chromium/third_party/webrtc/rtc_base/timestamp_aligner.h

/*
 *  Copyright (c) 2016 The WebRTC Project Authors. All rights reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

#ifndef RTC_BASE_TIMESTAMP_ALIGNER_H_
#define RTC_BASE_TIMESTAMP_ALIGNER_H_

#include <stdint.h>

#include "rtc_base/system/rtc_export.h"
#include "rtc_base/time_utils.h"

namespace rtc {

// The TimestampAligner class helps translating timestamps of a capture system
// into the same timescale as is used by rtc::TimeMicros(). Some capture systems
// provide timestamps, which comes from the capturing hardware (camera or sound
// card) or stamped close to the capturing hardware. Such timestamps are more
// accurate (less jittery) than reading the system clock, but may have a
// different epoch and unknown clock drift. Frame timestamps in webrtc should
// use rtc::TimeMicros (system monotonic time), and this class provides a filter
// which lets us use the rtc::TimeMicros timescale, and at the same time take
// advantage of higher accuracy of the capturer's clock.

// This class is not thread safe, so all calls to it must be synchronized
// externally.
class RTC_EXPORT TimestampAligner { … };

}  // namespace rtc

#endif  // RTC_BASE_TIMESTAMP_ALIGNER_H_