From 0efb8323d5957b824685b1e6b74229205aede25f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Olov=20Br=C3=A4ndstr=C3=B6m?= <brandstrom@google.com>
Date: Wed, 13 Sep 2023 19:18:07 +0200
Subject: [PATCH] Method for converting q32 to TimeDelta in capture clock
 offset updater
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In change https://webrtc-review.googlesource.com/c/src/+/319961, I changed a error. Also the same code will be added for video to enable Glass 2 Glass metric for Android. To me it make sense to add this method, and then change the audio code and video code to use it.

Bug: None
Change-Id: Id5d38c3bb8266213a93e67ceb82e88d65f29de53
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/320080
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Commit-Queue: Olov Brändström <brandstrom@google.com>
Cr-Commit-Position: refs/heads/main@{#40745}
---
 .../source/capture_clock_offset_updater.cc    | 10 +++++++++
 .../source/capture_clock_offset_updater.h     |  5 +++++
 .../capture_clock_offset_updater_unittest.cc  | 21 +++++++++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/modules/rtp_rtcp/source/capture_clock_offset_updater.cc b/modules/rtp_rtcp/source/capture_clock_offset_updater.cc
index a5b12cb422..ad935a94f0 100644
--- a/modules/rtp_rtcp/source/capture_clock_offset_updater.cc
+++ b/modules/rtp_rtcp/source/capture_clock_offset_updater.cc
@@ -10,6 +10,8 @@
 
 #include "modules/rtp_rtcp/source/capture_clock_offset_updater.h"
 
+#include "system_wrappers/include/ntp_time.h"
+
 namespace webrtc {
 
 absl::optional<int64_t>
@@ -25,6 +27,14 @@ CaptureClockOffsetUpdater::AdjustEstimatedCaptureClockOffset(
          static_cast<uint64_t>(*remote_to_local_clock_offset_);
 }
 
+absl::optional<TimeDelta> CaptureClockOffsetUpdater::ConvertsToTimeDela(
+    absl::optional<int64_t> q32x32) {
+  if (q32x32 == absl::nullopt) {
+    return absl::nullopt;
+  }
+  return TimeDelta::Millis(Q32x32ToInt64Ms(*q32x32));
+}
+
 void CaptureClockOffsetUpdater::SetRemoteToLocalClockOffset(
     absl::optional<int64_t> offset_q32x32) {
   remote_to_local_clock_offset_ = offset_q32x32;
diff --git a/modules/rtp_rtcp/source/capture_clock_offset_updater.h b/modules/rtp_rtcp/source/capture_clock_offset_updater.h
index 71d3eb4831..9b28848169 100644
--- a/modules/rtp_rtcp/source/capture_clock_offset_updater.h
+++ b/modules/rtp_rtcp/source/capture_clock_offset_updater.h
@@ -14,6 +14,7 @@
 #include <stdint.h>
 
 #include "absl/types/optional.h"
+#include "api/units/time_delta.h"
 
 namespace webrtc {
 
@@ -42,6 +43,10 @@ class CaptureClockOffsetUpdater {
   // Note that the value must be in Q32.32-formatted fixed-point seconds.
   void SetRemoteToLocalClockOffset(absl::optional<int64_t> offset_q32x32);
 
+  // Converts a signed Q32.32-formatted fixed-point to a TimeDelta.
+  static absl::optional<TimeDelta> ConvertsToTimeDela(
+      absl::optional<int64_t> q32x32);
+
  private:
   absl::optional<int64_t> remote_to_local_clock_offset_;
 };
diff --git a/modules/rtp_rtcp/source/capture_clock_offset_updater_unittest.cc b/modules/rtp_rtcp/source/capture_clock_offset_updater_unittest.cc
index 43e1dd1379..f6bea4ba96 100644
--- a/modules/rtp_rtcp/source/capture_clock_offset_updater_unittest.cc
+++ b/modules/rtp_rtcp/source/capture_clock_offset_updater_unittest.cc
@@ -55,4 +55,25 @@ TEST(AbsoluteCaptureTimeReceiverTest, EstimatedCaptureClockOffsetArithmetic) {
                                         *kRemoteToLocalClockOffset)));
 }
 
+TEST(AbsoluteCaptureTimeReceiverTest, ConvertClockOffset) {
+  constexpr TimeDelta kNegative = TimeDelta::Millis(-350);
+  constexpr int64_t kNegativeQ32x32 =
+      kNegative.ms() * (NtpTime::kFractionsPerSecond / 1000);
+  constexpr TimeDelta kPositive = TimeDelta::Millis(400);
+  constexpr int64_t kPositiveQ32x32 =
+      kPositive.ms() * (NtpTime::kFractionsPerSecond / 1000);
+  constexpr TimeDelta kEpsilon = TimeDelta::Millis(1);
+  absl::optional<TimeDelta> converted =
+      CaptureClockOffsetUpdater::ConvertsToTimeDela(kNegativeQ32x32);
+  EXPECT_GT(converted, kNegative - kEpsilon);
+  EXPECT_LT(converted, kNegative + kEpsilon);
+
+  converted = CaptureClockOffsetUpdater::ConvertsToTimeDela(kPositiveQ32x32);
+  EXPECT_GT(converted, kPositive - kEpsilon);
+  EXPECT_LT(converted, kPositive + kEpsilon);
+
+  EXPECT_FALSE(
+      CaptureClockOffsetUpdater::ConvertsToTimeDela(absl::nullopt).has_value());
+}
+
 }  // namespace webrtc