blob: 6c1deb467ef787de5947df7d70ef4384c56204fd [file] [log] [blame]
/*
* 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/base/checks.h"
#include "webrtc/modules/rtp_rtcp/source/rtcp_utility.h"
#include "webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
#include <assert.h>
#include <math.h> // ceil
#include <string.h> // memcpy
#include "webrtc/base/checks.h"
#include "webrtc/base/logging.h"
#include "webrtc/modules/rtp_rtcp/source/byte_io.h"
namespace webrtc {
namespace RTCPUtility {
NackStats::NackStats()
: max_sequence_number_(0),
requests_(0),
unique_requests_(0) {}
NackStats::~NackStats() {}
void NackStats::ReportRequest(uint16_t sequence_number) {
if (requests_ == 0 ||
webrtc::IsNewerSequenceNumber(sequence_number, max_sequence_number_)) {
max_sequence_number_ = sequence_number;
++unique_requests_;
}
++requests_;
}
uint32_t MidNtp(uint32_t ntp_sec, uint32_t ntp_frac) {
return (ntp_sec << 16) + (ntp_frac >> 16);
} // end RTCPUtility
}
// RTCPParserV2 : currently read only
RTCPUtility::RTCPParserV2::RTCPParserV2(const uint8_t* rtcpData,
size_t rtcpDataLength,
bool rtcpReducedSizeEnable)
: _ptrRTCPDataBegin(rtcpData),
_RTCPReducedSizeEnable(rtcpReducedSizeEnable),
_ptrRTCPDataEnd(rtcpData + rtcpDataLength),
_validPacket(false),
_ptrRTCPData(rtcpData),
_ptrRTCPBlockEnd(NULL),
_state(ParseState::State_TopLevel),
_numberOfBlocks(0),
num_skipped_blocks_(0),
_packetType(RTCPPacketTypes::kInvalid) {
Validate();
}
RTCPUtility::RTCPParserV2::~RTCPParserV2() {
}
ptrdiff_t
RTCPUtility::RTCPParserV2::LengthLeft() const
{
return (_ptrRTCPDataEnd- _ptrRTCPData);
}
RTCPUtility::RTCPPacketTypes
RTCPUtility::RTCPParserV2::PacketType() const
{
return _packetType;
}
const RTCPUtility::RTCPPacket&
RTCPUtility::RTCPParserV2::Packet() const
{
return _packet;
}
rtcp::RtcpPacket* RTCPUtility::RTCPParserV2::ReleaseRtcpPacket() {
return rtcp_packet_.release();
}
RTCPUtility::RTCPPacketTypes
RTCPUtility::RTCPParserV2::Begin()
{
_ptrRTCPData = _ptrRTCPDataBegin;
return Iterate();
}
RTCPUtility::RTCPPacketTypes
RTCPUtility::RTCPParserV2::Iterate()
{
// Reset packet type
_packetType = RTCPPacketTypes::kInvalid;
if (IsValid())
{
switch (_state)
{
case ParseState::State_TopLevel:
IterateTopLevel();
break;
case ParseState::State_ReportBlockItem:
IterateReportBlockItem();
break;
case ParseState::State_SDESChunk:
IterateSDESChunk();
break;
case ParseState::State_BYEItem:
IterateBYEItem();
break;
case ParseState::State_ExtendedJitterItem:
IterateExtendedJitterItem();
break;
case ParseState::State_RTPFB_NACKItem:
IterateNACKItem();
break;
case ParseState::State_RTPFB_TMMBRItem:
IterateTMMBRItem();
break;
case ParseState::State_RTPFB_TMMBNItem:
IterateTMMBNItem();
break;
case ParseState::State_PSFB_SLIItem:
IterateSLIItem();
break;
case ParseState::State_PSFB_RPSIItem:
IterateRPSIItem();
break;
case ParseState::State_PSFB_FIRItem:
IterateFIRItem();
break;
case ParseState::State_PSFB_AppItem:
IteratePsfbAppItem();
break;
case ParseState::State_PSFB_REMBItem:
IteratePsfbREMBItem();
break;
case ParseState::State_XRItem:
IterateXrItem();
break;
case ParseState::State_XR_DLLRItem:
IterateXrDlrrItem();
break;
case ParseState::State_AppItem:
IterateAppItem();
break;
default:
RTC_NOTREACHED() << "Invalid state!";
break;
}
}
return _packetType;
}
void
RTCPUtility::RTCPParserV2::IterateTopLevel()
{
for (;;)
{
RtcpCommonHeader header;
if (_ptrRTCPDataEnd <= _ptrRTCPData)
return;
if (!RtcpParseCommonHeader(_ptrRTCPData, _ptrRTCPDataEnd - _ptrRTCPData,
&header)) {
return;
}
_ptrRTCPBlockEnd = _ptrRTCPData + header.BlockSize();
if (_ptrRTCPBlockEnd > _ptrRTCPDataEnd)
{
++num_skipped_blocks_;
return;
}
switch (header.packet_type) {
case PT_SR:
{
// number of Report blocks
_numberOfBlocks = header.count_or_format;
ParseSR();
return;
}
case PT_RR:
{
// number of Report blocks
_numberOfBlocks = header.count_or_format;
ParseRR();
return;
}
case PT_SDES:
{
// number of SDES blocks
_numberOfBlocks = header.count_or_format;
const bool ok = ParseSDES();
if (!ok)
{
// Nothing supported found, continue to next block!
break;
}
return;
}
case PT_BYE:
{
_numberOfBlocks = header.count_or_format;
const bool ok = ParseBYE();
if (!ok)
{
// Nothing supported found, continue to next block!
break;
}
return;
}
case PT_IJ:
{
// number of Report blocks
_numberOfBlocks = header.count_or_format;
ParseIJ();
return;
}
case PT_RTPFB:
FALLTHROUGH();
case PT_PSFB:
{
if (!ParseFBCommon(header)) {
// Nothing supported found, continue to next block!
break;
}
return;
}
case PT_APP:
{
const bool ok = ParseAPP(header);
if (!ok)
{
// Nothing supported found, continue to next block!
break;
}
return;
}
case PT_XR:
{
const bool ok = ParseXr();
if (!ok)
{
// Nothing supported found, continue to next block!
break;
}
return;
}
default:
// Not supported! Skip!
++num_skipped_blocks_;
EndCurrentBlock();
break;
}
}
}
void
RTCPUtility::RTCPParserV2::IterateXrItem()
{
const bool success = ParseXrItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateXrDlrrItem()
{
const bool success = ParseXrDlrrItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateReportBlockItem()
{
const bool success = ParseReportBlockItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateSDESChunk()
{
const bool success = ParseSDESChunk();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateBYEItem()
{
const bool success = ParseBYEItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateExtendedJitterItem()
{
const bool success = ParseIJItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateNACKItem()
{
const bool success = ParseNACKItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateTMMBRItem()
{
const bool success = ParseTMMBRItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateTMMBNItem()
{
const bool success = ParseTMMBNItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateSLIItem()
{
const bool success = ParseSLIItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateRPSIItem()
{
const bool success = ParseRPSIItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateFIRItem()
{
const bool success = ParseFIRItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IteratePsfbAppItem()
{
const bool success = ParsePsfbAppItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IteratePsfbREMBItem()
{
const bool success = ParsePsfbREMBItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::IterateAppItem()
{
const bool success = ParseAPPItem();
if (!success)
{
Iterate();
}
}
void
RTCPUtility::RTCPParserV2::Validate()
{
if (_ptrRTCPData == nullptr)
return; // NOT VALID
RtcpCommonHeader header;
if (_ptrRTCPDataEnd <= _ptrRTCPDataBegin)
return; // NOT VALID
if (!RtcpParseCommonHeader(_ptrRTCPDataBegin,
_ptrRTCPDataEnd - _ptrRTCPDataBegin, &header))
return; // NOT VALID!
// * if (!reducedSize) : first packet must be RR or SR.
//
// * The padding bit (P) should be zero for the first packet of a
// compound RTCP packet because padding should only be applied,
// if it is needed, to the last packet. (NOT CHECKED!)
//
// * The length fields of the individual RTCP packets must add up
// to the overall length of the compound RTCP packet as
// received. This is a fairly strong check. (NOT CHECKED!)
if (!_RTCPReducedSizeEnable)
{
if ((header.packet_type != PT_SR) && (header.packet_type != PT_RR)) {
return; // NOT VALID
}
}
_validPacket = true;
}
bool
RTCPUtility::RTCPParserV2::IsValid() const
{
return _validPacket;
}
void
RTCPUtility::RTCPParserV2::EndCurrentBlock()
{
_ptrRTCPData = _ptrRTCPBlockEnd;
}
// 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
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// |V=2|P| IC | PT | length |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
//
// Common header for all RTCP packets, 4 octets.
bool RTCPUtility::RtcpParseCommonHeader(const uint8_t* packet,
size_t size_bytes,
RtcpCommonHeader* parsed_header) {
RTC_DCHECK(parsed_header != nullptr);
if (size_bytes < RtcpCommonHeader::kHeaderSizeBytes) {
LOG(LS_WARNING) << "Too little data (" << size_bytes << " byte"
<< (size_bytes != 1 ? "s" : "")
<< ") remaining in buffer to parse RTCP header (4 bytes).";
return false;
}
const uint8_t kRtcpVersion = 2;
uint8_t version = packet[0] >> 6;
if (version != kRtcpVersion) {
LOG(LS_WARNING) << "Invalid RTCP header: Version must be "
<< static_cast<int>(kRtcpVersion) << " but was "
<< static_cast<int>(version);
return false;
}
bool has_padding = (packet[0] & 0x20) != 0;
uint8_t format = packet[0] & 0x1F;
uint8_t packet_type = packet[1];
size_t packet_size_words =
ByteReader<uint16_t>::ReadBigEndian(&packet[2]) + 1;
if (size_bytes < packet_size_words * 4) {
LOG(LS_WARNING) << "Buffer too small (" << size_bytes
<< " bytes) to fit an RtcpPacket of " << packet_size_words
<< " 32bit words.";
return false;
}
size_t payload_size = packet_size_words * 4;
size_t padding_bytes = 0;
if (has_padding) {
if (payload_size <= RtcpCommonHeader::kHeaderSizeBytes) {
LOG(LS_WARNING) << "Invalid RTCP header: Padding bit set but 0 payload "
"size specified.";
return false;
}
padding_bytes = packet[payload_size - 1];
if (RtcpCommonHeader::kHeaderSizeBytes + padding_bytes > payload_size) {
LOG(LS_WARNING) << "Invalid RTCP header: Too many padding bytes ("
<< padding_bytes << ") for a packet size of "
<< payload_size << "bytes.";
return false;
}
payload_size -= padding_bytes;
}
payload_size -= RtcpCommonHeader::kHeaderSizeBytes;
parsed_header->version = kRtcpVersion;
parsed_header->count_or_format = format;
parsed_header->packet_type = packet_type;
parsed_header->payload_size_bytes = payload_size;
parsed_header->padding_bytes = padding_bytes;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseRR()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 8)
{
return false;
}
_ptrRTCPData += 4; // Skip header
_packetType = RTCPPacketTypes::kRr;
_packet.RR.SenderSSRC = *_ptrRTCPData++ << 24;
_packet.RR.SenderSSRC += *_ptrRTCPData++ << 16;
_packet.RR.SenderSSRC += *_ptrRTCPData++ << 8;
_packet.RR.SenderSSRC += *_ptrRTCPData++;
_packet.RR.NumberOfReportBlocks = _numberOfBlocks;
// State transition
_state = ParseState::State_ReportBlockItem;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseSR()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 28)
{
EndCurrentBlock();
return false;
}
_ptrRTCPData += 4; // Skip header
_packetType = RTCPPacketTypes::kSr;
_packet.SR.SenderSSRC = *_ptrRTCPData++ << 24;
_packet.SR.SenderSSRC += *_ptrRTCPData++ << 16;
_packet.SR.SenderSSRC += *_ptrRTCPData++ << 8;
_packet.SR.SenderSSRC += *_ptrRTCPData++;
_packet.SR.NTPMostSignificant = *_ptrRTCPData++ << 24;
_packet.SR.NTPMostSignificant += *_ptrRTCPData++ << 16;
_packet.SR.NTPMostSignificant += *_ptrRTCPData++ << 8;
_packet.SR.NTPMostSignificant += *_ptrRTCPData++;
_packet.SR.NTPLeastSignificant = *_ptrRTCPData++ << 24;
_packet.SR.NTPLeastSignificant += *_ptrRTCPData++ << 16;
_packet.SR.NTPLeastSignificant += *_ptrRTCPData++ << 8;
_packet.SR.NTPLeastSignificant += *_ptrRTCPData++;
_packet.SR.RTPTimestamp = *_ptrRTCPData++ << 24;
_packet.SR.RTPTimestamp += *_ptrRTCPData++ << 16;
_packet.SR.RTPTimestamp += *_ptrRTCPData++ << 8;
_packet.SR.RTPTimestamp += *_ptrRTCPData++;
_packet.SR.SenderPacketCount = *_ptrRTCPData++ << 24;
_packet.SR.SenderPacketCount += *_ptrRTCPData++ << 16;
_packet.SR.SenderPacketCount += *_ptrRTCPData++ << 8;
_packet.SR.SenderPacketCount += *_ptrRTCPData++;
_packet.SR.SenderOctetCount = *_ptrRTCPData++ << 24;
_packet.SR.SenderOctetCount += *_ptrRTCPData++ << 16;
_packet.SR.SenderOctetCount += *_ptrRTCPData++ << 8;
_packet.SR.SenderOctetCount += *_ptrRTCPData++;
_packet.SR.NumberOfReportBlocks = _numberOfBlocks;
// State transition
if(_numberOfBlocks != 0)
{
_state = ParseState::State_ReportBlockItem;
}else
{
// don't go to state report block item if 0 report blocks
_state = ParseState::State_TopLevel;
EndCurrentBlock();
}
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseReportBlockItem()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 24 || _numberOfBlocks <= 0)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packet.ReportBlockItem.SSRC = *_ptrRTCPData++ << 24;
_packet.ReportBlockItem.SSRC += *_ptrRTCPData++ << 16;
_packet.ReportBlockItem.SSRC += *_ptrRTCPData++ << 8;
_packet.ReportBlockItem.SSRC += *_ptrRTCPData++;
_packet.ReportBlockItem.FractionLost = *_ptrRTCPData++;
_packet.ReportBlockItem.CumulativeNumOfPacketsLost = *_ptrRTCPData++ << 16;
_packet.ReportBlockItem.CumulativeNumOfPacketsLost += *_ptrRTCPData++ << 8;
_packet.ReportBlockItem.CumulativeNumOfPacketsLost += *_ptrRTCPData++;
_packet.ReportBlockItem.ExtendedHighestSequenceNumber = *_ptrRTCPData++ << 24;
_packet.ReportBlockItem.ExtendedHighestSequenceNumber += *_ptrRTCPData++ << 16;
_packet.ReportBlockItem.ExtendedHighestSequenceNumber += *_ptrRTCPData++ << 8;
_packet.ReportBlockItem.ExtendedHighestSequenceNumber += *_ptrRTCPData++;
_packet.ReportBlockItem.Jitter = *_ptrRTCPData++ << 24;
_packet.ReportBlockItem.Jitter += *_ptrRTCPData++ << 16;
_packet.ReportBlockItem.Jitter += *_ptrRTCPData++ << 8;
_packet.ReportBlockItem.Jitter += *_ptrRTCPData++;
_packet.ReportBlockItem.LastSR = *_ptrRTCPData++ << 24;
_packet.ReportBlockItem.LastSR += *_ptrRTCPData++ << 16;
_packet.ReportBlockItem.LastSR += *_ptrRTCPData++ << 8;
_packet.ReportBlockItem.LastSR += *_ptrRTCPData++;
_packet.ReportBlockItem.DelayLastSR = *_ptrRTCPData++ << 24;
_packet.ReportBlockItem.DelayLastSR += *_ptrRTCPData++ << 16;
_packet.ReportBlockItem.DelayLastSR += *_ptrRTCPData++ << 8;
_packet.ReportBlockItem.DelayLastSR += *_ptrRTCPData++;
_numberOfBlocks--;
_packetType = RTCPPacketTypes::kReportBlockItem;
return true;
}
/* From RFC 5450: Transmission Time Offsets in RTP Streams.
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
hdr |V=2|P| RC | PT=IJ=195 | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| inter-arrival jitter |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. .
. .
. .
| inter-arrival jitter |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
bool
RTCPUtility::RTCPParserV2::ParseIJ()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 4)
{
return false;
}
_ptrRTCPData += 4; // Skip header
_packetType = RTCPPacketTypes::kExtendedIj;
// State transition
_state = ParseState::State_ExtendedJitterItem;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseIJItem()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 4 || _numberOfBlocks <= 0)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packet.ExtendedJitterReportItem.Jitter = *_ptrRTCPData++ << 24;
_packet.ExtendedJitterReportItem.Jitter += *_ptrRTCPData++ << 16;
_packet.ExtendedJitterReportItem.Jitter += *_ptrRTCPData++ << 8;
_packet.ExtendedJitterReportItem.Jitter += *_ptrRTCPData++;
_numberOfBlocks--;
_packetType = RTCPPacketTypes::kExtendedIjItem;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseSDES()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 8)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_ptrRTCPData += 4; // Skip header
_state = ParseState::State_SDESChunk;
_packetType = RTCPPacketTypes::kSdes;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseSDESChunk()
{
if(_numberOfBlocks <= 0)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_numberOfBlocks--;
// Find CName item in a SDES chunk.
while (_ptrRTCPData < _ptrRTCPBlockEnd)
{
const ptrdiff_t dataLen = _ptrRTCPBlockEnd - _ptrRTCPData;
if (dataLen < 4)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
uint32_t SSRC = *_ptrRTCPData++ << 24;
SSRC += *_ptrRTCPData++ << 16;
SSRC += *_ptrRTCPData++ << 8;
SSRC += *_ptrRTCPData++;
const bool foundCname = ParseSDESItem();
if (foundCname)
{
_packet.CName.SenderSSRC = SSRC; // Add SSRC
return true;
}
}
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
bool
RTCPUtility::RTCPParserV2::ParseSDESItem()
{
// Find CName
// Only the CNAME item is mandatory. RFC 3550 page 46
bool foundCName = false;
size_t itemOctetsRead = 0;
while (_ptrRTCPData < _ptrRTCPBlockEnd)
{
const uint8_t tag = *_ptrRTCPData++;
++itemOctetsRead;
if (tag == 0)
{
// End tag! 4 oct aligned
while ((itemOctetsRead++ % 4) != 0)
{
++_ptrRTCPData;
}
return foundCName;
}
if (_ptrRTCPData < _ptrRTCPBlockEnd)
{
const uint8_t len = *_ptrRTCPData++;
++itemOctetsRead;
if (tag == 1)
{
// CNAME
// Sanity
if ((_ptrRTCPData + len) >= _ptrRTCPBlockEnd)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
uint8_t i = 0;
for (; i < len; ++i)
{
const uint8_t c = _ptrRTCPData[i];
if ((c < ' ') || (c > '{') || (c == '%') || (c == '\\'))
{
// Illegal char
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packet.CName.CName[i] = c;
}
// Make sure we are null terminated.
_packet.CName.CName[i] = 0;
_packetType = RTCPPacketTypes::kSdesChunk;
foundCName = true;
}
_ptrRTCPData += len;
itemOctetsRead += len;
}
}
// No end tag found!
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
bool
RTCPUtility::RTCPParserV2::ParseBYE()
{
_ptrRTCPData += 4; // Skip header
_state = ParseState::State_BYEItem;
return ParseBYEItem();
}
bool
RTCPUtility::RTCPParserV2::ParseBYEItem()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 4 || _numberOfBlocks == 0)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kBye;
_packet.BYE.SenderSSRC = *_ptrRTCPData++ << 24;
_packet.BYE.SenderSSRC += *_ptrRTCPData++ << 16;
_packet.BYE.SenderSSRC += *_ptrRTCPData++ << 8;
_packet.BYE.SenderSSRC += *_ptrRTCPData++;
// we can have several CSRCs attached
// sanity
if(length >= 4*_numberOfBlocks)
{
_ptrRTCPData += (_numberOfBlocks -1)*4;
}
_numberOfBlocks = 0;
return true;
}
/*
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|V=2|P|reserved | PT=XR=207 | length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: report blocks :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
bool RTCPUtility::RTCPParserV2::ParseXr()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 8)
{
EndCurrentBlock();
return false;
}
_ptrRTCPData += 4; // Skip header
_packet.XR.OriginatorSSRC = *_ptrRTCPData++ << 24;
_packet.XR.OriginatorSSRC += *_ptrRTCPData++ << 16;
_packet.XR.OriginatorSSRC += *_ptrRTCPData++ << 8;
_packet.XR.OriginatorSSRC += *_ptrRTCPData++;
_packetType = RTCPPacketTypes::kXrHeader;
_state = ParseState::State_XRItem;
return true;
}
/* Extended report block format (RFC 3611).
BT: block type.
block length: length of report block in 32-bits words minus one (including
the header).
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 | type-specific | block length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
: type-specific block contents :
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
bool RTCPUtility::RTCPParserV2::ParseXrItem() {
const int kBlockHeaderLengthInBytes = 4;
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < kBlockHeaderLengthInBytes) {
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
uint8_t block_type = *_ptrRTCPData++;
_ptrRTCPData++; // Ignore reserved.
uint16_t block_length_in_4bytes = *_ptrRTCPData++ << 8;
block_length_in_4bytes += *_ptrRTCPData++;
switch (block_type) {
case kBtReceiverReferenceTime:
return ParseXrReceiverReferenceTimeItem(block_length_in_4bytes);
case kBtDlrr:
return ParseXrDlrr(block_length_in_4bytes);
case kBtVoipMetric:
return ParseXrVoipMetricItem(block_length_in_4bytes);
default:
return ParseXrUnsupportedBlockType(block_length_in_4bytes);
}
}
/* Receiver Reference Time Report Block.
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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
bool RTCPUtility::RTCPParserV2::ParseXrReceiverReferenceTimeItem(
int block_length_4bytes) {
const int kBlockLengthIn4Bytes = 2;
const int kBlockLengthInBytes = kBlockLengthIn4Bytes * 4;
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (block_length_4bytes != kBlockLengthIn4Bytes ||
length < kBlockLengthInBytes) {
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packet.XRReceiverReferenceTimeItem.NTPMostSignificant = *_ptrRTCPData++<<24;
_packet.XRReceiverReferenceTimeItem.NTPMostSignificant+= *_ptrRTCPData++<<16;
_packet.XRReceiverReferenceTimeItem.NTPMostSignificant+= *_ptrRTCPData++<<8;
_packet.XRReceiverReferenceTimeItem.NTPMostSignificant+= *_ptrRTCPData++;
_packet.XRReceiverReferenceTimeItem.NTPLeastSignificant = *_ptrRTCPData++<<24;
_packet.XRReceiverReferenceTimeItem.NTPLeastSignificant+= *_ptrRTCPData++<<16;
_packet.XRReceiverReferenceTimeItem.NTPLeastSignificant+= *_ptrRTCPData++<<8;
_packet.XRReceiverReferenceTimeItem.NTPLeastSignificant+= *_ptrRTCPData++;
_packetType = RTCPPacketTypes::kXrReceiverReferenceTime;
_state = ParseState::State_XRItem;
return true;
}
/* DLRR Report Block.
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=5 | reserved | block length |
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
| SSRC_1 (SSRC of first receiver) | sub-
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ block
| last RR (LRR) | 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| delay since last RR (DLRR) |
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
| SSRC_2 (SSRC of second receiver) | sub-
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ block
: ... : 2
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
*/
bool RTCPUtility::RTCPParserV2::ParseXrDlrr(int block_length_4bytes) {
const int kSubBlockLengthIn4Bytes = 3;
if (block_length_4bytes < 0 ||
(block_length_4bytes % kSubBlockLengthIn4Bytes) != 0) {
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kXrDlrrReportBlock;
_state = ParseState::State_XR_DLLRItem;
_numberOfBlocks = block_length_4bytes / kSubBlockLengthIn4Bytes;
return true;
}
bool RTCPUtility::RTCPParserV2::ParseXrDlrrItem() {
if (_numberOfBlocks == 0) {
_state = ParseState::State_XRItem;
return false;
}
const int kSubBlockLengthInBytes = 12;
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < kSubBlockLengthInBytes) {
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packet.XRDLRRReportBlockItem.SSRC = *_ptrRTCPData++ << 24;
_packet.XRDLRRReportBlockItem.SSRC += *_ptrRTCPData++ << 16;
_packet.XRDLRRReportBlockItem.SSRC += *_ptrRTCPData++ << 8;
_packet.XRDLRRReportBlockItem.SSRC += *_ptrRTCPData++;
_packet.XRDLRRReportBlockItem.LastRR = *_ptrRTCPData++ << 24;
_packet.XRDLRRReportBlockItem.LastRR += *_ptrRTCPData++ << 16;
_packet.XRDLRRReportBlockItem.LastRR += *_ptrRTCPData++ << 8;
_packet.XRDLRRReportBlockItem.LastRR += *_ptrRTCPData++;
_packet.XRDLRRReportBlockItem.DelayLastRR = *_ptrRTCPData++ << 24;
_packet.XRDLRRReportBlockItem.DelayLastRR += *_ptrRTCPData++ << 16;
_packet.XRDLRRReportBlockItem.DelayLastRR += *_ptrRTCPData++ << 8;
_packet.XRDLRRReportBlockItem.DelayLastRR += *_ptrRTCPData++;
_packetType = RTCPPacketTypes::kXrDlrrReportBlockItem;
--_numberOfBlocks;
_state = ParseState::State_XR_DLLRItem;
return true;
}
/* VoIP Metrics Report Block.
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=7 | reserved | block length = 8 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| SSRC of source |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| loss rate | discard rate | burst density | gap density |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| burst duration | gap duration |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| round trip delay | end system delay |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| signal level | noise level | RERL | Gmin |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| R factor | ext. R factor | MOS-LQ | MOS-CQ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| RX config | reserved | JB nominal |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| JB maximum | JB abs max |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
bool RTCPUtility::RTCPParserV2::ParseXrVoipMetricItem(int block_length_4bytes) {
const int kBlockLengthIn4Bytes = 8;
const int kBlockLengthInBytes = kBlockLengthIn4Bytes * 4;
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (block_length_4bytes != kBlockLengthIn4Bytes ||
length < kBlockLengthInBytes) {
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packet.XRVOIPMetricItem.SSRC = *_ptrRTCPData++ << 24;
_packet.XRVOIPMetricItem.SSRC += *_ptrRTCPData++ << 16;
_packet.XRVOIPMetricItem.SSRC += *_ptrRTCPData++ << 8;
_packet.XRVOIPMetricItem.SSRC += *_ptrRTCPData++;
_packet.XRVOIPMetricItem.lossRate = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.discardRate = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.burstDensity = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.gapDensity = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.burstDuration = *_ptrRTCPData++ << 8;
_packet.XRVOIPMetricItem.burstDuration += *_ptrRTCPData++;
_packet.XRVOIPMetricItem.gapDuration = *_ptrRTCPData++ << 8;
_packet.XRVOIPMetricItem.gapDuration += *_ptrRTCPData++;
_packet.XRVOIPMetricItem.roundTripDelay = *_ptrRTCPData++ << 8;
_packet.XRVOIPMetricItem.roundTripDelay += *_ptrRTCPData++;
_packet.XRVOIPMetricItem.endSystemDelay = *_ptrRTCPData++ << 8;
_packet.XRVOIPMetricItem.endSystemDelay += *_ptrRTCPData++;
_packet.XRVOIPMetricItem.signalLevel = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.noiseLevel = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.RERL = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.Gmin = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.Rfactor = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.extRfactor = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.MOSLQ = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.MOSCQ = *_ptrRTCPData++;
_packet.XRVOIPMetricItem.RXconfig = *_ptrRTCPData++;
_ptrRTCPData++; // skip reserved
_packet.XRVOIPMetricItem.JBnominal = *_ptrRTCPData++ << 8;
_packet.XRVOIPMetricItem.JBnominal += *_ptrRTCPData++;
_packet.XRVOIPMetricItem.JBmax = *_ptrRTCPData++ << 8;
_packet.XRVOIPMetricItem.JBmax += *_ptrRTCPData++;
_packet.XRVOIPMetricItem.JBabsMax = *_ptrRTCPData++ << 8;
_packet.XRVOIPMetricItem.JBabsMax += *_ptrRTCPData++;
_packetType = RTCPPacketTypes::kXrVoipMetric;
_state = ParseState::State_XRItem;
return true;
}
bool RTCPUtility::RTCPParserV2::ParseXrUnsupportedBlockType(
int block_length_4bytes) {
const int32_t kBlockLengthInBytes = block_length_4bytes * 4;
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < kBlockLengthInBytes) {
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
// Skip block.
_ptrRTCPData += kBlockLengthInBytes;
_state = ParseState::State_XRItem;
return false;
}
bool RTCPUtility::RTCPParserV2::ParseFBCommon(const RtcpCommonHeader& header) {
RTC_CHECK((header.packet_type == PT_RTPFB) ||
(header.packet_type == PT_PSFB)); // Parser logic check
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
// 4 * 3, RFC4585 section 6.1
if (length < 12) {
LOG(LS_WARNING)
<< "Invalid RTCP packet: Too little data (" << length
<< " bytes) left in buffer to parse a 12 byte RTPFB/PSFB message.";
return false;
}
_ptrRTCPData += 4; // Skip RTCP header
uint32_t senderSSRC = ByteReader<uint32_t>::ReadBigEndian(_ptrRTCPData);
_ptrRTCPData += 4;
uint32_t mediaSSRC = ByteReader<uint32_t>::ReadBigEndian(_ptrRTCPData);
_ptrRTCPData += 4;
if (header.packet_type == PT_RTPFB) {
// Transport layer feedback
switch (header.count_or_format) {
case 1:
{
// NACK
_packetType = RTCPPacketTypes::kRtpfbNack;
_packet.NACK.SenderSSRC = senderSSRC;
_packet.NACK.MediaSSRC = mediaSSRC;
_state = ParseState::State_RTPFB_NACKItem;
return true;
}
case 3:
{
// TMMBR
_packetType = RTCPPacketTypes::kRtpfbTmmbr;
_packet.TMMBR.SenderSSRC = senderSSRC;
_packet.TMMBR.MediaSSRC = mediaSSRC;
_state = ParseState::State_RTPFB_TMMBRItem;
return true;
}
case 4:
{
// TMMBN
_packetType = RTCPPacketTypes::kRtpfbTmmbn;
_packet.TMMBN.SenderSSRC = senderSSRC;
_packet.TMMBN.MediaSSRC = mediaSSRC;
_state = ParseState::State_RTPFB_TMMBNItem;
return true;
}
case 5:
{
// RTCP-SR-REQ Rapid Synchronisation of RTP Flows
// draft-perkins-avt-rapid-rtp-sync-03.txt
// trigger a new RTCP SR
_packetType = RTCPPacketTypes::kRtpfbSrReq;
// Note: No state transition, SR REQ is empty!
return true;
}
case 15: {
_packetType = RTCPPacketTypes::kTransportFeedback;
rtcp_packet_ =
rtcp::TransportFeedback::ParseFrom(_ptrRTCPData - 12, length);
// Since we parse the whole packet here, keep the TopLevel state and
// just end the current block.
if (rtcp_packet_.get()) {
EndCurrentBlock();
return true;
}
break;
}
default:
break;
}
// Unsupported RTPFB message. Skip and move to next block.
++num_skipped_blocks_;
return false;
} else if (header.packet_type == PT_PSFB) {
// Payload specific feedback
switch (header.count_or_format) {
case 1:
// PLI
_packetType = RTCPPacketTypes::kPsfbPli;
_packet.PLI.SenderSSRC = senderSSRC;
_packet.PLI.MediaSSRC = mediaSSRC;
// Note: No state transition, PLI FCI is empty!
return true;
case 2:
// SLI
_packetType = RTCPPacketTypes::kPsfbSli;
_packet.SLI.SenderSSRC = senderSSRC;
_packet.SLI.MediaSSRC = mediaSSRC;
_state = ParseState::State_PSFB_SLIItem;
return true;
case 3:
_packetType = RTCPPacketTypes::kPsfbRpsi;
_packet.RPSI.SenderSSRC = senderSSRC;
_packet.RPSI.MediaSSRC = mediaSSRC;
_state = ParseState::State_PSFB_RPSIItem;
return true;
case 4:
// FIR
_packetType = RTCPPacketTypes::kPsfbFir;
_packet.FIR.SenderSSRC = senderSSRC;
_packet.FIR.MediaSSRC = mediaSSRC;
_state = ParseState::State_PSFB_FIRItem;
return true;
case 15:
_packetType = RTCPPacketTypes::kPsfbApp;
_packet.PSFBAPP.SenderSSRC = senderSSRC;
_packet.PSFBAPP.MediaSSRC = mediaSSRC;
_state = ParseState::State_PSFB_AppItem;
return true;
default:
break;
}
return false;
}
else
{
RTC_NOTREACHED();
return false;
}
}
bool RTCPUtility::RTCPParserV2::ParseRPSIItem() {
// RFC 4585 6.3.3. Reference Picture Selection Indication (RPSI).
//
// 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
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | PB |0| Payload Type| Native RPSI bit string |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
// | defined per codec ... | Padding (0) |
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 4) {
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
if (length > 2 + RTCP_RPSI_DATA_SIZE) {
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kPsfbRpsi;
uint8_t padding_bits = *_ptrRTCPData++;
_packet.RPSI.PayloadType = *_ptrRTCPData++;
memcpy(_packet.RPSI.NativeBitString, _ptrRTCPData, length - 2);
_ptrRTCPData += length - 2;
_packet.RPSI.NumberOfValidBits =
static_cast<uint16_t>(length - 2) * 8 - padding_bits;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseNACKItem()
{
// RFC 4585 6.2.1. Generic NACK
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 4)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kRtpfbNackItem;
_packet.NACKItem.PacketID = *_ptrRTCPData++ << 8;
_packet.NACKItem.PacketID += *_ptrRTCPData++;
_packet.NACKItem.BitMask = *_ptrRTCPData++ << 8;
_packet.NACKItem.BitMask += *_ptrRTCPData++;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParsePsfbAppItem()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 4)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
if(*_ptrRTCPData++ != 'R')
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
if(*_ptrRTCPData++ != 'E')
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
if(*_ptrRTCPData++ != 'M')
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
if(*_ptrRTCPData++ != 'B')
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kPsfbRemb;
_state = ParseState::State_PSFB_REMBItem;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParsePsfbREMBItem()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 4)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packet.REMBItem.NumberOfSSRCs = *_ptrRTCPData++;
const uint8_t brExp = (_ptrRTCPData[0] >> 2) & 0x3F;
uint32_t brMantissa = (_ptrRTCPData[0] & 0x03) << 16;
brMantissa += (_ptrRTCPData[1] << 8);
brMantissa += (_ptrRTCPData[2]);
_ptrRTCPData += 3; // Fwd read data
_packet.REMBItem.BitRate = (brMantissa << brExp);
const ptrdiff_t length_ssrcs = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length_ssrcs < 4 * _packet.REMBItem.NumberOfSSRCs)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kPsfbRembItem;
for (int i = 0; i < _packet.REMBItem.NumberOfSSRCs; i++)
{
_packet.REMBItem.SSRCs[i] = *_ptrRTCPData++ << 24;
_packet.REMBItem.SSRCs[i] += *_ptrRTCPData++ << 16;
_packet.REMBItem.SSRCs[i] += *_ptrRTCPData++ << 8;
_packet.REMBItem.SSRCs[i] += *_ptrRTCPData++;
}
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseTMMBRItem()
{
// RFC 5104 4.2.1. Temporary Maximum Media Stream Bit Rate Request (TMMBR)
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 8)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kRtpfbTmmbrItem;
_packet.TMMBRItem.SSRC = *_ptrRTCPData++ << 24;
_packet.TMMBRItem.SSRC += *_ptrRTCPData++ << 16;
_packet.TMMBRItem.SSRC += *_ptrRTCPData++ << 8;
_packet.TMMBRItem.SSRC += *_ptrRTCPData++;
uint8_t mxtbrExp = (_ptrRTCPData[0] >> 2) & 0x3F;
uint32_t mxtbrMantissa = (_ptrRTCPData[0] & 0x03) << 15;
mxtbrMantissa += (_ptrRTCPData[1] << 7);
mxtbrMantissa += (_ptrRTCPData[2] >> 1) & 0x7F;
uint32_t measuredOH = (_ptrRTCPData[2] & 0x01) << 8;
measuredOH += _ptrRTCPData[3];
_ptrRTCPData += 4; // Fwd read data
_packet.TMMBRItem.MaxTotalMediaBitRate = ((mxtbrMantissa << mxtbrExp) / 1000);
_packet.TMMBRItem.MeasuredOverhead = measuredOH;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseTMMBNItem()
{
// RFC 5104 4.2.2. Temporary Maximum Media Stream Bit Rate Notification (TMMBN)
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 8)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kRtpfbTmmbnItem;
_packet.TMMBNItem.SSRC = *_ptrRTCPData++ << 24;
_packet.TMMBNItem.SSRC += *_ptrRTCPData++ << 16;
_packet.TMMBNItem.SSRC += *_ptrRTCPData++ << 8;
_packet.TMMBNItem.SSRC += *_ptrRTCPData++;
uint8_t mxtbrExp = (_ptrRTCPData[0] >> 2) & 0x3F;
uint32_t mxtbrMantissa = (_ptrRTCPData[0] & 0x03) << 15;
mxtbrMantissa += (_ptrRTCPData[1] << 7);
mxtbrMantissa += (_ptrRTCPData[2] >> 1) & 0x7F;
uint32_t measuredOH = (_ptrRTCPData[2] & 0x01) << 8;
measuredOH += _ptrRTCPData[3];
_ptrRTCPData += 4; // Fwd read data
_packet.TMMBNItem.MaxTotalMediaBitRate = ((mxtbrMantissa << mxtbrExp) / 1000);
_packet.TMMBNItem.MeasuredOverhead = measuredOH;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseSLIItem()
{
// RFC 5104 6.3.2. Slice Loss Indication (SLI)
/*
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| First | Number | PictureID |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 4)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kPsfbSliItem;
uint32_t buffer;
buffer = *_ptrRTCPData++ << 24;
buffer += *_ptrRTCPData++ << 16;
buffer += *_ptrRTCPData++ << 8;
buffer += *_ptrRTCPData++;
_packet.SLIItem.FirstMB = uint16_t((buffer>>19) & 0x1fff);
_packet.SLIItem.NumberOfMB = uint16_t((buffer>>6) & 0x1fff);
_packet.SLIItem.PictureId = uint8_t(buffer & 0x3f);
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseFIRItem()
{
// RFC 5104 4.3.1. Full Intra Request (FIR)
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 8)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kPsfbFirItem;
_packet.FIRItem.SSRC = *_ptrRTCPData++ << 24;
_packet.FIRItem.SSRC += *_ptrRTCPData++ << 16;
_packet.FIRItem.SSRC += *_ptrRTCPData++ << 8;
_packet.FIRItem.SSRC += *_ptrRTCPData++;
_packet.FIRItem.CommandSequenceNumber = *_ptrRTCPData++;
_ptrRTCPData += 3; // Skip "Reserved" bytes.
return true;
}
bool RTCPUtility::RTCPParserV2::ParseAPP(const RtcpCommonHeader& header) {
ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 12) // 4 * 3, RFC 3550 6.7 APP: Application-Defined RTCP Packet
{
EndCurrentBlock();
return false;
}
_ptrRTCPData += 4; // Skip RTCP header
uint32_t senderSSRC = *_ptrRTCPData++ << 24;
senderSSRC += *_ptrRTCPData++ << 16;
senderSSRC += *_ptrRTCPData++ << 8;
senderSSRC += *_ptrRTCPData++;
uint32_t name = *_ptrRTCPData++ << 24;
name += *_ptrRTCPData++ << 16;
name += *_ptrRTCPData++ << 8;
name += *_ptrRTCPData++;
length = _ptrRTCPBlockEnd - _ptrRTCPData;
_packetType = RTCPPacketTypes::kApp;
_packet.APP.SubType = header.count_or_format;
_packet.APP.Name = name;
_state = ParseState::State_AppItem;
return true;
}
bool
RTCPUtility::RTCPParserV2::ParseAPPItem()
{
const ptrdiff_t length = _ptrRTCPBlockEnd - _ptrRTCPData;
if (length < 4)
{
_state = ParseState::State_TopLevel;
EndCurrentBlock();
return false;
}
_packetType = RTCPPacketTypes::kAppItem;
if(length > kRtcpAppCode_DATA_SIZE)
{
memcpy(_packet.APP.Data, _ptrRTCPData, kRtcpAppCode_DATA_SIZE);
_packet.APP.Size = kRtcpAppCode_DATA_SIZE;
_ptrRTCPData += kRtcpAppCode_DATA_SIZE;
}else
{
memcpy(_packet.APP.Data, _ptrRTCPData, length);
_packet.APP.Size = (uint16_t)length;
_ptrRTCPData += length;
}
return true;
}
size_t RTCPUtility::RTCPParserV2::NumSkippedBlocks() const {
return num_skipped_blocks_;
}
RTCPUtility::RTCPPacketIterator::RTCPPacketIterator(uint8_t* rtcpData,
size_t rtcpDataLength)
: _ptrBegin(rtcpData),
_ptrEnd(rtcpData + rtcpDataLength),
_ptrBlock(NULL) {
memset(&_header, 0, sizeof(_header));
}
RTCPUtility::RTCPPacketIterator::~RTCPPacketIterator() {
}
const RTCPUtility::RtcpCommonHeader* RTCPUtility::RTCPPacketIterator::Begin() {
_ptrBlock = _ptrBegin;
return Iterate();
}
const RTCPUtility::RtcpCommonHeader*
RTCPUtility::RTCPPacketIterator::Iterate() {
if ((_ptrEnd <= _ptrBlock) ||
!RtcpParseCommonHeader(_ptrBlock, _ptrEnd - _ptrBlock, &_header)) {
_ptrBlock = nullptr;
return nullptr;
}
_ptrBlock += _header.BlockSize();
if (_ptrBlock > _ptrEnd) {
_ptrBlock = nullptr;
return nullptr;
}
return &_header;
}
const RTCPUtility::RtcpCommonHeader*
RTCPUtility::RTCPPacketIterator::Current() {
if (!_ptrBlock)
{
return NULL;
}
return &_header;
}
} // namespace webrtc