From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- .../inter_frame_delay_variation_calculator.cc | 71 ++++++++++++++++++++++ 1 file changed, 71 insertions(+) create mode 100644 third_party/libwebrtc/modules/video_coding/timing/inter_frame_delay_variation_calculator.cc (limited to 'third_party/libwebrtc/modules/video_coding/timing/inter_frame_delay_variation_calculator.cc') diff --git a/third_party/libwebrtc/modules/video_coding/timing/inter_frame_delay_variation_calculator.cc b/third_party/libwebrtc/modules/video_coding/timing/inter_frame_delay_variation_calculator.cc new file mode 100644 index 0000000000..69bc916199 --- /dev/null +++ b/third_party/libwebrtc/modules/video_coding/timing/inter_frame_delay_variation_calculator.cc @@ -0,0 +1,71 @@ +/* + * Copyright (c) 2011 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. + */ + +#include "modules/video_coding/timing/inter_frame_delay_variation_calculator.h" + +#include "absl/types/optional.h" +#include "api/units/frequency.h" +#include "api/units/time_delta.h" +#include "modules/include/module_common_types_public.h" + +namespace webrtc { + +namespace { +constexpr Frequency k90kHz = Frequency::KiloHertz(90); +} + +InterFrameDelayVariationCalculator::InterFrameDelayVariationCalculator() { + Reset(); +} + +void InterFrameDelayVariationCalculator::Reset() { + prev_wall_clock_ = absl::nullopt; + prev_rtp_timestamp_unwrapped_ = 0; +} + +absl::optional InterFrameDelayVariationCalculator::Calculate( + uint32_t rtp_timestamp, + Timestamp now) { + int64_t rtp_timestamp_unwrapped = unwrapper_.Unwrap(rtp_timestamp); + + if (!prev_wall_clock_) { + prev_wall_clock_ = now; + prev_rtp_timestamp_unwrapped_ = rtp_timestamp_unwrapped; + // Inter-frame delay variation is undefined for a single frame. + // TODO(brandtr): Should this return absl::nullopt instead? + return TimeDelta::Zero(); + } + + // Account for reordering in jitter variance estimate in the future? + // Note that this also captures incomplete frames which are grabbed for + // decoding after a later frame has been complete, i.e. real packet losses. + uint32_t cropped_prev = static_cast(prev_rtp_timestamp_unwrapped_); + if (rtp_timestamp_unwrapped < prev_rtp_timestamp_unwrapped_ || + !IsNewerTimestamp(rtp_timestamp, cropped_prev)) { + return absl::nullopt; + } + + // Compute the compensated timestamp difference. + TimeDelta delta_wall = now - *prev_wall_clock_; + int64_t d_rtp_ticks = rtp_timestamp_unwrapped - prev_rtp_timestamp_unwrapped_; + TimeDelta delta_rtp = d_rtp_ticks / k90kHz; + + // The inter-frame delay variation is the second order difference between the + // RTP and wall clocks of the two frames, or in other words, the first order + // difference between `delta_rtp` and `delta_wall`. + TimeDelta inter_frame_delay_variation = delta_wall - delta_rtp; + + prev_wall_clock_ = now; + prev_rtp_timestamp_unwrapped_ = rtp_timestamp_unwrapped; + + return inter_frame_delay_variation; +} + +} // namespace webrtc -- cgit v1.2.3