[mythtv-users] 1 CableDigital Lineup available to chose but need 2 sources from it

[Michael T. Dean]

On 10/16/2007 01:26 PM, David Brodbeck wrote:
> On Oct 16, 2007, at 10:14 AM, Michael T. Dean wrote:
>   
>> In this situation--by
>> definition--any channels in the analog-only lineup and the
>> unencrypted-digital-only lineup would be duplicated in the all- 
>> channels
>> lineup.  Therefore, we would waste bandwidth downloading the same
>> information multiple times.
> Wouldn't MythTV would cache it?  I have two different lineups that  
> have overlapping channels, and the overlapped ones are only  
> downloaded once.
>   

Myth downloads each SD lineup that's associated with a video source, so
if you have different SD lineups and they have the same channels, all
the redundant channels' data will be downloaded once for each lineup
that contains that channel.  When we request data for a lineup, we get
the data for the /entire/ lineup--all channels--there's no way to
request download of only some of the channels' data in a lineup. 
Therefore, the only time we can cache the data is if multiple video
sources use the same lineup.

To the end user, though, it may seem they're downloaded only once since
Myth doesn't report detailed information on the specifics of how things
are downloaded and since most users tend to configure their systems to
hide the fact that WOFL Fox 35 may actually be specified in 2 or more
channel( ID')s (each associated with a different video source)--i.e.
they're not duplicated in the guide--so the distinction isn't apparent
in normal usage.

>> Instead, perhaps those who work through this process can document  
>> their
>> approach and submit patches to Robert for his (much better than the  
>> one
>> I did on the lists) writeup (
>> http://mythtv.org/docs/mythtv-HOWTO-24.html#ss24.4 ) of how to  
>> configure
>> a system to use one lineup for multiple video sources.
>>     
> That has always seemed like kind of a hack to me, because it means  
> going back and forth a couple times with Myth and the SD channel  
> editor and then altering how MythTV runs its updates.  It just seems  
> clumsy and error prone.

There are other ways to do it--i.e. set up the lineup with all channels
and delete the extras from each video source--but someone needs to write
up detailed descriptions they created while actually doing the process. 
Also, it may make sense to describe different approaches depending on
channel distribution (i.e. one source contains all channels and another
source contains only a subset, two different sources contain different
subsets of the provider's channels, three or more different sources use
the same lineup, etc.).  This is what I'm suggesting those who have
found the approach in the HOWTO cumbersome should do--write up the most
efficient approach they found for configuring the video sources for
their systems.

I have only one lineup and only one provider (OTA), so although I could
write up the process, I have no way to test that the theory actually
works (or is actually a "usable" way of doing things).  Besides, anyone
who attempted to follow my original write-up (
http://www.gossamer-threads.com/lists/mythtv/users/285225#285225 ) would
probably vote for finding a different author.  :)

Mike