From a897f26f1729699628426d47f6615f77f2399b94 Mon Sep 17 00:00:00 2001
From: danilchap <danilchap@webrtc.org>
Date: Fri, 26 Aug 2016 05:42:41 -0700
Subject: [PATCH] AbsoluteSendTime rtp header extension publish MsTo24Bit
 conversion Since this conversion is used in multiple place and extension
 seems right place to keep it in.

BUG=webrtc:1994
NOTRY=true

Review-Url: https://codereview.webrtc.org/2272563010
Cr-Commit-Position: refs/heads/master@{#13934}
---
 .../modules/rtp_rtcp/source/rtp_header_extensions.cc  | 11 +++--------
 .../modules/rtp_rtcp/source/rtp_header_extensions.h   |  6 +++++-
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc
index 441c548906..2d5dbf91b4 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc
+++ b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.cc
@@ -37,18 +37,13 @@ bool AbsoluteSendTime::IsSupportedFor(MediaType type) {
   return true;
 }
 
-bool AbsoluteSendTime::Parse(const uint8_t* data, uint32_t* value) {
-  *value = ByteReader<uint32_t, 3>::ReadBigEndian(data);
+bool AbsoluteSendTime::Parse(const uint8_t* data, uint32_t* time_24bits) {
+  *time_24bits = ByteReader<uint32_t, 3>::ReadBigEndian(data);
   return true;
 }
 
 bool AbsoluteSendTime::Write(uint8_t* data, int64_t time_ms) {
-  const uint32_t kAbsSendTimeFraction = 18;
-  uint32_t time_24_bits =
-      static_cast<uint32_t>(((time_ms << kAbsSendTimeFraction) + 500) / 1000) &
-      0x00FFFFFF;
-
-  ByteWriter<uint32_t, 3>::WriteBigEndian(data, time_24_bits);
+  ByteWriter<uint32_t, 3>::WriteBigEndian(data, MsTo24Bits(time_ms));
   return true;
 }
 
diff --git a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
index 116aaa6b93..4800a60c39 100644
--- a/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
+++ b/webrtc/modules/rtp_rtcp/source/rtp_header_extensions.h
@@ -23,8 +23,12 @@ class AbsoluteSendTime {
   static constexpr uint8_t kValueSizeBytes = 3;
   static const char* kName;
   static bool IsSupportedFor(MediaType type);
-  static bool Parse(const uint8_t* data, uint32_t* time_ms);
+  static bool Parse(const uint8_t* data, uint32_t* time_24bits);
   static bool Write(uint8_t* data, int64_t time_ms);
+
+  static constexpr uint32_t MsTo24Bits(int64_t time_ms) {
+    return static_cast<uint32_t>(((time_ms << 18) + 500) / 1000) & 0x00FFFFFF;
+  }
 };
 
 class AudioLevel {