[mythtv] Use callsign for scheduling

Brian May bam at snoopy.apana.org.au
Sat Apr 17 19:54:27 EDT 2004

>>>>> "Bruce" == Bruce Markey <bjm at lvcm.com> writes:

    Bruce> When you tell a friend that a show is on a station, you don't
    Bruce> say "the one with the green background and a globe at an angle
    Bruce> with a line going through it" ;-). Every station has a name that
    Bruce> you know it as, even if it is not assigned by a government
    Bruce> agency. There is something that will fit in a varchar(20) that
    Bruce> tells you who the broadcaster is and that their listings are
    Bruce> associated with this channel. The field in the channel table
    Bruce> that contains the string to identify the broadcaster is the
    Bruce> "callsign" field. That is true even if you had previously
    Bruce> misunderstood and assumed that callsign was merely decoration.
    Bruce> This is a key piece of information that you need to fill in
    Bruce> if your grabber doesn't do it for you. If it's left blank then
    Bruce> myth will have to do what it needs to do to get the job done
    Bruce> which is to use the chanids in it's place.

In Australia, around capital cities, we refer to stations by channel,
eg. "Channel 9".  IIRC, the company name is similar. There is no other
way we can refer to it.

You want to use callsign for two purposes:
1. to display to user.
2. to use as database {primary,foreign} key.

However, this only makes sense in countries where users commonly refer
to channels by a callsign. In other countries, the callsign
essentially becomes a database key that has no direct meaning to the

As a workaround, we could set the callsign to be the channel, eg "9".
However, mythtv already knows the channel number, setting 9 up to be
the callsign would appear to be confusing (as both are displayed to
the user in MythTV).

As there is no allocated call sign though, the "callsign" entered is
subject to change (should I enter NINE, or 9, or Channel9, or Channel
9, or NIN, or what?), and has to be changed to update the user
interface display. As such I do not believe it should be used as a
primary or foreign key in the database, unless you want to ignore
countries outside USA.

However, I am running out of spare time, so this may be my last post
on the topic for now.

As always, there are exceptions to the above rules:

* the two government run channels (ABC and SBS). Even for these cases
  we commonly use "channel 2" and "channel 28" as equivalents. This is
  despite the fact channel 2 is often broadcast on channel 4 in some
  areas, IIRC.

* country areas. eg. "Channel 9" is rebroadcast (on a UHF channel), by
  another company thats calls itself "WIN TV" (hopefully I got the
  right one). "WIN TV" is almost identical to "Channel 9", except it
  is the only one available in country areas, only available in
  country areas, and the advertising is completely different. The name
  "WIN TV" has no meaning in city areas.

  In a country area if you say "go to Channel 9" you actually mean "go
  to the equivalent of channel 9 in this area". (this is one case I
  suspect mythtv can't handle very well at the moment, not tested).

* As above, "Channel 9" isn't always broadcast on channel 9 (just to
  make matters more confusing). Same for the over channels.

As perhaps an alternate solution, maybe we could invent "myth
standard" call signs for channels in countries that don't have any?
Perhaps base this on the xmltvid?
Brian May <bam at snoopy.apana.org.au>

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