Test and fix for huge bwe drop after alr state.

webrtc/modules/congestion_controller/bitrate_estimator.cc

 /*
  *  Copyright (c) 2017 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.
  */
 
-#include "webrtc/modules/congestion_controller/acknowledge_bitrate_estimator.h"
+#include "webrtc/modules/congestion_controller/bitrate_estimator.h"
 
 #include <cmath>
 
-#include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
-
 namespace webrtc {
 
 namespace {
-constexpr int kInitialRateWindowMs = 500;
-constexpr int kRateWindowMs = 150;
-
-bool IsInSendTimeHistory(const PacketFeedback& packet) {
-  return packet.send_time_ms >= 0;
-}
-
+constexpr int kInitialRateWindowMs = 50;
+constexpr int kRateWindowMs = 50;
 }  // namespace
 
-AcknowledgedBitrateEstimator::AcknowledgedBitrateEstimator()
+BitrateEstimator::BitrateEstimator()
     : sum_(0),
       current_win_ms_(0),
       prev_time_ms_(-1),
       bitrate_estimate_(-1.0f),
       bitrate_estimate_var_(50.0f) {}
 
-void AcknowledgedBitrateEstimator::IncomingPacketFeedbackVector(
-    const std::vector<PacketFeedback>& packet_feedback_vector) {
-  RTC_DCHECK(std::is_sorted(packet_feedback_vector.begin(),
-                            packet_feedback_vector.end(),
-                            PacketFeedbackComparator()));
-  for (const auto& packet : packet_feedback_vector) {
-    if (IsInSendTimeHistory(packet))
-      Update(packet.arrival_time_ms, packet.payload_size);
-  }
-}
+BitrateEstimator::~BitrateEstimator() = default;
 
-void AcknowledgedBitrateEstimator::Update(int64_t now_ms, int bytes) {
+void BitrateEstimator::Update(int64_t now_ms, int bytes) {
   int rate_window_ms = kRateWindowMs;
   // We use a larger window at the beginning to get a more stable sample that
   // we can use to initialize the estimate.
   if (bitrate_estimate_ < 0.f)
     rate_window_ms = kInitialRateWindowMs;
   float bitrate_sample = UpdateWindow(now_ms, bytes, rate_window_ms);
   if (bitrate_sample < 0.0f)
     return;
   if (bitrate_estimate_ < 0.0f) {
     // This is the very first sample we get. Use it to initialize the estimate.
@@ skipping 10 matching lines @@
   // The bitrate estimate uncertainty is increased with each update to model
   // that the bitrate changes over time.
   float pred_bitrate_estimate_var = bitrate_estimate_var_ + 5.f;
   bitrate_estimate_ = (sample_var * bitrate_estimate_ +
                        pred_bitrate_estimate_var * bitrate_sample) /
                       (sample_var + pred_bitrate_estimate_var);
   bitrate_estimate_var_ = sample_var * pred_bitrate_estimate_var /
                           (sample_var + pred_bitrate_estimate_var);
 }
 
-float AcknowledgedBitrateEstimator::UpdateWindow(int64_t now_ms,
-                                                 int bytes,
-                                                 int rate_window_ms) {
+float BitrateEstimator::UpdateWindow(int64_t now_ms,
+                                     int bytes,
+                                     int rate_window_ms) {
   // Reset if time moves backwards.
   if (now_ms < prev_time_ms_) {
     prev_time_ms_ = -1;
     sum_ = 0;
     current_win_ms_ = 0;
   }
   if (prev_time_ms_ >= 0) {
     current_win_ms_ += now_ms - prev_time_ms_;
     // Reset if nothing has been received for more than a full window.
     if (now_ms - prev_time_ms_ > rate_window_ms) {
       sum_ = 0;
       current_win_ms_ %= rate_window_ms;
     }
   }
   prev_time_ms_ = now_ms;
   float bitrate_sample = -1.0f;
   if (current_win_ms_ >= rate_window_ms) {
     bitrate_sample = 8.0f * sum_ / static_cast<float>(rate_window_ms);
     current_win_ms_ -= rate_window_ms;
     sum_ = 0;
   }
   sum_ += bytes;
   return bitrate_sample;
 }
 
-rtc::Optional<uint32_t> AcknowledgedBitrateEstimator::bitrate_bps() const {
+rtc::Optional<uint32_t> BitrateEstimator::bitrate_bps() const {
   if (bitrate_estimate_ < 0.f)
     return rtc::Optional<uint32_t>();
   return rtc::Optional<uint32_t>(bitrate_estimate_ * 1000);
 }
 
 }  // namespace webrtc