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A Guide to Digital TV
What is Digital Television?
Digital television (DTV) is a new way of transmitting high quality video and audio to your TV set.
Using DTV, broadcasters can transmit high definition TV (HDTV) images, Dolby digital surround
audio, and new services such as multicasting (transmitting more than one program on the same TV
channel) and datacasting (providing electronic program guides and interactive television). Several
of these services can be combined into a single digital broadcast.
Digital Television Services
Digital Picture Quality
DTV
programs are transmitted in two different formats. The first is Standard Definition Television
(SDTV) and the second is High Definition Television (HDTV).
SDTV
program formats include 480-line interlaced (480i) and 480-line progressive (480p) video.
480i programs are essentially a digital version of our current analog TV programs, while the 480p
format offers improved image detail over 480i. Some 480p programs are broadcast in widescreen
and are comparable to progressive-scan DVD movies in image quality.
HDTV
program formats include 1080-line interlaced (1080i) and 720-line progressive (720p). Both
HDTV formats are always broadcast in widescreen, and both offer much higher picture quality than
SDTV.
Dolby Digital Sound
With DTV, you can listen to a variety of Dolby Digital auto formats from Dolby Digital 2.0 to Dolby
Digital 5.1 using your home audio system. Many HDTV programs are now broadcast with Dolby
Digital 5.1 soundtracks.
Interactive Communications and Datacasting
DTV will allow you to interact with your television; choosing programs from a detailed program
guide and accessing ancillary data about a program.
How to View Digital Television
There are three ways to watch DTV. The first is to use an integrated digital TV; one with a
built-in digital television tuner. The second is to connect an external DTV set-top receiver to
a DTV-ready television or monitor. This type of TV or monitor will have wideband component
video and stereo audio inputs. You can also watch DTV signals with personal computer
(PC) tuner cards and computer monitors.
1. Integrated TVs versus DTV-ready TVs and monitors
The advantage of an integrated DTV set is that it can tune both analog and digital TV channels
at the same time. All you’ll need to do is add an external antenna and you are ready
to watch DTV.
However, integrated DTV sets are not as common as DTV-ready TVs and monitors. If you already
own a DTV-ready TV with component video, digital visual interface (DVI) or high definition
multimedia interface (HDMI) inputs, you can enjoy DTV broadcasts by simply adding a low-cost DTV
set-top receiver and antenna.
2. Using your existing analog TV set
Your analog TV set can be used to view down-converted DTV broadcasts by connecting the
DTV set-top receiver to your composite (yellow RCA jack) or S-video (black circular jack)
AV inputs, as well as connecting stereo audio inputs. While the picture quality won’t be as
good as you’d see on a DTV-ready TV set, it will be as good or slightly better than analog
TV broadcasts.
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2006-10-12 ｿﾀﾈﾄ 1:13:06
