Line data    Source code

       1             : /*
       2             :  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
       3             :  *
       4             :  *  Use of this source code is governed by a BSD-style license
       5             :  *  that can be found in the LICENSE file in the root of the source
       6             :  *  tree. An additional intellectual property rights grant can be found
       7             :  *  in the file PATENTS.  All contributing project authors may
       8             :  *  be found in the AUTHORS file in the root of the source tree.
       9             :  */
      10             : 
      11             : #include "webrtc/modules/rtp_rtcp/source/rtcp_packet/report_block.h"
      12             : 
      13             : #include "webrtc/base/checks.h"
      14             : #include "webrtc/base/logging.h"
      15             : #include "webrtc/modules/rtp_rtcp/source/byte_io.h"
      16             : 
      17             : namespace webrtc {
      18             : namespace rtcp {
      19             : 
      20             : // From RFC 3550, RTP: A Transport Protocol for Real-Time Applications.
      21             : //
      22             : // RTCP report block (RFC 3550).
      23             : //
      24             : //     0                   1                   2                   3
      25             : //     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
      26             : //    +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
      27             : //  0 |                 SSRC_1 (SSRC of first source)                 |
      28             : //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      29             : //  4 | fraction lost |       cumulative number of packets lost       |
      30             : //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      31             : //  8 |           extended highest sequence number received           |
      32             : //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      33             : // 12 |                      interarrival jitter                      |
      34             : //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      35             : // 16 |                         last SR (LSR)                         |
      36             : //    +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      37             : // 20 |                   delay since last SR (DLSR)                  |
      38             : // 24 +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
      39           0 : ReportBlock::ReportBlock()
      40             :     : source_ssrc_(0),
      41             :       fraction_lost_(0),
      42             :       cumulative_lost_(0),
      43             :       extended_high_seq_num_(0),
      44             :       jitter_(0),
      45             :       last_sr_(0),
      46           0 :       delay_since_last_sr_(0) {}
      47             : 
      48           0 : bool ReportBlock::Parse(const uint8_t* buffer, size_t length) {
      49           0 :   RTC_DCHECK(buffer != nullptr);
      50           0 :   if (length < ReportBlock::kLength) {
      51           0 :     LOG(LS_ERROR) << "Report Block should be 24 bytes long";
      52           0 :     return false;
      53             :   }
      54             : 
      55           0 :   source_ssrc_ = ByteReader<uint32_t>::ReadBigEndian(&buffer[0]);
      56           0 :   fraction_lost_ = buffer[4];
      57           0 :   cumulative_lost_ = ByteReader<uint32_t, 3>::ReadBigEndian(&buffer[5]);
      58           0 :   extended_high_seq_num_ = ByteReader<uint32_t>::ReadBigEndian(&buffer[8]);
      59           0 :   jitter_ = ByteReader<uint32_t>::ReadBigEndian(&buffer[12]);
      60           0 :   last_sr_ = ByteReader<uint32_t>::ReadBigEndian(&buffer[16]);
      61           0 :   delay_since_last_sr_ = ByteReader<uint32_t>::ReadBigEndian(&buffer[20]);
      62             : 
      63           0 :   return true;
      64             : }
      65             : 
      66           0 : void ReportBlock::Create(uint8_t* buffer) const {
      67             :   // Runtime check should be done while setting cumulative_lost.
      68           0 :   RTC_DCHECK_LT(cumulative_lost(), (1 << 24));  // Have only 3 bytes for it.
      69             : 
      70           0 :   ByteWriter<uint32_t>::WriteBigEndian(&buffer[0], source_ssrc());
      71           0 :   ByteWriter<uint8_t>::WriteBigEndian(&buffer[4], fraction_lost());
      72           0 :   ByteWriter<uint32_t, 3>::WriteBigEndian(&buffer[5], cumulative_lost());
      73           0 :   ByteWriter<uint32_t>::WriteBigEndian(&buffer[8], extended_high_seq_num());
      74           0 :   ByteWriter<uint32_t>::WriteBigEndian(&buffer[12], jitter());
      75           0 :   ByteWriter<uint32_t>::WriteBigEndian(&buffer[16], last_sr());
      76           0 :   ByteWriter<uint32_t>::WriteBigEndian(&buffer[20], delay_since_last_sr());
      77           0 : }
      78             : 
      79           0 : bool ReportBlock::SetCumulativeLost(uint32_t cumulative_lost) {
      80           0 :   if (cumulative_lost >= (1u << 24)) {  // Have only 3 bytes to store it.
      81           0 :     LOG(LS_WARNING) << "Cumulative lost is too big to fit into Report Block";
      82           0 :     return false;
      83             :   }
      84           0 :   cumulative_lost_ = cumulative_lost;
      85           0 :   return true;
      86             : }
      87             : 
      88             : }  // namespace rtcp
      89             : }  // namespace webrtc