libcurl RTSP client implementation c programming issue

Question

I'm implementing a RTSP client in c programming using libcurl.

In order to properly configure the RTP/RTCP sessions I require having the transmission port of the RTSP server (to send RTCP RR to it).

I've been looking on the documentation but without success.

I guess that it might be possible. Am I right? I've been trying with the "curl_easy_getinfo" method, but I don't see the desired parameter to handle my requirement.

Maybe I require parsing whole reply from the RTSP server (getting somehow the reply string from the server that the libcurl is showing once received). But, at least, I need to know that there is no other way. And, if there is no other way, which would be the best way to get such reply string?

Answer 1

In the rtsp sample rtsp.c, the RTSP answers are parsed by the libcurl user.

To get the RTP and RTCP port you will need to parse the Transport header of the SETUP answer.

This could be achieve with something like :

int rtpport=0;
int rtcpport=0;

char *t=strstr(rtspheader, "server_port=");
if (t != NULL)
{
    if (sscanf(t, "server_port=%d-%d", &rtpport, &rtcpport) == 2)
    {
        printf("Server ports RTP:%d RTCP:%d\n",rtpport, rtcpport);
    }
}