Refactored incoming bitrate estimator.

webrtc/modules/congestion_controller/incoming_bitrate_estimator.h

+/*
+ *  Copyright (c) 2017 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 WEBRTC_MODULES_CONGESTION_CONTROLLER_INCOMING_BITRATE_ESTIMATOR_H_
+#define WEBRTC_MODULES_CONGESTION_CONTROLLER_INCOMING_BITRATE_ESTIMATOR_H_
+
+#include "webrtc/base/optional.h"
+
+namespace webrtc {
+
+// Computes a bayesian estimate of the throughput given acks containing
+// the arrival time and payload size. Samples which are far from the current
+// estimate or are based on few packets are given a smaller weight, as they
+// are considered to be more likely to have been caused by, e.g., delay spikes
+// unrelated to congestion.
+class IncomingBitrateEstimator {

[terelius, 2017/06/01 15:15:04]

I'd prefer not calling it incoming bitrate, since it isn't related to the our
incoming bitrate. I think the "incoming" name goes back to when bandwidth
estimation was done on the receive side.

Maybe AcknowledgedBitrateEstimator?

[tschumi, 2017/06/02 11:48:44]

Acknowledged.

+ public:
+  IncomingBitrateEstimator();
+  void Update(int64_t now_ms, int bytes);
+  rtc::Optional<uint32_t> bitrate_bps() const;
+
+ private:
+  float UpdateWindow(int64_t now_ms, int bytes, int rate_window_ms);
+  int sum_;
+  int64_t current_win_ms_;
+  int64_t prev_time_ms_;
+  float bitrate_estimate_;
+  float bitrate_estimate_var_;
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_CONGESTION_CONTROLLER_INCOMING_BITRATE_ESTIMATOR_H_