[mythtv-users] satellite receiver tuner card

[Joe Votour]

> Joe Votour wrote:
>>
<snip>
>>
> I'm a little confused as to what my TV can do that a TV card couldn't.
> I get HD programing over COAX/UHF via antenna.  Wouldn't the cable box
> transmit HD over COAX to the TV or the TV card?  If it used firewire or
> hdmi or composite or svideo, aren't there cards that accept those?  Is
> the encryption issue dealing with cable cards?  I take it those are hard
> to come by for a PC?  I take it IR Blaster is either directly supported
> by mythtv, or is easy enough using something like lirc and the mythtv
> channel change command option?
>
> -Eric Hattemer
>

I don't know what kind of TV you have, so I couldn't say.  A TV that
supports connecting an HD capable antenna (UHF) has the equivalent
electronics of an ATSC/QAM receiver/demodulator in it.  This demodulator
converts the analog signal (which comes in either from QAM or OTA) into
the MPEG-2 data that was sent.  This MPEG-2 data cannot be displayed by a
regular TV, a MPEG-2 decoder is required, which these TVs would have.

To do this on a PC, you require a card capable of capturing these signals,
plus MPEG-2 playback on the PC.  What I have just described is the
simplest case.

Every cable/satellite company in the United States encrypts their digital
signals (all satellite signals are digital) for some reason (whether it's
at the request of the actual content providers, or the cable company is
trying to make people's lives difficult).  This encryption, for the most
part, has not been cracked - attempting to crack it in the United States
is a felony, punishable by the DMCA.  Thus, there are no cards available
in the United States right now that can decrypt them.(1)

Because of this, you'll have to use the satellite provider's set-top box
to decrypt the signal and feed it into some sort of capture device for
MythTV to use.  An IRBlaster is a device that sends IR codes to the
set-top box to tell it to change channels.  MythTV needs to be able to
control the set-top box in order to change channels for any sort of TV
operations.

My hope is that eventually CableCard will improve and become a fully
supported standard.  Then we can have a situation similar to those in
Europe have with DVB - there are a number of DVB cards (that work under
Linux even) that support CAM - Conditional Access Modules.  A DVB card
with  a CAM lets you insert the SmartCard that you received from your
provider and use it to decrypt the stream.  You receive a decrypted stream
from the card, which you can store to your hard drive and play back.

-- Joe

(1) Yes, there has been the announcement of ATi's CableCard box.  I've
heard nothing more than the annoucement - additionally, CableCard isn't
fully supported at many cable companies anyway.
As I said in my previous post, although I don't know the full details,
some people have pulled in Dish Network FTA programming using a DVB-S
card.


___________________________________________________________
$0 Web Hosting with up to 200MB web space, 1000 MB Transfer
10 Personalized POP and Web E-mail Accounts, and much more.
Signup at www.doteasy.com