HDTV Channel Broadcast
Information
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HDTV is a name given to two of
the digital television (DTV)
formats. HDTV provides high
resolution programming. A
current analog TV picture is
made up of horizontal lines on
the picture screen; an HDTV
picture can have more than twice
as many lines, allowing for
stunning picture detail.
HDTV uses a “widescreen format.”
“Widescreen format” refers to an
image's aspect ratio, which is a
comparison of screen width to
screen height. Analog television
has an aspect ratio of 4 by 3,
which means the screen is 4
units wide by 3 units high. The
aspect ratio of HDTV is 16 by 9,
similar to a movie theater
screen. HDTV programs can
include Dolby Digital surround
sound, the same digital sound
system used in many movie
theaters and DVDs.
HDTV uses the same amount of
bandwidth (the size of the
communications channel) as the
current analog system, but with
HDTV, about six times more
information is transmitted. This
capability translates to much
better quality in picture and
sound. |
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Is HDTV the same thing as DTV
(digital television)? |
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No. HDTV is the highest quality
of DTV, but it is only one of
many formats. In addition to
HDTV, the most common formats
are Standard Definition
Television (SDTV) and Enhanced
Definition Television (EDTV).
SDTV is the baseline display and
resolution for both analog and
digital. Transmission of SDTV
may be in either the traditional
(4:3) or wide-screen (16:9)
format. EDTV is a step up from
Analog Television. EDTV comes in
widescreen (16:9) or traditional
(4:3) format and provides better
picture quality than SDTV, but
not as high as HDTV. |
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Receiving the DTV and HDTV
signals over-the-air requires an
antenna and a new DTV receiver
that can decode the digital
signals. In general, an antenna
that provides quality reception
of over-the-air analog TV
signals will work for DTV
reception.
If you are a cable or satellite
customer, you may need a set-top
box to receive DTV signals and
convert them into the format of
your current analog television,
even after the DTV transition is
complete. A DTV set-top box also
may receive multicast channels
and high definition programming
and display them in analog
picture quality. Check with your
cable or satellite provider to
determine if and when you will
need a set-top box. |
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Why get HDTV broadcasts into
your home? |
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Viewers cannot ignore the
dramatic improvements offered by
the DTV conversion. Visually,
HDTV captures viewers with
crystal clear resolution and
razor sharp detail. Individual
hairs, labels on footballs and
the subtle effect of wind
blowing through grass are all
clearly visible through HDTV.
Also, the detailed resolution
and color provides an image akin
to movie-theater screens.
Combined with the capacity to
deliver enhanced Dolby Digital
surround sound, HDTV produces an
advanced home theater effect.
DTV provides viewers with
sharper images, better sound,
and more viewing options than
have ever been available over
the air. |
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Currently, television pictures
are made up of lines that are
scanned horizontally. HDTV
pictures are created by scanning
up to twice as many lines. This
resolution and other technical
factors improve the sharpness of
the pictures, allowing you to
read on your television screen
small text commonly seen on your
computer. HDTV sets have wider,
movie-theater like screens that
more closely resemble human
peripheral vision, making it
more natural to watch. |
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