fix source issue

app.py

@@ -33,7 +33,7 @@ def fun(img):
 with gr.Blocks(title="Realtime Keypoint Detection | Data Science Dojo", css="footer {display:none !important} .output-markdown{display:none !important}") as demo:
     with gr.Row():
         with gr.Column():
-            webcam_input = gr.Video(source="webcam", label="Webcam Input")
+            webcam_input = gr.Video(label="Webcam Input", format="mp4")  # Webcam input
 
         with gr.Column():
             output = gr.Image(label="Output Image")