[Asterisk-video] video RTP question

Neil Stratford neils at vipadia.com
Mon Aug 24 10:37:46 CDT 2009


> I'm not sure that the marker bit is passed through if the header is
> stripped. Let me know how to access the marker if it is stored
> somewhere. I may have just overlooked it when I read the code.

IIRC it is in fr->subclass:

if (mark)
    rtp->f.subclass |= 0x1;

> The frame rate would also be necessary to update the time stamp. In
> theory, you could use the system clock to measure time between RTP
> packet reception. In practice, I don't know how well this works over
> real networks with packet loss, and real encoders that may drop frames
> due to negotiated bit rate limits. I'll have to think about this
> carefully for a while.

I agree - there are likely issues with sequence number jumping as well. 
The same issues apply to playing video out from a file, so it would be 
nice if it was all done without relying on RTP headers.

Neil



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