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<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Hello,<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>in our
test setup we want to record an RTSP session containing 52 media tracks
(AVC/AAC). We also want all the tracks to be synchronized. For this purpose, we
use the openRTSP tool (using the QuickTimeFileSink through the -4 openRTSP
flag) (version: live.2009.09.28, building on linux).<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>We
experienced, however, that on rare occasions the recording does not start (i.e.
the output file's size does not increase).<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>We
tried to debug the code on such an event and we checked the syncOK function of
the SubsessionIOState class because, apparently, the
ioState->afterGettingFrame(packetDataSize, presentationTime); never got
called. We found out that in such an erroneous case, some tracks (mostly just
one) never get synchronized (the fHaveBeenSynced flag of the SubsessionIOstate
class does not get set).<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Therefore,
we went deeper into the code until the point of the BasicTaskscheduler. Here we
see that after calling the select statement in the "void
BasicTaskScheduler::SingleStep(unsigned maxDelayTime)" function, we only get
a limited number of readable sockets as a return value. If, for example, we
have 52 media tracks, we create at least 104 sockets (52 for RTP and 52 for
RTCP), but the result value is never 104 or higher, no matter how long we wait
in between two select calls. This makes us believe that the accompaniment
socket of the track is never read, and for example the RTCP SR is not parsed to
get that track synchronized.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>We
also observed that data is actually being send to all the sockets (and correct
port numbers) and that sockets are correctly created (socket number> -1) and
added to the read set before the select call.<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Do
you have any similar experiences or any ideas on what might go wrong here?<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Courier New"'>Kind
regards.<o:p></o:p></span></p>
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