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整理 nack/rtx/ssrc

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This commit is contained in:
ziyue 2021-05-12 20:51:51 +08:00
parent 12be56493e
commit 8fdfc14f6f
2 changed files with 85 additions and 58 deletions
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125
webrtc/WebRtcTransport.cpp
View File

@ -271,7 +271,8 @@ void WebRtcTransport::inputSockData(char *buf, size_t len, RTC::TransportTuple *
void WebRtcTransport::sendRtpPacket(char *buf, size_t len, bool flush, void *ctx) {
if (_srtp_session_send) {
CHECK(len + SRTP_MAX_TRAILER_LEN <= sizeof(_srtp_buf));
//预留rtx加入的两个字节
CHECK(len + SRTP_MAX_TRAILER_LEN + 2 <= sizeof(_srtp_buf));
memcpy(_srtp_buf, buf, len);
onBeforeEncryptRtp((char *) _srtp_buf, len, ctx);
if (_srtp_session_send->EncryptRtp(_srtp_buf, &len)) {
@ -395,40 +396,40 @@ bool WebRtcTransportImp::canRecvRtp() const{
}
const RtcSession& WebRtcTransportImp::getSdpWithSSRC() const{
auto &offer = getSdp(SdpType::offer);
auto &offer = getSdp(SdpType::answer);
if (offer.haveSSRC()) {
return offer;
}
auto &answer = getSdp(SdpType::answer);
auto &answer = getSdp(SdpType::offer);
CHECK(answer.haveSSRC());
return answer;
}
void WebRtcTransportImp::onStartWebRTC() {
//获取ssrc和pt相关信息,届时收到rtp和rtcp时分别可以根据pt和ssrc找到相关的信息
for (auto &m : getSdp(SdpType::offer).media) {
for (auto &plan : m.plan) {
auto hit_pan = getSdp(SdpType::answer).getMedia(m.type)->getPlan(plan.pt);
if (!hit_pan) {
continue;
}
auto m_with_ssrc = getSdpWithSSRC().getMedia(m.type);
for (auto &m_answer : getSdp(SdpType::answer).media) {
auto m_with_ssrc = getSdpWithSSRC().getMedia(m_answer.type);
for (auto &plan_answer : m_answer.plan) {
//获取offer端rtp的ssrc和pt相关信息
auto info = std::make_shared<RtpPayloadInfo>();
_rtp_info_pt.emplace(plan.pt, info);
info->plan = &plan;
_rtp_info_pt.emplace(plan_answer.pt, info);
info->media = m_with_ssrc;
info->is_common_rtp = getCodecId(plan.codec) != CodecInvalid;
info->is_common_rtp = getCodecId(plan_answer.codec) != CodecInvalid;
if (info->is_common_rtp) {
//rtp
_rtp_info_ssrc[m_with_ssrc->rtp_rtx_ssrc[0].ssrc] = info;
_rtp_info_ssrc[info->media->rtp_rtx_ssrc[0].ssrc] = info;
info->plan_rtp = &plan_answer;
info->plan_rtx = m_answer.getRelatedRtxPlan(plan_answer.pt);
} else {
//rtx
auto apt = atoi(plan.getFmtp("apt").data());
info->plan_apt = m.getPlan(apt);
if (info->media->rtp_rtx_ssrc.size() > 1) {
_rtp_info_ssrc[info->media->rtp_rtx_ssrc[1].ssrc] = info;
}
info->rtcp_context_recv = std::make_shared<RtcpContext>(info->plan->sample_rate, true);
info->rtcp_context_send = std::make_shared<RtcpContext>(info->plan->sample_rate, false);
info->plan_rtp = m_answer.getPlan(atoi(plan_answer.getFmtp("apt").data()));
info->plan_rtx = &plan_answer;
}
info->rtcp_context_recv = std::make_shared<RtcpContext>(info->plan_rtp->sample_rate, true);
info->rtcp_context_send = std::make_shared<RtcpContext>(info->plan_rtp->sample_rate, false);
info->receiver = std::make_shared<RtpReceiverImp>([info, this](RtpPacket::Ptr rtp) mutable {
onSortedRtp(*info, std::move(rtp));
});
@ -436,9 +437,9 @@ void WebRtcTransportImp::onStartWebRTC() {
onNack(*info, nack);
});
}
if (m.type != TrackApplication) {
if (m_answer.type != TrackApplication) {
//记录rtp ext类型与id的关系，方便接收或发送rtp时修改rtp ext id
for (auto &ext : m.extmap) {
for (auto &ext : m_answer.extmap) {
auto ext_type = RtpExt::getExtType(ext.ext);
_rtp_ext_id_to_type.emplace(ext.id, ext_type);
_rtp_ext_type_to_id.emplace(ext_type, ext.id);
@ -499,8 +500,8 @@ void WebRtcTransportImp::onCheckSdp(SdpType type, RtcSession &sdp){
sdp.origin.address = m.addr.address;
}
if (!canSendRtp() || getSdp(SdpType::offer).haveSSRC()) {
//offer sdp未包含ssrc相关信息，那么我们才在answer sdp中回复ssrc相关信息
if (!canSendRtp()) {
//设置我们发送的rtp的ssrc
return;
}
@ -596,7 +597,7 @@ void WebRtcTransportImp::onRtcp(const char *buf, size_t len) {
auto rr = it->second->rtcp_context_recv->createRtcpRR(sr->items.ssrc, sr->ssrc);
sendRtcpPacket(rr->data(), rr->size(), true);
} else {
WarnL << "未识别的sr rtcp包:" << (uint32_t)sr->ssrc;
WarnL << "未识别的sr rtcp包:" << rtcp->dumpString();
}
break;
}
@ -604,12 +605,14 @@ void WebRtcTransportImp::onRtcp(const char *buf, size_t len) {
_alive_ticker.resetTime();
//对方汇报rtp接收情况
RtcpRR *rr = (RtcpRR *) rtcp;
auto it = _rtp_info_ssrc.find(rr->ssrc);
for (auto item : rr->getItemList()) {
auto it = _rtp_info_ssrc.find(item->ssrc);
if (it != _rtp_info_ssrc.end()) {
auto sr = it->second->rtcp_context_send->createRtcpSR(rr->items.ssrc);
auto sr = it->second->rtcp_context_send->createRtcpSR(item->ssrc);
sendRtcpPacket(sr->data(), sr->size(), true);
} else {
WarnL << "未识别的rr rtcp包:" << (uint32_t)rr->ssrc;
WarnL << "未识别的rr rtcp包:" << rtcp->dumpString();
}
}
break;
}
@ -619,10 +622,13 @@ void WebRtcTransportImp::onRtcp(const char *buf, size_t len) {
for (auto ssrc : bye->getSSRC()) {
auto it = _rtp_info_ssrc.find(*ssrc);
if (it == _rtp_info_ssrc.end()) {
WarnL << "未识别的bye rtcp包:" << *ssrc;
WarnL << "未识别的bye rtcp包:" << rtcp->dumpString();
continue;
}
_rtp_info_pt.erase(it->second->plan->pt);
_rtp_info_pt.erase(it->second->plan_rtp->pt);
if (it->second->plan_rtx) {
_rtp_info_pt.erase(it->second->plan_rtx->pt);
}
_rtp_info_ssrc.erase(it);
}
onShutdown(SockException(Err_eof, "rtcp bye message received"));
@ -630,18 +636,18 @@ void WebRtcTransportImp::onRtcp(const char *buf, size_t len) {
}
case RtcpType::RTCP_PSFB:
case RtcpType::RTCP_RTPFB: {
RtcpFB *fb = (RtcpFB *) rtcp;
auto it = _rtp_info_ssrc.find(fb->ssrc);
if (it == _rtp_info_ssrc.end()) {
WarnL << "未识别的 rtcp包:" << rtcp->dumpString();
return;
}
if ((RtcpType) rtcp->pt == RtcpType::RTCP_PSFB) {
break;
}
//RTPFB
switch ((RTPFBType) rtcp->report_count) {
case RTPFBType::RTCP_RTPFB_NACK : {
RtcpFB *fb = (RtcpFB *) rtcp;
auto it = _rtp_info_ssrc.find(fb->ssrc_media);
if (it == _rtp_info_ssrc.end()) {
WarnL << "未识别的 rtcp包:" << rtcp->dumpString();
return;
}
auto &fci = fb->getFci<FCI_NACK>();
it->second->nack_list.for_each_nack(fci, [&](const RtpPacket::Ptr &rtp) {
//rtp重传
@ -702,7 +708,7 @@ void WebRtcTransportImp::onRtp_l(const char *buf, size_t len, bool rtx) {
if (info->is_common_rtp) {
//这是普通的rtp数据
auto seq = ntohs(rtp->seq);
#if 0
#if 1
if (!rtx && info->media->type == TrackVideo && seq % 100 == 0) {
//此处模拟接受丢包
DebugL << "recv dropped:" << seq;
@ -715,12 +721,12 @@ void WebRtcTransportImp::onRtp_l(const char *buf, size_t len, bool rtx) {
//修改ext id至统一
changeRtpExtId(rtp, _rtp_ext_id_to_type);
//时间戳转换成毫秒
auto stamp_ms = ntohl(rtp->stamp) * uint64_t(1000) / info->plan->sample_rate;
auto stamp_ms = ntohl(rtp->stamp) * uint64_t(1000) / info->plan_rtp->sample_rate;
//统计rtp收到的情况，好做rr汇报
info->rtcp_context_recv->onRtp(seq, stamp_ms, len);
}
//解析并排序rtp
info->receiver->inputRtp(info->media->type, info->plan->sample_rate, (uint8_t *) buf, len);
info->receiver->inputRtp(info->media->type, info->plan_rtp->sample_rate, (uint8_t *) buf, len);
return;
}
@ -736,7 +742,7 @@ void WebRtcTransportImp::onRtp_l(const char *buf, size_t len, bool rtx) {
InfoL << "received rtx rtp: " << origin_seq;
rtp->seq = htons(origin_seq);
rtp->ssrc = htonl(info->media->rtp_rtx_ssrc[0].ssrc);
rtp->pt = info->plan_apt->pt;
rtp->pt = info->plan_rtp->pt;
memmove((uint8_t *) buf + 2, buf, payload - (uint8_t *) buf);
buf += 2;
len -= 2;
@ -782,31 +788,52 @@ void WebRtcTransportImp::onSendRtp(const RtpPacket::Ptr &rtp, bool flush, bool r
//统计rtp发送情况，好做sr汇报
info->rtcp_context_send->onRtp(rtp->getSeq(), rtp->getStampMS(), rtp->size() - RtpPacket::kRtpTcpHeaderSize);
info->nack_list.push_back(rtp);
#if 0
#if 1
//此处模拟发送丢包
if(rtp->getSeq() % 100 == 0){
DebugL << "send droped:" << rtp->getSeq();
DebugL << "send dropped:" << rtp->getSeq();
return;
}
#endif
} else {
WarnL << "send rtx rtp:" << rtp->getSeq();
}
sendRtpPacket(rtp->data() + RtpPacket::kRtpTcpHeaderSize, rtp->size() - RtpPacket::kRtpTcpHeaderSize, flush, info.get());
pair<bool/*rtx*/, RtpPayloadInfo *> ctx{rtx, info.get()};
sendRtpPacket(rtp->data() + RtpPacket::kRtpTcpHeaderSize, rtp->size() - RtpPacket::kRtpTcpHeaderSize, flush, &ctx);
_bytes_usage += rtp->size() - RtpPacket::kRtpTcpHeaderSize;
}
void WebRtcTransportImp::onBeforeEncryptRtp(const char *buf, size_t len, void *ctx) {
RtpPayloadInfo *info = reinterpret_cast<RtpPayloadInfo *>(ctx);
auto header = (RtpHeader *)buf;
//修改目标pt和ssrc
header->pt = info->plan->pt;
header->ssrc = htons(info->media->rtp_rtx_ssrc[0].ssrc);
void WebRtcTransportImp::onBeforeEncryptRtp(const char *buf, size_t &len, void *ctx) {
auto pr = (pair<bool/*rtx*/, RtpPayloadInfo *> *) ctx;
auto header = (RtpHeader *) buf;
changeRtpExtId(header, _rtp_ext_type_to_id);
}
void WebRtcTransportImp::onBeforeEncryptRtcp(const char *buf, size_t len, void *ctx) {
if (!pr->first || !pr->second->plan_rtx) {
//普通的rtp,或者不支持rtx, 修改目标pt和ssrc
header->pt = pr->second->plan_rtp->pt;
header->ssrc = htonl(pr->second->media->rtp_rtx_ssrc[0].ssrc);
} else {
//重传的rtp, rtx
header->pt = pr->second->plan_rtx->pt;
if (pr->second->media->rtp_rtx_ssrc.size() > 1) {
//有rtx单独的ssrc
header->ssrc = htonl(pr->second->media->rtp_rtx_ssrc[1].ssrc);
}
auto origin_seq = ntohs(header->seq);
//seq跟原来的不一样
header->seq = htons(origin_seq + 100);
auto payload = header->getPayloadData();
auto payload_size = header->getPayloadSize(len);
if (payload_size) {
//rtp负载后移两个字节，这两个字节用于存放osn
//https://datatracker.ietf.org/doc/html/rfc4588#section-4
memmove(payload + 2, payload, payload_size);
}
payload[0] = origin_seq >> 8;
payload[1] = origin_seq & 0xFF;
len += 2;
}
}
void WebRtcTransportImp::onShutdown(const SockException &ex){

12
webrtc/WebRtcTransport.h
View File

@ -101,8 +101,8 @@ protected:
virtual void onRtp(const char *buf, size_t len) = 0;
virtual void onRtcp(const char *buf, size_t len) = 0;
virtual void onShutdown(const SockException &ex) = 0;
virtual void onBeforeEncryptRtp(const char *buf, size_t len, void *ctx) = 0;
virtual void onBeforeEncryptRtcp(const char *buf, size_t len, void *ctx) = 0;
virtual void onBeforeEncryptRtp(const char *buf, size_t &len, void *ctx) = 0;
virtual void onBeforeEncryptRtcp(const char *buf, size_t &len, void *ctx) = 0;
protected:
const RtcSession& getSdp(SdpType type) const;
@ -301,8 +301,8 @@ protected:
void onRtp_l(const char *buf, size_t len, bool rtx);
void onRtcp(const char *buf, size_t len) override;
void onBeforeEncryptRtp(const char *buf, size_t len, void *ctx) override;
void onBeforeEncryptRtcp(const char *buf, size_t len, void *ctx) override;
void onBeforeEncryptRtp(const char *buf, size_t &len, void *ctx) override;
void onBeforeEncryptRtcp(const char *buf, size_t &len, void *ctx) override {};
void onShutdown(const SockException &ex) override;
@ -345,8 +345,8 @@ private:
using Ptr = std::shared_ptr<RtpPayloadInfo>;
bool is_common_rtp;
const RtcCodecPlan *plan;
const RtcCodecPlan *plan_apt;
const RtcCodecPlan *plan_rtp;
const RtcCodecPlan *plan_rtx;
const RtcMedia *media;
std::shared_ptr<RtpReceiverImp> receiver;
RtcpContext::Ptr rtcp_context_recv;