| /* |
| * Copyright (c) 2021 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 MODULES_RTP_RTCP_SOURCE_CAPTURE_CLOCK_OFFSET_UPDATER_H_ |
| #define MODULES_RTP_RTCP_SOURCE_CAPTURE_CLOCK_OFFSET_UPDATER_H_ |
| |
| #include <stdint.h> |
| |
| #include <optional> |
| |
| #include "api/units/time_delta.h" |
| |
| namespace webrtc { |
| |
| // |
| // Helper class for calculating the clock offset against the capturer's clock. |
| // |
| // This is achieved by adjusting the estimated capture clock offset in received |
| // Absolute Capture Time RTP header extension (see |
| // https://webrtc.org/experiments/rtp-hdrext/abs-capture-time/), which |
| // represents the clock offset between a remote sender and the capturer, by |
| // adding local-to-remote clock offset. |
| |
| class CaptureClockOffsetUpdater { |
| public: |
| // Adjusts remote_capture_clock_offset, which originates from Absolute Capture |
| // Time RTP header extension, to get the local clock offset against the |
| // capturer's clock. |
| std::optional<int64_t> AdjustEstimatedCaptureClockOffset( |
| std::optional<int64_t> remote_capture_clock_offset) const; |
| |
| // Sets the NTP clock offset between the sender system (which may be different |
| // from the capture system) and the local system. This information is normally |
| // provided by passing half the value of the Round-Trip Time estimation given |
| // by RTCP sender reports (see DLSR/DLRR). |
| // |
| // Note that the value must be in Q32.32-formatted fixed-point seconds. |
| void SetRemoteToLocalClockOffset(std::optional<int64_t> offset_q32x32); |
| |
| // Converts a signed Q32.32-formatted fixed-point to a TimeDelta. |
| static std::optional<TimeDelta> ConvertsToTimeDela( |
| std::optional<int64_t> q32x32); |
| |
| private: |
| std::optional<int64_t> remote_to_local_clock_offset_; |
| }; |
| |
| } // namespace webrtc |
| |
| #endif // MODULES_RTP_RTCP_SOURCE_CAPTURE_CLOCK_OFFSET_UPDATER_H_ |