More Simulation Framework features

webrtc/modules/remote_bitrate_estimator/test/estimators/nada.cc

 /*
  *  Copyright (c) 2015 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.
  *
  */
 
 //  Implementation of Network-Assisted Dynamic Adaptation's (NADA's) proposal.
 //  Version according to Draft Document (mentioned in references)
 //  http://tools.ietf.org/html/draft-zhu-rmcat-nada-06
 //  From March 26, 2015.
 
 #include <math.h>
 #include <algorithm>
 #include <vector>
-#include <iostream>
 
 #include "webrtc/base/common.h"
 #include "webrtc/modules/remote_bitrate_estimator/test/estimators/nada.h"
 #include "webrtc/modules/remote_bitrate_estimator/test/bwe_test_logging.h"
 #include "webrtc/modules/rtp_rtcp/interface/receive_statistics.h"
 
 namespace webrtc {
 namespace testing {
 namespace bwe {
 
-const int NadaBweSender::kMinRefRateKbps = 150;
-const int NadaBweSender::kMaxRefRateKbps = 1500;
 const int64_t NadaBweReceiver::kReceivingRateTimeWindowMs = 500;
 
 NadaBweReceiver::NadaBweReceiver(int flow_id)
-    : BweReceiver(flow_id),
+    : BweReceiver(flow_id, kReceivingRateTimeWindowMs),
       clock_(0),
       last_feedback_ms_(0),
       recv_stats_(ReceiveStatistics::Create(&clock_)),
-      baseline_delay_ms_(0),
+      baseline_delay_ms_(10000),  // Initialized as an upper bound.
       delay_signal_ms_(0),
       last_congestion_signal_ms_(0),
       last_delays_index_(0),
       exp_smoothed_delay_ms_(-1),
       est_queuing_delay_signal_ms_(0) {
 }
 
 NadaBweReceiver::~NadaBweReceiver() {
 }
 
 void NadaBweReceiver::ReceivePacket(int64_t arrival_time_ms,
                                     const MediaPacket& media_packet) {
   const float kAlpha = 0.1f;                 // Used for exponential smoothing.
   const int64_t kDelayLowThresholdMs = 50;   // Referred as d_th.
   const int64_t kDelayMaxThresholdMs = 400;  // Referred as d_max.
 
   clock_.AdvanceTimeMilliseconds(arrival_time_ms - clock_.TimeInMilliseconds());
   recv_stats_->IncomingPacket(media_packet.header(),
                               media_packet.payload_size(), false);
   int64_t delay_ms = arrival_time_ms -
                      media_packet.creation_time_us() / 1000;  // Refered as x_n.
+
   // The min should be updated within the first 10 minutes.
   if (clock_.TimeInMilliseconds() < 10 * 60 * 1000) {
     baseline_delay_ms_ = std::min(baseline_delay_ms_, delay_ms);
   }
+
   delay_signal_ms_ = delay_ms - baseline_delay_ms_;  // Refered as d_n.
   const int kMedian = ARRAY_SIZE(last_delays_ms_);
   last_delays_ms_[(last_delays_index_++) % kMedian] = delay_signal_ms_;
   int size = std::min(last_delays_index_, kMedian);
+
   int64_t median_filtered_delay_ms_ = MedianFilter(last_delays_ms_, size);
   exp_smoothed_delay_ms_ = ExponentialSmoothingFilter(
       median_filtered_delay_ms_, exp_smoothed_delay_ms_, kAlpha);
 
   if (exp_smoothed_delay_ms_ < kDelayLowThresholdMs) {
     est_queuing_delay_signal_ms_ = exp_smoothed_delay_ms_;
   } else if (exp_smoothed_delay_ms_ < kDelayMaxThresholdMs) {
     est_queuing_delay_signal_ms_ = static_cast<int64_t>(
         pow((static_cast<double>(kDelayMaxThresholdMs -
                                  exp_smoothed_delay_ms_)) /
@@ skipping 23 matching lines @@
   int64_t congestion_signal_ms = est_queuing_delay_signal_ms_ + loss_signal_ms;
 
   float derivative = 0.0f;
   if (last_feedback_ms_ > 0) {
     derivative = (congestion_signal_ms - last_congestion_signal_ms_) /
                  static_cast<float>(now_ms - last_feedback_ms_);
   }
   last_feedback_ms_ = now_ms;
   last_congestion_signal_ms_ = congestion_signal_ms;
 
-  PacketIdentifierNode* latest = *(received_packets_.begin());
-  int64_t corrected_send_time_ms =
-      latest->send_time_ms + now_ms - latest->arrival_time_ms;
+  int64_t corrected_send_time_ms = 0L;
+
+  if (!received_packets_.empty()) {
+    PacketIdentifierNode* latest = *(received_packets_.begin());
+    corrected_send_time_ms =
+        latest->send_time_ms + now_ms - latest->arrival_time_ms;
+  }
 
   // Sends a tuple containing latest values of <d_hat_n, d_tilde_n, x_n, x'_n,
   // R_r> and additional information.
-  return new NadaFeedback(flow_id_, now_ms, exp_smoothed_delay_ms_,
+  return new NadaFeedback(flow_id_, now_ms * 1000, exp_smoothed_delay_ms_,
                           est_queuing_delay_signal_ms_, congestion_signal_ms,
-                          derivative, RecentReceivingRate(),
-                          corrected_send_time_ms);
-}
-
-// For a given time window, compute the receiving speed rate in kbps.
-// As described below, three cases are considered depending on the number of
-// packets received.
-size_t NadaBweReceiver::RecentReceivingRate() {
-  // If the receiver didn't receive any packet, return 0.
-  if (received_packets_.empty()) {
-    return 0.0f;
-  }
-  size_t total_size = 0;
-  int number_packets = 0;
-
-  PacketNodeIt node_it = received_packets_.begin();
-
-  int64_t last_time_ms = (*node_it)->arrival_time_ms;
-  int64_t start_time_ms = last_time_ms;
-  PacketNodeIt end = received_packets_.end();
-
-  // Stops after including the first packet out of the timeWindow.
-  // Ameliorates results when there are wide gaps between packets.
-  // E.g. Large packets : p1(0ms), p2(3000ms).
-  while (node_it != end) {
-    total_size += (*node_it)->payload_size;
-    last_time_ms = (*node_it)->arrival_time_ms;
-    ++number_packets;
-    if ((*node_it)->arrival_time_ms <
-        start_time_ms - kReceivingRateTimeWindowMs) {
-      break;
-    }
-    ++node_it;
-  }
-
-  int64_t corrected_time_ms;
-  // If the receiver received a single packet, return its size*8/timeWindow.
-  if (number_packets == 1) {
-    corrected_time_ms = kReceivingRateTimeWindowMs;
-  }
-  // If the receiver received multiple packets, use as time interval the gap
-  // between first and last packet falling in the timeWindow corrected by the
-  // factor number_packets/(number_packets-1).
-  // E.g: Let timeWindow = 500ms, payload_size = 500 bytes, number_packets = 2,
-  // packets received at t1(0ms) and t2(499 or 501ms). This prevent the function
-  // from returning ~2*8, sending instead a more likely ~1*8 kbps.
-  else {
-    corrected_time_ms = (number_packets * (start_time_ms - last_time_ms)) /
-                        (number_packets - 1);
-  }
-
-  // Converting from bytes/ms to kbits/s.
-  return static_cast<size_t>(8 * total_size / corrected_time_ms);
+                          derivative, RecentKbps(), corrected_send_time_ms);
 }
 
 int64_t NadaBweReceiver::MedianFilter(int64_t* last_delays_ms, int size) {
   // Typically, size = 5.
   std::vector<int64_t> array_copy(last_delays_ms, last_delays_ms + size);
   std::nth_element(array_copy.begin(), array_copy.begin() + size / 2,
                    array_copy.end());
   return array_copy.at(size / 2);
 }
 
 int64_t NadaBweReceiver::ExponentialSmoothingFilter(int64_t new_value,
                                                     int64_t last_smoothed_value,
                                                     float alpha) {
   if (last_smoothed_value < 0) {
     return new_value;  // Handling initial case.
   }
   return static_cast<int64_t>(alpha * new_value +
                               (1.0f - alpha) * last_smoothed_value + 0.5f);
 }
 
 // Implementation according to Cisco's proposal by default.
 NadaBweSender::NadaBweSender(int kbps, BitrateObserver* observer, Clock* clock)
-    : clock_(clock),
+    : BweSender(kbps),  // Referred as "Reference Rate" = R_n.,
+      clock_(clock),
       observer_(observer),
-      bitrate_kbps_(kbps),
       original_operating_mode_(true) {
 }
 
 NadaBweSender::NadaBweSender(BitrateObserver* observer, Clock* clock)
-    : clock_(clock),
+    : BweSender(kMinBitrateKbps),  // Referred as "Reference Rate" = R_n.
+      clock_(clock),
       observer_(observer),
-      bitrate_kbps_(kMinRefRateKbps),
       original_operating_mode_(true) {
 }
 
 NadaBweSender::~NadaBweSender() {
 }
 
 int NadaBweSender::GetFeedbackIntervalMs() const {
   return 100;
 }
 
@@ skipping 29 matching lines @@
         fb.derivative() < kDerivativeUpperBound) {
       AcceleratedRampUp(fb);
     } else {
       GradualRateUpdate(fb, delta_s, 1.0);
     }
   } else {
     // Modified if conditions and rate update; new ramp down mode.
     if (fb.congestion_signal() == fb.est_queuing_delay_signal_ms() &&
         fb.est_queuing_delay_signal_ms() < kQueuingDelayUpperBoundMs &&
         fb.exp_smoothed_delay_ms() <
-            kMinRefRateKbps / kProportionalityDelayBits &&
+            kMinBitrateKbps / kProportionalityDelayBits &&
         fb.derivative() < kDerivativeUpperBound &&
-        fb.receiving_rate() > kMinRefRateKbps) {
+        fb.receiving_rate() > kMinBitrateKbps) {
       AcceleratedRampUp(fb);
     } else if (fb.congestion_signal() > kMaxCongestionSignalMs ||
                fb.exp_smoothed_delay_ms() > kMaxCongestionSignalMs) {
       AcceleratedRampDown(fb);
     } else {
       double bitrate_reference =
-          (2.0 * bitrate_kbps_) / (kMaxRefRateKbps + kMinRefRateKbps);
+          (2.0 * bitrate_kbps_) / (kMaxBitrateKbps + kMinBitrateKbps);
       double smoothing_factor = pow(bitrate_reference, 0.75);
       GradualRateUpdate(fb, delta_s, smoothing_factor);
     }
   }
 
-  bitrate_kbps_ = std::min(bitrate_kbps_, kMaxRefRateKbps);
-  bitrate_kbps_ = std::max(bitrate_kbps_, kMinRefRateKbps);
+  bitrate_kbps_ = std::min(bitrate_kbps_, kMaxBitrateKbps);
+  bitrate_kbps_ = std::max(bitrate_kbps_, kMinBitrateKbps);
 
   observer_->OnNetworkChanged(1000 * bitrate_kbps_, 0, rtt_ms);
 }
 
 int64_t NadaBweSender::TimeUntilNextProcess() {
   return 100;
 }
 
 int NadaBweSender::Process() {
   return 0;
@@ skipping 23 matching lines @@
                                       double smoothing_factor) {
   const float kTauOMs = 500.0f;           // Referred as tau_o.
   const float kEta = 2.0f;                // Referred as eta.
   const float kKappa = 1.0f;              // Referred as kappa.
   const float kReferenceDelayMs = 10.0f;  // Referred as x_ref.
   const float kPriorityWeight = 1.0f;     // Referred as w.
 
   float x_hat = fb.congestion_signal() + kEta * kTauOMs * fb.derivative();
 
   float kTheta =
-      kPriorityWeight * (kMaxRefRateKbps - kMinRefRateKbps) * kReferenceDelayMs;
+      kPriorityWeight * (kMaxBitrateKbps - kMinBitrateKbps) * kReferenceDelayMs;
 
   int original_increase =
       static_cast<int>((kKappa * delta_s *
-                        (kTheta - (bitrate_kbps_ - kMinRefRateKbps) * x_hat)) /
+                        (kTheta - (bitrate_kbps_ - kMinBitrateKbps) * x_hat)) /
                            (kTauOMs * kTauOMs) +
                        0.5f);
 
   bitrate_kbps_ = bitrate_kbps_ + smoothing_factor * original_increase;
 }
 
 }  // namespace bwe
 }  // namespace testing
 }  // namespace webrtc