зеркало из https://github.com/mozilla/gecko-dev.git
64 строки
2.5 KiB
C++
64 строки
2.5 KiB
C++
/*
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* Copyright (c) 2018 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 CALL_RECEIVE_TIME_CALCULATOR_H_
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#define CALL_RECEIVE_TIME_CALCULATOR_H_
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#include <stdint.h>
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#include <memory>
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#include "api/field_trials_view.h"
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#include "api/units/time_delta.h"
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#include "rtc_base/experiments/field_trial_parser.h"
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namespace webrtc {
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struct ReceiveTimeCalculatorConfig {
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explicit ReceiveTimeCalculatorConfig(const FieldTrialsView& field_trials);
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ReceiveTimeCalculatorConfig(const ReceiveTimeCalculatorConfig&);
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ReceiveTimeCalculatorConfig& operator=(const ReceiveTimeCalculatorConfig&) =
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default;
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~ReceiveTimeCalculatorConfig();
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FieldTrialParameter<TimeDelta> max_packet_time_repair;
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FieldTrialParameter<TimeDelta> stall_threshold;
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FieldTrialParameter<TimeDelta> tolerance;
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FieldTrialParameter<TimeDelta> max_stall;
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};
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// The receive time calculator serves the purpose of combining packet time
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// stamps with a safely incremental clock. This assumes that the packet time
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// stamps are based on lower layer timestamps that have more accurate time
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// increments since they are based on the exact receive time. They might
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// however, have large jumps due to clock resets in the system. To compensate
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// this they are combined with a safe clock source that is guaranteed to be
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// consistent, but it will not be able to measure the exact time when a packet
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// is received.
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class ReceiveTimeCalculator {
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public:
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static std::unique_ptr<ReceiveTimeCalculator> CreateFromFieldTrial(
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const FieldTrialsView& field_trials);
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explicit ReceiveTimeCalculator(const FieldTrialsView& field_trials);
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int64_t ReconcileReceiveTimes(int64_t packet_time_us_,
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int64_t system_time_us_,
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int64_t safe_time_us_);
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private:
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int64_t last_corrected_time_us_ = -1;
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int64_t last_packet_time_us_ = -1;
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int64_t last_system_time_us_ = -1;
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int64_t last_safe_time_us_ = -1;
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int64_t total_system_time_passed_us_ = 0;
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int64_t static_clock_offset_us_ = 0;
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int64_t small_reset_during_stall_ = false;
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ReceiveTimeCalculatorConfig config_;
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};
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} // namespace webrtc
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#endif // CALL_RECEIVE_TIME_CALCULATOR_H_
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