diff --git a/av1/qmode_rc/ratectrl_qmode_interface.h b/av1/qmode_rc/ratectrl_qmode_interface.h
index 26166c3..18beec1 100644
--- a/av1/qmode_rc/ratectrl_qmode_interface.h
+++ b/av1/qmode_rc/ratectrl_qmode_interface.h
@@ -229,6 +229,9 @@
   // TODO(jingning): This can be removed once the framework is up running.
   int display_tracker;  // Track the number of frames displayed proceeding a
                         // current coding frame.
+  double base_q_ratio;  // The adjustment ratio, based on which the base QP
+                        // index of this Gop will be adjusted from
+                        // RateControlParam::base_q_index.
   std::vector<GopFrame> gop_frame_list;
 };