[mythtv-users] Alternative to Zap2It?

[Michael T. Dean]

Richard Legault wrote:

> My VCR gets it programming guide directly from the cable feed.
> I think the data is in between the image frames or something.
> The VCR has a limit of 24 hours advance on the listings.
> Is this something that a computer based PVR can use?

This has been discussed many times before on the list.  Depending on 
where you live, time of day, and program content, the technology is 
called either Program Delivery Control (PDC) or Video Program System 
(VPS) or Universal Television Program Code (UTPC) or Automated 
Measurement of Line-ups (AMOL) (and we'll just ignore the name 
StarText).  Do searches for VPS and PDC ( 
http://www.gossamer-threads.com/lists/mythtv/ ) and you'll see a lot of 
discussion.

The primary problems with the approach include:
    a) You must have a tuner card tuned to the channel for which you 
want the guide data and it must be extracting and interpreting the VBI 
(vertical blanking interval) data.
    b) The guide data for each channel is transmitted only on that channel.
    c) Not all channels transmit this data.
    d) Attempting to incorporate this guide data would wreak havoc on 
the MythTV scheduler--especially when channels are not broadcasting "on 
time" (remember, also, that each channel has it's own idea of the 
current time).  Some channels may be chronically early or late, and all 
channels experience occasional interruptions.   These occasional 
interruptions may be handled by shifting the programming schedule or 
with the, "We now return you to our regularly scheduled programming, 
already in progress"-because-who-needs-to-see-the-first-75%-of-the-show 
approach.

The benefits include:
    a) You'll still get that episode of the Simpsons that's aired 49min 
late after the game goes into overtime--or at least the last 11 minutes 
of it. ;)
    b) When the evil corporation that runs Zap2It, TMS, decides that the 
cost/benefit of direct billing a few thousand MythTV users in North 
America will bring in as much money as billing TiVo once for all its 
customers, you'll be all set.  ;)

That being said, it's probably better to attempt to find a way to use it 
in conjunction with--not as an alternative to--Zap2It.

HTH.
Mike