[mythtv-users] Interesting false match

Nick knowledgejunkie at gmail.com
Sat Dec 24 18:14:06 EST 2005

On 23/12/05, Bruce Markey <bjm at lvcm.com> wrote:
> > Using the uk_rt XMLTV grabber, all of my program entries have a
> > seriesid, even movies. This is where category="film" and
> Hum. Movies aren't serial. This is probably the result of some
> misunderstanding. AFAIK no one contacted me or any other dev
> about how to best use these fields for the sake of searching
> and scheduling in myth.
> > category_type="movie". The programid is the seriesid prepended with
> > "MV", and only movies have a programid.
> Checking for 'programid LIKE 'MV%' was a quick optimization for
> DataDirect once we first had programids and this looks like a
> smart way to piggyback this. However, category_type is more
> consistent and doesn't involve a wildcard to find a match. I've
> always disliked the name "category_type" and the these are
> hard coded lower case strings in the English language. In the
> future I expect that I'll pick another field name for an enum
> int such as
> 0 = ptTVShow
> 1 = ptMovie
> 2 = ptSeries
> 3 = ptSports
> so 'if (proginfo->program_type == ptMovie)' or whatever.
> > The showtype field is unused
> > for all program entries.
> This was added along with a bunch of other DD specific fields.
> This is informational and not used for searching or scheduling.
> mysql> select count(showtype),showtype from program group by showtype;
> +-----------------+------------------+
> | count(showtype) | showtype         |
> +-----------------+------------------+
> |            7883 |                  |
> |            1824 | Limited Series   |
> |              39 | Miniseries       |
> |            3625 | Paid Programming |
> |               7 | Serial           |
> |           19353 | Series           |
> |              97 | Short Film       |
> |            1681 | Special          |
> +-----------------+------------------+
> 8 rows in set (0.13 sec)
> > After the fun of setting up MythTV, I think anyone would take a Type I
> > error over a Type II error any day of the week!
> Well, nothing in your message was labeled Type I or II nor is
> there a clear compare and contrast so there is no way to know
> what you are talking about but I'm pretty sure that an exclamation
> point doesn't elevate an assumption to become a fact. If you were
> assuming that testing the category_type also would be a cure all
> for all ills, this hypothesis is incorrect.

Sorry, these are standard statistical terms which I didn't state. A
false positive - Type I -  (the scheduler flagging an 'incorrect'
program and recording it) would always be preferable (diskspace
allowing) to a false negative - Type II - (the scheduler does not flag
a desired program, and so it is not recorded. The frequency with which
such a situation like Allan's occurs must be very small - and like
him, I'm frequently checking the upcoming recordings via MythWeb to
see that my desired pograms are being scheduled (although this is
usually due to listings information, rather than the scheduler

With the uk_rt grabber, the only entries in the program table that
have a category_type are movies, the rest are blank, so there's no way
that my suggested comparison of category_types would work with this
particular source of listings. I'm guessing that the US Data Direct
grabber is able to provide more information, or the category_type
information is derived from the listings data for DD that may not be
created from other listings sources? Certainly, none of the sports
events that have a category of "Sports" have a category_type set - is
the category_type field used to group together entries with similar
category values?

SQL-query: SELECT distinct `category` FROM `program`;

Game show
News and Current Affairs
Music and Arts
Show / Game Show
News / Current Affairs
Talk show
Current affairs
No Genre

SQL-query: SELECT distinct `category_type` FROM `program`;


> The reason that I posted a long message on seriesid is because
> I don't think there has ever been a posting in the archives
> explaining why we decided to not use them (I kind of anticipate
> that Mike Dean will post links to that message when someone asks
> about seriesids =).

Thanks so much for providing such a detailed explanation - I'm sure
that many users will find this a very useful addition to the archive.


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