1 files changed, 103 insertions, 0 deletions
diff --git a/third_party/libwebrtc/modules/remote_bitrate_estimator/overuse_detector.cc b/third_party/libwebrtc/modules/remote_bitrate_estimator/overuse_detector.cc
new file mode 100644
index 0000000000..888f18cd9e
--- /dev/null
+++ b/third_party/libwebrtc/modules/remote_bitrate_estimator/overuse_detector.cc
@@ -0,0 +1,103 @@
+/*
+ *  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 <stdio.h>
+
+#include <algorithm>
+#include <string>
+
+#include "modules/remote_bitrate_estimator/test/bwe_test_logging.h"
+#include "rtc_base/checks.h"
+#include "rtc_base/numerics/safe_minmax.h"
+
+namespace webrtc {
+namespace {
+
+constexpr double kMaxAdaptOffsetMs = 15.0;
+constexpr double kOverUsingTimeThreshold = 10;
+constexpr int kMaxNumDeltas = 60;
+constexpr double kUp = 0.0087;
+constexpr double kDown = 0.039;
+
+}  // namespace
+
+OveruseDetector::OveruseDetector() = default;
+
+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, kMaxNumDeltas) * 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_ > kOverUsingTimeThreshold && 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 (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_ ? kDown : kUp;
+  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