| /* |
| * Copyright (c) 2012 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. |
| */ |
| |
| #include "modules/remote_bitrate_estimator/overuse_detector.h" |
| |
| #include <math.h> |
| #include <stdlib.h> |
| |
| #include <algorithm> |
| #include <sstream> |
| #include <string> |
| |
| #include "modules/remote_bitrate_estimator/include/bwe_defines.h" |
| #include "modules/remote_bitrate_estimator/test/bwe_test_logging.h" |
| #include "modules/rtp_rtcp/source/rtp_utility.h" |
| #include "rtc_base/checks.h" |
| #include "rtc_base/logging.h" |
| #include "rtc_base/safe_minmax.h" |
| #include "system_wrappers/include/field_trial.h" |
| |
| namespace webrtc { |
| |
| const char kAdaptiveThresholdExperiment[] = "WebRTC-AdaptiveBweThreshold"; |
| const char kEnabledPrefix[] = "Enabled"; |
| const size_t kEnabledPrefixLength = sizeof(kEnabledPrefix) - 1; |
| const char kDisabledPrefix[] = "Disabled"; |
| const size_t kDisabledPrefixLength = sizeof(kDisabledPrefix) - 1; |
| |
| const double kMaxAdaptOffsetMs = 15.0; |
| const double kOverUsingTimeThreshold = 10; |
| const int kMinNumDeltas = 60; |
| |
| bool AdaptiveThresholdExperimentIsDisabled() { |
| std::string experiment_string = |
| webrtc::field_trial::FindFullName(kAdaptiveThresholdExperiment); |
| const size_t kMinExperimentLength = kDisabledPrefixLength; |
| if (experiment_string.length() < kMinExperimentLength) |
| return false; |
| return experiment_string.substr(0, kDisabledPrefixLength) == kDisabledPrefix; |
| } |
| |
| // Gets thresholds from the experiment name following the format |
| // "WebRTC-AdaptiveBweThreshold/Enabled-0.5,0.002/". |
| bool ReadExperimentConstants(double* k_up, double* k_down) { |
| std::string experiment_string = |
| webrtc::field_trial::FindFullName(kAdaptiveThresholdExperiment); |
| const size_t kMinExperimentLength = kEnabledPrefixLength + 3; |
| if (experiment_string.length() < kMinExperimentLength || |
| experiment_string.substr(0, kEnabledPrefixLength) != kEnabledPrefix) |
| return false; |
| return sscanf(experiment_string.substr(kEnabledPrefixLength + 1).c_str(), |
| "%lf,%lf", k_up, k_down) == 2; |
| } |
| |
| OveruseDetector::OveruseDetector() |
| // Experiment is on by default, but can be disabled with finch by setting |
| // the field trial string to "WebRTC-AdaptiveBweThreshold/Disabled/". |
| : in_experiment_(!AdaptiveThresholdExperimentIsDisabled()), |
| k_up_(0.0087), |
| k_down_(0.039), |
| overusing_time_threshold_(100), |
| threshold_(12.5), |
| last_update_ms_(-1), |
| prev_offset_(0.0), |
| time_over_using_(-1), |
| overuse_counter_(0), |
| hypothesis_(BandwidthUsage::kBwNormal) { |
| if (!AdaptiveThresholdExperimentIsDisabled()) |
| InitializeExperiment(); |
| } |
| |
| OveruseDetector::~OveruseDetector() {} |
| |
| BandwidthUsage OveruseDetector::State() const { |
| return hypothesis_; |
| } |
| |
| BandwidthUsage OveruseDetector::Detect(double offset, |
| double ts_delta, |
| int num_of_deltas, |
| int64_t now_ms) { |
| if (num_of_deltas < 2) { |
| return BandwidthUsage::kBwNormal; |
| } |
| 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); |
| |
| return hypothesis_; |
| } |
| |
| void OveruseDetector::UpdateThreshold(double modified_offset, int64_t now_ms) { |
| if (!in_experiment_) |
| return; |
| |
| 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; |
| } |
| |
| void OveruseDetector::InitializeExperiment() { |
| RTC_DCHECK(in_experiment_); |
| double k_up = 0.0; |
| double k_down = 0.0; |
| overusing_time_threshold_ = kOverUsingTimeThreshold; |
| if (ReadExperimentConstants(&k_up, &k_down)) { |
| k_up_ = k_up; |
| k_down_ = k_down; |
| } |
| } |
| } // namespace webrtc |