RTP proxy通过UDP收流，调整udp recv socket buffer size成配置 (#3336)

国标推流有些情况需要UDP方式接收流，端口复用同一个UDP端口可能需要根据服务器性能

src/Common/config.cpp

@@ -345,6 +345,7 @@ const string kPSPT = RTP_PROXY_FIELD "ps_pt";
 const string kOpusPT = RTP_PROXY_FIELD "opus_pt";
 const string kGopCache = RTP_PROXY_FIELD "gop_cache";
 const string kRtpG711DurMs = RTP_PROXY_FIELD "rtp_g711_dur_ms";
+const string kUdpRecvSocketBuffer = RTP_PROXY_FIELD "udp_recv_socket_buffer";
 
 static onceToken token([]() {
     mINI::Instance()[kDumpDir] = "";
@@ -356,6 +357,7 @@ static onceToken token([]() {
     mINI::Instance()[kOpusPT] = 100;
     mINI::Instance()[kGopCache] = 1;
     mINI::Instance()[kRtpG711DurMs] = 100;
+    mINI::Instance()[kUdpRecvSocketBuffer] = 4 * 1024 * 1024;
 });
 } // namespace RtpProxy
 

src/Common/config.h

@@ -400,6 +400,8 @@ extern const std::string kGopCache;
 //国标发送g711 rtp 打包时，每个包的语音时长是多少，默认是100 ms，范围为20~180ms (gb28181-2016，c.2.4规定)，
 //最好为20 的倍数，程序自动向20的倍数取整
 extern const std::string kRtpG711DurMs;
+// udp recv socket buffer size
+extern const std::string kUdpRecvSocketBuffer;
 } // namespace RtpProxy
 
 /**