zqz/platform-external-webrtc
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge OveruseDetector into the TrendlineEstimator (send side BWE only)

Browse Source 
Merge OveruseDetector into the TrendlineEstimator (send side BWE only) and remove the OveruseDetector from DelayBasedBwe. The behavior should be the same as before. One expection is that if no packets were received for kStreamTimeOutMs (2 seconds), it would previously reset the trendline estimator but not the detector. Since they have been merged, it now resets both.

Create an interface that the estimators will implement to facilitate experimentation with different estimators/detectors.

Bug: webrtc:8729
Change-Id: I5c3d2161a0d0dcb2e8a140c0fd887f0286d70fd4
Reviewed-on: https://webrtc-review.googlesource.com/38781
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Commit-Queue: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21852}
This commit is contained in:
Bjorn Terelius
2018-02-01 15:48:14 +01:00
committed by Commit Bot
parent c67f18e89c
commit b90a64a449
6 changed files with 175 additions and 33 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
modules/congestion_controller/BUILD.gn
View File

@ -84,6 +84,7 @@ rtc_source_set("estimators") {
"acknowledged_bitrate_estimator.h",
"bitrate_estimator.cc",
"bitrate_estimator.h",
"delay_increase_detector_interface.h",
"median_slope_estimator.cc",
"median_slope_estimator.h",
"probe_bitrate_estimator.cc",

37
modules/congestion_controller/delay_based_bwe.cc
View File

@ -17,6 +17,7 @@
#include "logging/rtc_event_log/events/rtc_event_bwe_update_delay_based.h"
#include "logging/rtc_event_log/rtc_event_log.h"
#include "modules/congestion_controller/trendline_estimator.h"
#include "modules/pacing/paced_sender.h"
#include "modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h"
#include "modules/remote_bitrate_estimator/test/bwe_test_logging.h"
@ -88,8 +89,7 @@ DelayBasedBwe::DelayBasedBwe(RtcEventLog* event_log, const Clock* clock)
: event_log_(event_log),
clock_(clock),
inter_arrival_(),
trendline_estimator_(),
detector_(),
delay_detector_(),
last_seen_packet_ms_(-1),
uma_recorded_(false),
probe_bitrate_estimator_(event_log),
@ -105,6 +105,9 @@ DelayBasedBwe::DelayBasedBwe(RtcEventLog* event_log, const Clock* clock)
RTC_LOG(LS_INFO)
<< "Using Trendline filter for delay change estimation with window size "
<< trendline_window_size_;
delay_detector_.reset(new TrendlineEstimator(trendline_window_size_,
trendline_smoothing_coeff_,
trendline_threshold_gain_));
}
DelayBasedBwe::~DelayBasedBwe() {}
@ -133,17 +136,17 @@ DelayBasedBwe::Result DelayBasedBwe::IncomingPacketFeedbackVector(
}
bool delayed_feedback = true;
bool recovered_from_overuse = false;
BandwidthUsage prev_detector_state = detector_.State();
BandwidthUsage prev_detector_state = delay_detector_->State();
for (const auto& packet_feedback : packet_feedback_vector) {
if (packet_feedback.send_time_ms < 0)
continue;
delayed_feedback = false;
IncomingPacketFeedback(packet_feedback);
if (prev_detector_state == BandwidthUsage::kBwUnderusing &&
detector_.State() == BandwidthUsage::kBwNormal) {
delay_detector_->State() == BandwidthUsage::kBwNormal) {
recovered_from_overuse = true;
}
prev_detector_state = detector_.State();
prev_detector_state = delay_detector_->State();
}
if (delayed_feedback) {
@ -185,9 +188,9 @@ void DelayBasedBwe::IncomingPacketFeedback(
inter_arrival_.reset(
new InterArrival((kTimestampGroupLengthMs << kInterArrivalShift) / 1000,
kTimestampToMs, true));
trendline_estimator_.reset(new TrendlineEstimator(
trendline_window_size_, trendline_smoothing_coeff_,
trendline_threshold_gain_));
delay_detector_.reset(new TrendlineEstimator(trendline_window_size_,
trendline_smoothing_coeff_,
trendline_threshold_gain_));
}
last_seen_packet_ms_ = now_ms;
@ -209,11 +212,8 @@ void DelayBasedBwe::IncomingPacketFeedback(
now_ms, packet_feedback.payload_size,
&ts_delta, &t_delta, &size_delta)) {
double ts_delta_ms = (1000.0 * ts_delta) / (1 << kInterArrivalShift);
trendline_estimator_->Update(t_delta, ts_delta_ms,
packet_feedback.arrival_time_ms);
detector_.Detect(trendline_estimator_->trendline_slope(), ts_delta_ms,
trendline_estimator_->num_of_deltas(),
packet_feedback.arrival_time_ms);
delay_detector_->Update(t_delta, ts_delta_ms,
packet_feedback.arrival_time_ms);
}
if (packet_feedback.pacing_info.probe_cluster_id !=
PacedPacketInfo::kNotAProbe) {
@ -230,7 +230,7 @@ DelayBasedBwe::Result DelayBasedBwe::MaybeUpdateEstimate(
rtc::Optional<int> probe_bitrate_bps =
probe_bitrate_estimator_.FetchAndResetLastEstimatedBitrateBps();
// Currently overusing the bandwidth.
if (detector_.State() == BandwidthUsage::kBwOverusing) {
if (delay_detector_->State() == BandwidthUsage::kBwOverusing) {
if (acked_bitrate_bps &&
rate_control_.TimeToReduceFurther(now_ms, *acked_bitrate_bps)) {
result.updated =
@ -260,8 +260,9 @@ DelayBasedBwe::Result DelayBasedBwe::MaybeUpdateEstimate(
result.recovered_from_overuse = recovered_from_overuse;
}
}
BandwidthUsage detector_state = delay_detector_->State();
if ((result.updated && prev_bitrate_ != result.target_bitrate_bps) ||
detector_.State() != prev_state_) {
detector_state != prev_state_) {
uint32_t bitrate_bps =
result.updated ? result.target_bitrate_bps : prev_bitrate_;
@ -269,11 +270,11 @@ DelayBasedBwe::Result DelayBasedBwe::MaybeUpdateEstimate(
if (event_log_) {
event_log_->Log(rtc::MakeUnique<RtcEventBweUpdateDelayBased>(
bitrate_bps, detector_.State()));
bitrate_bps, detector_state));
}
prev_bitrate_ = bitrate_bps;
prev_state_ = detector_.State();
prev_state_ = detector_state;
}
return result;
}
@ -283,7 +284,7 @@ bool DelayBasedBwe::UpdateEstimate(int64_t now_ms,
uint32_t* target_bitrate_bps) {
// 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(delay_detector_->State(), acked_bitrate_bps, 0);
*target_bitrate_bps = rate_control_.Update(&input, now_ms);
return rate_control_.ValidEstimate();
}

8
modules/congestion_controller/delay_based_bwe.h
View File

@ -15,14 +15,11 @@
#include <utility>
#include <vector>
#include "modules/congestion_controller/median_slope_estimator.h"
#include "modules/congestion_controller/delay_increase_detector_interface.h"
#include "modules/congestion_controller/probe_bitrate_estimator.h"
#include "modules/congestion_controller/trendline_estimator.h"
#include "modules/remote_bitrate_estimator/aimd_rate_control.h"
#include "modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h"
#include "modules/remote_bitrate_estimator/inter_arrival.h"
#include "modules/remote_bitrate_estimator/overuse_detector.h"
#include "modules/remote_bitrate_estimator/overuse_estimator.h"
#include "rtc_base/checks.h"
#include "rtc_base/constructormagic.h"
#include "rtc_base/race_checker.h"
@ -73,8 +70,7 @@ class DelayBasedBwe {
RtcEventLog* const event_log_;
const Clock* const clock_;
std::unique_ptr<InterArrival> inter_arrival_;
std::unique_ptr<TrendlineEstimator> trendline_estimator_;
OveruseDetector detector_;
std::unique_ptr<DelayIncreaseDetectorInterface> delay_detector_;
int64_t last_seen_packet_ms_;
bool uma_recorded_;
AimdRateControl rate_control_;

37
modules/congestion_controller/delay_increase_detector_interface.h Normal file
View File

@ -0,0 +1,37 @@
/*
* Copyright (c) 2018 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_CONGESTION_CONTROLLER_DELAY_INCREASE_DETECTOR_INTERFACE_H_
#define MODULES_CONGESTION_CONTROLLER_DELAY_INCREASE_DETECTOR_INTERFACE_H_
#include <stdint.h>
#include "modules/remote_bitrate_estimator/include/bwe_defines.h"
#include "rtc_base/constructormagic.h"
namespace webrtc {
class DelayIncreaseDetectorInterface {
public:
DelayIncreaseDetectorInterface() {}
virtual ~DelayIncreaseDetectorInterface() {}
// Update the detector with a new sample. The deltas should represent deltas
// between timestamp groups as defined by the InterArrival class.
virtual void Update(double recv_delta_ms,
double send_delta_ms,
int64_t arrival_time_ms) = 0;
virtual BandwidthUsage State() const = 0;
RTC_DISALLOW_COPY_AND_ASSIGN(DelayIncreaseDetectorInterface);
};
} // namespace webrtc
#endif // MODULES_CONGESTION_CONTROLLER_DELAY_INCREASE_DETECTOR_INTERFACE_H_

96
modules/congestion_controller/trendline_estimator.cc
View File

@ -10,11 +10,14 @@
#include "modules/congestion_controller/trendline_estimator.h"
#include <math.h>
#include <algorithm>
#include "api/optional.h"
#include "modules/remote_bitrate_estimator/test/bwe_test_logging.h"
#include "rtc_base/checks.h"
#include "rtc_base/numerics/safe_minmax.h"
namespace webrtc {
@ -42,6 +45,11 @@ rtc::Optional<double> LinearFitSlope(
return rtc::nullopt;
return numerator / denominator;
}
constexpr double kMaxAdaptOffsetMs = 15.0;
constexpr double kOverUsingTimeThreshold = 10;
constexpr int kMinNumDeltas = 60;
} // namespace
enum { kDeltaCounterMax = 1000 };
@ -53,11 +61,20 @@ TrendlineEstimator::TrendlineEstimator(size_t window_size,
smoothing_coef_(smoothing_coef),
threshold_gain_(threshold_gain),
num_of_deltas_(0),
first_arrival_time_ms(-1),
first_arrival_time_ms_(-1),
accumulated_delay_(0),
smoothed_delay_(0),
delay_hist_(),
trendline_(0) {}
trendline_(0),
k_up_(0.0087),
k_down_(0.039),
overusing_time_threshold_(kOverUsingTimeThreshold),
threshold_(12.5),
last_update_ms_(-1),
prev_offset_(0.0),
time_over_using_(-1),
overuse_counter_(0),
hypothesis_(BandwidthUsage::kBwNormal) {}
TrendlineEstimator::~TrendlineEstimator() {}
@ -68,8 +85,8 @@ void TrendlineEstimator::Update(double recv_delta_ms,
++num_of_deltas_;
if (num_of_deltas_ > kDeltaCounterMax)
num_of_deltas_ = kDeltaCounterMax;
if (first_arrival_time_ms == -1)
first_arrival_time_ms = arrival_time_ms;
if (first_arrival_time_ms_ == -1)
first_arrival_time_ms_ = arrival_time_ms;
// Exponential backoff filter.
accumulated_delay_ += delta_ms;
@ -82,7 +99,7 @@ void TrendlineEstimator::Update(double recv_delta_ms,
// Simple linear regression.
delay_hist_.push_back(std::make_pair(
static_cast<double>(arrival_time_ms - first_arrival_time_ms),
static_cast<double>(arrival_time_ms - first_arrival_time_ms_),
smoothed_delay_));
if (delay_hist_.size() > window_size_)
delay_hist_.pop_front();
@ -92,6 +109,75 @@ void TrendlineEstimator::Update(double recv_delta_ms,
}
BWE_TEST_LOGGING_PLOT(1, "trendline_slope", arrival_time_ms, trendline_);
Detect(trendline_slope(), send_delta_ms, num_of_deltas(), arrival_time_ms);
}
BandwidthUsage TrendlineEstimator::State() const {
return hypothesis_;
}
void TrendlineEstimator::Detect(double offset,
double ts_delta,
int num_of_deltas,
int64_t now_ms) {
if (num_of_deltas < 2) {
hypothesis_ = BandwidthUsage::kBwNormal;
return;
}
const double T = std::min(num_of_deltas, kMinNumDeltas) * offset;
BWE_TEST_LOGGING_PLOT(1, "T", now_ms, T);
BWE_TEST_LOGGING_PLOT(1, "threshold", now_ms, threshold_);
if (T > threshold_) {
if (time_over_using_ == -1) {
// Initialize the timer. Assume that we've been
// over-using half of the time since the previous
// sample.
time_over_using_ = ts_delta / 2;
} else {
// Increment timer
time_over_using_ += ts_delta;
}
overuse_counter_++;
if (time_over_using_ > overusing_time_threshold_ && overuse_counter_ > 1) {
if (offset >= prev_offset_) {
time_over_using_ = 0;
overuse_counter_ = 0;
hypothesis_ = BandwidthUsage::kBwOverusing;
}
}
} else if (T < -threshold_) {
time_over_using_ = -1;
overuse_counter_ = 0;
hypothesis_ = BandwidthUsage::kBwUnderusing;
} else {
time_over_using_ = -1;
overuse_counter_ = 0;
hypothesis_ = BandwidthUsage::kBwNormal;
}
prev_offset_ = offset;
UpdateThreshold(T, now_ms);
}
void TrendlineEstimator::UpdateThreshold(double modified_offset,
int64_t now_ms) {
if (last_update_ms_ == -1)
last_update_ms_ = now_ms;
if (fabs(modified_offset) > threshold_ + kMaxAdaptOffsetMs) {
// Avoid adapting the threshold to big latency spikes, caused e.g.,
// by a sudden capacity drop.
last_update_ms_ = now_ms;
return;
}
const double k = fabs(modified_offset) < threshold_ ? k_down_ : k_up_;
const int64_t kMaxTimeDeltaMs = 100;
int64_t time_delta_ms = std::min(now_ms - last_update_ms_, kMaxTimeDeltaMs);
threshold_ += k * (fabs(modified_offset) - threshold_) * time_delta_ms;
threshold_ = rtc::SafeClamp(threshold_, 6.f, 600.f);
last_update_ms_ = now_ms;
}
} // namespace webrtc

29
modules/congestion_controller/trendline_estimator.h
View File

@ -16,11 +16,12 @@
#include <deque>
#include <utility>
#include "modules/congestion_controller/delay_increase_detector_interface.h"
#include "rtc_base/constructormagic.h"
namespace webrtc {
class TrendlineEstimator {
class TrendlineEstimator : public DelayIncreaseDetectorInterface {
public:
// |window_size| is the number of points required to compute a trend line.
// |smoothing_coef| controls how much we smooth out the delay before fitting
@ -31,13 +32,16 @@ class TrendlineEstimator {
TrendlineEstimator(size_t window_size,
double smoothing_coef,
double threshold_gain);
~TrendlineEstimator();
~TrendlineEstimator() override;
// Update the estimator with a new sample. The deltas should represent deltas
// between timestamp groups as defined by the InterArrival class.
void Update(double recv_delta_ms,
double send_delta_ms,
int64_t arrival_time_ms);
int64_t arrival_time_ms) override;
BandwidthUsage State() const override;
// Returns the estimated trend k multiplied by some gain.
// 0 < k < 1 -> the delay increases, queues are filling up
@ -49,6 +53,13 @@ class TrendlineEstimator {
unsigned int num_of_deltas() const { return num_of_deltas_; }
private:
void Detect(double offset,
double ts_delta,
int num_of_deltas,
int64_t now_ms);
void UpdateThreshold(double modified_offset, int64_t now_ms);
// Parameters.
const size_t window_size_;
const double smoothing_coef_;
@ -56,7 +67,7 @@ class TrendlineEstimator {
// Used by the existing threshold.
unsigned int num_of_deltas_;
// Keep the arrival times small by using the change from the first packet.
int64_t first_arrival_time_ms;
int64_t first_arrival_time_ms_;
// Exponential backoff filtering.
double accumulated_delay_;
double smoothed_delay_;
@ -64,6 +75,16 @@ class TrendlineEstimator {
std::deque<std::pair<double, double>> delay_hist_;
double trendline_;
const double k_up_;
const double k_down_;
double overusing_time_threshold_;
double threshold_;
int64_t last_update_ms_;
double prev_offset_;
double time_over_using_;
int overuse_counter_;
BandwidthUsage hypothesis_;
RTC_DISALLOW_COPY_AND_ASSIGN(TrendlineEstimator);
};
} // namespace webrtc