Delete VieRemb class, move functionality to PacketRouter.

webrtc/modules/pacing/packet_router.cc

Index: webrtc/modules/pacing/packet_router.cc
diff --git a/webrtc/modules/pacing/packet_router.cc b/webrtc/modules/pacing/packet_router.cc
index ab86bfa4bd82551f8014cd5652540e743577ce8d..871ba0fcec984b99d7696a498e21b967bd2d5b8a 100644
--- a/webrtc/modules/pacing/packet_router.cc
+++ b/webrtc/modules/pacing/packet_router.cc
@@ -12,13 +12,17 @@
 
 #include "webrtc/base/atomicops.h"
 #include "webrtc/base/checks.h"
+#include "webrtc/base/timeutils.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
 
 namespace webrtc {
 
-PacketRouter::PacketRouter() : transport_seq_(0) {
+PacketRouter::PacketRouter()
+    : last_remb_time_ms_(rtc::TimeMillis()),
+      last_send_bitrate_bps_(0),
+      transport_seq_(0) {
   pacer_thread_checker_.DetachFromThread();
 }
 
@@ -31,11 +35,23 @@ void PacketRouter::AddSendRtpModule(RtpRtcp* rtp_module) {
   rtc::CritScope cs(&modules_crit_);
   RTC_DCHECK(std::find(rtp_send_modules_.begin(), rtp_send_modules_.end(),
                        rtp_module) == rtp_send_modules_.end());
+  if (rtp_send_modules_.empty() && !rtp_receive_modules_.empty()) {
+    rtp_receive_modules_.front()->SetREMBStatus(false);
+  }
+
   // Put modules which can use regular payload packets (over rtx) instead of
   // padding first as it's less of a waste
   if ((rtp_module->RtxSendStatus() & kRtxRedundantPayloads) > 0) {
+    if (!rtp_send_modules_.empty()) {
+      rtp_send_modules_.front()->SetREMBStatus(false);
+    }
     rtp_send_modules_.push_front(rtp_module);
+    rtp_module->SetREMBStatus(true);
   } else {
+    if (rtp_send_modules_.empty()) {
+      rtp_module->SetREMBStatus(true);
+    }
+
     rtp_send_modules_.push_back(rtp_module);
   }
 }
@@ -45,12 +61,21 @@ void PacketRouter::RemoveSendRtpModule(RtpRtcp* rtp_module) {
   RTC_DCHECK(std::find(rtp_send_modules_.begin(), rtp_send_modules_.end(),
                        rtp_module) != rtp_send_modules_.end());
   rtp_send_modules_.remove(rtp_module);
+  rtp_module->SetREMBStatus(false);
+  if (!rtp_send_modules_.empty()) {
+    rtp_send_modules_.front()->SetREMBStatus(true);
+  } else if (!rtp_receive_modules_.empty()) {
+    rtp_receive_modules_.front()->SetREMBStatus(true);
+  }
 }
 
 void PacketRouter::AddReceiveRtpModule(RtpRtcp* rtp_module) {
   rtc::CritScope cs(&modules_crit_);
   RTC_DCHECK(std::find(rtp_receive_modules_.begin(), rtp_receive_modules_.end(),
                        rtp_module) == rtp_receive_modules_.end());
+  if (rtp_send_modules_.empty() && rtp_receive_modules_.empty()) {
+    rtp_module->SetREMBStatus(true);
+  }
   rtp_receive_modules_.push_back(rtp_module);
 }
 
@@ -60,6 +85,12 @@ void PacketRouter::RemoveReceiveRtpModule(RtpRtcp* rtp_module) {
                              rtp_receive_modules_.end(), rtp_module);
   RTC_DCHECK(it != rtp_receive_modules_.end());
   rtp_receive_modules_.erase(it);
+  if (rtp_send_modules_.empty()) {
+    rtp_module->SetREMBStatus(false);
+    if (!rtp_receive_modules_.empty()) {
+      rtp_receive_modules_.front()->SetREMBStatus(true);
+    }
+  }
 }
 
 bool PacketRouter::TimeToSendPacket(uint32_t ssrc,
@@ -121,7 +152,62 @@ uint16_t PacketRouter::AllocateSequenceNumber() {
   return new_seq;
 }
 
-bool PacketRouter::SendFeedback(rtcp::TransportFeedback* packet) {
+void PacketRouter::OnReceiveBitrateChanged(const std::vector<uint32_t>& ssrcs,
+                                           uint32_t bitrate_bps) {
+  const int kRembSendIntervalMs = 200;
+
+  // % threshold for if we should send a new REMB asap.
+  const uint32_t kSendThresholdPercent = 97;
+
+  int64_t now_ms = rtc::TimeMillis();
+  {
+    rtc::CritScope lock(&remb_crit_);
+
+    // If we already have an estimate, check if the new total estimate is below
+    // kSendThresholdPercent of the previous estimate.
+    if (last_send_bitrate_bps_ > 0) {
+      uint32_t new_remb_bitrate_bps =
+          last_send_bitrate_bps_ - bitrate_bps_ + bitrate_bps;
+
+      if (new_remb_bitrate_bps <
+          kSendThresholdPercent * last_send_bitrate_bps_ / 100) {
+        // The new bitrate estimate is less than kSendThresholdPercent % of the
+        // last report. Send a REMB asap.
+        last_remb_time_ms_ = now_ms - kRembSendIntervalMs;
+      }
+    }
+    bitrate_bps_ = bitrate_bps;
+
+    if (now_ms - last_remb_time_ms_ < kRembSendIntervalMs) {
+      return;
+    }
+    // NOTE: Updated if we intend to send the data; we might not have
+    // a module to actually send it.
+    last_remb_time_ms_ = now_ms;
+    last_send_bitrate_bps_ = bitrate_bps;
+  }
+  SendRemb(bitrate_bps, ssrcs);
+}
+
+bool PacketRouter::SendRemb(uint32_t bitrate_bps,
+                            const std::vector<uint32_t>& ssrcs) {
+  rtc::CritScope lock(&modules_crit_);
+  RtpRtcp* remb_module;
+  if (!rtp_send_modules_.empty())
+    remb_module = rtp_send_modules_.front();
+  else if (!rtp_receive_modules_.empty())
+    remb_module = rtp_receive_modules_.front();
+  else
+    return false;
+  // The Add* and Remove* methods above ensure that this (and only this) module
+  // has REMB enabled. REMB should be disabled on all other modules, because
+  // otherwise, they will send REMB with stale info.
+  RTC_DCHECK(remb_module->REMB());
+  remb_module->SetREMBData(bitrate_bps, ssrcs);
+  return true;
+}
+
+bool PacketRouter::SendTransportFeedback(rtcp::TransportFeedback* packet) {
   RTC_DCHECK(pacer_thread_checker_.CalledOnValidThread());
   rtc::CritScope cs(&modules_crit_);
   // Prefer send modules.