Update app.py

app.py

@@ -51,7 +51,7 @@ def predict(pilimg,video_in_filepath,threshold):
     if pilimg:
         image_np = pil_image_as_numpy_array(pilimg)
         return predict2(image_np,threshold),None
-    else:
+    elif video_in_filepath:
         video_reader = cv2.VideoCapture(video_in_filepath)
         
         nb_frames = int(video_reader.get(cv2.CAP_PROP_FRAME_COUNT))
@@ -91,7 +91,8 @@ def predict(pilimg,video_in_filepath,threshold):
         cv2.destroyAllWindows() 
         cv2.waitKey(1)
         return None,video_out_filepath
-
+    else:
+        return None, None
 
 
 def predict2(image_np,threshold):