[mythtv-users] Changing System Time

[Joseph A. Caputo]

> -----Original Message-----
> From: mythtv-users-bounces at mythtv.org
> [mailto:mythtv-users-bounces at mythtv.org]On Behalf Of Christian Hack
> Sent: Tuesday, August 05, 2003 11:10 PM
> To: 'Discussion about mythtv'
> Subject: RE: [mythtv-users] Changing System Time
>
>
> > [mailto:mythtv-users-bounces at mythtv.org] On Behalf Of Isaac Richards
> > Sent: Wednesday, 6 August 2003 1:03 PM
> > To: Discussion about mythtv
> > Subject: Re: [mythtv-users] Changing System Time
> >
> >
> > On Tuesday 05 August 2003 10:55 pm, Christian Hack wrote:
> > > Since my system's time seems to drift a bit (it's a new
> > Asus MB :( ), I
> > > have had to update it manually lately since I haven't got around to
> > > setting up NTP.
> > >
> > > When I change my system time using the date command (my machine runs
> > > fast so it's back in time), while viewing anything (live TV or a
> > > recording), mythfrontend locks up. The display just stops.
> > Telnet into
> > > the box and kill and restart mythfrontend no problem. As far as I am
> > > aware any current recording in the backend process continues along
> > > happily.
> > >
> > > Any ideas why this might occur? Something peculiar to my
> > system or is
> > > mythfrontend going to get to stroppy at me for changing the
> > time? I'm
> > > changing it about no more than 2 minutes.
> >
> > Many things depend on timing during playback.  You can't
> > change it by that
> > much and keep things going properly.
> >
>
> OK fair enough, so what sort of time would be the maximum I can change?
> I can easily set something up to slide the time slowly OR make sure the
> time is constantly updated so it doesn't have to be changed by so much.
> If I can work out roughly how fast it runs, I can then adjust for that
> to keep it a lot closer.
>
> Currently I only have dialup, so setting up ntp in a cron job isn't all
> that feasible.


There are two issues here... one is the underlying protocol, the other is
the Myth software.  Sometimes, if you adjust the system time, a
connection-based protocol like TCP/IP could think the connection has timed
out.  The other issue is Myth itself, if it keeps track of network
communications with any kind of heartbeat or timer, it can get confused.
And, as Isaac said, playback (and probably recording, too) is highly
time-sensitive.

-JAC