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--></style><title>Re: [Live-devel] Calculating rtptime for
RTSP/PLAY-Respons</title></head><body>
<div>First, let's make sure that we're talking about the same thing.
I assume that you're referring to the way that our RTSP *server*
implementation fills in the "RTP-Info:" header that it
includes in the response to each RTSP "PLAY" request.
If you're instead referring to something else, then please correct
me.</div>
<div><br></div>
<blockquote type="cite" cite><font face="Verdana" size="-1"
color="#0000FF">The crux of my question concerns the *delta* that a
reference implementation (Helix USM) applies to one of the rtptime=X
values that is reported in the RTP-Info header. All of our testing
(with ~30 different brand/model combinations) has shown that this is
critical for many mobile phones to correctly apply A/V
sync.</font></blockquote>
<div><br></div>
<div>What exactly is this 'delta', and which RFC (or Internet-Draft)
document defines it?</div>
<div><br></div>
<blockquote type="cite" cite><font face="Verdana" size="-1"
color="#0000FF">The live555 code (the 2008.07.25 release) does not
adjust (calculate a delta) the RTP-Info header in this way. It simply
reports the seqNum & rtptime of the first packet on each
stream.</font></blockquote>
<div><br></div>
<div>I believe that the information that we put in the
"RTP-Info:" header is correct. It is the information
defined in section 12.33 of RFC 2326 (the RTSP specification).</div>
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</pre></x-sigsep>
<div><br>
Ross Finlayson<br>
Live Networks, Inc.<br>
http://www.live555.com/</div>
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