ccrtp-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Ccrtp-devel] timing problem


From: Federico Montesino Pouzols
Subject: Re: [Ccrtp-devel] timing problem
Date: Tue, 22 Jul 2003 14:15:15 +0200
User-agent: Mutt/1.3.28i

        Hi. Yes, it loses precision. However, at first sight it seems
to me that the loss is not cumulative within ccRTP, so it shouldn't
result in a stationary error. I will test it later.

On Thu, Jul 03, 2003 at 11:09:47AM +0200, Luuk van Dijk wrote:
> Hi,
> 
> I have 2 timing problems with a streaming audio app. over ccrtp.
> 
> I'm using 1.0.1
> 
> one is that although I tell my soundcard to sample at 44100 Hz, 
> it is slow compared to the system clock: I start the timestamp with
> getCurrentTimestamp, and increment the timestamp by the number of
> samples, but then the ratio timestamp/system clock starts at 1 but
> withing some tens of seconds settles around .9825
> 
> when the difference between my timestamp and getCUrrentTimsstamp reaches
> the ExpireTimeout all transmission stops. (of course)
> 
> The second timing problem is that about half of my packets are dropped. 
> I saw a related discussion on this list's archive, and it was presumably
> fixed, (somewhere in the calculation of the reminder of the timeout),
> but I still have the problem, although, admittedly, it gets worse if I
> replace
>               send.tv_usec = (1000ul*rem) / (rate/1000ul); // 10^6 * rem/rate
> 
> by .... = (1000*1000*rem)/rate
> 
> still I think the first one loses precision at rate = 44100 
> 
> any ideas?
> 
> thanks,
>       Luuk



> _______________________________________________
> Ccrtp-devel mailing list
> address@hidden
> http://mail.gnu.org/mailman/listinfo/ccrtp-devel





reply via email to

[Prev in Thread] Current Thread [Next in Thread]