Use loss based bwe v2 in the start phase.
TESTED=manual before:screen/ANtkMApoYczA2V5; after:screen/9kBoSvYKzKZR4sK
Bug: webrtc:12707
Change-Id: Ic156e363625c4b7476011059f3cd95641972091c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/320840
Commit-Queue: Diep Bui <diepbp@webrtc.org>
Reviewed-by: Per Kjellander <perkj@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#40789}
diff --git a/modules/congestion_controller/goog_cc/loss_based_bwe_v2.cc b/modules/congestion_controller/goog_cc/loss_based_bwe_v2.cc
index 3ad910b..b58f0f7 100644
--- a/modules/congestion_controller/goog_cc/loss_based_bwe_v2.cc
+++ b/modules/congestion_controller/goog_cc/loss_based_bwe_v2.cc
@@ -136,6 +136,10 @@
num_observations_ > 0;
}
+bool LossBasedBweV2::ReadyToUseInStartPhase() const {
+ return IsReady() && config_->use_in_start_phase;
+}
+
LossBasedBweV2::Result LossBasedBweV2::GetLossBasedResult() const {
Result result;
result.state = current_state_;
@@ -238,9 +242,12 @@
SetProbeBitrate(probe_bitrate);
if (!IsValid(current_estimate_.loss_limited_bandwidth)) {
- RTC_LOG(LS_VERBOSE)
- << "The estimator must be initialized before it can be used.";
- return;
+ if (!IsValid(delay_based_estimate)) {
+ RTC_LOG(LS_WARNING) << "The delay based estimate must be finite: "
+ << ToString(delay_based_estimate);
+ return;
+ }
+ current_estimate_.loss_limited_bandwidth = delay_based_estimate;
}
ChannelParameters best_candidate = current_estimate_;
@@ -416,6 +423,7 @@
TimeDelta::Seconds(10));
FieldTrialParameter<bool> not_use_acked_rate_in_alr("NotUseAckedRateInAlr",
false);
+ FieldTrialParameter<bool> use_in_start_phase("UseInStartPhase", false);
if (key_value_config) {
ParseFieldTrial({&enabled,
&bandwidth_rampup_upper_bound_factor,
@@ -453,7 +461,8 @@
&high_loss_rate_threshold,
&bandwidth_cap_at_high_loss_rate,
&slope_of_bwe_high_loss_func,
- ¬_use_acked_rate_in_alr},
+ ¬_use_acked_rate_in_alr,
+ &use_in_start_phase},
key_value_config->Lookup("WebRTC-Bwe-LossBasedBweV2"));
}
@@ -516,6 +525,7 @@
config->probe_integration_enabled = probe_integration_enabled.Get();
config->probe_expiration = probe_expiration.Get();
config->not_use_acked_rate_in_alr = not_use_acked_rate_in_alr.Get();
+ config->use_in_start_phase = use_in_start_phase.Get();
return config;
}
diff --git a/modules/congestion_controller/goog_cc/loss_based_bwe_v2.h b/modules/congestion_controller/goog_cc/loss_based_bwe_v2.h
index 649e765..cd49d05 100644
--- a/modules/congestion_controller/goog_cc/loss_based_bwe_v2.h
+++ b/modules/congestion_controller/goog_cc/loss_based_bwe_v2.h
@@ -57,11 +57,13 @@
// initialized with a BWE and then has received enough `PacketResult`s.
bool IsReady() const;
+ // Returns true if loss based BWE is ready to be used in the start phase.
+ bool ReadyToUseInStartPhase() const;
+
// Returns `DataRate::PlusInfinity` if no BWE can be calculated.
Result GetLossBasedResult() const;
void SetAcknowledgedBitrate(DataRate acknowledged_bitrate);
- void SetBandwidthEstimate(DataRate bandwidth_estimate);
void SetMinMaxBitrate(DataRate min_bitrate, DataRate max_bitrate);
void UpdateBandwidthEstimate(
rtc::ArrayView<const PacketResult> packet_results,
@@ -70,6 +72,9 @@
absl::optional<DataRate> probe_bitrate,
bool in_alr);
+ // For unit testing only.
+ void SetBandwidthEstimate(DataRate bandwidth_estimate);
+
private:
struct ChannelParameters {
double inherent_loss = 0.0;
@@ -114,6 +119,7 @@
bool probe_integration_enabled = false;
TimeDelta probe_expiration = TimeDelta::Zero();
bool not_use_acked_rate_in_alr = false;
+ bool use_in_start_phase = false;
};
struct Derivatives {
diff --git a/modules/congestion_controller/goog_cc/loss_based_bwe_v2_test.cc b/modules/congestion_controller/goog_cc/loss_based_bwe_v2_test.cc
index bdd7498..ca8596f 100644
--- a/modules/congestion_controller/goog_cc/loss_based_bwe_v2_test.cc
+++ b/modules/congestion_controller/goog_cc/loss_based_bwe_v2_test.cc
@@ -1530,6 +1530,34 @@
acked_rate);
}
+TEST_P(LossBasedBweV2Test, NotReadyToUseInStartPhase) {
+ ExplicitKeyValueConfig key_value_config(
+ "WebRTC-Bwe-LossBasedBweV2/"
+ "Enabled:true,UseInStartPhase:true/");
+ LossBasedBweV2 loss_based_bandwidth_estimator(&key_value_config);
+ // Make sure that the estimator is not ready to use in start phase because of
+ // lacking TWCC feedback.
+ EXPECT_FALSE(loss_based_bandwidth_estimator.ReadyToUseInStartPhase());
+}
+
+TEST_P(LossBasedBweV2Test,
+ ReadyToUseInStartPhase) {
+ ExplicitKeyValueConfig key_value_config(
+ "WebRTC-Bwe-LossBasedBweV2/"
+ "Enabled:true,ObservationDurationLowerBound:200ms,UseInStartPhase:true/");
+ LossBasedBweV2 loss_based_bandwidth_estimator(&key_value_config);
+ std::vector<PacketResult> enough_feedback =
+ CreatePacketResultsWithReceivedPackets(
+ /*first_packet_timestamp=*/Timestamp::Zero());
+
+ loss_based_bandwidth_estimator.UpdateBandwidthEstimate(
+ enough_feedback, /*delay_based_estimate=*/DataRate::KilobitsPerSec(600),
+ BandwidthUsage::kBwNormal,
+ /*probe_estimate=*/absl::nullopt,
+ /*upper_link_capacity=*/DataRate::PlusInfinity(), /*in_alr=*/false);
+ EXPECT_TRUE(loss_based_bandwidth_estimator.ReadyToUseInStartPhase());
+}
+
INSTANTIATE_TEST_SUITE_P(LossBasedBweV2Tests,
LossBasedBweV2Test,
::testing::Bool());
diff --git a/modules/congestion_controller/goog_cc/send_side_bandwidth_estimation.cc b/modules/congestion_controller/goog_cc/send_side_bandwidth_estimation.cc
index 9f97c06..3102466 100644
--- a/modules/congestion_controller/goog_cc/send_side_bandwidth_estimation.cc
+++ b/modules/congestion_controller/goog_cc/send_side_bandwidth_estimation.cc
@@ -492,7 +492,8 @@
// We trust the REMB and/or delay-based estimate during the first 2 seconds if
// we haven't had any packet loss reported, to allow startup bitrate probing.
- if (last_fraction_loss_ == 0 && IsInStartPhase(at_time)) {
+ if (last_fraction_loss_ == 0 && IsInStartPhase(at_time) &&
+ !loss_based_bandwidth_estimator_v2_.ReadyToUseInStartPhase()) {
DataRate new_bitrate = current_target_;
// TODO(srte): We should not allow the new_bitrate to be larger than the
// receiver limit here.
@@ -503,9 +504,6 @@
if (LossBasedBandwidthEstimatorV1Enabled()) {
loss_based_bandwidth_estimator_v1_.Initialize(new_bitrate);
}
- if (LossBasedBandwidthEstimatorV2Enabled()) {
- loss_based_bandwidth_estimator_v2_.SetBandwidthEstimate(new_bitrate);
- }
if (new_bitrate != current_target_) {
min_bitrate_history_.clear();
