diff --git a/tracklab/engine/offline.py b/tracklab/engine/offline.py
index 6214adf2..77325763 100644
--- a/tracklab/engine/offline.py
+++ b/tracklab/engine/offline.py
@@ -1,6 +1,7 @@
 import logging
 
 from tracklab.engine import TrackingEngine
+from tracklab.engine.engine import merge_dataframes
 from tracklab.utils.cv2 import cv2_load_image
 
 log = logging.getLogger(__name__)
@@ -19,7 +20,11 @@ def video_loop(self, tracker_state, video, video_id):
         model_names = self.module_names
         for model_name in model_names:
             if self.models[model_name].level == "video":
-                detections = self.models[model_name].process(detections, image_pred)
+                batch_detections = self.models[model_name].process(detections, image_pred)
+                if isinstance(batch_detections, tuple):
+                    batch_detections, batch_metadata = batch_detections
+                    image_pred = merge_dataframes(image_pred, batch_metadata)
+                detections = merge_dataframes(detections, batch_detections)
                 continue
             self.datapipes[model_name].update(image_filepaths, image_pred, detections)
             self.callback(