1 /* 2 * Copyright (c) 2021 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 #ifndef MODULES_CONGESTION_CONTROLLER_REMB_THROTTLER_H_ 11 #define MODULES_CONGESTION_CONTROLLER_REMB_THROTTLER_H_ 12 13 #include <functional> 14 #include <vector> 15 16 #include "api/units/data_rate.h" 17 #include "api/units/time_delta.h" 18 #include "api/units/timestamp.h" 19 #include "modules/remote_bitrate_estimator/include/remote_bitrate_estimator.h" 20 #include "rtc_base/synchronization/mutex.h" 21 22 namespace webrtc { 23 24 // RembThrottler is a helper class used for throttling RTCP REMB messages. 25 // Throttles small changes to the received BWE within 200ms. 26 class RembThrottler : public RemoteBitrateObserver { 27 public: 28 using RembSender = 29 std::function<void(int64_t bitrate_bps, std::vector<uint32_t> ssrcs)>; 30 RembThrottler(RembSender remb_sender, Clock* clock); 31 32 // Ensures the remote party is notified of the receive bitrate no larger than 33 // `bitrate` using RTCP REMB. 34 void SetMaxDesiredReceiveBitrate(DataRate bitrate); 35 36 // Implements RemoteBitrateObserver; 37 // Called every time there is a new bitrate estimate for a receive channel 38 // group. This call will trigger a new RTCP REMB packet if the bitrate 39 // estimate has decreased or if no RTCP REMB packet has been sent for 40 // a certain time interval. 41 void OnReceiveBitrateChanged(const std::vector<uint32_t>& ssrcs, 42 uint32_t bitrate_bps) override; 43 44 private: 45 const RembSender remb_sender_; 46 Clock* const clock_; 47 mutable Mutex mutex_; 48 Timestamp last_remb_time_ RTC_GUARDED_BY(mutex_); 49 DataRate last_send_remb_bitrate_ RTC_GUARDED_BY(mutex_); 50 DataRate max_remb_bitrate_ RTC_GUARDED_BY(mutex_); 51 }; 52 53 } // namespace webrtc 54 #endif // MODULES_CONGESTION_CONTROLLER_REMB_THROTTLER_H_ 55