[mythtv-users] LIRC help needed with IguanaIR and PACE DC50X

Michael T. Dean mtdean at thirdcontact.com
Fri Jul 2 17:34:45 UTC 2010

  On 07/02/2010 01:10 PM, Jarod Wilson wrote:
> On Fri, Jul 2, 2010 at 10:58 AM, Brad Fuller wrote:
>> On Fri, Jul 2, 2010 at 04:21, wrote:
>>>> My next problem is the setting in myth setup. I have a PVR250 and
>>>> placed the channel changer script in the appropriate place, set it to
>>>> channel 3 and tested it with Live TV.  All I got was a blank screen.
>>>> (I have 3 other tuners that work fine and I switched to this one.)
>>>> I see in the WIKI that Myth does not take channel number but freq ID.
>>>> Is that still the case (don't know if the wiki is up to date)
>> Anyone confirm or deny this?
> I think that's correct. But for channels coming through a cable box,
> unless you've manually changed the channel number the station is
> mapped to, they're going to be identical. It definitely needs it to
> use freqid though, because if you've reassigned, say, channel 505 to
> channel 5 in your frontend, what you need to send to the cable box to
> get it to the intended channel is 505... But yeah, on my own setup,
> for every channel coming through a cable box, channum == freqid.

Yes.  Exactly.

Channel numbers allow Live TV users to switch directly to a specific 
channel using a remote (so the channel numbers are user-assignable, 
allowing you to fix the stupid numbers your cable company gives so you 
can tune Fox 35 with the channel number 35 instead of channel 3 that 
your cable company uses).

Channel frequency IDs tell the tuner/tuning script how to tune a 
specific channel.  They are user-editable, but are required to be some 
value that the tuner/tuning script understands (so they're "assigned" by 
the broadcaster or the writer of the tuning script).  So, if you're 
using some internal tuner, you'd need to use the frequency identifier 
(i.e. number withing a frequency map) or frequency in kHz, but you can 
use a channel-change script that maps whatever values you want to 
specific tuning commands.  Generally, though, for a channel-change 
script, it makes the most sense to use just specify a frequency ID that 
can be passed directly through to the external tuner (the STB).

Channel callsign tells the scheduler which channels are distinct (as 
distinct callsigns mean that channels are distinct for the purposes of 
scheduling).  Callsigns are used for "this channel" rules to determine 
which channels to consider (where callsigns match).  Channel callsigns 
should never be the same unless the content on the channels is identical.

And, the combination of channel number and channel callsign can be used 
to prevent redundant display of data in the EPG.  If multiple channels 
have identical channel numbers and callsigns, they will be displayed 
only once in the EPG (rather than display multiple rows with identical 
data right next to each other).  Note, also, that--because the channel 
number is used to allow Live TV users to switch directly to a specific 
channel--if you set multiple channels with identical channel numbers, 
you won't be able to tell MythTV which of those identical channels to 
tune in Live TV:  i.e. you're saying they're truly identical for all 
purposes--scheduling, Live TV viewing, and EPG--and you don't care at 
all which is used.


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