[mythtv-users] MythTV and TV

[yan seiner]

R. G. Newbury wrote:

>You cannot just change the Input Connection if the Source is a different 
>type.
>The order in which things are done in mythtv-setup is slightly 
>misleading in that a user can infer that the *card* is the most 
>important part of the process. Actually the *lineup* is the most important.
>The channel lineup, at least for North American users, will 
>differentiate among cable, cable digital and broadcast.  Labs.zap2it.com 
>will allow you ONE lineup of each of those types. Each of those has 
>different connotations:  'cable' runs from 2 to 71 or so, 
>'cable-digital' has "channel numbers" which run up to 999 I guess, but 
>the frequencies involved are all actually the same range as 'cable' but 
>with subchannels. Broadcast can be analog or digital. Broadcast digital 
>is handled in a similar manner to cable-digital, but the numbering 
>scheme is different.
>
>Cards handle either analog or digital streams (NTSC or ATSC),  BUT NOT 
>BOTH AT THE SAME TIME.
>
>That differentiation also determines what tuning information ( a 'tuning 
>set') that mythtv sends to the card. Changing the information in mythtv, 
>without any change to the lineup can produce a useless tuning set. I 
>don't know what your card is, but if you are using an HD level (ATSC) 
>card for OTA, then no wonder it will not work properly if you tell the 
>card (through myth) that it should tune as if the input were a cable 
>channel. Although transmission frequencies are the same for analog 
>broadcast and analog cable channels and the underlying frequency may be 
>the same for an HD digital broadcast, the manner in which the card 
>abstracts the digital stream is quite different for a digital broadcast. 
>To get an analog stream (channel 9 not channel 9_1) needs an analog 
>module setup. ( For the pcHD3000, you use cx88_dvb for ATSC, and cx8800 
>for NTSC).
>
>Digital broadcast is not the same thing as Analog broadcast and requires 
>not only a different kernel module for the card but also a different 
>setup in myth even if the lineup is still the same.
>
>Note also, that if the lineup type remains the same, you will run into 
>problems if that lineup includes both analog and digital channels, since 
>myth does not actually know that a card cannot do both. You must set up 
>lineup <-> card pairings where that card can actually tune all of the 
>channels in that lineup. So a PVR500 should never be paired against a 
>cable-digital lineup or a broadcast lineup which includes digital 
>channels: it cannot tune those channels. Similarly, a pcHD3000 should 
>not be paired with a lineup which includes analog channels unless the 
>card is set up to use an analog tuning module...
>
>And as far as I can tell, you cannot switch modules, 'on-the-fly' while 
>myth is running, since myth checks each input card on startup, and would 
>fail when it did not find the 'other' type of input.
>
>Geoff
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Thanks.  I finally got around to reading this in peace.  Lots of good 
information.

The card I have currently is in fact an analog card - bt878, and, as 
from my previous posting, I had digital channels mixed in there.  So I 
will set it up accordingly.

I also have a pcHDTV 3000 coming next week; I will set it up to receive 
digital channels.  It's good to know that I have to set it up for one or 
the other; I am very new to this part of Mythtv....

My hope is to be able to use both cards simultaenously, but for now I 
will be happy to get one to work... :-)

--Yan