xref: /aosp_15_r20/external/webrtc/modules/video_coding/timing/timestamp_extrapolator.h (revision d9f758449e529ab9291ac668be2861e7a55c2422)
1 /*
2  *  Copyright (c) 2011 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_VIDEO_CODING_TIMING_TIMESTAMP_EXTRAPOLATOR_H_
12 #define MODULES_VIDEO_CODING_TIMING_TIMESTAMP_EXTRAPOLATOR_H_
13 
14 #include <stdint.h>
15 
16 #include "absl/types/optional.h"
17 #include "api/units/timestamp.h"
18 #include "modules/include/module_common_types_public.h"
19 
20 namespace webrtc {
21 
22 // Not thread safe.
23 class TimestampExtrapolator {
24  public:
25   explicit TimestampExtrapolator(Timestamp start);
26   void Update(Timestamp now, uint32_t ts90khz);
27   absl::optional<Timestamp> ExtrapolateLocalTime(uint32_t timestamp90khz) const;
28   void Reset(Timestamp start);
29 
30  private:
31   void CheckForWrapArounds(uint32_t ts90khz);
32   bool DelayChangeDetection(double error);
33 
34   double w_[2];
35   double p_[2][2];
36   Timestamp start_;
37   Timestamp prev_;
38   absl::optional<int64_t> first_unwrapped_timestamp_;
39   TimestampUnwrapper unwrapper_;
40   absl::optional<int64_t> prev_unwrapped_timestamp_;
41   uint32_t packet_count_;
42   double detector_accumulator_pos_;
43   double detector_accumulator_neg_;
44 };
45 
46 }  // namespace webrtc
47 
48 #endif  // MODULES_VIDEO_CODING_TIMING_TIMESTAMP_EXTRAPOLATOR_H_
49