Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 71 insertions, 0 deletions

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<TimeDelta> 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<uint32_t>(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