[mythtv-users] Tuner cards that do HD?

[R. G. Newbury]

Brian Long wrote:
> On 4/16/07, R. G. Newbury <newbury at mandamus.org> wrote:
>>
>> <snip>
>> There is one slightly difficult bit: Not in getting the hardware to
>> work, but in matching it to your cable lineup (see below).
>> The hardware side is dead easy.
> 
> 
> <snip>
>>
> So although myth can identify 'a' channel, at 74#3 it has NO knowledge
>> about how that stream is identified at zap2it. It is up to the user to
>> determine that the one originally called '74#3' is really described as
>> 125 by your cablco....and that 125 is xmltvid 10123, callsign WXYZ.
>>
>> Once you tell myth that you want the channel tuned at 74#3 described as
>> 'Channel 125' and 'WXYZ' (as listed by zap2it) it knows how to pull down
>> the listings for the channel, and to tune that channel when requested.
>>
>> Now whether the mythfilldatabase listings actually match the tv
>> listings, and whether you have actually discovered the correct channel
>> are......unknown...
> 
> 
> Gee whiz, this is unintuitive.  Have there been any discussions on making
> this easier for end users?  Could we start a central repository of
> geographical mappings based on each service provider so only one poor soul
> has to go through this pain?  I wonder if Zap2It could be expanded to
> provide this mapping for us...

It's not so much unintuitive as it is arbitrary. There is really no way 
to make it easier.
The cablecos put digital streams (or analog channels for that matter) at 
places within their spectrum entirely at their discretion. They are 
motivated by all sorts of factors. In the greater Toronto area, Rogers 
Cable has 3 distinct areas, with *different* analog lineups and with 
different digital structures. Why? Age and capabilities of the 
infrastructure?? ....Size of the general manager's left foot? (Although 
with Ted Rogers well-known proclivity for micro-management, he would 
only allow *his* foot to be used for measurement of anything where a 
foot was required...).

But so far as I can tell, Rogers uses the same virtual (arbitrary) 
channel numbering for all of the digital streams. It changes the actual 
broadcast frequency of channels quite often (but rarely the serviceid). 
This likely means that  zap2it could not (or would not) help. Zap2it 
only 'knows' the xmltvid, callsign (name) and virtual channel within a 
particular mapping area for a particular cableco. The xmltvid and 
callsign are unique. The cableco/area/channel data is a 'many to one' 
relation stretching continent wide.. Zap2it does not need (nor likely 
want) to have to keep track of the actual frequency plus serviceid plus 
virutal channel number.

It would be DAMN nice if it did! Anyone know anyone who can be prevailed 
  upon to ask for this info from the cablecos????

Since as far as I can tell, neither the FCC nor CRTC request this or 
require that this information be made public...

The info is likely only available within an encrypted control stream, 
sent to the set-top box, and I would make a small wager that the box 
must be programmed with keys provided by the cableco, in order for the 
box to understand that stream and to re-program itself to react to 
lineup changes. (I have never played with an STB so i do not know how 
they react to frequency moves.)

As to helping ourselves: it will take at least one poor soul to do this, 
for each and every cableco, in each and every distinct service area... 
and post the results in the wiki...

Geoff

           newbury at mandamus.org

        Helping with the HTTP issue
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