diff --git a/trunk/src/app/srs_app_gb28181.cpp b/trunk/src/app/srs_app_gb28181.cpp
index 64fd33d51c..9e1df764cd 100644
--- a/trunk/src/app/srs_app_gb28181.cpp
+++ b/trunk/src/app/srs_app_gb28181.cpp
@@ -1946,7 +1946,7 @@ srs_error_t SrsGbMuxer::write_h265_ipb_frame(char* frame, int frame_size, uint32
     SrsHevcNaluType nt = SrsHevcNaluTypeParse(frame[0]);
 
     // F.3.29 intra random access point (IRAP) picture
-    // ITU-T-H.265-2021.pdf, page 28.
+    // ITU-T-H.265-2021.pdf, page 462.
     SrsVideoAvcFrameType frame_type = SrsVideoAvcFrameTypeInterFrame;
     if (nt >= SrsHevcNaluType_CODED_SLICE_BLA && nt <= SrsHevcNaluType_RESERVED_23) {
         frame_type = SrsVideoAvcFrameTypeKeyFrame;