[vdr] Re: unique channel id

["Rienecker, Fa. Evenio, ITS P, M" <C.Rienecker@deutschepost.de>]

[...]

> > How to construct a unique channel ID:
> > Don't use anything related to real world values. Especially tuning
> > parameters, because they _ARE_ changing.
> > Don't use plain channel names, because people use different names for the
> > same channel ('PRO7', 'PRO 7', 'Pro 7', 'Pro-7', 'PRO-7', ...)
> > The easiest Way would be to just start numbering, starting from 1 and add
> > new channels at the bottom of the list.
> > Artificial keys have proven to be the best way to perform a join over two
> > tables (the channel list and the tuning parameter list).
> > 
> > Of course there are channels available from different sources, i.e. various
> > tuning parameters. E.g. 'ARD - Das Erste' is available in Berlin from cable,
> > terrestrial, Astra, Hotbird and maybe more.
> > Basiccally there are two ways to handle this:
> > 1. Assign one unique channels ID for each sourse and let the user decide
> > which one to use in his personal channel list.
> > 2. Assign just one unique channel ID to ARD and make vdr aware of the
> > capabilities of the local equipment. E.g. VDR is configured to only receive
> > Astra and subsequently choses the tuning parameters related to Astra
> > ignoring the other ones matching the unique channel ID.
> > 
> > I don't want to offend anyone, but my personal opinion is that the way
> > 1.1.16 is implemented we have introduced restrictions without gaining
> > benefits.
> > 
> > My suggestion would be something like this:
> > add a field 'unique channel ID' to the channels.conf, keep everything else
> > the same for compatibility reasons.
> > Actually the ca filed must still be used since this is something that might
> > dependend on the local setup.
> > 
> > channels.conf:
> > ----schnipp----
> > :@1 RTL
> > RTL::::::::0:;1
> > RTL2::::::::0:;4
> > :@11 ProSiebenSat1
> > Sat.1::::::::0:;2
> > Pro-7::::::::0:;3
> > :@21 ARD
> > Das Erste::::::::0:;5
> > ----schnapp----
> > 
> > And add a new file 'tuner.conf' that has the unique channel ID instead of
> > the channel names.
> > 
> > tuner.conf
> > ----schnipp----
> > :Astra
> > 1:12188:h:S19.2E:27500:163:104:105:0:12003
> > 2:12480:v:S19.2E:27500:1791:1792:34:0:46
> > 3:12480:v:S19.2E:27500:255:256;257:32:0:898
> > 4:12188:h:S19.2E:27500:166:128:68:0:12020
> > 5:11837:h:S19.2E:27500:101:102:104:0:28106
> > :terr Berlin
> > 1:658000:I0C23D0M16B8T8G8Y0:T:27500:337:338:0:0:16405
> > 2:658000:I0C23D0M16B8T8G8Y0:T:27500:385:386:0:0:16408
> > 3:658000:I0C23D0M16B8T8G8Y0:T:27500:305:306;307:0:0:16403
> > 4:658000:I0C23D0M16B8T8G8Y0:T:27500:353:354:0:0:16406
> > :telekom cable
> > 5:410:M64:C:6900:101:102:104:0:28106
> > ----schnapp----
> 
> 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.

> 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. 
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 ?

Maybe we can use this.

CU,
Christian.


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