[Live-devel] RTCP and synchronization

[Ross Finlayson]

>  > Because they're not useful to you.
>>
>>  I'll say this yet again (and hopefully for the last time): Our
>>  RTP/RTCP implementation automatically computes synchronized
>>  presentation times using RTP timestamps and RTCP reports.  Code that
>>  receives a RTP stream (using our library) should never have to look
>>  at RTP timestamps.  Instead, just use the presentation time.  If you
>>  are also using RTCP (which you should be), then the presentaton time
>>  *will* be properly synchronized.
>>  
>
>And if the receiver does NOT use Live555?

It shouldn't matter, provided that the receiver also follows the 
RTP/RTCP standard.


>  > Just make sure that frames of the transcoded stream get correct
>>  presentation times (and that you create a new "RTCPInstance" object
>>  for the new outgoing stream).
>>  
>
>
>OK, I do use an RTCPInstance.
>What does "correct" in this context mean? I record the first incoming
>presentationTime for the first outgoing frame and add a constant value
>(correspoding to one frame duration) to it for every following frame. Is
>that "corrrect"?

Yes.  It's important, though, that the first presentationTime (that 
you generate for the first frame) is generated by calling 
"gettimeofday()".
-- 

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