[Live-devel] Streaming Redirection

[Jeff Oliver]

I actually got the redirection code working last night...apparently I 
had a problem with my Transport Header parsing and it was picking up the 
wrong ports for the client side.  Well it works as well as I need it to.

But here's a list of things I had to change to get this to work.  I 
think its fairly straight forward.
1) I completely rewrote the parseTransportHeader to get more 
information.  Multicast/Unicast, Destination, TTL, Client_Port.
2) Modified the getStreamParameters function to create a socket to the 
destinationAddress instead of the client address.  Commented out the 
destinationAddress = clientAddress.
3) Before the call to getStreamParameters, determined if the destination 
parameter was used. if not, then copied the client address into the 
destination address.

That was about it.  I used a different pc to do the RTSP request and 
told my server to send the data to a different client to decode the 
stream.  pretty sweet.  I haven't tried reroute to a multicast address 
yet, but if it doesn't work, i figure it shouldn't be much work to get 
that going.

I hope i can post code snippets here.  This snippet is acutally in the 
handleCmd_PLAY function.  In my version of the server we stripped out 
the describe and setup commands...

    // Look for a "Transport:" header in the request string,
    // to extract client RTP and RTCP ports, if present:
    unsigned short clientRTPPortNum = 0; // default
    unsigned short clientRTCPPortNum = 1; // default
    Boolean isMulticast;
    netAddressBits destinationAddress = 0;
    u_int8_t destinationTTL = 255;
    char *transportHeader = strstr(fullRequestStr, "Transport:");
    if (transportHeader != NULL)
    {
        parseTransportHeader(transportHeader, clientRTPPortNum, 
clientRTCPPortNum,
                             isMulticast, destinationAddress, 
destinationTTL);
       
        Port clientRTPPort(clientRTPPortNum);
        Port clientRTCPPort(clientRTCPPortNum);
       
        Port serverRTPPort(0);
        Port serverRTCPPort(0);
       
        // Direct stream to the destination, if the dest wasnt 
specified, then
        //  send it to the client.
       
        if (destinationAddress == 0)
        {
            destinationAddress = fClientAddr.sin_addr.s_addr;
        }
       
        subsession->getStreamParameters(fClientAddr.sin_addr.s_addr,
                                        clientRTPPort, clientRTCPPort,
                                        isMulticast, destinationAddress, 
destinationTTL,
                                        serverRTPPort, serverRTCPPort,
                                        
fStreamStates[streamNum].streamToken);
        sprintf((char*)transportResponse, "Transport: 
RTP/AVP;unicast;client_port=%d-%d;server_port=%d-%d\r\n"
                "Media: vpid=?;apid=?;len=?\r\n",
                ntohs(clientRTPPort.num()), ntohs(clientRTCPPort.num()), 
ntohs(serverRTPPort.num()), ntohs(serverRTCPPort.num()));
    }

Im not sure how portable this is, but i figure if someone wants to make 
it more portable they can.

Jeff Oliver




Cavalera Claudio wrote:

>>-----Original Message-----
>>From: Jeff Oliver [mailto:Jeffrey.Oliver at mascorp.com] 
>>Sent: martedì 27 gennaio 2004 22.25
>>To: LIVE.COM Streaming Media - development & use
>>Subject: Re: [Live-devel] Streaming Redirection
>>
>>
>>I too am interested in the redirection feature.  I was playing around 
>>with some of the code to get this to work, but I don't have anything 
>>working yet.  I added code to parse the destination field and changed 
>>around the code that opens up the sockets, but i couldn't get the 
>>streamer to actually send the RTP data.  If I get a chance I'll take 
>>another look at it and see if I can get it working.
>>    
>>
>
>You mean you have already modified Open RTSP to use the destination field?
>Have you tested only with the live streaming server or also with other platforms?
>Thanks
>Claudio
>
>_______________________________________________
>live-devel mailing list
>live-devel at lists.live.com
>http://lists.live.com/mailman/listinfo/live-devel
>
>
>  
>


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