add srt config for lantency multiplier

conf/config.ini

@@ -291,6 +291,9 @@ timeoutSec=5
 #该端口是多线程的，同时支持客户端网络切换导致的连接迁移
 port=9000
 
+#srt 协议中延迟缓存的估算参数，在握手阶段估算rtt ,然后lantencyMul*rtt 为最大缓存时长，此参数越大，表示等待重传的时长就越大
+lantencyMul=4
+
 
 [rtsp]
 #rtsp专有鉴权方式是采用base64还是md5方式

srt/SrtTransport.cpp

@@ -11,6 +11,8 @@ const std::string kTimeOutSec = SRT_FIELD"timeoutSec";
 //srt 单端口udp服务器
 const std::string kPort =  SRT_FIELD"port";
 
+const std::string kLantencyMul = SRT_FIELD"lantencyMul";
+
 static std::atomic<uint32_t> s_srt_socket_id_generate{125};
 ////////////  SrtTransport //////////////////////////
 SrtTransport::SrtTransport(const EventPoller::Ptr &poller)
@@ -155,7 +157,7 @@ void SrtTransport::handleHandshakeConclusion(HandshakePacket &pkt, struct sockad
         HSExtMessage::Ptr req;
         HSExtStreamID::Ptr sid;
         uint32_t srt_flag = 0xbf;
-        uint16_t delay = DurationCountMicroseconds(_now - _induction_ts)*4/1000;
+        uint16_t delay = DurationCountMicroseconds(_now - _induction_ts)*getLantencyMul()/1000;
 
         for (auto ext : pkt.ext_list) {
             //TraceL << getIdentifier() << " ext " << ext->dump();
@@ -210,8 +212,6 @@ void SrtTransport::handleHandshakeConclusion(HandshakePacket &pkt, struct sockad
     }
     _last_ack_pkt_seq_num = _init_seq_number;
 }
-void SrtTransport::bufCheckInterval(){
-}
 void SrtTransport::handleHandshake(uint8_t *buf, int len, struct sockaddr_storage *addr){
     HandshakePacket pkt;
     assert(pkt.loadFromData(buf,len));

srt/SrtTransport.hpp

@@ -21,6 +21,7 @@ using namespace toolkit;
 
 extern const std::string kPort;
 extern const std::string kTimeOutSec;
+extern const std::string kLantencyMul;
 
 class SrtTransport : public std::enable_shared_from_this<SrtTransport> {
 public:
@@ -81,13 +82,14 @@ private:
     void sendShutDown();
     void sendMsgDropReq(uint32_t first ,uint32_t last);
 
-    void bufCheckInterval();
-
     size_t getPayloadSize();
 protected:
     void sendDataPacket(DataPacket::Ptr pkt,char* buf,int len,bool flush = false);
     void sendControlPacket(ControlPacket::Ptr pkt,bool  flush = true);
     virtual void sendPacket(Buffer::Ptr pkt,bool flush =  true);
+    virtual int getLantencyMul(){
+        return 4;
+    };
 private:
     //当前选中的udp链接
     Session::Ptr _selected_session;

srt/SrtTransportImp.cpp

@@ -273,5 +273,10 @@ void SrtTransportImp::doCachedFunc() {
     _cached_func.clear();
 }
 
+int SrtTransportImp::getLantencyMul(){
+    GET_CONFIG(int, lantencyMul, kLantencyMul);
+    return lantencyMul;
+}
+
 
 } // namespace SRT

srt/SrtTransportImp.hpp

@@ -38,6 +38,7 @@ protected:
     void onHandShakeFinished(std::string& streamid,struct sockaddr_storage *addr) override;
     void onSRTData(DataPacket::Ptr pkt) override;
     void onShutdown(const SockException &ex) override;
+    int getLantencyMul() override;
 
     void sendPacket(Buffer::Ptr pkt,bool flush =  true) override{
         _total_bytes += pkt->size();