HDTV Glossary

Compliments of Voom satellite service for this basic copy that has been expanded.

(Note: list includes many changes, edits, and additions to the Voom Glossary, adjusted for this report.)


Aspect ratio is defined as the ratio of width to height of your television screen. The newer HDTV standard aspect ratio is 16:9 while the vintage NTSC is 4:3. Aspect ratio describes the width of the TV screen in proportion to its height. Standard TVs have an aspect ratio of 4:3, slightly wider than a square. Many HDTVs have an aspect ratio of 16:9, which is closer to the aspect ratio of your local movie theater's 70mm film format. When people talk about wide-screen TV's, they are referring to the 16:9 aspect ratio. It fills more of your natural field of vision and creates a more cinematic experience. Wide-screen television is not the same as large-screen televisions that were created in the 1980's and early 1990's to produce a larger NTSC screen.
The Advanced Television Systems Committee, Inc. (ATSC), is an international, nonprofit membership organization developing voluntary standards for the entire spectrum of advanced television systems. Specifically, ATSC is working to coordinate television standards among different communications media focusing on digital television, interactive systems, and broadband multimedia communications. ATSC is also developing digital television implementation strategies and presenting educational seminars on the ATSC standards.
The Advanced Television Technology Center is a private, nonprofit corporation organized by members of the television broadcasting and consumer products industries to test and recommend solutions for delivery and reception of a new U.S. terrestrial transmission system for digital television (DTV) service, including high definition television (HDTV).

DISPLAY STANDARDS (There are three digital resolution standards):

There are three digital resolution standards. Note that there is an "i" and a "p" after each standard shown below. The "i" stands for Interlaced and the "p" stands for Progressive, describing the method used to scan the image on the screen. Interlaced produces 1/2 the screen in 1/60th of a second (analog television) while progressive refreshes the entire screen every 1/60th of a second.

480 is the Enhanced Definition format, while the 720 and 1080 are the true high-definition (HD) formats. Wide-screen HDTV television sets are designed to be the only ones that can properly receive and display the HD format's unique 16:9 aspect ratio (see Aspect Ratio above)

1080i - 1080 High-Definition TV (HDTV) horizontal lines that are displayed in an interlaced fashion (Figure based on computer resolution 1922 x 1080.)

720p - 720 High-Definition TV (HDTV) horizontal scan lines that are displayed in a progressive fashion. (Figure based on computer resolution 1280 x 720.)

480i - 480 Horizontal scan lines that are displayed in an interlaced fashion, known as SDTV or Standard Definition TV. (Figure based on computer resolution 640 x 480.)

480p - 480 Horizontal scan lines that are displayed progressively. This is not "High Definition", but is instead called Enhanced Definition TV (EDTV), the resolution that DVDs are encoded at. (Figure based on computer resolution 640 x 480.)


Digital Video Interface is a pure digital-to-digital interface between a source and display unit through an output and input jack called a DVI. The DVI is for the picture only and does not include any audio. It transmits progressive scan in DVD and HDTV format to a wide-screen HDTV set. It's the best HDTV picture quality choice over component and S-Video signal inputs when an HDTV signal is being received.


Splits the video signal into separate color channels, red, green and blue, for superior results when compared to using an RF output signal. Transmits progressive scan DVD and HDTV. (Note: SD Component Video uses the same cables, but does NOT transmit progressive scan or HDTV. Still, it's a step above S-Video.)


This is a type of video signal where all information on the red, blue and green signals are mixed together. TV's in the United States commonly use this signal type. This is in contrast to most computer monitors, which use RGB Video and has three separate channels for red, green, and blue.

When looking at cable bundles, the single yellow cable is the one that transmits the composite video information. If your television has S-Video or component video inputs and you have a source with the same outputs, use these instead for better picture quality.


Digital is the best way of transmitting information when you want to eliminate as much noise as possible from an analog signal. Instead of using sine waves and curves to send information that may contain noise or hiss, information is passed digitally as 1's and 0's (On and Off), digital values assigned to each point in the sine curve.


AC Nielsen Media Research stands for Designated Market Area, which represents assigned demographic areas Nielsen Media Research has determined to be where people watch TV. You can see a list of the different DMA's at Nielsen's web site

Dolby Digital 5.1

Dolby Digital 5.1 is the standard for multichannel surround sound. It sends a digital audio signal to 5 (the 5 in 5.1) speakers arranged throughout the room. Five of them are full-range channels: left, center, right, left surround and right surround. The sixth channel handles low-frequency effects (LFE), which take up one-tenth of the bandwidth compared to the other channels. .1 (in Dolby digital 5.1) represents the sub-woofer needed to reproduce the deep, rich non-directional base sound.


Digital Reality Creation is Sony's upconverter that is built into many of their HDTV capable TV's. DRC has received many praises since its debut in 1999!


Stands for Digital Satellite System. It's the system you use to receive signals from satellite providers such as VOOM.


Digital Television (DTV) is the transmission of television signals in digital format. Digital is superior over analog when transmitting signals. It provides better resolution for any given bandwidth; interactive content; superior audio quality; capacity for multicasting; compatibility with computers along with consistent reception over a long distance.


See Receiver


DVI / HDCP stands for Digital Video Interface and High Definition Content Protection. Television manufacturers are trying to use DVI/HDCP as a way of protecting copyrighted material that is broadcast to your home. When using DVI/HDCP you will not be able to duplicate material that is copyrighted.


Enhanced Definition Television, which is 480p resolution. While it can be considered to be a form of Digital TV, it is not to be confused with High Definition Television.


High Definition Copy Protection. Take a look at the term 'DVI / HDCP' for more information.


Backed by some of the industry's biggest names, High-Definition Multimedia Interface (HDMI) will enable true high-definition audio/video content for consumers. Content providers, system operators, and consumer electronics manufacturers are rallying behind a standard that will finally deliver on DTV's long-awaited promises.


High-Definition Video Processor. This is a video processor that can transform your computer into a HD home entertainment system.

Excellent URL that describes the short version of the history of television signals and formats, ranging from the transmission of signals using the early mechanical television format to quick overviews of the definitions of PAL and SECAM. You can visit the History of Television now provided by the Clear lead Inc. Directory.


Home Theater Personal Computer. This is a device many people are starting to use in place of their Progressive Scan DVD player, Line Doubler, Video Scaler/Processor, HDTV Tuner/STB (Set Top Box) and video game console.

IEEE 1394

This was meant to be an enabling technology that would allow all things in your home theater to connect using this compressed digital interface called FireWire. Think of FireWire as a backbone where you can connect many devices using a single port. IEEE 1394 makes allowances for 5C, which would allow original broadcasters the ability to choose which type of copy control they want to use. The options given to broadcasters are: Allow copying; allow copying only once; or no copying allowed.

IEEE stands for the Institute of Electrical and Electronics Engineers and is responsible for developing electronic standards the world over.


HDTV is scanned in two different ways, one being progressive and the other being interlaced.

Interlaced scanning is when the TV uses two separate passes to make a complete image on the TV. The first pass will display the odd horizontal lines such as 1, 3, 5, 7 and so on. On the next pass it displays the even lines such as 2, 4, 6, 8 and so on. Since this is done so fast the human eye sees this as being one picture instead of two. After the second pass the third will go back to displaying the odd lines, then even again and so on.


Letterbox is the term used for watching a movie in its intended wide-screen format on a regular 4:3 aspect ratio television. While the picture is wide, it is not as wide as the actual movie version. It is also a viewable option in the settings of some DVD movies. A black bar accompanies this viewing format on the top and bottom of the screen and a picture that is similar to the aspect ratio of 16:9.


This is simply a de-interlacer. For instance, it could take a 480i picture and double it to 480p, thus taking an interlaced image to converting it to progressive. A line doubler can also take a 480i image and convert it to 960i, as the 240 lines being shown in 1/60 are the same as showing 480 lines at 1/60 second. Bob is a line doubling technique that repeats the last line to create new lines. Weave is another technique that combines one half the image (here being 240 fields) with the previous or next 240 fields to create a single 480 line frame.


A line scaler is a line doubler that de-interlaces the image and then scales it up to a higher resolution. Many times scalers simply scale up to the native resolution of your display.


Usually describes the actual resolution of the display device. If you see native resolution used with LCD, DLP, dILA or Plasma, this will be an exact number. With CRT's, this number is an approximation. Either way, if you see a Max Resolution for the display device, your device will simply scale the image down to its native resolution. See Scaling / Doubling for more information on that subject.


A unit of luminance equal to 1 candle per square meter measured perpendicular to the rays from the source (related to rear-projection TV brightness.)


NTSC is the National Television Standards Committee and was responsible for developing a standard protocol for broadcasting TV signals in 1953. Not many changes have been made to this protocol since its creation except the addition of new parameters for color broadcasts. The NTSC broadcast has 525 horizontal scan lines, which are drawn in an interlaced fashion. The result is one frame every 1/30 a second.


Original Aspect Ratio (1.85, 2.35, etc.) This is the width-to-height aspect ratio. All HDTV programming is at 16x9 OAR. If it is not, it is not considered *true* high definition. If a signal is sent with black bars on the top or bottom (letterbox), and is still in a 16x9 format, then it can be considered HDTV.


Plasma Display Panel (See Chapter 11.)


Pixels are the picture elements that make up a.) the image on-screen and b.) the screen display. The number of pixels determines the resolution. More pixels means higher resolution and more detail. A 1080i HDTV image has a resolution of 1920 pixels by 1080 pixels. A 720p HDTV image has a resolution of 1280 x 720. Standard TV detail pales in comparison. If you're watching an HDTV broadcast on a Plasma, LCD, or DLP viewing formats, the screen has a fixed-pixel native resolution.

To display a 720p program in true HDTV, the screen needs a native resolution of 1280 x 720 or higher. If the native resolution is lower, the HDTV signal must be converted to be displayed on the screen.


HDTV is scanned in two different ways, one being progressive and the other being interlaced. Click here to see an excellent animated site that explains all forms of scanning an image.

Progressive scanning is accomplished when each horizontal line is displayed right after the previous one. The lines are scanned in order from top to bottom so that it goes 1, 2, 3, 4, 5, 6 and so on. This means the image is displayed in one pass instead of two as it is done with interlaced scanning.

The benefits of a progressive image, such as the 480p that comes from a DVD, is that the interlaced lines are removed in the case that some people might pick up the flicker of 1/30 odd scan lines and 1/30 of a second even scan lines that form the picture.

Also the progressive scan seems smoother, giving the image that "rich film" look of movies. Again the key word here is "seems," as the difference between interlace and progressive scans is more an issue of esthethics than an actual techical increase in the quality of the image.


This is a unique technology developed by Mitsubishi that enables the upgradeability of equipment to be compatible with HDTV receiver-decoders, IEEE 1394 networking, 5C copy protection, and HAVi software.


The classic stereo pair of analog cables color-coded in red and white. It's important you honor the red to red and white to white or your left - right audio channels will be flipped

(Note: if your audio inputs are backward, audio of a car going from left to right will not match the one on the screen going from right to left.)

RECEIVER (Cable Decoder Box)

In video terms, this is the same thing as a Cable Decoder Box. This sophisticated box can provide several benefits to your television watching based on the capability of your cable provider. The cable box can provide all cable channels to a television set's non-cable channel tuner by tuning the TV's tuner to channel 3 or 4, based on the setting on the back of the cable box.

The box can also decode premium channels if you have subscribed to the service, such as when a subscriber updates to a cable company's movie package or HDTV channel package.

Finally, the cable box can also be used to control the volume of the channel you are watching.

How it works:

On non-remote sets, you would have to first set the television's manual sound to a high level without distortion with the cable remote sound also turned up. Then you can use the cable remote to turn the sound all the way down.

If you here a slight hiss on your television speaker when the cable volume is turned down or all the way down, the manual volume on your television set is set to high, your actually hearing the molecules of the transistors moving electronically. Tube audio sound will not produce any hiss.

For VHF/UHF sets with remote volume controls, turn the volume up using the set's remote and leave it there as you would with a manual volume control. That should work, (may not in all cases) since most televisions will remember the last volume setting as long as the television has not been unplugged. When unplugged, the volume memory will probably be forgotten.


This is the rate at which the television / monitor refreshes the picture, interlaced or progressive scans.


Resolution describes the number of horizontal and vertical pixels that make up the image on-screen and the screen display itself. At best, the image you see on an analog TV is 705 x 485 (width by height). HDTV offers much higher wide-screen resolutions: 720p (1280 x 720) and 1080i (1920 x 1080). In order to display true HD, you'll need to have a 720p or 1080i signal coming into your TV, and an HDTV with a resolution of 1280 x 720 or higher. Lower resolution screens may be able to convert the HD signal, but will not show an actual HDTV picture.


When you see a resolution of 640 x 480 resolution for a computer monitor, the first number always represents the number of pixels on the horizontal axis with the second number representing the number of pixels on the vertical axis. The clarity of the image is in direct correlation to the resolution vs. the size of the display.

In other words, the higher the resolution the more detail reproduced, creating a sharper picture. For watching VCR tapes on wide-screen televisions, you may actually want to turn down the sharpness of the picture (using the sharpness control) to hide the noise caused by the low resolution from the VCR heads. Beta tapes will look better than VHS because of the Beta's higher writing speed when the fastest recording speed is selected.


RF signals blend the composite video signal with the audio signal. If possible, use another connection that is strictly dedicated to video. When you use an RF signal to view an image, the television set's circuits have to strip out the video and audio signal from the RF. This causes a loss in the picture and audio quality. But by using the video output, you are bypassing this needed conversion creating a slightly better picture and sound. Again, if better video formats are available to you (S-Video, Component, DVI), use them instead.


RGB stands for Red, Green, and Blue and is a way of transmitting signals in three separate channels - each one dedicated to each of the colors. RGB is the opposite of 'Composite Video' because composite video combines each of the three color signals into a single "composite signal," which uses a single cable with RCA plugs at each end that are color-coded yellow for input and output connections.


Standard Definition TV is the same as 480i. It's not considered to be DTV or HDTV, instead the regular NTSC broadcast signal all people are used to.

(The only one who wouldn't be used to it might be Richy Rich, who may have never seen an NTSC television set in his life using VOOM for all HDTV channels on his HDTV television, never seeing a 4:5 aspect ratio screen.)


Super-In-Plane-Switching technology that helps attain wider viewing angles and color consistency.


Stands for Set-Top-Box and is the receiver you use to decode high definition signals. STBs are often called a 'decoder', a 'receiver', or a 'tuner'. The term decoder is the more appropriate term as the word receiver can often mean the stereo equipment component. The box with today's sophisticated cable systems would be called a "Digital Cable Decoder."


Splits the video signal into two parts: chrominance (the color of the image) and luminance (the brightness of the image). Better than composite video, but not as efficient as HDTV or SD component video. Remember with an S-Video plug you also need separate audio cables, which is also true of video, DVI, and component video inputs. Only RF carries the audio and video signal together, and why it is worst signal source for picture quality.

Do not confuse this with the RF (physical-looking) cable that comes into your home from the cable provider. This cable usually carries a digital signal that is converted by the decoder box to usable high-quality outputs including RF in case you have an old television without any other kinds of inputs.


Scanning Velocity Modulation (SVM) will speed up or slow down how the phosphors on your CRT television are scanned. If you leave SVM on it can bring 'ringing' into the edges of your image and can reduce the detail of your image by over-enhancing the lines.

Many videophiles will not buy a television if it doesn't have the option to turn SVM off. However, most high-end televisions have this option. It is strongly recommended to turn this feature Off if its default is On when you get your television home. Keep in mind you might have to do this again if your set is unplugged with the set reverts back to its default again.


The process of taking a SDTV image and enhancing it to look better on a high-definition monitor.


Sony's line of DTV (Digital Television) products.


A new form of modulation that should allow a single coaxial cable to carry up to 500 HDTV Channels. The great thing about this type of modulation is its immunity to noise and its ability to coexist with other wavelets and with other modulation schemes without being altered.


The term used to describe a screen that has an aspect ratio that is wider then the NTSC 4:3 ratio. Most HDTV's and EDTV's have an aspect ratio of 16:9. While most major motion picture screen look like they are 16:9, 70mm film actual provides a wider image.

When motion pictures are converted for use on NTSC television screens, the image is squeezed and cropped so it will fit the smaller 4:3 format screen. This leaves out the far left and far right sides of the image while slightly distorting the part that is being seen.


If you haven't visited our complete sample current price list by screen size, format, price, manufacturer, and model, please click here.

For general questions on television trivia, have fun by visiting the Answer Bag.

For current HDTV technology news, you can visit Cybertheater.com. (Note - loads slow.)

For a list of contributors of photos, graphics, and specific information for this non-profit report other than a URL link, click here.


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