[Live-devel] RTP/RTCP startup behaviuor

[Ross Finlayson]

> > If you want to continue to use a 'guessed' presentation time for an
> > elementary stream - even after
> > "RTPSource::hasBeenSynchronizedUsingRTCP()" returns True, then just
> > call "gettimeofday()".
>
>I'm afraid this would not work for e.g. MPEG video, where RTP timestamps
>describe presentation order, but the frames are sent in decoding order.
>By ignoring RTP timestamps and just calling gettimeofday() you'll reverse
>the order of P and B frames...

Well, OK, if you *really* want to compute a 'guessed' presentation 
time for a stream even after an accurate, RTCP-synchronized 
presentation time has been made available to you, then you could do 
by calling "gettimeofday()" only for the first-received data, and 
thereafter adjusting it using "RTPSource::timestampFrequency()" and 
"RTPSource::curPacketRTPTimestamp()".  (This is what the 
"RTPSource.cpp" code already does to compute presentation times - see 
lines 307-351.)


	Ross Finlayson
	Live Networks, Inc. (LIVE555.COM)
	<http://www.live555.com/>