33102745a0
Bug: webrtc:8468 Change-Id: Id9feb8e2c015f0a895a093d20caedae4a8b1337e Reviewed-on: https://webrtc-review.googlesource.com/29161 Reviewed-by: Erik Språng <sprang@webrtc.org> Reviewed-by: Per Kjellander <perkj@webrtc.org> Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org> Cr-Commit-Position: refs/heads/master@{#21075}
91 lines
3.1 KiB
C++
91 lines
3.1 KiB
C++
/*
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* Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#ifndef SYSTEM_WRAPPERS_INCLUDE_RTP_TO_NTP_ESTIMATOR_H_
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#define SYSTEM_WRAPPERS_INCLUDE_RTP_TO_NTP_ESTIMATOR_H_
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#include <list>
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#include "api/optional.h"
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#include "modules/include/module_common_types_public.h"
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#include "rtc_base/numerics/moving_median_filter.h"
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#include "system_wrappers/include/ntp_time.h"
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#include "typedefs.h" // NOLINT(build/include)
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namespace webrtc {
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// Class for converting an RTP timestamp to the NTP domain in milliseconds.
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// The class needs to be trained with (at least 2) RTP/NTP timestamp pairs from
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// RTCP sender reports before the convertion can be done.
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class RtpToNtpEstimator {
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public:
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RtpToNtpEstimator();
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~RtpToNtpEstimator();
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// RTP and NTP timestamp pair from a RTCP SR report.
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struct RtcpMeasurement {
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RtcpMeasurement(uint32_t ntp_secs,
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uint32_t ntp_frac,
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int64_t unwrapped_timestamp);
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bool IsEqual(const RtcpMeasurement& other) const;
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NtpTime ntp_time;
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int64_t unwrapped_rtp_timestamp;
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};
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// Estimated parameters from RTP and NTP timestamp pairs in |measurements_|.
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struct Parameters {
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// Implicit conversion from int because MovingMedianFilter returns 0
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// internally if no samples are present. However, it should never happen as
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// we don't ask smoothing_filter_ to return anything if there were no
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// samples.
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Parameters(const int& value) { // NOLINT
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RTC_NOTREACHED();
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}
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Parameters() : frequency_khz(0.0), offset_ms(0.0) {}
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double frequency_khz;
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double offset_ms;
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// Needed to make it work inside MovingMedianFilter
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bool operator<(const Parameters& other) const;
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bool operator==(const Parameters& other) const;
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bool operator<=(const Parameters& other) const;
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bool operator!=(const Parameters& other) const;
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};
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// Updates measurements with RTP/NTP timestamp pair from a RTCP sender report.
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// |new_rtcp_sr| is set to true if a new report is added.
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bool UpdateMeasurements(uint32_t ntp_secs,
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uint32_t ntp_frac,
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uint32_t rtp_timestamp,
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bool* new_rtcp_sr);
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// Converts an RTP timestamp to the NTP domain in milliseconds.
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// Returns true on success, false otherwise.
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bool Estimate(int64_t rtp_timestamp, int64_t* rtp_timestamp_ms) const;
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// Returns estimated rtp to ntp linear transform parameters.
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const rtc::Optional<Parameters> params() const;
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static const int kMaxInvalidSamples = 3;
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private:
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void UpdateParameters();
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int consecutive_invalid_samples_;
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std::list<RtcpMeasurement> measurements_;
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MovingMedianFilter<Parameters> smoothing_filter_;
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bool params_calculated_;
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mutable TimestampUnwrapper unwrapper_;
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};
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} // namespace webrtc
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#endif // SYSTEM_WRAPPERS_INCLUDE_RTP_TO_NTP_ESTIMATOR_H_
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