[vdr] Re: Recording programes followin one another from the same channel

[Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de>]

Rainer Zocholl wrote:
> 
> andreas@eudoxus.xcapenet.de(Andreas Gebel)  17.10.01 10:02
> 
> Once upon a time Andreas Gebel shaped the electrons to say...
> 
> >Hi
> 
> >when trying to record programmes following one another there is a
> >problem that vdr stops the recording at the end of the first timer and
> >re-enters the recording mode just after that. This will always cause a
> >few seconds lost between the two recordings.
> 
> Currently VDR seems to look only for the minutes.
> "While timer time is equal "now" do record."
> So the overlap/missing maybe upto 59sec.
> 
> timer 15:00 .. 15:30
> will record from 15:00:00 to 15:30:59 (AFAIK)

Did you actually test that?

As far as I know (and from what I can see in my logs and from the
source code) a timer that has a stop time of 15:00 ends at *15:00*.
Ok, recently I have introduced a one second offset, so it actually
ends at 14:59:59, but I guess that really doesn't matter. The reason
I did this was to make sure a timer with a stop time of 15:00 ends
_before_ a timer with a start time of 15:00 starts. This keeps them
from unnecessarily occupying the primary card on a two card system.

> To record the entire and not more than required
> the user have to programm
> 
> timer 14:59 .. 15:29
> 
> to record from 14:59:00 to 15:29:59.
> 
> That's not "look and feel" :-)
> 
> I think it would be easier if VDR would take the seconds
> into account, asymmetrical..
> 
> Example:
> 
> timer 15:00 .. 15:30  (as the user "thinks" and sees in the EPG etc.)
> will record from 14:59:55 to 15:29:59

With respect to the stop time, that is exactly what's happening.
IMO it makes no sense to shift the start time - no tv station
performs _that_ exact a timing (I do wish they would, though).

> There would be only 4sec "overlap"
> (
> Why not start at 14:59:59 or 15:00:00?
>   Because the first seconds are often/sometimes a little "garbeled"...
>   and if the device is not blocked: Why annoy the user?
> Why is starting at 15:00:00 not sufficient?
>   Because the PC-clock may not be so precise so the first, sometimes
>   important seconds are not recorded.
>   The next "step" would be a 60sec margin...giving a large
>   unexceptable gap/overlap.
> Why not recording in one file?
>   Because this do not help if it should record from
>   different channels.
>   Because "auto naming" would not work.
>   Because it is very unconvienent.
>   Because both records may not have the same priority and hold time.
> )
> 
> actually nothing from the 15:30-transmission will be lost, maybe
> one second of the end of 15:00-transmission, which is normaly not
> so important to view... (if it is, the problem is due to be solved by
> the user, for example by buying an extra card. VDR can't)
> 
> And the user do not have to bother with "margins".
> 
> This "shift second(s)" may be user
> configurable because it depends on the accuracy of the PC-clock,
> which varrie from PC to PC.
> 
> (Problem: Some TV channels do not transmit exact time.
> Had someone tested which time MTV (for example) uses to
> start transmssions? If DCF or so, then it would be nice
> to be able to block systimer setting for specific channels
> (easier: allow it for only a few known "have to be by law"
> precise like ZDF) in channels.conf or similar.)

That's going to happen (some day). But since I don't use that
feature it has low priority (at least for me). I keep my machines
in temporal sync with Linux tools (like 'netdate' or 'ntpd').

> >No problem if there is a commercial break between the two programmes
> >but on channels like ProSieben there is often not.
> >My suggestion is that vdr looks if overlapping timers are programmed
> >on the same channel and writes the dvb data to the two recording files
> >simultaneusly.
> 
> This would be real elegant, but i think it would really become complicate.
> The next point will be:
> VDR should check all timers for resource overlaps...
> That might require a redesign of this part of VDR...
> 
> >I have no idea about coding such a thing but I think this would be a
> >nice to have feature that is usefull for others, too.
> 
> I would be lucky if VDR would do the 55-seconds-"trick"
> (resp. "shift start second").
> That does not sound so very complicate, or?

You're free to do that. However, I prefer to have timers start and stop
at the times *I* have set. You always need to add a few minutes to the
beginning and end to make sure you catch the whole show. And even then,
there's always an unexpected "heute spezial" that shifts everything...

Klaus
-- 
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Klaus Schmidinger                       Phone: +49-8635-6989-10
CadSoft Computer GmbH                   Fax:   +49-8635-6989-40
Hofmark 2                               Email:   kls@cadsoft.de
D-84568 Pleiskirchen, Germany           URL:     www.cadsoft.de
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