Make class of static functions in rtp_to_ntp.h:

webrtc/system_wrappers/source/rtp_to_ntp.cc

Index: webrtc/system_wrappers/source/rtp_to_ntp.cc
diff --git a/webrtc/system_wrappers/source/rtp_to_ntp.cc b/webrtc/system_wrappers/source/rtp_to_ntp.cc
deleted file mode 100644
index cbd5020a1f0fadf6247c0b7d114765a9c2710503..0000000000000000000000000000000000000000
--- a/webrtc/system_wrappers/source/rtp_to_ntp.cc
+++ /dev/null
@@ -1,195 +0,0 @@
-/*
- *  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) /
-      static_cast<double>(rtcp_ntp_ms1 - rtcp_ntp_ms2);
-  return true;
-}
-
-// Detects if there has been a wraparound between |old_timestamp| and
-// |new_timestamp|, and compensates by adding 2^32 if that is the case.
-bool CompensateForWrapAround(uint32_t new_timestamp,
-                             uint32_t old_timestamp,
-                             int64_t* compensated_timestamp) {
-  int64_t wraps = CheckForWrapArounds(new_timestamp, old_timestamp);
-  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_time(0, 0), rtp_timestamp(0) {}
-
-RtcpMeasurement::RtcpMeasurement(uint32_t ntp_secs,
-                                 uint32_t ntp_frac,
-                                 uint32_t 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_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_time.Valid())
-    return false;
-
-  int64_t ntp_ms_new = other.ntp_time.ToMs();
-  for (const auto& it : list) {
-    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() != 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 = 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;
-  }
-
-  // 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;
-}
-
-// Converts |rtp_timestamp| to the NTP time base using the NTP and RTP timestamp
-// pairs in |rtcp|. The converted timestamp is returned in
-// |rtp_timestamp_in_ms|. This function compensates for wrap arounds in RTP
-// timestamps and returns false if it can't do the conversion due to reordering.
-bool RtpToNtpMs(int64_t rtp_timestamp,
-                const RtcpMeasurements& rtcp,
-                int64_t* rtp_timestamp_in_ms) {
-  if (!rtcp.params.calculated || rtcp.list.empty())
-    return false;
-
-  uint32_t rtcp_timestamp_old = rtcp.list.back().rtp_timestamp;
-  int64_t rtp_timestamp_unwrapped;
-  if (!CompensateForWrapAround(rtp_timestamp, rtcp_timestamp_old,
-                               &rtp_timestamp_unwrapped)) {
-    return false;
-  }
-
-  double rtp_timestamp_ms =
-      (static_cast<double>(rtp_timestamp_unwrapped) - rtcp.params.offset_ms) /
-          rtcp.params.frequency_khz +
-      0.5f;
-  if (rtp_timestamp_ms < 0) {
-    return false;
-  }
-  *rtp_timestamp_in_ms = rtp_timestamp_ms;
-  return true;
-}
-
-int CheckForWrapArounds(uint32_t new_timestamp, uint32_t old_timestamp) {
-  if (new_timestamp < old_timestamp) {
-    // This difference should be less than -2^31 if we have had a wrap around
-    // (e.g. |new_timestamp| = 1, |rtcp_rtp_timestamp| = 2^32 - 1). Since it is
-    // cast to a int32_t, it should be positive.
-    if (static_cast<int32_t>(new_timestamp - old_timestamp) > 0) {
-      // Forward wrap around.
-      return 1;
-    }
-  } 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