RE: [Linphone-developers] Linphone in 32-bit calculations

[Micha Nelissen]

Micha Nelissen wrote:
> I also regularly see:
> 
> ortp-message-synchronizing timestamp, diff=-1760
> warning! alsa write underrun!
> ortp-message-synchronizing timestamp, diff=960

Turns out the cause for this was the system (linux) clock running too
slowly in comparison with the soundcard providing samples. The following
piece of code:

        if ((diff > delta) || (diff < -(delta * 5))) {
                d->tsoff = curts - packet_ts;
                netts = packet_ts + d->tsoff;
                ms_message("synchronizing timestamp, diff=%i", diff);
        }

Was then executed, which caused a (backward) timestamp jump in the sent
packets. This in turn causes the receiver to drop packets because they
are too old.

I think the media streamer should try not to send timestamps that are
older than the last sent ?

TBH, I don't entirely see the point of the timestamps, since there are
also sequence numbers already ? Anyone have a good doc on this ?

Thanks,

Micha