Remove GetFeedbackInterval in sender side BWE.

webrtc/modules/congestion_controller/delay_based_bwe.cc

Index: webrtc/modules/congestion_controller/delay_based_bwe.cc
diff --git a/webrtc/modules/congestion_controller/delay_based_bwe.cc b/webrtc/modules/congestion_controller/delay_based_bwe.cc
index e8d9d21050f21d1b931999b758979b95ec953bcb..25229d24c147cbd683bfff00002d78f9f92d00d1 100644
--- a/webrtc/modules/congestion_controller/delay_based_bwe.cc
+++ b/webrtc/modules/congestion_controller/delay_based_bwe.cc
@@ -155,15 +155,21 @@ DelayBasedBwe::BitrateEstimator::BitrateEstimator()
       bitrate_estimate_(-1.0f),
       bitrate_estimate_var_(50.0f),
       old_estimator_(kBitrateWindowMs, 8000),
-      in_experiment_(BitrateEstimateExperimentIsEnabled()) {}
+      in_experiment_(BitrateEstimateExperimentIsEnabled()),
+      last_result_was_valid_(false) {}
 
 void DelayBasedBwe::BitrateEstimator::Update(int64_t now_ms, int bytes) {
   if (!in_experiment_) {
     old_estimator_.Update(bytes, now_ms);
     rtc::Optional<uint32_t> rate = old_estimator_.Rate(now_ms);
     bitrate_estimate_ = -1.0f;
-    if (rate)
+    if (rate) {
       bitrate_estimate_ = *rate / 1000.0f;
+      last_result_was_valid_ = true;

[terelius, 2017/03/29 15:14:29]

I'm a little bit worried that this might reset the estimator too often. Stefan
has a CL up that removes old_estimator and the "if (!in_experiment_) {...}" code
(https://codereview.webrtc.org/2749803002/). If we can land his CL first we
wouldn't need this hack.

[michaelt, 2017/04/11 11:04:33]

Ok the hack is removed. 

+    } else if (last_result_was_valid_) {
+      old_estimator_.Reset();
+      last_result_was_valid_ = false;
+    }
     return;
   }
   int rate_window_ms = kRateWindowMs;
@@ -240,7 +246,6 @@ DelayBasedBwe::DelayBasedBwe(RtcEventLog* event_log, const Clock* clock)
       trendline_estimator_(),
       detector_(),
       receiver_incoming_bitrate_(),
-      last_update_ms_(-1),
       last_seen_packet_ms_(-1),
       uma_recorded_(false),
       probe_bitrate_estimator_(event_log),
@@ -290,15 +295,14 @@ DelayBasedBwe::Result DelayBasedBwe::IncomingPacketFeedbackVector(
                               BweNames::kBweNamesMax);
     uma_recorded_ = true;
   }
-  Result aggregated_result;
+  bool overusing = false;
   bool delayed_feedback = true;
   for (const auto& packet_feedback : sorted_packet_feedback_vector) {
     if (packet_feedback.send_time_ms < 0)
       continue;
     delayed_feedback = false;
-    Result result = IncomingPacketFeedback(packet_feedback);
-    if (result.updated)
-      aggregated_result = result;
+    IncomingPacketFeedback(packet_feedback);
+    overusing |= detector_.State() == kBwOverusing;
   }
   if (delayed_feedback) {
     ++consecutive_delayed_feedbacks_;
@@ -306,11 +310,11 @@ DelayBasedBwe::Result DelayBasedBwe::IncomingPacketFeedbackVector(
     consecutive_delayed_feedbacks_ = 0;
   }
   if (consecutive_delayed_feedbacks_ >= kMaxConsecutiveFailedLookups) {
-    aggregated_result = OnLongFeedbackDelay(
-        sorted_packet_feedback_vector.back().arrival_time_ms);
     consecutive_delayed_feedbacks_ = 0;
+    return OnLongFeedbackDelay(
+        sorted_packet_feedback_vector.back().arrival_time_ms);
   }
-  return aggregated_result;
+  return MaybeUpdateEstimate(overusing);
 }
 
 DelayBasedBwe::Result DelayBasedBwe::OnLongFeedbackDelay(
@@ -330,7 +334,7 @@ DelayBasedBwe::Result DelayBasedBwe::OnLongFeedbackDelay(
   return result;
 }
 
-DelayBasedBwe::Result DelayBasedBwe::IncomingPacketFeedback(
+void DelayBasedBwe::IncomingPacketFeedback(
     const PacketFeedback& packet_feedback) {
   int64_t now_ms = clock_->TimeInMilliseconds();
 
@@ -391,40 +395,35 @@ DelayBasedBwe::Result DelayBasedBwe::IncomingPacketFeedback(
                        packet_feedback.arrival_time_ms);
     }
   }
-
-  int probing_bps = 0;
   if (packet_feedback.pacing_info.probe_cluster_id !=
       PacedPacketInfo::kNotAProbe) {
-    probing_bps =
-        probe_bitrate_estimator_.HandleProbeAndEstimateBitrate(packet_feedback);
+    probe_bitrate_estimator_.HandleProbeAndEstimateBitrate(packet_feedback);
   }
+}
+
+DelayBasedBwe::Result DelayBasedBwe::MaybeUpdateEstimate(bool overusing) {
+  Result result;
   rtc::Optional<uint32_t> acked_bitrate_bps =
       receiver_incoming_bitrate_.bitrate_bps();
+  int64_t now_ms = clock_->TimeInMilliseconds();
+  rtc::Optional<int> probe_bitrate_bps =
+      probe_bitrate_estimator_.FetchAndResetLastEstimatedBitrateBps();
   // Currently overusing the bandwidth.
-  if (detector_.State() == kBwOverusing) {
+  if (overusing) {
     if (acked_bitrate_bps &&
         rate_control_.TimeToReduceFurther(now_ms, *acked_bitrate_bps)) {
       result.updated =
-          UpdateEstimate(packet_feedback.arrival_time_ms, now_ms,
-                         acked_bitrate_bps, &result.target_bitrate_bps);
+          UpdateEstimate(now_ms, acked_bitrate_bps, overusing, &result);
+    }
+  } else {
+    if (probe_bitrate_bps) {
+      rate_control_.SetEstimate(*probe_bitrate_bps, now_ms);
+      result.probe = true;
     }
-  } else if (probing_bps > 0) {
-    // No overuse, but probing measured a bitrate.
-    rate_control_.SetEstimate(probing_bps, packet_feedback.arrival_time_ms);
-    result.probe = true;
-    result.updated =
-        UpdateEstimate(packet_feedback.arrival_time_ms, now_ms,
-                       acked_bitrate_bps, &result.target_bitrate_bps);
-  }
-  if (!result.updated &&
-      (last_update_ms_ == -1 ||
-       now_ms - last_update_ms_ > rate_control_.GetFeedbackInterval())) {
     result.updated =
-        UpdateEstimate(packet_feedback.arrival_time_ms, now_ms,
-                       acked_bitrate_bps, &result.target_bitrate_bps);
+        UpdateEstimate(now_ms, acked_bitrate_bps, overusing, &result);
   }
   if (result.updated) {
-    last_update_ms_ = now_ms;
     BWE_TEST_LOGGING_PLOT(1, "target_bitrate_bps", now_ms,
                           result.target_bitrate_bps);
     if (event_log_ && (result.target_bitrate_bps != last_logged_bitrate_ ||
@@ -435,19 +434,21 @@ DelayBasedBwe::Result DelayBasedBwe::IncomingPacketFeedback(
       last_logged_state_ = detector_.State();
     }
   }
-
   return result;
 }
 
-bool DelayBasedBwe::UpdateEstimate(int64_t arrival_time_ms,
-                                   int64_t now_ms,
+bool DelayBasedBwe::UpdateEstimate(int64_t now_ms,
                                    rtc::Optional<uint32_t> acked_bitrate_bps,
-                                   uint32_t* target_bitrate_bps) {
+                                   bool overusing,
+                                   Result* result) {
   // TODO(terelius): RateControlInput::noise_var is deprecated and will be
   // removed. In the meantime, we set it to zero.
-  const RateControlInput input(detector_.State(), acked_bitrate_bps, 0);
+  const RateControlInput input(overusing ? kBwOverusing : detector_.State(),
+                               acked_bitrate_bps, 0);
   rate_control_.Update(&input, now_ms);
-  *target_bitrate_bps = rate_control_.UpdateBandwidthEstimate(now_ms);
+  result->target_bitrate_bps = rate_control_.UpdateBandwidthEstimate(now_ms);
+  BWE_TEST_LOGGING_PLOT(1, "target_bitrate_bps", now_ms,
+                        result->target_bitrate_bps);
   return rate_control_.ValidEstimate();
 }