Revert "Correctly handle retransmissions/padding in early loss detection."

This reverts commit e9ae4729e03f60dbe3b1828dd9009b401097cd3f.

Reason for revert: Internal test failure

Original change's description:
> Correctly handle retransmissions/padding in early loss detection.
>
> This CL makes sure we don't cull packets from the history based on
> incorrect ack mapping, just like it's predecessor:
> https://webrtc-review.googlesource.com/c/src/+/218000
>
> It also changes the logic to make sure retransmits counts towards
> history pruning - and properly ignores padding/fec.
>
> Bug: webrtc:12713
> Change-Id: I7835d10e483687e960a9cce41d4e2f1a6c3189b4
> Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/221863
> Reviewed-by: Björn Terelius <terelius@webrtc.org>
> Reviewed-by: Philip Eliasson <philipel@webrtc.org>
> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
> Commit-Queue: Erik Språng <sprang@webrtc.org>
> Cr-Commit-Position: refs/heads/master@{#34293}

TBR=danilchap@webrtc.org,terelius@webrtc.org,sprang@webrtc.org,philipel@webrtc.org,webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com

Change-Id: Iaca6dc7739d953e97add5f5d516139b4819e43ee
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: webrtc:12713
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/222601
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34294}
diff --git a/call/rtp_video_sender.cc b/call/rtp_video_sender.cc
index e20ba32..110e28b 100644
--- a/call/rtp_video_sender.cc
+++ b/call/rtp_video_sender.cc
@@ -932,45 +932,43 @@
   // Map from SSRC to all acked packets for that RTP module.
   std::map<uint32_t, std::vector<uint16_t>> acked_packets_per_ssrc;
   for (const StreamPacketInfo& packet : packet_feedback_vector) {
-    if (packet.received && packet.ssrc) {
-      acked_packets_per_ssrc[*packet.ssrc].push_back(
-          packet.rtp_sequence_number);
+    if (packet.received) {
+      acked_packets_per_ssrc[packet.ssrc].push_back(packet.rtp_sequence_number);
     }
   }
 
-  // Map from SSRC to vector of RTP sequence numbers that are indicated as
-  // lost by feedback, without being trailed by any received packets.
-  std::map<uint32_t, std::vector<uint16_t>> early_loss_detected_per_ssrc;
+    // Map from SSRC to vector of RTP sequence numbers that are indicated as
+    // lost by feedback, without being trailed by any received packets.
+    std::map<uint32_t, std::vector<uint16_t>> early_loss_detected_per_ssrc;
 
-  for (const StreamPacketInfo& packet : packet_feedback_vector) {
-    // Only include new media packets, not retransmissions/padding/fec.
-    if (!packet.received && packet.ssrc && !packet.is_retransmission) {
-      // Last known lost packet, might not be detectable as lost by remote
-      // jitter buffer.
-      early_loss_detected_per_ssrc[*packet.ssrc].push_back(
-          packet.rtp_sequence_number);
-    } else {
-      // Packet received, so any loss prior to this is already detectable.
-      early_loss_detected_per_ssrc.erase(*packet.ssrc);
+    for (const StreamPacketInfo& packet : packet_feedback_vector) {
+      if (!packet.received) {
+        // Last known lost packet, might not be detectable as lost by remote
+        // jitter buffer.
+        early_loss_detected_per_ssrc[packet.ssrc].push_back(
+            packet.rtp_sequence_number);
+      } else {
+        // Packet received, so any loss prior to this is already detectable.
+        early_loss_detected_per_ssrc.erase(packet.ssrc);
+      }
     }
-  }
 
-  for (const auto& kv : early_loss_detected_per_ssrc) {
-    const uint32_t ssrc = kv.first;
-    auto it = ssrc_to_rtp_module_.find(ssrc);
-    RTC_CHECK(it != ssrc_to_rtp_module_.end());
-    RTPSender* rtp_sender = it->second->RtpSender();
-    for (uint16_t sequence_number : kv.second) {
-      rtp_sender->ReSendPacket(sequence_number);
+    for (const auto& kv : early_loss_detected_per_ssrc) {
+      const uint32_t ssrc = kv.first;
+      auto it = ssrc_to_rtp_module_.find(ssrc);
+      RTC_DCHECK(it != ssrc_to_rtp_module_.end());
+      RTPSender* rtp_sender = it->second->RtpSender();
+      for (uint16_t sequence_number : kv.second) {
+        rtp_sender->ReSendPacket(sequence_number);
+      }
     }
-  }
 
   for (const auto& kv : acked_packets_per_ssrc) {
     const uint32_t ssrc = kv.first;
     auto it = ssrc_to_rtp_module_.find(ssrc);
     if (it == ssrc_to_rtp_module_.end()) {
-      // No media, likely FEC or padding. Ignore since there's no RTP history to
-      // clean up anyway.
+      // Packets not for a media SSRC, so likely RTX or FEC. If so, ignore
+      // since there's no RTP history to clean up anyway.
       continue;
     }
     rtc::ArrayView<const uint16_t> rtp_sequence_numbers(kv.second);
diff --git a/call/rtp_video_sender_unittest.cc b/call/rtp_video_sender_unittest.cc
index 334d97c..85934cc 100644
--- a/call/rtp_video_sender_unittest.cc
+++ b/call/rtp_video_sender_unittest.cc
@@ -462,13 +462,11 @@
   lost_packet_feedback.rtp_sequence_number = rtp_sequence_numbers[0];
   lost_packet_feedback.ssrc = kSsrc1;
   lost_packet_feedback.received = false;
-  lost_packet_feedback.is_retransmission = false;
 
   StreamFeedbackObserver::StreamPacketInfo received_packet_feedback;
   received_packet_feedback.rtp_sequence_number = rtp_sequence_numbers[1];
   received_packet_feedback.ssrc = kSsrc1;
   received_packet_feedback.received = true;
-  lost_packet_feedback.is_retransmission = false;
 
   test.router()->OnPacketFeedbackVector(
       {lost_packet_feedback, received_packet_feedback});
@@ -640,13 +638,11 @@
   first_packet_feedback.rtp_sequence_number = frame1_rtp_sequence_number;
   first_packet_feedback.ssrc = kSsrc1;
   first_packet_feedback.received = false;
-  first_packet_feedback.is_retransmission = false;
 
   StreamFeedbackObserver::StreamPacketInfo second_packet_feedback;
   second_packet_feedback.rtp_sequence_number = frame2_rtp_sequence_number;
   second_packet_feedback.ssrc = kSsrc2;
   second_packet_feedback.received = true;
-  first_packet_feedback.is_retransmission = false;
 
   test.router()->OnPacketFeedbackVector(
       {first_packet_feedback, second_packet_feedback});
diff --git a/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc b/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc
index 933abd9..138cdb6 100644
--- a/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc
+++ b/modules/congestion_controller/rtp/transport_feedback_adapter_unittest.cc
@@ -27,9 +27,9 @@
 using ::testing::Invoke;
 
 namespace webrtc {
+namespace webrtc_cc {
 
 namespace {
-constexpr uint32_t kSsrc = 8492;
 const PacedPacketInfo kPacingInfo0(0, 5, 2000);
 const PacedPacketInfo kPacingInfo1(1, 8, 4000);
 const PacedPacketInfo kPacingInfo2(2, 14, 7000);
@@ -77,6 +77,10 @@
   return res;
 }
 
+}  // namespace
+
+namespace test {
+
 class MockStreamFeedbackObserver : public webrtc::StreamFeedbackObserver {
  public:
   MOCK_METHOD(void,
@@ -85,8 +89,6 @@
               (override));
 };
 
-}  // namespace
-
 class TransportFeedbackAdapterTest : public ::testing::Test {
  public:
   TransportFeedbackAdapterTest() : clock_(0) {}
@@ -106,7 +108,7 @@
 
   void OnSentPacket(const PacketResult& packet_feedback) {
     RtpPacketSendInfo packet_info;
-    packet_info.media_ssrc = kSsrc;
+    packet_info.ssrc = kSsrc;
     packet_info.transport_sequence_number =
         packet_feedback.sent_packet.sequence_number;
     packet_info.rtp_sequence_number = 0;
@@ -120,6 +122,8 @@
         packet_feedback.sent_packet.send_time.ms(), rtc::PacketInfo()));
   }
 
+  static constexpr uint32_t kSsrc = 8492;
+
   SimulatedClock clock_;
   std::unique_ptr<TransportFeedbackAdapter> adapter_;
 };
@@ -389,7 +393,7 @@
 
   // Add a packet and then mark it as sent.
   RtpPacketSendInfo packet_info;
-  packet_info.media_ssrc = kSsrc;
+  packet_info.ssrc = kSsrc;
   packet_info.transport_sequence_number = packet.sent_packet.sequence_number;
   packet_info.length = packet.sent_packet.size.bytes();
   packet_info.pacing_info = packet.sent_packet.pacing_info;
@@ -408,4 +412,6 @@
   EXPECT_FALSE(duplicate_packet.has_value());
 }
 
+}  // namespace test
+}  // namespace webrtc_cc
 }  // namespace webrtc
diff --git a/modules/congestion_controller/rtp/transport_feedback_demuxer.cc b/modules/congestion_controller/rtp/transport_feedback_demuxer.cc
index 6ab3ad8..c958a1c 100644
--- a/modules/congestion_controller/rtp/transport_feedback_demuxer.cc
+++ b/modules/congestion_controller/rtp/transport_feedback_demuxer.cc
@@ -38,16 +38,15 @@
 
 void TransportFeedbackDemuxer::AddPacket(const RtpPacketSendInfo& packet_info) {
   MutexLock lock(&lock_);
-
-  StreamFeedbackObserver::StreamPacketInfo info;
-  info.ssrc = packet_info.media_ssrc;
-  info.rtp_sequence_number = packet_info.rtp_sequence_number;
-  info.received = false;
-  info.is_retransmission =
-      packet_info.packet_type == RtpPacketMediaType::kRetransmission;
-  history_.insert(
-      {seq_num_unwrapper_.Unwrap(packet_info.transport_sequence_number), info});
-
+  if (packet_info.ssrc != 0) {
+    StreamFeedbackObserver::StreamPacketInfo info;
+    info.ssrc = packet_info.ssrc;
+    info.rtp_sequence_number = packet_info.rtp_sequence_number;
+    info.received = false;
+    history_.insert(
+        {seq_num_unwrapper_.Unwrap(packet_info.transport_sequence_number),
+         info});
+  }
   while (history_.size() > kMaxPacketsInHistory) {
     history_.erase(history_.begin());
   }
diff --git a/modules/congestion_controller/rtp/transport_feedback_demuxer_unittest.cc b/modules/congestion_controller/rtp/transport_feedback_demuxer_unittest.cc
index 482f58d..6514a4e 100644
--- a/modules/congestion_controller/rtp/transport_feedback_demuxer_unittest.cc
+++ b/modules/congestion_controller/rtp/transport_feedback_demuxer_unittest.cc
@@ -16,11 +16,7 @@
 namespace webrtc {
 namespace {
 
-using ::testing::AllOf;
-using ::testing::ElementsAre;
-using ::testing::Field;
-using PacketInfo = StreamFeedbackObserver::StreamPacketInfo;
-
+using ::testing::_;
 static constexpr uint32_t kSsrc = 8492;
 
 class MockStreamFeedbackObserver : public webrtc::StreamFeedbackObserver {
@@ -32,65 +28,41 @@
 };
 
 RtpPacketSendInfo CreatePacket(uint32_t ssrc,
-                               uint16_t rtp_sequence_number,
-                               int64_t transport_sequence_number,
-                               bool is_retransmission) {
+                               int16_t rtp_sequence_number,
+                               int64_t transport_sequence_number) {
   RtpPacketSendInfo res;
-  res.media_ssrc = ssrc;
+  res.ssrc = ssrc;
   res.transport_sequence_number = transport_sequence_number;
   res.rtp_sequence_number = rtp_sequence_number;
-  res.packet_type = is_retransmission ? RtpPacketMediaType::kRetransmission
-                                      : RtpPacketMediaType::kVideo;
   return res;
 }
 }  // namespace
-
 TEST(TransportFeedbackDemuxerTest, ObserverSanity) {
   TransportFeedbackDemuxer demuxer;
   MockStreamFeedbackObserver mock;
   demuxer.RegisterStreamFeedbackObserver({kSsrc}, &mock);
 
-  const uint16_t kRtpStartSeq = 55;
-  const int64_t kTransportStartSeq = 1;
-  demuxer.AddPacket(CreatePacket(kSsrc, kRtpStartSeq, kTransportStartSeq,
-                                 /*is_retransmit=*/false));
-  demuxer.AddPacket(CreatePacket(kSsrc, kRtpStartSeq + 1,
-                                 kTransportStartSeq + 1,
-                                 /*is_retransmit=*/false));
-  demuxer.AddPacket(CreatePacket(
-      kSsrc, kRtpStartSeq + 2, kTransportStartSeq + 2, /*is_retransmit=*/true));
+  demuxer.AddPacket(CreatePacket(kSsrc, 55, 1));
+  demuxer.AddPacket(CreatePacket(kSsrc, 56, 2));
+  demuxer.AddPacket(CreatePacket(kSsrc, 57, 3));
 
   rtcp::TransportFeedback feedback;
-  feedback.SetBase(kTransportStartSeq, 1000);
-  ASSERT_TRUE(feedback.AddReceivedPacket(kTransportStartSeq, 1000));
-  // Drop middle packet.
-  ASSERT_TRUE(feedback.AddReceivedPacket(kTransportStartSeq + 2, 3000));
+  feedback.SetBase(1, 1000);
+  ASSERT_TRUE(feedback.AddReceivedPacket(1, 1000));
+  ASSERT_TRUE(feedback.AddReceivedPacket(2, 2000));
+  ASSERT_TRUE(feedback.AddReceivedPacket(3, 3000));
 
-  EXPECT_CALL(
-      mock, OnPacketFeedbackVector(ElementsAre(
-                AllOf(Field(&PacketInfo::received, true),
-                      Field(&PacketInfo::ssrc, kSsrc),
-                      Field(&PacketInfo::rtp_sequence_number, kRtpStartSeq),
-                      Field(&PacketInfo::is_retransmission, false)),
-                AllOf(Field(&PacketInfo::received, false),
-                      Field(&PacketInfo::ssrc, kSsrc),
-                      Field(&PacketInfo::rtp_sequence_number, kRtpStartSeq + 1),
-                      Field(&PacketInfo::is_retransmission, false)),
-                AllOf(Field(&PacketInfo::received, true),
-                      Field(&PacketInfo::ssrc, kSsrc),
-                      Field(&PacketInfo::rtp_sequence_number, kRtpStartSeq + 2),
-                      Field(&PacketInfo::is_retransmission, true)))));
+  EXPECT_CALL(mock, OnPacketFeedbackVector(_)).Times(1);
   demuxer.OnTransportFeedback(feedback);
 
   demuxer.DeRegisterStreamFeedbackObserver(&mock);
 
-  demuxer.AddPacket(
-      CreatePacket(kSsrc, kRtpStartSeq + 3, kTransportStartSeq + 3, false));
+  demuxer.AddPacket(CreatePacket(kSsrc, 58, 4));
   rtcp::TransportFeedback second_feedback;
-  second_feedback.SetBase(kTransportStartSeq + 3, 4000);
-  ASSERT_TRUE(second_feedback.AddReceivedPacket(kTransportStartSeq + 3, 4000));
+  second_feedback.SetBase(4, 4000);
+  ASSERT_TRUE(second_feedback.AddReceivedPacket(4, 4000));
 
-  EXPECT_CALL(mock, OnPacketFeedbackVector).Times(0);
+  EXPECT_CALL(mock, OnPacketFeedbackVector(_)).Times(0);
   demuxer.OnTransportFeedback(second_feedback);
 }
 }  // namespace webrtc
diff --git a/modules/rtp_rtcp/include/rtp_rtcp_defines.h b/modules/rtp_rtcp/include/rtp_rtcp_defines.h
index ca12adf..59c0f29 100644
--- a/modules/rtp_rtcp/include/rtp_rtcp_defines.h
+++ b/modules/rtp_rtcp/include/rtp_rtcp_defines.h
@@ -228,10 +228,8 @@
   RtpPacketSendInfo() = default;
 
   uint16_t transport_sequence_number = 0;
-  // TODO(bugs.webrtc.org/12713): Remove once downstream usage is gone.
   uint32_t ssrc = 0;
-  absl::optional<uint32_t> media_ssrc;
-  uint16_t rtp_sequence_number = 0;  // Only valid if |ssrc| is set.
+  uint16_t rtp_sequence_number = 0;
   uint32_t rtp_timestamp = 0;
   size_t length = 0;
   absl::optional<RtpPacketMediaType> packet_type;
@@ -269,13 +267,9 @@
 class StreamFeedbackObserver {
  public:
   struct StreamPacketInfo {
-    bool received;
-
-    // |rtp_sequence_number| and |is_retransmission| are only valid if |ssrc|
-    // is populated.
-    absl::optional<uint32_t> ssrc;
+    uint32_t ssrc;
     uint16_t rtp_sequence_number;
-    bool is_retransmission;
+    bool received;
   };
   virtual ~StreamFeedbackObserver() = default;
 
diff --git a/modules/rtp_rtcp/source/deprecated/deprecated_rtp_sender_egress.cc b/modules/rtp_rtcp/source/deprecated/deprecated_rtp_sender_egress.cc
index 33a1b8e..3f7d22c 100644
--- a/modules/rtp_rtcp/source/deprecated/deprecated_rtp_sender_egress.cc
+++ b/modules/rtp_rtcp/source/deprecated/deprecated_rtp_sender_egress.cc
@@ -313,7 +313,7 @@
     }
 
     RtpPacketSendInfo packet_info;
-    packet_info.media_ssrc = ssrc_;
+    packet_info.ssrc = ssrc_;
     packet_info.transport_sequence_number = packet_id;
     packet_info.rtp_sequence_number = packet.SequenceNumber();
     packet_info.length = packet_size;
diff --git a/modules/rtp_rtcp/source/rtp_sender_egress.cc b/modules/rtp_rtcp/source/rtp_sender_egress.cc
index 126b89c..55dd9ff 100644
--- a/modules/rtp_rtcp/source/rtp_sender_egress.cc
+++ b/modules/rtp_rtcp/source/rtp_sender_egress.cc
@@ -142,9 +142,6 @@
 
   RTC_DCHECK(packet->packet_type().has_value());
   RTC_DCHECK(HasCorrectSsrc(*packet));
-  if (packet->packet_type() == RtpPacketMediaType::kRetransmission) {
-    RTC_DCHECK(packet->retransmitted_sequence_number().has_value());
-  }
 
   const uint32_t packet_ssrc = packet->Ssrc();
   const int64_t now_ms = clock_->TimeInMilliseconds();
@@ -412,34 +409,13 @@
     }
 
     RtpPacketSendInfo packet_info;
+    packet_info.ssrc = ssrc_;
     packet_info.transport_sequence_number = packet_id;
+    packet_info.rtp_sequence_number = packet.SequenceNumber();
     packet_info.rtp_timestamp = packet.Timestamp();
     packet_info.length = packet_size;
     packet_info.pacing_info = pacing_info;
     packet_info.packet_type = packet.packet_type();
-
-    switch (*packet_info.packet_type) {
-      case RtpPacketMediaType::kAudio:
-      case RtpPacketMediaType::kVideo:
-        packet_info.media_ssrc = ssrc_;
-        packet_info.rtp_sequence_number = packet.SequenceNumber();
-        break;
-      case RtpPacketMediaType::kRetransmission:
-        // For retransmissions, we're want to remove the original media packet
-        // if the rentrasmit arrives - so populate that in the packet info.
-        packet_info.media_ssrc = ssrc_;
-        packet_info.rtp_sequence_number =
-            *packet.retransmitted_sequence_number();
-        break;
-      case RtpPacketMediaType::kPadding:
-      case RtpPacketMediaType::kForwardErrorCorrection:
-        // We're not interested in feedback about these packets being received
-        // or lost.
-        break;
-    }
-    // TODO(bugs.webrtc.org/12713): Remove once downstream usage is gone.
-    packet_info.ssrc = packet_info.media_ssrc.value_or(0);
-
     transport_feedback_observer_->OnAddPacket(packet_info);
   }
 }
diff --git a/modules/rtp_rtcp/source/rtp_sender_egress_unittest.cc b/modules/rtp_rtcp/source/rtp_sender_egress_unittest.cc
index 4f3990c..663638f 100644
--- a/modules/rtp_rtcp/source/rtp_sender_egress_unittest.cc
+++ b/modules/rtp_rtcp/source/rtp_sender_egress_unittest.cc
@@ -221,7 +221,7 @@
   EXPECT_CALL(
       feedback_observer_,
       OnAddPacket(AllOf(
-          Field(&RtpPacketSendInfo::media_ssrc, kSsrc),
+          Field(&RtpPacketSendInfo::ssrc, kSsrc),
           Field(&RtpPacketSendInfo::transport_sequence_number,
                 kTransportSequenceNumber),
           Field(&RtpPacketSendInfo::rtp_sequence_number, kStartSequenceNumber),
@@ -246,8 +246,6 @@
 
   std::unique_ptr<RtpPacketToSend> retransmission = BuildRtpPacket();
   retransmission->set_packet_type(RtpPacketMediaType::kRetransmission);
-  retransmission->set_retransmitted_sequence_number(
-      media_packet->SequenceNumber());
   sender->SendPacket(retransmission.get(), PacedPacketInfo());
   EXPECT_TRUE(transport_.last_packet()->options.is_retransmit);
 }
@@ -409,7 +407,6 @@
   std::unique_ptr<RtpPacketToSend> packet = BuildRtpPacket();
   packet->SetExtension<TransportSequenceNumber>(kTransportSequenceNumber);
   packet->set_packet_type(RtpPacketMediaType::kRetransmission);
-  packet->set_retransmitted_sequence_number(packet->SequenceNumber());
   sender->SendPacket(packet.get(), PacedPacketInfo());
 }
 
@@ -468,7 +465,6 @@
     // Mark all packets as retransmissions - will cause total and retransmission
     // rates to be equal.
     packet->set_packet_type(RtpPacketMediaType::kRetransmission);
-    packet->set_retransmitted_sequence_number(packet->SequenceNumber());
     total_data_sent += DataSize::Bytes(packet->size());
 
     EXPECT_CALL(observer, Notify(_, _, kSsrc))
@@ -524,8 +520,6 @@
   std::unique_ptr<RtpPacketToSend> retransmission = BuildRtpPacket();
   retransmission->set_allow_retransmission(true);
   retransmission->set_packet_type(RtpPacketMediaType::kRetransmission);
-  retransmission->set_retransmitted_sequence_number(
-      retransmission->SequenceNumber());
   sender->SendPacket(retransmission.get(), PacedPacketInfo());
   EXPECT_FALSE(packet_history_.GetPacketState(retransmission->SequenceNumber())
                    .has_value());
@@ -606,8 +600,6 @@
   // and retransmitted packet statistics.
   std::unique_ptr<RtpPacketToSend> retransmission_packet = BuildRtpPacket();
   retransmission_packet->set_packet_type(RtpPacketMediaType::kRetransmission);
-  retransmission_packet->set_retransmitted_sequence_number(
-      retransmission_packet->SequenceNumber());
   media_packet->SetPayloadSize(7);
   expected_transmitted_counter.packets += 1;
   expected_transmitted_counter.payload_bytes +=
@@ -718,7 +710,6 @@
   rtx_packet->set_packet_type(RtpPacketMediaType::kRetransmission);
   rtx_packet->SetSsrc(kRtxSsrc);
   rtx_packet->SetPayloadSize(7);
-  rtx_packet->set_retransmitted_sequence_number(media_packet->SequenceNumber());
   sender->SendPacket(rtx_packet.get(), PacedPacketInfo());
   time_controller_.AdvanceTime(TimeDelta::Zero());
 
@@ -794,7 +785,6 @@
   std::unique_ptr<RtpPacketToSend> retransmission = BuildRtpPacket();
   retransmission->SetExtension<TransportSequenceNumber>(kPacketId + 1);
   retransmission->set_packet_type(RtpPacketMediaType::kRetransmission);
-  retransmission->set_retransmitted_sequence_number(packet->SequenceNumber());
   sender->SendPacket(retransmission.get(), PacedPacketInfo());
   EXPECT_TRUE(transport_.last_packet()->options.is_retransmit);
 }
@@ -825,7 +815,6 @@
   std::unique_ptr<RtpPacketToSend> rtx_packet = BuildRtpPacket();
   rtx_packet->SetSsrc(kRtxSsrc);
   rtx_packet->set_packet_type(RtpPacketMediaType::kRetransmission);
-  rtx_packet->set_retransmitted_sequence_number(video_packet->SequenceNumber());
   rtx_packet->SetPayloadSize(kPayloadSize);
   rtx_packet->SetExtension<TransportSequenceNumber>(2);
 
@@ -865,115 +854,6 @@
   EXPECT_EQ(rtx_stats.retransmitted.packets, 1u);
 }
 
-TEST_P(RtpSenderEgressTest, TransportFeedbackObserverWithRetransmission) {
-  const uint16_t kTransportSequenceNumber = 17;
-  header_extensions_.RegisterByUri(kTransportSequenceNumberExtensionId,
-                                   TransportSequenceNumber::kUri);
-  std::unique_ptr<RtpPacketToSend> retransmission = BuildRtpPacket();
-  retransmission->set_packet_type(RtpPacketMediaType::kRetransmission);
-  retransmission->SetExtension<TransportSequenceNumber>(
-      kTransportSequenceNumber);
-  uint16_t retransmitted_seq = retransmission->SequenceNumber() - 2;
-  retransmission->set_retransmitted_sequence_number(retransmitted_seq);
-
-  std::unique_ptr<RtpSenderEgress> sender = CreateRtpSenderEgress();
-  EXPECT_CALL(
-      feedback_observer_,
-      OnAddPacket(AllOf(
-          Field(&RtpPacketSendInfo::media_ssrc, kSsrc),
-          Field(&RtpPacketSendInfo::rtp_sequence_number, retransmitted_seq),
-          Field(&RtpPacketSendInfo::transport_sequence_number,
-                kTransportSequenceNumber))));
-  sender->SendPacket(retransmission.get(), PacedPacketInfo());
-}
-
-TEST_P(RtpSenderEgressTest, TransportFeedbackObserverWithRtxRetransmission) {
-  const uint16_t kTransportSequenceNumber = 17;
-  header_extensions_.RegisterByUri(kTransportSequenceNumberExtensionId,
-                                   TransportSequenceNumber::kUri);
-
-  std::unique_ptr<RtpPacketToSend> rtx_retransmission = BuildRtpPacket();
-  rtx_retransmission->SetSsrc(kRtxSsrc);
-  rtx_retransmission->SetExtension<TransportSequenceNumber>(
-      kTransportSequenceNumber);
-  rtx_retransmission->set_packet_type(RtpPacketMediaType::kRetransmission);
-  uint16_t rtx_retransmitted_seq = rtx_retransmission->SequenceNumber() - 2;
-  rtx_retransmission->set_retransmitted_sequence_number(rtx_retransmitted_seq);
-
-  std::unique_ptr<RtpSenderEgress> sender = CreateRtpSenderEgress();
-  EXPECT_CALL(
-      feedback_observer_,
-      OnAddPacket(AllOf(
-          Field(&RtpPacketSendInfo::media_ssrc, kSsrc),
-          Field(&RtpPacketSendInfo::rtp_sequence_number, rtx_retransmitted_seq),
-          Field(&RtpPacketSendInfo::transport_sequence_number,
-                kTransportSequenceNumber))));
-  sender->SendPacket(rtx_retransmission.get(), PacedPacketInfo());
-}
-
-TEST_P(RtpSenderEgressTest, TransportFeedbackObserverPadding) {
-  const uint16_t kTransportSequenceNumber = 17;
-  header_extensions_.RegisterByUri(kTransportSequenceNumberExtensionId,
-                                   TransportSequenceNumber::kUri);
-  std::unique_ptr<RtpPacketToSend> padding = BuildRtpPacket();
-  padding->SetPadding(224);
-  padding->set_packet_type(RtpPacketMediaType::kPadding);
-  padding->SetExtension<TransportSequenceNumber>(kTransportSequenceNumber);
-
-  std::unique_ptr<RtpSenderEgress> sender = CreateRtpSenderEgress();
-  EXPECT_CALL(
-      feedback_observer_,
-      OnAddPacket(AllOf(Field(&RtpPacketSendInfo::media_ssrc, absl::nullopt),
-                        Field(&RtpPacketSendInfo::transport_sequence_number,
-                              kTransportSequenceNumber))));
-  sender->SendPacket(padding.get(), PacedPacketInfo());
-}
-
-TEST_P(RtpSenderEgressTest, TransportFeedbackObserverRtxPadding) {
-  const uint16_t kTransportSequenceNumber = 17;
-  header_extensions_.RegisterByUri(kTransportSequenceNumberExtensionId,
-                                   TransportSequenceNumber::kUri);
-
-  std::unique_ptr<RtpPacketToSend> rtx_padding = BuildRtpPacket();
-  rtx_padding->SetPadding(224);
-  rtx_padding->SetSsrc(kRtxSsrc);
-  rtx_padding->set_packet_type(RtpPacketMediaType::kPadding);
-  rtx_padding->SetExtension<TransportSequenceNumber>(kTransportSequenceNumber);
-
-  std::unique_ptr<RtpSenderEgress> sender = CreateRtpSenderEgress();
-  EXPECT_CALL(
-      feedback_observer_,
-      OnAddPacket(AllOf(Field(&RtpPacketSendInfo::media_ssrc, absl::nullopt),
-                        Field(&RtpPacketSendInfo::transport_sequence_number,
-                              kTransportSequenceNumber))));
-  sender->SendPacket(rtx_padding.get(), PacedPacketInfo());
-}
-
-TEST_P(RtpSenderEgressTest, TransportFeedbackObserverFec) {
-  const uint16_t kTransportSequenceNumber = 17;
-  header_extensions_.RegisterByUri(kTransportSequenceNumberExtensionId,
-                                   TransportSequenceNumber::kUri);
-
-  std::unique_ptr<RtpPacketToSend> fec_packet = BuildRtpPacket();
-  fec_packet->SetSsrc(kFlexFecSsrc);
-  fec_packet->set_packet_type(RtpPacketMediaType::kForwardErrorCorrection);
-  fec_packet->SetExtension<TransportSequenceNumber>(kTransportSequenceNumber);
-
-  const rtc::ArrayView<const RtpExtensionSize> kNoRtpHeaderExtensionSizes;
-  FlexfecSender flexfec(kFlexfectPayloadType, kFlexFecSsrc, kSsrc, /*mid=*/"",
-                        /*header_extensions=*/{}, kNoRtpHeaderExtensionSizes,
-                        /*rtp_state=*/nullptr, time_controller_.GetClock());
-  RtpRtcpInterface::Configuration config = DefaultConfig();
-  config.fec_generator = &flexfec;
-  auto sender = std::make_unique<RtpSenderEgress>(config, &packet_history_);
-  EXPECT_CALL(
-      feedback_observer_,
-      OnAddPacket(AllOf(Field(&RtpPacketSendInfo::media_ssrc, absl::nullopt),
-                        Field(&RtpPacketSendInfo::transport_sequence_number,
-                              kTransportSequenceNumber))));
-  sender->SendPacket(fec_packet.get(), PacedPacketInfo());
-}
-
 INSTANTIATE_TEST_SUITE_P(WithAndWithoutOverhead,
                          RtpSenderEgressTest,
                          ::testing::Values(TestConfig(false),
diff --git a/rtc_tools/rtc_event_log_visualizer/analyzer.cc b/rtc_tools/rtc_event_log_visualizer/analyzer.cc
index 0f727f2..7690d7d 100644
--- a/rtc_tools/rtc_event_log_visualizer/analyzer.cc
+++ b/rtc_tools/rtc_event_log_visualizer/analyzer.cc
@@ -1267,7 +1267,7 @@
       const RtpPacketType& rtp_packet = *rtp_iterator->second;
       if (rtp_packet.rtp.header.extension.hasTransportSequenceNumber) {
         RtpPacketSendInfo packet_info;
-        packet_info.media_ssrc = rtp_packet.rtp.header.ssrc;
+        packet_info.ssrc = rtp_packet.rtp.header.ssrc;
         packet_info.transport_sequence_number =
             rtp_packet.rtp.header.extension.transportSequenceNumber;
         packet_info.rtp_sequence_number = rtp_packet.rtp.header.sequenceNumber;
diff --git a/rtc_tools/rtc_event_log_visualizer/log_simulation.cc b/rtc_tools/rtc_event_log_visualizer/log_simulation.cc
index c0b418d..4dbaf0b 100644
--- a/rtc_tools/rtc_event_log_visualizer/log_simulation.cc
+++ b/rtc_tools/rtc_event_log_visualizer/log_simulation.cc
@@ -84,7 +84,7 @@
     }
 
     RtpPacketSendInfo packet_info;
-    packet_info.media_ssrc = packet.ssrc;
+    packet_info.ssrc = packet.ssrc;
     packet_info.transport_sequence_number = packet.transport_seq_no;
     packet_info.rtp_sequence_number = packet.stream_seq_no;
     packet_info.length = packet.size;