High-Def Terminology

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1080i

1080 refers to the number of pixels the image is displayed at, which is 1920 x 1080. The higher the number, the better the quality. "i" stands for "interlaced." 1080i is poorer in quality compared to 1080p.

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1080p

1080 refers to the number of pixels the image is displayed at, which is 1920 x 1080. The higher the number, the better the quality. "p" stands for "progressive." 1080p is better in quality compared to 1080i.

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5.1

5.1 is a surround sound setup that consists of five speakers that emit five audio channels--center, right, left, and surround sound right and left--and one subwoofer speaker that emits a low-frequency sound.

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6.1

6.1 is a surround sound setup that consists of six speakers that emit six audio channels--center, right, left, and surround sound right and left, and rear--and one subwoofer speaker that emits a low-frequency sound.

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7.1

7.1 is a surround sound setup that consists of seven speakers which emit seven audio channels--center, right, left, and surround sound right and left, and two in the rear--and one subwoofer speaker that emits a low-frequency sound.

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Aliasing

Aliasing is when unwanted distortions or artifacts occur after an image is interlaced--that is, taken apart and displayed in pieces. Various methods called anti-aliasing have been developed to improve the image.

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Analog Signal

An analog sound system uses a physical medium to record sound, such as a record. This signal produced or relayed by an analog device is modulated and susceptible to noise. Though theoretically as good as, if not better than, a digital signal, in practice most digital signals are superior to analog ones because their flaws are often able to be fixed and digital signals are cheaper to produce than analog ones.

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Anti-aliasing

Anti-aliasing is a method by which video flaws or "artifacts" that come about by interlacing and compression are reduced by blurring or smoothing the image.

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Aspect Ratio

The aspect ratio of an image is its width divided by height. Standard definition has an aspect ratio of 4:3 and displays video in "full screen," while high definition has an aspect ratio of 16:9 and displays images in "widescreen."

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ATSC Tuner

An ATSC tuner allows those with an HDTV to receive over-the-air high-def television. It can also be called an ATSC receiver, or simply an HDTV tuner. All HDTVs and interface devices that carry a tuner, such as a Blu-ray Disc player, come with a built-in ATSC tuner, as of March, 2007. Many HDTVs since 2005 have come with these built-in, but many others do not, and retailers are still able to sell TVs and interface devices, manufactured before March 2007, that do not have the tuner built-in. In this case, the owner must purchase an external ATSC tuner in order to receive over-the-air High-def programming.

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Bandwidth

Bandwidth, roughly defined, is the volume of space a broadcast TV signal has in order to move from one point to another. Imagine bandwidth as a garden hose and video as water--the larger the bandwidth you have, the greater is the size of video that can be processed. If you have large progressive scan video, you must have greater bandwidth in order to accommodate for it. Interlacing was devised as a means of preserving video image resolution while decreasing the amount of bandwidth it uses by dividing an image into odd and even pieces and broadcasting them one after the other.

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Black Level

Black level is the measurement of the deepest level of black as configured in a TV’s settings. Most TVs need to be calibrated so that the black level is a true black; otherwise the colors will be muddled.

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Blu-ray

Blu-ray disc is a next-generation entertainment optical storage format. Supported by manufacturers and movie studios, Blu-ray is recognized as the current standard high-def format . Though it resembles a DVD, a Blu-ray disc has a current maximum capacity of 50 GB and can only be played on a player with a Blu-ray drive. This produces a progressive video image resolution of up to 1920 x 1080, better known as 1080p--the best picture quality currently available. Blu-ray's picture presentation even tops that of an HDTV broadcast, and its hard coating is also much more resistant to scratches and fingerprints than DVDs or CDs. Learn more about Blu-ray from our related topic, High-Def Movies and Disc Players.

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Brightness

Red, green, and blue--the three colors that make up the foundations for all other colors--are their reddest, greenest, and bluest at a decimal number of 255. When all three of these colors are set to 255, the color produced is the whitest white. Brightness should be calibrated on a TV so that white is the brightest it can be--true white--just as the black level should be calibrated to true black if the TV has the capacity.

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CableCARD

CableCARD is an actual credit card-sized card that cable television companies provide to their users so that they can receive high-definition television programming. The card is fitted into an High-def-ready TV. The term can also refer to systems of giving their users high-definition TV without an actual card that some cable companies provide.

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Calibration

To properly enjoy television or movies in high definition, your new HDTV needs to be calibrated so that the black levels are true black and the white levels are true white--this keeps the colors from getting muddled. You can do this yourself or hire a professional to calibrate your HDTV for you.

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Center Channel Speaker

The center channel speaker is the speaker that is placed directly above or below the TV. Dialogue and action are sent to the center channel. The central speaker should be placed above or below the TV, head high.

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Coaxial Cables: Analog and Digital

Coaxial cables are analog and are used to carry high-frequency signals over long distances and are shielded by three layers to prevent accumulating background noise over the journey. They are still in wide use today for transmitting radio communication, cable television, and Internet.

Digital coaxial cables are used for connecting things over short distances, such as those between DVD players and TVs. They are falling out of favor in preference of component video cables and, even more so, HDMI cables.

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Component Video

Component video is the division of colors and other video information when being transferred from its source, such as a DVD player, to a receiver like a TV, so that they do not intermingle and confound each other. The YPbPr or "yipper" scheme is a common method of dividing and carrying video for DVD players. The component video is processed from a DVD player to a TV via a cord divided into three parts that are inserted into three different plugs on the back of a TV, each of which carry different information. Component video cables, unlike HDMI cables, do not carry sound, and you must use other audio component cables to transfer sound from your DVD player to your TV.

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Contrast Ratio

Contrast ratio is the difference between the white and black portions of video displayed on a screen. The greater the contrast ratio, the better the picture. If contrast ratio is low, then black color will never be truly black--this desaturates all other colors, making them less crisp.

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Digital Cable

Digital cable providers can hook you up with cable TV broadcasts. Ask your digital cable provider for high-definition TV broadcasts.

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Digital Light Processing (DLP)

DLP is an image-projection technology used in rear-projection HDTVs. The technology uses a series of microscopic mirrors, one for each pixel of the TV. Rear-projection TVs offer a fantastic high-definition image and are significantly cheaper than LCD or plasma HDTVs. They take up more space, but not as much as CRT TVs.

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Digital Optical Audio

Digital audio is transfered from a source using a digital optical audio cable which uses fiber optics. They digital optical audio cables are used to transfer high-definition sound from a source to a receiver. Though not as good as HDMI, which transfers both video and audio, digital optical cables are seen as superior to analog or digital coaxial cables.

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Digital Television (DTV)

DTV transmits information digitally, as opposed to an analog system that transmits information mechanically or through a tangible medium. Digital transmitting codes information and requires it to be interpreted on the receiving end. While theoretically inferior in quality to an analog signal, it often offers a better sound or image since a digital signal picks up little to no noise, unlike an analog signal.

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Direct-View

Direct-View TVs do not use projection in order to render an image like rear-projection TVs. The term usually refers to traditional CRT TVs.

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Dolby Digital

Dolby Digital reproduces three-dimensional sound using a surround-sound speaker system. It is used to record and broadcast sound and for creating surround sound with 5.1, 6.1, and 7.1 speaker systems.

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DVI

DVI is a connector interface designed for carrying uncompressed video between a source like a computer to a display like a monitor. They are still in wide use but are rivaled by HDMI connectors.

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DVR

DVR stands for Digital Video Recorder. A DVR allows you to record programming digitally, as opposed to a VCR which produced analog recordings. TiVo, which records television allowing the viewer to rewind a show or save it for later, is an example of a DVR.

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HD DVD

HD DVD is a DVD with content in high definition and was designed for the storage of movies and other programming. HD DVD was created to succeed the standard DVD format but found competition in rival high-def format Blu-ray. In 2008, manufacturing and studio support sided with Blu-ray, and HD DVD affiliated manufacturers announced a withdrawal of HD DVD marketing and development. Learn more about Blu-ray from our related topic, High-Def Movies and Disc Players.

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HD-Ready TV

An HD-ready TV is a TV that comes with a built-in ATSC (or HDTV) tuner, and is capable of displaying programming in high definition. It can display high definition video from an HD DVD or Blu-ray Disc player, or it can pick up high-def broadcasting over-the-air.

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HD Tuner

The tuner receives local TV channels that are broadcast in high definition. HD tuners and antennas are available for purchase, while some high-end HDTVs come with HD tuners built-in. However, your TV doesn't need a tuner if you have cable or satellite service.

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HD Built-In Digital Cable Ready TVs

Some HDTVs, in addition to having built-in HD tuners, also have an HD cable card slot installed, ready for high-definition cable broadcasts, without needing any additional equipment.

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HDI

HDI is Microsoft's implementation of the HD interactive layer, which allows filmmakers to provide bonus materials in HD DVDs. HDI provides games, dual-decoder picture-in-picture, user defined chapter bookmarks, zoom, internet interactivity and other extra content, not found on standard DVDs.

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HDMI

The newest and currently the best type of cable connection for your HDTV is HDMI (High-Definition Multimedia Interface). An all-digital interface, HDMI carries both high-resolution video and uncompressed multichannel audio through a single cable. Use it to connect any digital audio/video source (set-top box, DVD player, PC, video game system, or AV receiver) with a compatible digital audio and/or video monitor (HDTV). It is an alternative to component video, separate video, DVI, coaxial, and other forms of connector interfaces, and is primarily used for transmitting video in high definition. Learn more about HDMI cables from our related topic, HDMI and High-Def Cables.

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HDMI 1.3

HDMI 1.3 is a new technology standard that roughly doubles the data-carrying bandwidth of HDMI cable from 5 Gbps to 10 Gbps. In order for this to happen, your HDMI input/outputs and HDMI cable must all be of the 1.3 standard. The extra data capacity enables even better picture (a wider range of colors can be displayed) and sound (more audio formats).

If you already have a home entertainment system, HDMI 1.3 is backwards compatible with HDMI 1.1, which is the current standard for most HDTVs, receivers, high and standard definition players.

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HDTV

HDTVs are TVs capable of displaying movies and programming in high definition. A cable or satellite broadcast that comes in high definition is also called HDTV.

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LCD

A liquid-crystal-display HDTV uses a fluid substance to form pixels of color in front of a backlight (much like a laptop screen). LCDs can't match a plasma TV's deep black and gray areas but they're lighter, can be less fragile, and are considered easier to set up. LCDs are catching up to plasmas in terms of available screen size and price and are expected to surpass them in the marketplace.

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Interlace

When video is interlaced, this means that it has been transformed in order to improve the picture resolution without increasing bandwidth. The image is divided into odd and even lines that are displayed on the screen at different times, but so close to each other that they appear to be one complete image. In order for the image to appear whole, it is blurred (called anti-aliasing), which reduces image quality. Because a single image is, in essence, divided in two, the frame rate is doubled when compared to non-interlaced video (that is, a new image is displayed on the screen twice as often in order for the divided image to appear as one, complete image). Interlaced images have a lower resolution than progressive scan images.

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Over the Air Broadcasts

High definition is often broadcast over the air; you can pick up these signals using an HD tuner, depending on your area.

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Persistence

Persistence, or persistent storage, refers to the retention of data, even when an electronic device is powered down. Information that is stored in a device's random access memory (RAM) disappears when the device is powered down. For instance, if you copy something onto your clipboard, it will vanish when you restart your computer unless you save the data in a file. Many newer HD DVD players have "firmware" that can be updated, fine tuning the device's performance as technology progresses. Retaining firmware updates is an example of persistent storage.

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Plasma

These TVs use a tube of glass illuminated by electricity to form pixels. Plasma screens come in bigger sizes than LCDs and sometimes offer brighter colors and blacker blacks. Older or less-expensive models can suffer permanent screen damage if an unchanging image, such as a stock ticker or video game, is displayed too long. This problem has been fixed in most newer models.

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Progressive Scan

Progressive scanning displays video as complete sequential frames. This gives the picture high resolution with great quality and no blurring, but it eats up an enormous amount of bandwidth. Interlacing, which divides the video into odd and even strips and broadcasts them separately, was developed in order to preserve bandwidth. Progressive scanned video has higher resolution and a slower frame rate compared to interlaced video.

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Projection

Front- and rear-projection TVs throw light on a screen. Though not as thin as plasmas or LCDs (and not "wall hangable"), rear-projection TVs are still less bulky than standard CRT models, offer stellar picture quality, and can provide a low-priced alternative to LCD or plasma at comparable screen sizes.

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Receivers

A receiver is the heart and soul of your new home theater sound system. It receives audio from your movie, interprets it, and sends the sounds to the appropriate speakers that are connected to it. Through it you can control the volume of your sound. All your new speakers are dead unless connected to a good receiver capable of processing 5.1, 6.1, or 7.1 sound.

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Resolution

Resolution refers to the number of pixels a TV or computer monitor can display. The higher the resolution of a video image, the better it looks. The standard video resolutions for HDTV are 720 and 1080. If there is a "p" next to the number it means that the video image is "progressive scan," which has higher image resolution. If there is an "i" next to the number it means that the video image is "interlaced," which has a higher frame rate but lower quality.

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Right and Left Channel Speakers

The right and left channel speakers are placed to the right and left side of the TV, facing the viewer, and cooperate with the center channel speaker to enhance action. They are often used to simulate movement by moving sound from one speaker to another--for instance, having a squawking bird fly from left to right or having the main character turning and hearing sounds change from his point of view. The left and right speakers should be positioned on the left and right sides of the TV at head height, pointed towards the listener.

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Satellite

Some HDTV programming is broadcast via satellite and one must use a satellite dish to receive it.

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Separate Video

Separate Video (S-video) divides information from a video source such as a DVD player or cable TV connection into two signals, color and brightness. S-video is typical of standard definition.

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Set-Top Box

If you don't want to use a CableCARD, you can buy a set-top box in order to connect to high-definition cable television.

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Subwoofers

Subwoofers are used for bass and other sounds that register very low. Guttural grunts, thunder, musical beats, thuds, creaks, and rumbles that carry weight--all of these sounds that are so integral to a viewer's audio experience--need a subwoofer in order to sound proper.

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Surge Protector

In order to protect your home-theater system from harmful voltage spikes, plug it into a surge protector, which regulates voltage sent to electronic devices.

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Surround Sound Speakers

In a surround-sound speaker system, the surround-sound speakers are the ones positioned on the walls, facing the listener, and which emit ambiance and sound effects.

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Universal Remote

Each device in your home-theater system will probably come with a remote: a TV remote, an HD DVD player remote, a receiver remote, and so forth. To simplify the process, get a universal remote so that you can control all of your systems with just one hand.

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Upconverter

Upconverting a DVD player consists of taking a standard-definition DVD and "upsampling" it to appear to be at a higher resolution. Despite the labels that they are "1080i" or "1080p" DVD upconverters, they are not the same as watching your DVDs in true high definition, since the source content is still limited by the content on the DVD disc itself. What you will see is some increased detail and clearer colors, however. Upconverting works best on displays with fixed pixels--namely plasma or LCD TVs. If you use them with standard CRT televisions or with some projectors, the upscaling feature may not result in a better image. It's also important to note that Blu-ray (and HD DVD) players are excellent DVD upconverters.

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Viewing Angle

The viewing angle determines where you can sit in relation to a television and still enjoy high picture quality. A wide viewing angle (about 170 degrees) means that wherever you are in front of an HDTV the picture should always look good. It's important to test this before purchasing a TV, especially if the set will be located in a large room.

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VGA Outputs

VGA or "Video Graphics Array" outputs are some of the earliest connectors devised and produce a 640 x 480 resolution, which has long since been surpassed. They are commonly used to connect monitors to computers and can be found on many computers, mobile devices, and video game consoles.

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