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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> Hi Ross,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Thanks for your analysis of the appropriate channel to use
depending on kind of data.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I would like to use RTP header extension in order to send if frame
is a synchronisation point, and timestamps (recording time).<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Do you think it's possible to give a callback to the RTSPClient ?<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>For the server side, it seems needed to make some stuff in
MultiFramedRTPSink to allow to set the X bit, and to fill the extended buffer,
isn't it ?<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Thanks & Regards,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'> Michel.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>[@@THALES GROUP RESTRICTED@@]<o:p></o:p></span></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0cm 0cm 0cm'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>De :</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
live-devel-bounces@ns.live555.com [mailto:live-devel-bounces@ns.live555.com] <b>De
la part de</b> Ross Finlayson<br>
<b>Envoyé :</b> mercredi 16 janvier 2013 16:05<br>
<b>À :</b> LIVE555 Streaming Media - development & use<br>
<b>Objet :</b> Re: [Live-devel] RTP header extension<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>I guess this could be interesting to carry information inside
the stream independandly of codec used.</span><o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>That might be "interesting", but not necessarily
appropriate. It depends on what sort of 'information' this is. The
use of a RTP header extension is appropriate ***only if*** the information is
directly related to the RTP packets (not just the stream as a whole). For
example, one can imagine some RTP packets carrying an extra timestamp (e.g., a
'decoding timestamp'), in addition to the usual RTP timestamp (from which a
'presentation timestamp' is derived). <o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>If the 'information' is static, and unchanging, then it
could be put in the stream's SDP description (e.g., the 'info' or 'description'
SDP lines). There are (optional) parameters to
"ServerMediaSession::createNew()" to provide this information, and
also - at the receiving end - member functions of "MediaSession" to
get this information:<o:p></o:p></p>
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<p class=MsoNormal><span class=apple-tab-span> </span>sessionName();<o:p></o:p></p>
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<p class=MsoNormal><span class=apple-tab-span> </span>sessionDescription();<o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>Another way to get information that's static (or doesn't
change much) is to use the RTSP "GET_PARAMETER" command, as you've
done.<o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>For information that is time-based - i.e., changes over time
- but is not directly related to an existing media stream (i.e., the audio or
video stream) - then the information could itself be its own RTP media
stream - e.g., using the "text" media type. Note, for example,
that we support time-varying T.140 text streams over RTP, using the class
"T140TextRTPSink". (That's used for transmitting text over RTP;
for receiving such streams, we just use "SimpleRTPSource".) We use
such streams to transmit the 'subtitle' tracks from Matroska files (and VLC,
when used as a RTP receiver, will also display these as subtitles).<o:p></o:p></p>
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<p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p>
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<p class=MsoNormal><span class=apple-style-span><span style='font-size:13.5pt;
font-family:"Helvetica","sans-serif";color:black'>Ross Finlayson</span></span><span
style='font-size:13.5pt;font-family:"Helvetica","sans-serif";color:black'><br>
<span class=apple-style-span>Live Networks, Inc.</span><br>
<span class=apple-style-span><a href="http://www.live555.com/">http://www.live555.com/</a></span></span>
<o:p></o:p></p>
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