[mythtv-users] Need help with meaning of channel table fields

R. G. Newbury newbury at mandamus.org
Tue Jan 16 16:58:39 UTC 2007

Nick Morrott wrote:
> On 15/01/07, R. G. Newbury <newbury at mandamus.org> wrote:
>> zap2it lineup accordingly by deleting the 'wrong' one. You cannot have a
>> channel appear in 2 different lineups. Xmltvid's are supposed to be
>> unique in the channel table: in fact, I am not sure how you were able to
> For non-US users, note that these restrictions do not always apply.
> For the uk_rt XMLTV grabber, channels carrying the same station on
> different video sources can share the same XMLTV ID, and stations (for
> example BBC ONE, ITV1) can exist on more than one video source. As I
> understand and have things configured, all channels available on a
> given video source (analogue/DVB/cable/satellite) should be configured
> to give the scheduler the most flexibility when scheduling recordings
> across multiple input sources.
> Nick

And, on reflection I am wrong in stating that you cannot have a 
"channel" in two different lineups, for the same reasons you state. But 
in that case, each channel table entry must completely set out the 
tuning parameters for the channel as if it were the only instance of 
that channel.

The confusion arises from the sloppy wording we use. We can call it a 
'channel', when we mean a program source, but also when we mean a 
delivery method, which may be done by completely different physical routes.

We really need to be more precise at defining what we mean. For an 
analogy, think of the program listings of TV station X as a catalog, 
which may be delivered to you, by (snail) mail, by facsimile, or by 
email as text, or by email as pdf. Describing how it is delivered is 
distinct from which catalog(s) you want delivered.

A 'lineup' is a list of those catalogs, each described by an xmltvid, 
which can be delivered by a similar setup and through the same hardware.
(which delivery method has priority is a separate myth problem!)

If your catalog can be delivered by 2 distinct methods, the only 
overlapping item would be the xmltvid. There must be 2 channel table 
entries, each with its proper supporting tables (if required).


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