Use NtpTime in RtcpMeasurement instead of uint sec/uint frac.

webrtc/system_wrappers/source/rtp_to_ntp.cc

 /*
  *  Copyright (c) 2012 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 "webrtc/system_wrappers/include/rtp_to_ntp.h"
 
 #include "webrtc/base/logging.h"
 #include "webrtc/system_wrappers/include/clock.h"
 
 namespace webrtc {
 namespace {
+// Number of RTCP SR reports to use to map between RTP and NTP.
+const size_t kNumRtcpReportsToUse = 2;
+
 // Calculates the RTP timestamp frequency from two pairs of NTP/RTP timestamps.
 bool CalculateFrequency(int64_t rtcp_ntp_ms1,
                         uint32_t rtp_timestamp1,
                         int64_t rtcp_ntp_ms2,
                         uint32_t rtp_timestamp2,
                         double* frequency_khz) {
   if (rtcp_ntp_ms1 <= rtcp_ntp_ms2) {
     return false;
   }
   *frequency_khz = static_cast<double>(rtp_timestamp1 - rtp_timestamp2) /
@@ skipping 10 matching lines @@
   if (wraps < 0) {
     // Reordering, don't use this packet.
     return false;
   }
   *compensated_timestamp = new_timestamp + (wraps << 32);
   return true;
 }
 }  // namespace
 
 // Class holding RTP and NTP timestamp from a RTCP SR report.
-RtcpMeasurement::RtcpMeasurement()
-    : ntp_secs(0), ntp_frac(0), rtp_timestamp(0) {}
+RtcpMeasurement::RtcpMeasurement() : ntp_time(0, 0), rtp_timestamp(0) {}
 
 RtcpMeasurement::RtcpMeasurement(uint32_t ntp_secs,
                                  uint32_t ntp_frac,
                                  uint32_t timestamp)
-    : ntp_secs(ntp_secs), ntp_frac(ntp_frac), rtp_timestamp(timestamp) {}
+    : ntp_time(ntp_secs, ntp_frac), rtp_timestamp(timestamp) {}
 
 bool RtcpMeasurement::IsEqual(const RtcpMeasurement& other) const {
   // Use || since two equal timestamps will result in zero frequency and in
   // RtpToNtpMs, |rtp_timestamp_ms| is estimated by dividing by the frequency.
-  return (ntp_secs == other.ntp_secs && ntp_frac == other.ntp_frac) ||
-         (rtp_timestamp == other.rtp_timestamp);
+  return (ntp_time == other.ntp_time) || (rtp_timestamp == other.rtp_timestamp);
 }
 
 // Class holding list of RTP and NTP timestamp pairs.
 RtcpMeasurements::RtcpMeasurements() {}
 RtcpMeasurements::~RtcpMeasurements() {}
 
 bool RtcpMeasurements::Contains(const RtcpMeasurement& other) const {
   for (const auto& it : list) {
     if (it.IsEqual(other))
       return true;
   }
   return false;
 }
 
 bool RtcpMeasurements::IsValid(const RtcpMeasurement& other) const {
-  if (other.ntp_secs == 0 && other.ntp_frac == 0) {
-    // Invalid or not defined.
+  if (!other.ntp_time.Valid())
     return false;
-  }
-  int64_t ntp_ms_new = Clock::NtpToMs(other.ntp_secs, other.ntp_frac);
+
+  int64_t ntp_ms_new = other.ntp_time.ToMs();
   for (const auto& it : list) {
-    if (ntp_ms_new <= Clock::NtpToMs(it.ntp_secs, it.ntp_frac)) {
+    if (ntp_ms_new <= it.ntp_time.ToMs()) {
       // Old report.
       return false;
     }
     int64_t timestamp_new = other.rtp_timestamp;
     if (!CompensateForWrapAround(timestamp_new, it.rtp_timestamp,
                                  &timestamp_new)) {
       return false;
     }
     if (timestamp_new <= it.rtp_timestamp) {
       LOG(LS_WARNING) << "Newer RTCP SR report with older RTP timestamp.";
       return false;
     }
   }
   return true;
 }
 
 void RtcpMeasurements::UpdateParameters() {
-  if (list.size() != 2)
+  if (list.size() != kNumRtcpReportsToUse)
     return;
 
   int64_t timestamp_new = list.front().rtp_timestamp;
   int64_t timestamp_old = list.back().rtp_timestamp;
   if (!CompensateForWrapAround(timestamp_new, timestamp_old, &timestamp_new))
     return;
 
-  int64_t ntp_ms_new =
-      Clock::NtpToMs(list.front().ntp_secs, list.front().ntp_frac);
-  int64_t ntp_ms_old =
-      Clock::NtpToMs(list.back().ntp_secs, list.back().ntp_frac);
+  int64_t ntp_ms_new = list.front().ntp_time.ToMs();
+  int64_t ntp_ms_old = list.back().ntp_time.ToMs();
 
   if (!CalculateFrequency(ntp_ms_new, timestamp_new, ntp_ms_old, timestamp_old,
                           &params.frequency_khz)) {
     return;
   }
   params.offset_ms = timestamp_new - params.frequency_khz * ntp_ms_new;
   params.calculated = true;
 }
 
 // Updates list holding NTP and RTP timestamp pairs.
 bool UpdateRtcpList(uint32_t ntp_secs,
                     uint32_t ntp_frac,
                     uint32_t rtp_timestamp,
                     RtcpMeasurements* rtcp_measurements,
                     bool* new_rtcp_sr) {
   *new_rtcp_sr = false;
 
   RtcpMeasurement measurement(ntp_secs, ntp_frac, rtp_timestamp);
   if (rtcp_measurements->Contains(measurement)) {
     // RTCP SR report already added.
     return true;
   }
 
   if (!rtcp_measurements->IsValid(measurement)) {
     // Old report or invalid parameters.
     return false;
   }
 
-  // Two RTCP SR reports are needed to map between RTP and NTP.
-  // More than two will not improve the mapping.
-  if (rtcp_measurements->list.size() == 2)
+  // Insert new RTCP SR report.
+  if (rtcp_measurements->list.size() == kNumRtcpReportsToUse)
     rtcp_measurements->list.pop_back();
 
   rtcp_measurements->list.push_front(measurement);
   *new_rtcp_sr = true;
 
   // List updated, calculate new parameters.
   rtcp_measurements->UpdateParameters();
   return true;
 }
 
@@ skipping 36 matching lines @@
     }
   } else if (static_cast<int32_t>(old_timestamp - new_timestamp) > 0) {
     // This difference should be less than -2^31 if we have had a backward wrap
     // around. Since it is cast to a int32_t, it should be positive.
     return -1;
   }
   return 0;
 }
 
 }  // namespace webrtc