[Live-devel] hasBeenSynchronizedUsingRTCP()

[Jeff Shanab]

Well, there is a problem here then..

From: live-devel-bounces at ns.live555.com [mailto:live-devel-bounces at ns.live555.com] On Behalf Of Ross Finlayson
Sent: Friday, July 29, 2011 2:19 PM
To: LIVE555 Streaming Media - development & use
Subject: Re: [Live-devel] hasBeenSynchronizedUsingRTCP()


On Jul 29, 2011, at 2:49 PM, Jeff Shanab wrote:


I traced the code and I AM getting the packets....

But every rtp timestamp is 0!

Arggh, now you're talking about something completely different: RTP timestamps - which I specifically said you don't need to care about!!!

So, are you talking about "hasBeenSynchronizedUsingRTCP()", RTP timestamps (which you don't need to care about), or presentation times (which you do need to care about)?

My call to "hasBeenSynchronizedUsingRTCP()" is always returning false.

But anyway, to summarize (and this will be my last posting on this thread):

1/ If you ever reach the code at line 380 of "liveMedia/RTPSource.cpp", then
            - You have received a RTCP "SR" packet, and
            - "hasBeenSynchronizedUsingRTCP()" will always return True from then on, and
            - the presentation times for video (and audio, if present) should be correctly synchronized from then on.

I am hitting this line and fHasBeenSyncronized is therefore being set to true. (at that moment in time) (Perhaps I need to protect it)
2/ If "hasBeenSynchronizedUsingRTCP()" always returns False, then that must mean that you're not receiving any RTCP "SR" packets, which is probably because the server does not send any. But that doesn't really matter, unless you're receiving both a video stream and an audio stream (in which case they can never be synchronized).
But hasBeenSynchronizedUsingRTCP() does not return fHasBeenSyncronized, it returns fCurPacketHasBeenSynchronizedUsingRTCP which I have not yet found where it is set. I see construted to false and I see returned and I see passed in nextPacket->use.  Now on 428 in MultiframedRtpSource I see where it would be set as a return argument, but at that breakpoint it is 0.   Not sure where that gets reset.  But when I manipulate the camera settings and it starts to have a nonzero rtpTimestamp. It starts to work at the higher level ok. So a non-zero or at least changing rtp timestamp does seem to make a difference.
3/ All you really care about is the presentation times, anyway.
I was depending on them being syncyed, file split boundries and names are derived from this.
4/ You absolutely do not need to 'hack' the supplied code.
                AMEN!, (and I agree)

Again, this will be my last posting on this thread.
                Darn :(

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.live555.com/pipermail/live-devel/attachments/20110729/972cc974/attachment.html>