RTCP SR NTP to string UTC time and gst_rtcp_ntp_to_unix

[Mario Montagud Climent]

Dear all,

I have a similar problem. I have the C code for the transmission and  
reception RTP/RTCP pipelines, and I am able to retrieve the fields  
from the RTCP packets using the provided callbacks.

Next, I want to compare the value of the "sr-ntptime" field to the  
value of a current timestamp. I have tried with the current NTP  
timestamp, the current UNIX timestamp (using the  
gst_rtcp_ntp_to_unix() method) or to the local clock of the rtpbin  
element (or of the pipeline), but I do not obtain close coherent  
values in any of such options.

I have tried this by setting the "ntp-sync" property of rtpbin to TRUE  
and the "use-pipeline-clock" to both TRUE and FALSE.

So, basically, my question is: which clock value (and in which format)  
is used to fill the NTP timestamp field of the RTCP SR packets? How  
can I compare the NTP timestamp from the received RTCP SR packet with  
a current timestamp from my C code?

Your comments will be much appreciated.

Thank you very much in advance!

Best,

Mario

Marc Lievens <ml at bigbrother-security.be> escribió:

> Hi,
> How can I convert in gstreamer the RTCP SR NTP time to a string  
> based UTC (like 29 jan 2015 09:09:51.767990000 UTC)
> All my NTP to UTC converions seems to go wrong.
> I used combinations with gst_rtcp_ntp_to_unix,  
> g_time_val_to_iso8601, and other, but I seems doing something wrong
>
> Any help is welkom
>
>
>
>
> Met vriendelijke groet, Sincerely, Cordialement,
>
> Marc Lievens
> Research & Development
>
>
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