Add error handling

app.py

@@ -1,9 +1,14 @@
 import gradio as gr
 
 def process_video(video, visualize_features):
-    # Placeholder: In a real app, process the video and visualize features if requested
-    msg = "Feature visualization enabled." if visualize_features else "Feature visualization disabled."
-    return video, msg
+    if video is None:
+        return None, "Error: No video uploaded."
+    try:
+        # Placeholder: In a real app, process the video and visualize features if requested
+        msg = "Feature visualization enabled." if visualize_features else "Feature visualization disabled."
+        return video, msg
+    except Exception as e:
+        return None, f"Error: {str(e)}"
 
 with gr.Blocks(theme=gr.themes.Base(), css=".gradio-container {background: #111827; color: #d1d5db;}") as demo:
     gr.Markdown(