[vdr] Re: unique channel id

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

"Rienecker, Fa. Evenio, ITS P, M" wrote:
> 
> ...
> > I don't agree. The unique channel ID ***MUST*** be soemthing
> > that can be derived from the
> > data transmitted in the DVB broadcast. The can ***NOT*** be
> > some artificial number.
> 
> O.K. I agree.
> How about the channel name 'as transmitted' in the TS.

I think we should go with the SRC-NID-TID-SID-RID method as posted in another
message in this thread. Two different channels might easily have the same name.

> > Who would take care of registering these numbers and keeping them unique??
> 
> Good question.
> 
> > It was posted several times on this list that a combination of NID, TID and SID
> > would uniquely identify any channel (plus the 'source' parameter, in case we're[...]
> 
> That's correct.
> But some networks like Premiere tend to change the channel that is transmitted on a specific combination of NID, TID, and SID.
> The unique criteria should be the channel related not the frequency or any other tuning related parameter as they are varying.

That will be how it is done. I just started this by using the transponde frequency
(and setting NID to 0) in order to have something to work with, without having to
go all the way to actually using NID+TID. That will be done shortly, but I have to extend
the channels.conf records in order to do so. And as it turned out, radio channels need
an additional RID.

> Compare this to RDS on FM-Radio. Users don't care about certain frequencies. They want to tune to a specific station and the radio does the rest.
> 
> IIRC, DVB has the feature that for every TS (i.e. Transponder) you can tune to PID 0 and get a whole bunch of information (name, vpid, apid, tpid, sid, ...?) about all channels that are within the stream ?

That's surely something VDR will do in the future, but then you still have the problem
that you need to check whether any of these channels is already in your existing channel
list. So you need to uniquely identify them, and as far as I know this can only be
done through SRC-NID-TID-SID-RID. That's an ID that anybody can generate for _any_
given channel, without having to first consult some higher authority to request some
generated number - the number _is_ already there.

Klaus
-- 
_______________________________________________________________

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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