[Live-devel] RTCP usage

[Ross Finlayson]

At 03:21 PM 1/28/04, you wrote:
>I was wondering if you had any examples in the code of how RTCP code is 
>read or used.

At present, receivers record data from incoming RTCP "Sender Report" (SR) 
packets into the RTPSource's 'reception stats database'.  This is done in 
the call to "receptionStats.noteIncomingSR()" in "liveMedia/RTCP.cpp" (line 
334).

The 'reception stats database' itself is defined in 
"liveMedia/include/RTPSource.hh", and implemented in "liveMedia/RTPSource.cpp".

For an example of code that actually uses this information, you could look 
at the implementation of openRTSP's "-Q" option.  See, in particular, 
"qosMeasurementRecord::periodicQOSMeasurement()", starting at line 799 of 
"testProgs/playCommon.cpp".

Note, however, that data from RTCP "RR" (Receiver Report) packets (i.e., 
coming from receivers back to the sender) are currently not processed at 
all - except to record the identity (SSRC) of the receiver.  (This allows 
the sender to call the "RTCPInstance::numMembers()" member function to get 
a count of the number of receivers, for example.)


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