[Live-devel] How can I receive RTCP message when using SimpleRTPSink

[Ross Finlayson]

>In my program, I have the following code to create a Program Stream

No, for the code you've writtenn, the input source should be a *Transport* 
Stream, not a Program Stream.  (To stream a Program Stream, you use a MIME 
subtype of "mp2p" (rather than "mp2t"), and must use a dynamic payload type 
(i.e., >= 96, *not* 33).)

>and send
>to a SimpleRTPSink.
>
>   aSimpleRTPSink = SimpleRTPSink::createNew(*env, rtpGroupsock, 33, 90000,
>"video", "mp2t");
>   // Create (and start) a 'RTCP instance' for this RTP sink:
>   const unsigned maxCNAMElen = 100;
>   unsigned char CNAME[maxCNAMElen+1];
>   gethostname((char*)CNAME, maxCNAMElen);
>   CNAME[maxCNAMElen] = '\0'; // just in case
>
>   // Create (and start) a 'RTCP instance' for this RTP sink:
>   const unsigned totalSessionBandwidth = 4500; // in kbps; for RTCP b/w
>share
>
>   RTCPInstance::createNew(*env, rtcpGroupsock,
>               totalSessionBandwidth, CNAME,
>               aSimpleRTPSink, NULL /* we're a server */, isSSM);
>   // Note: This starts RTCP running automatically
>   aSimpleRTPSink->startPlaying(*fileSource, afterPlaying, aSimpleRTPSink);

This code is correct - provided that your input source is a Transport 
Stream (not a Program Stream).

>Then I use VLC to view the content using "udp://@239.255.42.42:6666". I can
>view the stream with noises since I am transferring a program stream using a
>transport stream format. But I didn't observe any RTCP RR messages.

This is the fault of VLC.  It's handling of "udp://" URLs is a hack, and 
doesn't use the LIVE.COM code.  It just ignores the RTP header (if 
present), and doesn't process or send back RTCP at all.


	Ross Finlayson
	LIVE.COM
	<http://www.live.com/>