Index: webrtc/modules/congestion_controller/probe_controller.cc |
diff --git a/webrtc/modules/congestion_controller/probe_controller.cc b/webrtc/modules/congestion_controller/probe_controller.cc |
new file mode 100644 |
index 0000000000000000000000000000000000000000..cf7f3e1b6157b28f4250e7451cc3cf630b04e09f |
--- /dev/null |
+++ b/webrtc/modules/congestion_controller/probe_controller.cc |
@@ -0,0 +1,113 @@ |
+/* |
+ * Copyright (c) 2016 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 "webrtc/modules/congestion_controller/probe_controller.h" |
+ |
+#include <initializer_list> |
+ |
+#include "webrtc/base/logging.h" |
+ |
+namespace webrtc { |
+ |
+namespace { |
+ |
+// Number of deltas between probes per cluster. On the very first cluster, |
+// we will need kProbeDeltasPerCluster + 1 probes, but on a cluster following |
+// another, we need kProbeDeltasPerCluster probes. |
+constexpr int kProbeDeltasPerCluster = 5; |
+ |
+// Maximum waiting time from the time of initiating probing to getting |
+// the measured results back. |
+constexpr int64_t kMaxWaitingTimeForProbingResultMs = 1000; |
+ |
+// Value of |min_bitrate_to_probe_further_bps_| that indicates |
+// further probing is disabled. |
+constexpr int kExponentialProbingDisabled = 0; |
+ |
+} // namespace |
+ |
+ProbeController::ProbeController(PacedSender* pacer, Clock* clock) |
+ : pacer_(pacer), |
+ clock_(clock), |
+ state_(State::kInit), |
+ min_bitrate_to_probe_further_bps_(kExponentialProbingDisabled), |
+ time_last_probing_initiated_ms_(0), |
+ estimated_bitrate_bps_(0), |
+ max_bitrate_bps_(0) {} |
+ |
+void ProbeController::SetBitrates(int min_bitrate_bps, |
+ int start_bitrate_bps, |
+ int max_bitrate_bps) { |
+ rtc::CritScope cs(&critsect_); |
+ if (state_ == State::kInit) { |
+ // When probing at 1.8 Mbps ( 6x 300), this represents a threshold of |
+ // 1.2 Mbps to continue probing. |
+ InitiateProbing({3 * start_bitrate_bps, 6 * start_bitrate_bps}, |
+ 4 * start_bitrate_bps); |
+ } |
+ |
+ // Only do probing if: |
+ // - we are mid-call, which we consider to be if |
+ // |estimated_bitrate_bps_| != 0, and |
+ // - the current bitrate is lower than the new |max_bitrate_bps|, and |
+ // - we actually want to increase the |max_bitrate_bps_|. |
+ if (estimated_bitrate_bps_ != 0 && estimated_bitrate_bps_ < max_bitrate_bps && |
+ max_bitrate_bps > max_bitrate_bps_) { |
+ InitiateProbing({max_bitrate_bps}, kExponentialProbingDisabled); |
+ } |
+ max_bitrate_bps_ = max_bitrate_bps; |
+} |
+ |
+void ProbeController::SetEstimatedBitrate(int bitrate_bps) { |
+ rtc::CritScope cs(&critsect_); |
+ if (state_ == State::kWaitingForProbingResult) { |
+ if ((clock_->TimeInMilliseconds() - time_last_probing_initiated_ms_) > |
+ kMaxWaitingTimeForProbingResultMs) { |
+ LOG(LS_INFO) << "kWaitingForProbingResult: timeout"; |
+ state_ = State::kProbingComplete; |
+ min_bitrate_to_probe_further_bps_ = kExponentialProbingDisabled; |
+ } else { |
+ // Continue probing if probing results indicate channel has greater |
+ // capacity. |
+ LOG(LS_INFO) << "Measured bitrate: " << bitrate_bps |
+ << " Minimum to probe further: " |
+ << min_bitrate_to_probe_further_bps_; |
+ if (min_bitrate_to_probe_further_bps_ != kExponentialProbingDisabled && |
+ bitrate_bps > min_bitrate_to_probe_further_bps_) { |
+ // Double the probing bitrate and expect a minimum of 25% gain to |
+ // continue probing. |
+ InitiateProbing({2 * bitrate_bps}, 1.25 * bitrate_bps); |
+ } |
+ } |
+ } |
+ estimated_bitrate_bps_ = bitrate_bps; |
+} |
+ |
+void ProbeController::InitiateProbing( |
+ std::initializer_list<int> bitrates_to_probe, |
+ int min_bitrate_to_probe_further_bps) { |
+ bool first_cluster = true; |
+ for (int bitrate : bitrates_to_probe) { |
+ if (first_cluster) { |
+ pacer_->CreateProbeCluster(bitrate, kProbeDeltasPerCluster + 1); |
+ first_cluster = false; |
+ } else { |
+ pacer_->CreateProbeCluster(bitrate, kProbeDeltasPerCluster); |
+ } |
+ } |
+ min_bitrate_to_probe_further_bps_ = min_bitrate_to_probe_further_bps; |
+ time_last_probing_initiated_ms_ = clock_->TimeInMilliseconds(); |
+ if (min_bitrate_to_probe_further_bps == kExponentialProbingDisabled) |
+ state_ = State::kProbingComplete; |
+ else |
+ state_ = State::kWaitingForProbingResult; |
+} |
+ |
+} // namespace webrtc |