H264SpsPpsTracker class which keep tracks of SPS/PPS.

webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc

Index: webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc b/webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc
index 27479458315de126fa3e551128a748b618a81714..01792d6e5e18688ac258317b7596ed2d56d83156 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_format_h264.cc
@@ -411,6 +411,10 @@ bool RtpDepacketizerH264::ProcessStapAOrSingleNalu(
 
     NaluInfo nalu;
     nalu.type = payload_data[start_offset] & kTypeMask;
+    if (nalu.type != H264::NaluType::kFuA) {
+      nalu.offset = start_offset;
+      nalu.size = end_offset - start_offset;
+    }
     nalu.sps_id = -1;
     nalu.pps_id = -1;
     start_offset += H264::kNaluTypeSize;