[CALUG] [Fwd: Re: Digital TV Tuner card]
dododge at dododge.net
Thu Sep 22 01:02:52 CDT 2005
On Wed, Sep 21, 2005 at 12:24:31AM -0400, Rajiv Gunja wrote:
> a. To receive digital channels, I need a PC card like the HD3000
You need some sort of digital tuner; the HD3000 is the most common
tuner with working Linux drivers.
> b. I can receive and view HDTV channels on my PC. (Dont I need a monitor
> which can do HD lines (1080i or something like that ?)
The system should be able to scale the video to fit your display.
Bear in mind that HD pictures have 16:9 aspect ratio, so they have to
be scaled anyway for most computer monitors. Also, 1080i video is
designed to be displayed interlaced, which is something else the
system will have to deal with since most computer video is not
The HD3000 captures the compressed bitstream from the transmitter; it
does not provide any assistance with decompressing that bitstream into
a viewable picture. For HD resolutions and bitrates, decompression
requires a lot of work and a high fill rate.
So you'll probably also need a relatively fast machine and video card,
with drivers that support hardware motion compensation (XvMC). Recent
NVIDIA models with their binary driver should work (BTW: NVIDIA broke
high-resolution DVI support in the 7664 release and I don't think
they've fixed it yet)
> c. With this card, I can receive channels which are over the air ( ofcourse
> with an HD-Antenna)
An "HD-Antenna" is just an ordinary UHF TV antenna. But unlike analog
UHF, the signals don't handle degradation, reflections, or
interference very well, so you'll need an antenna that gets you a
solid signal. You usually either get a perfect picture or a blank
screen. The size and quality of the antenna required depends on your
location and the surrounding terrain.
> and decode any HD Channels I get via Comcast.
You'll only be able to view the unencrypted ones. And because cable
uses a different modulation scheme (QAM instead of 8-VSB) you might
need a different driver than the one normally used with the card. It
would be a good idea to look through the HD3000 forums before buying
As I mentioned at the LUG meeting, I've managed to use the HD3000 for
S-Video capture (for example from a VCR or Playstation), but it was
not very easy, and most capture tools can't get a picture from it at
all. The driver also seems to be unable to provide the full sampling
resolution of the card's analog chipset, so the picture quality (again
analog, not digital) is not as good as it might be.
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