[Live-devel] RTT Calculation (clarification)

Ross Finlayson finlayson at live.com
Wed Apr 14 19:56:55 PDT 2004

>RTT is indeed round trip time. I want to use RTCP to provide the RTT. So I
>saw that in the file "RTPSink.cpp" in liveMedia folder, the procedure
>noteIncomingRR does print out the estimated RTT (the calculation is
>according to the suggestion from RFC3550).

OK, thanks for the clarification.  Yes, this should work, provided that the 
receiver is sending back correct RTCP RR packets.

>The funny thing is that if my receiver uses Windows Media Player, the RTT is

Windows Media Player??  Wow!  This is the first time I have heard of anyone 
succesfully using Windows Media Player to play RTSP/RTP streams from the 
the LIVE.COM server code.  Which of the LIVE.COM test program(s) have you 
used to successfully stream to Windows Media Player?

>  It only provides wrong RTT when the receiver uses Quick Time Player
>to view the RTSP stream.

Which version of QuickTime Player are you using?

>  Moreover, when Quick Time Player is used, the
>streaming server usually prompts for unrecognisable RTCP packet.

Are you referring to the "UNSUPPORTED TYPE" message printed within 
"RTCP.cpp" (when DEBUG is defined)?  If so, then this is perfectly OK; it 
just means that the RTCP packet contains components that the LIVE.COM code 
doesn't (need to) handle.

>Anyway, my receivers will always use Windows Media Player to view the

You could also try VLC <http://www.videolan.org/vlc/>.  That player should 
definitely work (because it uses the LIVE.COM code to implement RTSP/RTP :-)

	Ross Finlayson

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