[mythtv-users] Overlapping channels and program info duplication

Bruce Markey bjm at lvcm.com
Sun Oct 31 01:17:14 UTC 2004


Julian Edwards wrote:
> I searched the archives but nothing seems appropriate to this problem.  
> I've got two video sources (NTL cable via a PVR-250 and a Nova-T DVB 
> card) that have some overlapping channels.

One thing that is a potential issue in situations like this is
that just because it is the station doesn't necessarily mean
the listings are identical. People have mentioned that they get
a station part of the day on one source and 24hrs from another
source. Sometimes there is a digital and analog channel where the
digital has some special extra programming that isn't on analog.
However, if your grabbing the exact same XML this can't be an
issue for your data even if there are issues for your channels.

> Currently I have to download two XML files for mythfilldatabase which a) 
> means downloading data twice unecessarily, and b) duplicated data in mysql.
> 
> I have the overlapping channels defined twice, once in each source.  I 
> set the callsign and channel number the same so that they don't appear 
> twice in the guide.

Good. The channel priority screen now shows the source number
for each channel so you can see what you're doing if you want
to make one channel prefer one source and another channel prefer
the other source (you cannot do this with the procedure below). 

> Is there a better way of doing this or am I stuck with duplicated data?

I don't think your concerns are that big of a deal and you should
leave it as it is. However, it is possible to associate more than
one source with an input though you can't set it up through the GUI,
it isn't supported and your on your own for what happens when you
change channels, cards, inputs in live TV.

The scheduler knows that it can only use one inputid on a card at
a time and will schedule a show for the appropriate input. Which
physical input it points to doesn't matter(!). Therefore you can
make two inputids with different sourceids pointing to the same
physical input. I've done this in testing and briefly for one
channel that was screwed up in my listing for production.

In this example, let's say I have two cards. One coax has channels
2-999 the other has 2-99. the right thing to do is to set source 1
for 2-999, source 2 2-99, stop reading this and go back to taking
care of your infant child. Or, you could set source 1 for 2-99,
source 2 100-999 then set the card 1 TV input for source 1, card 2
TV input for source 1 and card 1 composite for source 2. From the
mysql prompt, it should look like this:

mysql> select cardinputid,cardid,sourceid,inputname,startchan from cardinput;
+-------------+--------+----------+------------+-----------+
| cardinputid | cardid | sourceid | inputname  | startchan |
+-------------+--------+----------+------------+-----------+
|           1 |      1 |        1 | Television | 3         |
|           2 |      2 |        1 | Television | 3         |
|           3 |      1 |        2 | Composite1 | 200       |
+-------------+--------+----------+------------+-----------+
3 rows in set (0.00 sec)

Inputid 1 and 3 are both on card 1 so the scheduler and card
selection for live TV know that they can not be used at the
same time. However, there is nothing on Composite1 and the
system doesn't care which available input is used when it is
asked to use input 3. So:

mysql> update cardinput set inputname="Television" where cardinputid=3;
Query OK, 1 row affected (0.00 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select cardinputid,cardid,sourceid,inputname,startchan from cardinput;
+-------------+--------+----------+------------+-----------+
| cardinputid | cardid | sourceid | inputname  | startchan |
+-------------+--------+----------+------------+-----------+
|           1 |      1 |        1 | Television | 3         |
|           2 |      2 |        1 | Television | 3         |
|           3 |      1 |        2 | Television | 200       |
+-------------+--------+----------+------------+-----------+
3 rows in set (0.00 sec)

Source 1 channels 2-99 are now available on the Television
input for card 1 or card 2. Source 2 channels are available
only on card 2's Television input.

If a show is scheduled on source 1, it goes to card's TV input
(look at the "S C I" columns for source, card and input). If
a movie is scheduled on a source 2 station, it goes to card 1s
TV input (3) and the source 1 show is moved to card 2.

--- print list start ---
Title - Subtitle                Chan ChID Day Start  End   S C I  T N Pri
CSI: Crime Scene Investigation     5 1005  30 19:00-20:00  1 1 1  S 1   3
---  print list end  ---

--- print list start ---
Title - Subtitle                Chan ChID Day Start  End   S C I  T N Pri
CSI: Crime Scene Investigation     5 1005  30 19:00-20:00  1 2 2  S 2   3
Star Trek: Nemesis               245 2245  30 19:00-21:00  2 1 3  S 1   3
---  print list end  ---

Anyway, don't do this.

--  bjm



More information about the mythtv-users mailing list