[mythtv-users] Questions about v4l, digital cable, and the WinTV-D

Joseph H. Fry joe at thefrys.com
Fri Mar 14 22:05:14 UTC 2003

Digital Cable <> Digital Television

Digital Cable was designed to transport the video signal to the set top
box using digital technology in order to improve signal quality, allow
for Dolby digital surround sound, and potentially carry High Definition
TV (Digital) television signals.  The reason for digital cable boxes is
similar to the purpose for satellite boxes, to decode the digital
signal, and to provide security so only subscribed users can use the
digital signals.

I guess what I'm saying is that no, the digital tv card will not decode
digital cable signals... it is designed to support HDTV signals received
via a rooftop antenna.  (Ever notice the "High Definition where
Available" message on many network shows?)

So in your situation the only way to get digital cable signals into your
mythtv box would be to use the digital cable box to decode the signals.
And to control it with an IR blaster

I just wish they made TV cards for DSS and Digital Cable but then we'd
all have one wouldn't we. Wouldn't no analog to digital conversion be


-----Original Message-----
From: mythtv-users-bounces at snowman.net
[mailto:mythtv-users-bounces at snowman.net] On Behalf Of Ray Olszewski
Sent: Friday, March 14, 2003 3:56 PM
To: Discussion about mythtv
Subject: Re: [mythtv-users] Questions about v4l, digital cable, and the

At 03:33 PM 3/14/2003 -0500, Joey Adams wrote:
>First of all I'm very impressed with what I've seen of MythTV so I've 
>decided to build a machine to run it on.  I have digital cable 
>(Scientific-Atlanta decoder box) but I didn't want to have to go the IR

>Blaster route so I started looking for a tv tuner that could decode it.
>found the Hauppauge WinTV-D 
>that looked like it might do the job, at least it does Digital TV.
>DTV is the same as "digital cable" right?

The "standards" (standards? hah! we don't need no stinkin' standards)
digitizing TV signals are a mess. As a general rule for TV products,
assume *anything* digital works with *anything else* digital unless you 
have specific reason to believe it does. In this case ... I don't know
sure, but I believe the Hauppauge card you refer to supports some
form of broadcast TV, not any of the common digital-cable formats.

>And if it is, is the card even supported under linux?   I'm guessing
>but the only reference to the card that I found was from the middle of

 From the link above, the card appears to present to the linux-v4l
as though it were a standard bt878 card (seemingly with some hidden, 
internal stuff to handle digital signals on some of the channels). I'd 
**guess** from this description that it does work with Linux  for
analog signals -AND- probably for standard Digital-TV signals, but -NOT-

with digital cable. I offer this only as a guess based on reading the
description, though, not as a definitive answer based on actual
with it.

>I was reading through the links on the Video for Linux Resources page
>apparently Hauppauge cards aren't the best supported either...

Nonsense. I've used the standard, analog-TV Hauppauge cards for over a
now, and they play (the newer, bt878 ones, anyway) very well with v4l 
(specifically, the bttv module in newer kernels).

>    am I doomed to just using analog or an IR Blaster?

Yes, but not because Hauppauge cards aren't "the best supported" ...
because the digitizing of cable TV remains unstandardized.

BTW,  if I am wrong in any major way here, I'd very much appreciate a 
correction. I've resisted my cable company's unending appeals to
to digital service because I too do not want to be stuck using an IR 
Blaster solution (partly because it seems like such a clunky workaround,

partly because it means renting another decoder from the cable
So if there is a tidy way to use a v4l-based device with digital cable,
love to learn about it.

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