Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 116 insertions, 0 deletions

diff --git a/third_party/libwebrtc/modules/remote_bitrate_estimator/aimd_rate_control.h b/third_party/libwebrtc/modules/remote_bitrate_estimator/aimd_rate_control.h
new file mode 100644
index 0000000000..97fa490adf
--- /dev/null
+++ b/third_party/libwebrtc/modules/remote_bitrate_estimator/aimd_rate_control.h
@@ -0,0 +1,116 @@
+/*
+ *  Copyright (c) 2014 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.
+ */
+
+#ifndef MODULES_REMOTE_BITRATE_ESTIMATOR_AIMD_RATE_CONTROL_H_
+#define MODULES_REMOTE_BITRATE_ESTIMATOR_AIMD_RATE_CONTROL_H_
+
+#include <stdint.h>
+
+#include "absl/types/optional.h"
+#include "api/field_trials_view.h"
+#include "api/transport/network_types.h"
+#include "api/units/data_rate.h"
+#include "api/units/timestamp.h"
+#include "modules/congestion_controller/goog_cc/link_capacity_estimator.h"
+#include "modules/remote_bitrate_estimator/include/bwe_defines.h"
+#include "rtc_base/experiments/field_trial_parser.h"
+
+namespace webrtc {
+// A rate control implementation based on additive increases of
+// bitrate when no over-use is detected and multiplicative decreases when
+// over-uses are detected. When we think the available bandwidth has changes or
+// is unknown, we will switch to a "slow-start mode" where we increase
+// multiplicatively.
+class AimdRateControl {
+ public:
+  explicit AimdRateControl(const FieldTrialsView& key_value_config);
+  AimdRateControl(const FieldTrialsView& key_value_config, bool send_side);
+  ~AimdRateControl();
+
+  // Returns true if the target bitrate has been initialized. This happens
+  // either if it has been explicitly set via SetStartBitrate/SetEstimate, or if
+  // we have measured a throughput.
+  bool ValidEstimate() const;
+  void SetStartBitrate(DataRate start_bitrate);
+  void SetMinBitrate(DataRate min_bitrate);
+  TimeDelta GetFeedbackInterval() const;
+
+  // Returns true if the bitrate estimate hasn't been changed for more than
+  // an RTT, or if the estimated_throughput is less than half of the current
+  // estimate. Should be used to decide if we should reduce the rate further
+  // when over-using.
+  bool TimeToReduceFurther(Timestamp at_time,
+                           DataRate estimated_throughput) const;
+  // As above. To be used if overusing before we have measured a throughput.
+  bool InitialTimeToReduceFurther(Timestamp at_time) const;
+
+  DataRate LatestEstimate() const;
+  void SetRtt(TimeDelta rtt);
+  DataRate Update(const RateControlInput& input, Timestamp at_time);
+  void SetInApplicationLimitedRegion(bool in_alr);
+  void SetEstimate(DataRate bitrate, Timestamp at_time);
+  void SetNetworkStateEstimate(
+      const absl::optional<NetworkStateEstimate>& estimate);
+
+  // Returns the increase rate when used bandwidth is near the link capacity.
+  double GetNearMaxIncreaseRateBpsPerSecond() const;
+  // Returns the expected time between overuse signals (assuming steady state).
+  TimeDelta GetExpectedBandwidthPeriod() const;
+
+ private:
+  enum class RateControlState { kRcHold, kRcIncrease, kRcDecrease };
+
+  friend class GoogCcStatePrinter;
+  // Update the target bitrate based on, among other things, the current rate
+  // control state, the current target bitrate and the estimated throughput.
+  // When in the "increase" state the bitrate will be increased either
+  // additively or multiplicatively depending on the rate control region. When
+  // in the "decrease" state the bitrate will be decreased to slightly below the
+  // current throughput. When in the "hold" state the bitrate will be kept
+  // constant to allow built up queues to drain.
+  void ChangeBitrate(const RateControlInput& input, Timestamp at_time);
+
+  DataRate ClampBitrate(DataRate new_bitrate) const;
+  DataRate MultiplicativeRateIncrease(Timestamp at_time,
+                                      Timestamp last_ms,
+                                      DataRate current_bitrate) const;
+  DataRate AdditiveRateIncrease(Timestamp at_time, Timestamp last_time) const;
+  void UpdateChangePeriod(Timestamp at_time);
+  void ChangeState(const RateControlInput& input, Timestamp at_time);
+
+  DataRate min_configured_bitrate_;
+  DataRate max_configured_bitrate_;
+  DataRate current_bitrate_;
+  DataRate latest_estimated_throughput_;
+  LinkCapacityEstimator link_capacity_;
+  absl::optional<NetworkStateEstimate> network_estimate_;
+  RateControlState rate_control_state_;
+  Timestamp time_last_bitrate_change_;
+  Timestamp time_last_bitrate_decrease_;
+  Timestamp time_first_throughput_estimate_;
+  bool bitrate_is_initialized_;
+  double beta_;
+  bool in_alr_;
+  TimeDelta rtt_;
+  const bool send_side_;
+  // Allow the delay based estimate to only increase as long as application
+  // limited region (alr) is not detected.
+  const bool no_bitrate_increase_in_alr_;
+  // If true, subtract an additional 5kbps when backing off.
+  const bool subtract_additional_backoff_term_;
+  // If "Disabled",  estimated link capacity is not used as upper bound.
+  FieldTrialFlag disable_estimate_bounded_increase_{"Disabled"};
+  FieldTrialParameter<bool> use_current_estimate_as_min_upper_bound_{"c_upper",
+                                                                     false};
+  absl::optional<DataRate> last_decrease_;
+};
+}  // namespace webrtc
+
+#endif  // MODULES_REMOTE_BITRATE_ESTIMATOR_AIMD_RATE_CONTROL_H_