[mythtv-users] HD Homerun Prime Scripting

Eric Sharkey eric at lisaneric.org
Wed Oct 19 13:37:06 UTC 2011


On Wed, Oct 19, 2011 at 6:11 AM, Mike Perkins
<mikep at randomtraveller.org.uk> wrote:
> On 18/10/11 21:07, Eric Sharkey wrote:
>> On Tue, Oct 18, 2011 at 11:48 AM, Kirk Bocek<t004 at kbocek.com>  wrote:
>>
>> I still feel that it would be best to have a single video source for
>> both prime and non-prime tuners, but, since the devs seem to have no
>> aesthetic problems with the current proliferation of video sources,
>> we're pretty much stuck with having to maintain the non-prime source
>> based on external information.
>>
> A 'source' defines the channels available to a single method of tuning, plus the
> means of tuning them. Therefore, you /cannot/ use the same source for both prime
> and non-prime channels, since by definition the lists of channels available will
> be different. (If they are not, why are you bothering?)

That's the current mythtv design, yes.  I'm critiquing that design and
expressing that I fundamentally disagree with design decisions for the
mythtv database schema.

The problem, as I see it, is that the database has lots of duplicate
information and fails to measure up to a single source of truth
design:

http://en.wikipedia.org/wiki/Single_Source_of_Truth

When Comcast sends me a channel, they send it once.  It has one
frequency, one call sign, one xmltvid, one virtual channel number,
etc.  Why do I need to have this channel information duplicated in the
database?  It's important that this channel have the same call sign in
all of its entries but the call sign is usually slightly different
when doing a clear qam scan vs. downloading the list from schedules
direct and it's up to the end user to sort this out.  Why is that?

You could separate this out by splitting the channel table in two.
Have chanid, callsign, xmltvid, virtual channel number, etc. in one
table, and make the video sources table be just the sourceid, chanid,
and tuning information for that that channel on that source.  That
would simplify maintenance of the qam channel list considerably.

Eric


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