modules/rtp_rtcp/source/rtcp_packet/rrtr.cc

/*
 *  Copyright (c) 2015 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/rtp_rtcp/source/rtcp_packet/rrtr.h"

#include "modules/rtp_rtcp/source/byte_io.h"
#include "rtc_base/checks.h"

namespace webrtc {
namespace rtcp {
// Receiver Reference Time Report Block (RFC 3611).
//
//   0                   1                   2                   3
//   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//  |     BT=4      |   reserved    |       block length = 2        |
//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//  |              NTP timestamp, most significant word             |
//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//  |             NTP timestamp, least significant word             |
//  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

void Rrtr::Parse(const uint8_t* buffer) {
  RTC_DCHECK(buffer[0] == kBlockType);
  // reserved = buffer[1];
  RTC_DCHECK(ByteReader<uint16_t>::ReadBigEndian(&buffer[2]) == kBlockLength);
  uint32_t seconds = ByteReader<uint32_t>::ReadBigEndian(&buffer[4]);
  uint32_t fraction = ByteReader<uint32_t>::ReadBigEndian(&buffer[8]);
  ntp_.Set(seconds, fraction);
}

void Rrtr::Create(uint8_t* buffer) const {
  const uint8_t kReserved = 0;
  buffer[0] = kBlockType;
  buffer[1] = kReserved;
  ByteWriter<uint16_t>::WriteBigEndian(&buffer[2], kBlockLength);
  ByteWriter<uint32_t>::WriteBigEndian(&buffer[4], ntp_.seconds());
  ByteWriter<uint32_t>::WriteBigEndian(&buffer[8], ntp_.fractions());
}

}  // namespace rtcp
}  // namespace webrtc