Update Annotation_with_action_lerobotv21/README.md

Annotation_with_action_lerobotv21/README.md

@@ -169,6 +169,25 @@ Each annotation has a corresponding quality indicator prefixed with `Q_annotatio
 
 ---
 
+## Download & Extract
+
+The `data/` and `videos/` directories are distributed as `.tar` archives (one per chunk) to reduce the number of files during transfer. After downloading, extract them in place:
+
+```bash
+cd Annotation_with_action_lerobotv21
+
+for dataset in lerobot_droid_anno lerobot_rh20t_anno; do
+  for subdir in data videos; do
+    cd ${dataset}/${subdir}
+    for f in *.tar; do tar xf "$f" && rm "$f"; done
+    cd ../..
+  done
+done
+```
+
+After extraction, each `data/` will contain `chunk-000/`, `chunk-001/`, ... with `.parquet` files, and each `videos/` will contain `chunk-000/`, `chunk-001/`, ... with `.mp4` files. The `meta/` directories are ready to use without extraction.
+
+
 ## Quick Start
 
 The dataloader code is at [RoboInterData/lerobot_dataloader](https://github.com/InternRobotics/RoboInter/tree/main/RoboInterData/lerobot_dataloader).