Use RtcpPacket to send FIR in RtcpSender

webrtc/modules/rtp_rtcp/source/rtcp_sender.cc

 /*
  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 546 matching lines @@
   TRACE_EVENT_INSTANT0(TRACE_DISABLED_BY_DEFAULT("webrtc_rtp"),
                        "RTCPSender::PLI");
   ++packet_type_counter_.pli_packets;
   TRACE_COUNTER_ID1(TRACE_DISABLED_BY_DEFAULT("webrtc_rtp"), "RTCP_PLICount",
                     ssrc_, packet_type_counter_.pli_packets);
 
   return BuildResult::kSuccess;
 }
 
 RTCPSender::BuildResult RTCPSender::BuildFIR(RtcpContext* ctx) {
-  // sanity
-  if (ctx->position + 20 >= IP_PACKET_SIZE)
+  if (!ctx->repeat)
+    ++sequence_number_fir_;  // Do not increase if repetition.
+
+  rtcp::Fir fir;
+  fir.From(ssrc_);
+  fir.To(remote_ssrc_);
+  fir.WithCommandSeqNum(sequence_number_fir_);
+
+  PacketBuiltCallback callback(ctx);
+  if (!callback.BuildPacket(fir))
     return BuildResult::kTruncated;
 
-  if (!ctx->repeat)
-    sequence_number_fir_++;  // do not increase if repetition
-
-  // add full intra request indicator
-  uint8_t FMT = 4;
-  *ctx->AllocateData(1) = 0x80 + FMT;
-  *ctx->AllocateData(1) = 206;
-
-  //Length of 4
-  *ctx->AllocateData(1) = 0;
-  *ctx->AllocateData(1) = 4;
-
-  // Add our own SSRC
-  ByteWriter<uint32_t>::WriteBigEndian(ctx->AllocateData(4), ssrc_);
-
-  // RFC 5104     4.3.1.2.  Semantics
-  // SSRC of media source
-  ByteWriter<uint32_t>::WriteBigEndian(ctx->AllocateData(4), 0);
-
-  // Additional Feedback Control Information (FCI)
-  ByteWriter<uint32_t>::WriteBigEndian(ctx->AllocateData(4), remote_ssrc_);
-
-  *ctx->AllocateData(1) = sequence_number_fir_;
-  *ctx->AllocateData(1) = 0;
-  *ctx->AllocateData(1) = 0;
-  *ctx->AllocateData(1) = 0;
-
   TRACE_EVENT_INSTANT0(TRACE_DISABLED_BY_DEFAULT("webrtc_rtp"),
                        "RTCPSender::FIR");
   ++packet_type_counter_.fir_packets;
   TRACE_COUNTER_ID1(TRACE_DISABLED_BY_DEFAULT("webrtc_rtp"), "RTCP_FIRCount",
                     ssrc_, packet_type_counter_.fir_packets);
 
   return BuildResult::kSuccess;
 }
 
 /*
@@ skipping 880 matching lines @@
 
 bool RTCPSender::AllVolatileFlagsConsumed() const {
   for (const ReportFlag& flag : report_flags_) {
     if (flag.is_volatile)
       return false;
   }
   return true;
 }
 
 }  // namespace webrtc