Glossary Of Important HDTV Terms

A

AC-3: Also known as Dolby Digital, it is a 5.1 channel sound system meant for HDTV. It provides CD-quality digital audio, sub-woofer, low frequency effect and five full bandwidth channels for front left, front right, center, surround left and surround right speakers.

ATSC: Advanced Television Systems Committee that is responsible for developing and establishing Digital-HDTV Standards, as well as all formats of Digital TV.

A/D: This is the analog to digital conversion or converter used at the transmission end of broadcasting.

Addressable Resolution: It is the highest resolution signal that a display device like a monitor or a TV can accept. Although it may receive the resolution signal, the device may not be able to display it.

Analog TV: It is the NTSC standard for traditional television broadcast. Analog signal vary continuously representing fluctuations in color and brightness.

Artifacts: Refer to unwanted visual images caused due to disturbances in transmission or image processing. They are referred to as hanging dots’ or ‘edge crawl’ in analog pictures, and ‘pixelation’ in digital pictures.

Aspect Ratio: It refers to a width of a picture in relation to its height. The 4:3 aspect ratio means the picture is 4 feet wide and 3 feet high. HDTV has a 16:9 aspect ratio.

ATV: A term used to refer to the advances and development of a digital television, now referred to as DTV.

B

Bandwidth: It refers to a range of frequencies to transmit information such as audio or video. The FCC has allocated 6 Mhz for each channel. For a DTV the maximum bit rate possible within a bandwidth is 19.4Mbps, which can accommodate 1 HDTV channel.

Bit Rate: It is used to express the rate at which data is transmitted or processes and measured as bits per second. The higher the bit rates the higher the pictures resolution.

C

Channel: It is the 6MHz section of a broadcasting spectrum allocated for one analog NTSC transmission.

Component (HD) Video Connection: It refers to the output of a HDTV set-top box or the input of a HDTV monitor or receiver.

Composite Video: It includes vertical and horizontal synchronizing Information in an analog encoded video signal. Since brightness and color signal are encoded together, a single connection wire is sufficient such as a RCA cable.

Compression: It refers to the method of electronically reducing the number of bits required to store or transmit data within a specified time or space. MPEG2 is the compression method adopted by DTV.

D

D/A: Refers to the conversion of digital signals to analog signals. A D/A converter is used to convert and decode digital signals to analog signals.

DBS: Digital Broadcasting Satellite refers to digital TV transmission through satellite.

DLP: Digital light processing is based on a Digital Micro-Mirror device {DMD}. It is a chip with microscopic mirrors attached to it. Red, Blue and green light filtered through a colored wheel are directed at the DMD which switches on and off up to 5,000 times a second. The reflected light is directed to a lens and onto a screen, creating an image. HDTV use 3 chips each for red, blue and green colors.

Dolby Digital: Means the same as AC3.

Down Convert: With regards to DTV refers to the conversion of a higher resolution input signal to a lower one. Some DTV receivers can down convert HDTV signals to those that any TV can transmit.

DTCP: Digital Transmission Copy Protection of a HDTV is otherwise referred to as the 5C.

DTLA: Digital Transmission Licensing Administrator is the licensing organization for the 5C DTCP HDTV copy-protection technology.

DTS: Digital Theater Systems sound similar to a Dolby Digital system, used in movie theaters and DVD.

DVI: Digital Visual Interface is a high-bandwidth video connection that carries digitized RGB picture information and can support copy-protection methods.

D-VHS: Digital-Video Home System capable of recording HDTV, manufactured by Mitsubishi and JVC.

DVR: Digital video recorder is a TV recorder and it can record an entire series or programming defined by keywords, genre, or personnel. It offers pause control over ‘live’ broadcasts and is also called personal video recorder (PVR) or hard disk video recorder.

E

EPG: Electronic program guide is an on-screen display of channels and program data.

F

Frequency: It refers to the number of times per second that a signal fluctuates. Television is broadcast in frequencies ranging from 54 MHz to 216 MHz (VHF) and 470 MHz to 806 MHz (UHF).

H

HDTV: High Definition Television has twice the horizontal and vertical resolution of a normal NTSC TV; therefore the picture is twice as clear and sharp. HDTV offers reduced motion artifacts and offers 5.1 independent channels of Dolby Digital Quality.

HDCP: High-bandwidth Digital Content Protection to be used in conjunction with DVI and HDMI connections.

HDMI:  High-Definition Multimedia Interface that is like an USB that can transmit uncompressed digital audio and video signals.

HD-DVD: High-definition digital videodisc has several formats including Blu-ray.

I

IEEE 1394 Fire Wire: It is a digital interface that can transport data at 100, 200, or 400 Mbps. It can be used to connect digital television devices together. 

Interactive Television: This TV will enable the viewer to interact with the TV programs, combining normal TV viewing with the interactivity of a personal computer.

Interlaced Scanning: Refers to the process of re-assembling a picture from a series of electrical video signals.

I/O: Refers to the input/output or sending information or data signals to and from devices.

ISDN: Integrated Services Digital Network enables transmission of data at high speeds, Basic Rate of 64 Kb/sec up to a Primary Rate of 2 Mbps, using a telephone line.

L

LCD: Liquid Crystal Display television or monitor uses liquid crystals that behave like "shutters" within the television screen.  LCD monitors typically only display video signals in a progressive scan format, do not use phosphors and are not susceptible to screen burn.

Line Doubling: It refers to the method of presenting wide screen images on a standard screen television.

Lossy compression: It refers to the reduction of data by discarding data that is not important. Both audio and video for DTV use this method.

Luminance: Refers to the component in video signals providing information about its brightness.

M

Megabyte: Refers to 1000 kb or kilobytes.

Modem: It is used to transform a typical two-level computer signal into a form suitable for transmission over a telephone line and vice versa.

MPEG: It is the Compression standards for moving images advanced by the Motion Pictures Expert Group {MPEG}.

MPEG-2: It is the compression used by the ATSC and DVB standards.

N

NTSC: National Television System Committee standard combines blue, red, and green signals modulated as an AM signal with an FM signal for audio.

P

PAL: Phase Alternate Line is the television broadcast standard in Europe and parts of Asia. PAL signals have 25 frames per second, making them incompatible with NTSC TV. 

Pan and Scan: Refers to the method by which an original wide screen picture is cropped to fit a conventional TV, some times resulting in critical loss of details.

Parallel cable: Refers to a multi-conductor cable carrying simultaneous transmission of digital data bits.

Parallel data: Transmission of data bits through a collection of wires called a bus.

Parallel digital:  It is a Digital video interface that utilizes twisted pair wiring and 25-pin d connectors to transmit bits of a digital video signal in parallel.

PCM: Pulse code modulation refers to the method by which sounds are reproduced by modulating the playback rate and amplitude of the sampled digital pulses.

Pillar-box: When conventional TV images are made to fit a wide screen causing the picture to display black bars on both the sides of the picture.

Pixel:  This is short form of referring to Picture cell or Picture element. HDTV Pixels are virtually square-shaped and fairly smaller.  

Progressive Scan:  Method by which all, horizontal scan lines are scanned on to the screen at the same time.

Protocol: Set of rules defining exchange of data including items such as timing, format, sequencing, error checking, etc.

PSIP: Program and System Information Protocol enables a DTV receiver to identify program information from a station and use it to create easy-to-recognize electronic program guides for the viewer.

Plasma Display: A Plasma TV display makes use of numerous embedded cells to produce a picture. However, plasma pixel-cells deteriorate over time causing the picture quality to diminish significantly.

R

Resolution: Refers to the measurement of the smallest that is visible in a video image. It is expresses in terms of the number of pixels in an image.

Standard Digital TV Resolutions:

• SDTV: 480i - The picture is 704x480 pixels, sent at 60 interlaced frames per second (30 complete frames per second).
• NTSC-Analog TV: 480p - The picture is 704x480 pixels, sent at 60 complete frames per second.    
• HDTV: 720p - The picture is 1280x720 pixels, sent at 60 complete frames per second.
• 1080i - The picture is 1920x1080 pixels, sent at 60 interlaced frames per second (30 complete frames per second).
• 1080p - The picture is 1920x1080 pixels, sent at 60 complete frames per second. 

Return Loss: Refers to the ratio of the signal power transmitted into a system, to the power reflected or returned.

RGB: Refers to the red, green and blue, the primary colors of television. TV screens have red, green and blue phosphors that are illuminated by red, green and blue guns.

S

SECAM:  Système Electronique Couleur Avec Mémoire (SECAM) is a signal format used in video equipment in France and the former Soviet Union.

Set-top Box: This is also known as a decoder, receiver or tuner. It is a unit that is capable of receiving and decoding DTV broadcasts.

Spectrum: Refers to the range of frequencies available for over-the-air transmission.

SDTV: Standard Definition Television refers to digital transmissions with 480-line resolution, either in interlaced or progressive scanned formats.

S-Video: Separated video is encoded video signal that separates the brightness from color data.

U

UHF: Ultra high frequency refers to the range used by TV channels.

Upconvert: Refers to the conversion of a lower apparent resolution to a higher number.

V

VHF: Very high frequency refers to the range used by some TV channels.

Y

Y/Pb/Pr: Refers to an advanced method for interconnecting decoded video data. It is generally used designation for HDTV component type connections.

Y/U/V or Y/Cr/Cb: Refers to Component" type Digital TV connector/cable. Three wires are used, one wire for "Y"- designates Light or Brightness; one wire is "Cr" - Red; and the last wire is "Cb"- Blue.  

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