[Live-devel] Local clock drift/offset compensation?

[Marian Durkovic]

Hi all,

   in RTPSource.cpp, PresentationTime of the RTP packet is computed using
the RTCP SR's as reference and RTPTimestamps as offset to that reference.
It means that the PresentationTime is set based on the sender's timebase.

   If both the client and the sender have synchronized clocks (e.g. by using
NTP), the clien't timebase is identical to sender's timebase and
everything is fine.

   However - what happens, if the client has a freerunning clock with some
offset and frequency difference compared to the server's clock? Is there no
risk of buffer overruns/underruns? Or is the mediaplayer supposed to
compensate for the offset/drift between the local clock and PresentationTime
as computed by liveMedia library?


	Thanks & kind regards,

		M.

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----   Marian Durkovic                       network  manager         ----
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