目录
前端WEB
服务器收到请求
POST /index/api/webrtc?app=live&stream=test&type=play HTTP/1.1
HttpSession::onRecvHeader
HttpSession::Handle_Req_POST
HttpSession::Handle_Req_POST
if (totalContentLen > 0 && (size_t)totalContentLen < maxReqSize )
_contentCallBack = [this,parserCopy](const char *data,size_t len) {
//恢复http头
_parser = parserCopy;
//设置content
_parser.setContent(string(data,len));
//触发http事件，emitHttpEvent内部会选择是否关闭连接
emitHttpEvent(true);
//清空数据,节省内存
_parser.Clear();
//content已经接收完毕
return false;
};
HttpSession::onRecvContent(const char *data,size_t len)
if (_contentCallBack)
_contentCallBack(data,len);
HttpSession::emitHttpEvent
// 广播HTTP事件
NoticeCenter::Instance().emitEvent(Broadcast::kBroadcastHttpRequest,_parser,invoker,
consumed,static_cast<SockInfo &>(*this));服务端的处理
// 主函数中调用web接口安装函数
installWebApi
addHttpListener();
api_regist("/index/api/webrtc",[](API_ARGS_STRING_ASYNC){
auto type = allArgs["type"];
auto offer = allArgs.getArgs();
WebRtcPluginManager::Instance().getAnswerSdp(*(static_cast<Session *>(&sender)), type,
WebRtcArgsImp(allArgs, sender.getIdentifier()),
[invoker, val, offer, headerOut](const WebRtcInterface &exchanger) mutable {
headerOut["Content-Type"] = HttpFileManager::getContentType(".json");
headerOut["Access-Control-Allow-Origin"] = "*";
val["sdp"] = const_cast<WebRtcInterface &>(exchanger).getAnswerSdp(offer);
val["id"] = exchanger.getIdentifier();
val["type"] = "answer";
invoker(200, headerOut, val.toStyledString());
});
});
addHttpListener
//注册监听kBroadcastHttpRequest事件
NoticeCenter::Instance().addListener(&web_api_tag, Broadcast::kBroadcastHttpRequest,
[](BroadcastHttpRequestArgs) {
auto it = s_map_api.find(parser.Url());
it->second(parser, invoker, sender);
} 根据url找到对应的事件回调，最终会调用WebRtcPluginManager::Instance().getAnswerSdp。
WebRtcPluginManager::getAnswerSdp
auto it = _map_creator.find(type);
it->second(sender, args, cb);
// 静态注册插件
WebRtcPluginManager::Instance().registerPlugin("play", play_plugin);
void play_plugin(Session &sender, const WebRtcArgs &args, const WebRtcPluginManager::onCreateRtc &cb)
// 使用rtsp媒体源，两者均是传输的rtp流
info._schema = RTSP_SCHEMA;
MediaSource::findAsync(info, session_ptr, [=](const MediaSource::Ptr &src_in) mutable {
auto src = dynamic_pointer_cast<RtspMediaSource>(src_in);
// 还原成rtc，目的是为了hook时识别哪种播放协议
info._schema = RTC_SCHEMA;
auto rtc = WebRtcPlayer::create(EventPollerPool::Instance().getPoller(), src, info, preferred_tcp);
cb(*rtc); // 发送answer SDP给web端
}); 
播放
拉流
Web端首先根据协商的IP和端口，服务端webrtc的端口是8000，发送STUN命令再次获取STUN地址。
首次连接，服务端会创建对应的session。
WebRtcSession::WebRtcSession(const Socket::Ptr &sock) : Session(sock)
socklen_t addr_len = sizeof(_peer_addr);
getpeername(sock->rawFD(), (struct sockaddr *)&_peer_addr, &addr_len);
WebRtcSession::onRecv_l(const char *data, size_t len)
// 首次进入，根据username获取之前创建的transport.
auto user_name = getUserName(data, len); // 此处的username就是之前设置的transport标识
auto transport = WebRtcTransportManager::Instance().getItem(user_name);
transport->setSession(shared_from_this());
_transport = std::move(transport);
_transport->inputSockData((char *)data, len, (struct sockaddr *)&_peer_addr);
WebRtcTransport::inputSockData
// 处理STUN消息
if (RTC::StunPacket::IsStun((const uint8_t *)buf, len))
std::unique_ptr<RTC::StunPacket> packet(RTC::StunPacket::Parse((const uint8_t *)buf, len));
_ice_server->ProcessStunPacket(packet.get(), tuple);
return;
// 处理
if (is_dtls(buf))
_dtls_transport->ProcessDtlsData((uint8_t *)buf, len);
return;
// 由于是拉流，不存在rtp数据，但是有rtcp数据
if (is_rtcp(buf))
if (_srtp_session_recv->DecryptSrtcp((uint8_t *)buf, &len))
onRtcp(buf, len);
DTLS交互完成后，接下来启动媒体传输
WebRtcTransport::OnDtlsTransportConnected
onStartWebRTC();
WebRtcPlayer::onStartWebRTC
WebRtcTransportImp::onStartWebRTC();
_reader = _play_src->getRing()->attach(getPoller(), true);
weak_ptr<WebRtcPlayer> weak_self = static_pointer_cast<WebRtcPlayer>(shared_from_this());
weak_ptr<Session> weak_session = getSession();
_reader->setReadCB([weak_self](const RtspMediaSource::RingDataType &pkt) {
size_t i = 0;
pkt->for_each([&](const RtpPacket::Ptr &rtp) {
strong_self->onSendRtp(rtp, ++i == pkt->size());
});
});