1 /* 2 * Copyright (c) 2014 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 11 #ifndef MODULES_RTP_RTCP_INCLUDE_REMOTE_NTP_TIME_ESTIMATOR_H_ 12 #define MODULES_RTP_RTCP_INCLUDE_REMOTE_NTP_TIME_ESTIMATOR_H_ 13 14 #include <memory> 15 16 #include "rtc_base/constructormagic.h" 17 #include "rtc_base/numerics/moving_median_filter.h" 18 #include "system_wrappers/include/rtp_to_ntp_estimator.h" 19 20 namespace webrtc { 21 22 class Clock; 23 24 // RemoteNtpTimeEstimator can be used to estimate a given RTP timestamp's NTP 25 // time in local timebase. 26 // Note that it needs to be trained with at least 2 RTCP SR (by calling 27 // |UpdateRtcpTimestamp|) before it can be used. 28 class RemoteNtpTimeEstimator { 29 public: 30 explicit RemoteNtpTimeEstimator(Clock* clock); 31 32 ~RemoteNtpTimeEstimator(); 33 34 // Updates the estimator with round trip time |rtt|, NTP seconds |ntp_secs|, 35 // NTP fraction |ntp_frac| and RTP timestamp |rtcp_timestamp|. 36 bool UpdateRtcpTimestamp(int64_t rtt, uint32_t ntp_secs, uint32_t ntp_frac, 37 uint32_t rtp_timestamp); 38 39 // Estimates the NTP timestamp in local timebase from |rtp_timestamp|. 40 // Returns the NTP timestamp in ms when success. -1 if failed. 41 int64_t Estimate(uint32_t rtp_timestamp); 42 43 private: 44 Clock* clock_; 45 MovingMedianFilter<int64_t> ntp_clocks_offset_estimator_; 46 RtpToNtpEstimator rtp_to_ntp_; 47 int64_t last_timing_log_ms_; 48 RTC_DISALLOW_COPY_AND_ASSIGN(RemoteNtpTimeEstimator); 49 }; 50 51 } // namespace webrtc 52 53 #endif // MODULES_RTP_RTCP_INCLUDE_REMOTE_NTP_TIME_ESTIMATOR_H_ 54