle to video
     progress(0.8, desc=ui_lang["progress_add_subtitle"])
     add_subtitle_to_video(input_file, base_subtitle_file,