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GLOSSARY
Aspect Ratio
Audio Video (A/V)
ATSC
CVBS
DTV
The ratio between the width and height of the TV picture on the screen. In a normal TV set the aspect ratio is 4
to 3 (4:3). The aspect ratio in HDTV is 16:9, w
h
ich resembles the aspect ratio in a movie theatre (Widescreen).
New TV systems support both 4:3 and 16:9 aspect ratio and can automatically switch between them.
A term often used when discussing a channel on a TV receiver or on video equipment, which has been
especially designed to accept VCR audio-video signal.
The A/V channel automatically activates special circuitry
within the TV set to prevent picture distortion and skewing. It is also used for audio-video processors,
which
handle both types of signal.
ATSC: Advance Television Systems Committee.
Formed to establish technical standards for advanced
television systems, including digital high definition television (HDTV).
Composite Video Baseband Signal.
In broadcast television this refers to the video signal.
including the colour information and syncs.
Digital television.
Generic term that refers to all digital television formats, including high-definition television
(HDTV) and standard-definition television (SDTV).
Digital Tuner
A digital tuner serves as the decoder required to receive and display digital broadcasts. It can be included inside TV sets or
via a set-top box.
HDTV
The generally agreed upon definition of HDTV is approximately twice the vertical and horizontal picture resolution of today s
NTSC TV, which essentially makes the picture twice as sharp. HDTV also has a screen ratio of 16:9. HDTV offers reduced
motion artifacts (i.e. ghosting, dot crawl),
and offers 5.1 independent channels of CD-quality stereo surround sound,(also
referred to as AC-3).
,
NTSC
National Television System Committee.
The organization that developed the analog television standard currently in use in the
U.S., Canada, and Japan. Now generally used to refer to that standard.
The NTSC standard combines blue, red and green
signals modulated as an AM signal with an FM signal for audio.
Progressive Scan
In Progressive Scanning all the horizontal scan lines are scanned on to the screen at one time.
The Digital TV and HDTV
standards accept both Interlaced Scan and Progressive S
c
an broadcast and display methods.
Resolution
Resolution: A measurement of the finest (smallest) detail that is visible in a video image.
TV resolutions may be expressed as
number of pixels in an image, or more commonly as Total Number of (horizontally scanned) Lines used to create the image.
Standard Digital TV Resolutions:
SDTV: 480i - The picture is 704x480 pixels, 480p - The picture is 704x480 pixels.
HDTV: 720p - The picture is 1280x720 pixels, 1080i - The picture is 1920x1080 pixels, 1080p - The picture is 1920x1080 pixels.
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