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