diff --git a/src/llamafactory/data/mm_plugin.py b/src/llamafactory/data/mm_plugin.py
index 55db4626..3de51904 100644
--- a/src/llamafactory/data/mm_plugin.py
+++ b/src/llamafactory/data/mm_plugin.py
@@ -383,6 +383,7 @@ class CpmOPlugin(BasePlugin):
         self._validate_input(images, videos)
         image_bounds_list = []
         valid_image_nums_ls = []
+        
         for input_ids in batch_ids:
             input_ids_ = torch.tensor(input_ids)
             start_cond = (input_ids_ == processor.tokenizer.im_start_id) | (