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Aspect Ratio
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The ratio of width to height in a video picture or other graphic image; describes the shape of a TV screen or program, not an actual inch measurement.
- 4:3: standard "square" screen TV aspect ratio.
- 16:9: typical widescreen TV aspect ratio. |
ATSC
(Advanced Television Systems Committee) |
Type of digital tuner that allows TV to receive “over-the-air” HDTV broadcasts. |
| Bit Rate |
The measure of how many bits of data are transmitted or received in a specified amount of time, such as kilobits per second; a low bit rate means lower quality and a smaller file size, while a high bit rate means better quality and larger files. |
| Blu-ray |
Format for HD DVD that uses a shorter-wave blue laser developed to enable recording, rewriting and playback of HD video, offering more than 5 times the storage capacity of a traditional DVD. |
| Brightness |
See Luminance. |
| Child Lockout/V-Chip |
Allows parents restrictive authority over what their children watch.
- Child Lockout: restricts access to certain channels with a special code.
- V-Chip: select the maturity level of appropriate programming based on the TV Rating System. |
| Chrominance |
Portion of a TV signal that carries color information. |
| Color Decoder |
Translates color-signal information from the source for display on all color TVs. |
| Comb Filter |
Separates the chrominance and luminance from one another in composite-video connections; good comb filtering enhances fine detail, cleans up image outlines, and eliminates most extraneous colors. |
| Component Video |
Jacks or cables that transmit the video signal in 3 parts: brightness (Y), blue color (Pb) and red color (Pr); better for external devices like progressive-scan DVD players that require higher resolution quality; resolution quality is still dependent upon the quality of the source (the equipment which outputs the signal). |
| Composite Video |
Standard RCA jacks or cables that hook up audio and video components to each other, typically colored red, white and yellow (for audio and video inputs); not considered to provide the best picture because they mix color and black and white signals together. |
| Compression |
Any technology that enables data to take up less space; can be applied to data files, images, audio or video. |
| Contrast Ratio |
The difference in light intensity between the brightest white and the darkest black that a display device can produce; higher contrast ratios provide a sharper picture than lower ones. |
| CRT (Cathode-Ray Tube) |
A type of vacuum tube that creates a screen image by shooting a high-speed electron beam onto a phosphorescent screen. |
| Digital Cable Ready |
Allows for direct, plug-in access to HDTV and digital cable without having to use a separate set-top box. |
| DivX |
Compressed video format based on the MPEG-4 standard that enables a feature-length movie to fit on a CD-ROM. |
| Dolby Digital |
A proprietary technology used for creating and reproducing digital surround sound (also called AC-3 or 5.1). |
| Downconvert |
In DTV, the conversion from a higher-resolution input signal number to a lower one. |
| DTV (Digital Television) |
Generic term that refers to all digital TV formats, including high-definition TV (HDTV) and standard-definition TV (SDTV). |
| DTV Tuner |
Allows the set to receive over-the-air HDTV broadcasts without having to attach a set-top box. |
| DVR (Digital Video Recorder) |
Digitally records video to a disk drive or other memory medium within a device and offers pause and rewind control over live broadcasts. |
| Flat-Panel TV |
Usually refers to LCDs used for TV displays; also refers to other technologies, like plasma, that produce flat-shaped screens as opposed to bulkier CRT technology. |
| FPS (Frames Per Second) |
The number of individual still pictures that pass by every second to create a moving image; the higher the number the more seamless the flow of images. |
| Ghosting |
A visual phenomenon in digital displays when an image moves faster than the display can redraw it, leaving a trail of former versions of the image in the wake of the redrawn image; as LCDs evolve, faster pixel-response times are reducing the ghosting problem. |
| HDCP (High-bandwidth Digital Content Protection) |
Helps prevent unauthorized capture or duplication of copyrighted digital audio and video content. |
| HDMI (High-Definition Multimedia Interface) |
Transfers uncompressed digital video and multichannel audio with HDCP copy protection, reducing signal loss caused by compression. |
| HD-DVD (High-Definition Digital Video Disc) |
High-density discs designed to hold HD video; can hold approx. 3 times as much video as a standard DVD. |
| HDTV (High-Definition Television) |
TV signal that offers a much higher resolution and a wider aspect ratio than traditional broadcast signals; also a TV set that picks up these signals. |
| HDTV-Enabled |
Any TV that has a built-in tuner allowing the display of HDTV signals without a separate tuner or set-top box. |
| HDTV-Ready |
Any TV that can display HD formats when connected to a separate HDTV tuner or source; usually able to receive analog broadcasts, but not over-the-air HDTV signals. |
| Horizontal Resolution |
Number of vertical lines or pixels that can be resolved from one side of an image to the other; varies according to the source. |
| Integrated HDTV Tuner |
Allows the set to receive over-the-air HDTV broadcasts without having to attach a set-top box. |
| Interlaced Scanning |
Method in which odd-numbered lines are scanned or “painted” in succession and then the remaining even-numbered lines are filled in; less stable than progressive scanning. |
| LCD (Liquid-Crystal Display) |
Slim, lightweight device that uses an electrified reactive liquid crystal substance to produce a screen image. |
| LCD TV |
Employs a liquid-crystal display screen rather than a CRT screen; resulting in a thinner, more lightweight device. |
| Letterbox |
A widescreen movie on DVD or videotape presented in its original theatrical widescreen width on a standard square-screen 4:3 TV. |
| Lumens |
The unit of measure for the light output of a projector. |
| Luminance |
Portion of a TV signal that controls brightness; usually expressed as cd/m2 or candle brightness per square meter; the higher this number, the better. |
| Mbps (Megabits Per Second) |
Measure of networking bandwidth or data transmission speed, expressed in millions of binary bits per second. |
MPEG
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A set of standards for compressing multimedia files.
- MPEG-1 is used in CD-ROMs.
- MPEG-2 is used for a broad range of formats, including DVD, HDTV, and surround sound; MPEG-3 was merged into MPEG-2.
- MPEG-4 is a standard for low-bandwidth video and multimedia. |
| Native Resolution |
Resolution at which a TV or monitor is designed to display images; image signals higher or lower than a specified native resolution must be converted to be displayed accurately. |
| NTSC (National Television System Committee) |
Type of analog tuner used for broadcast TV. |
| Pan-and-Scan |
Process of transferring a movie or other program to videocassette, DVD or broadcast so that it fits a standard, square-screen TV; results in lost picture information; displays the disclaimer "...formatted to fit your TV." |
| Pixel (short for “picture element”) |
A single point on a TV display; in a monitor, each point in the display grid constitutes a pixel. |
| Plasma Display Panel |
Slim, lightweight device that uses an electrified ionized gas to produce a screen image. |
| Progressive Scan |
Method of displaying images in which all the lines of a picture are drawn in one quick burst. |
| QAM (Quadrature Amplitude Modulation) |
Digital cable tuner that can tune unscrambled digital cable channels, but to view scrambled channels a CableCard or set-top box is required. |
| RF Jack (Radio Frequency Jack) |
Carries video and stereo audio simultaneously from a broadcast, cable or satellite source to a device with a tuner; provides the lowest video quality of any connection. |
| Resolution |
A measure used to describe the quality of images a screen can display; refers to the number of pixels in the entire screen; for example, a resolution of 1280x1024 means that 1024 lines are drawn from the top to the bottom of the screen and each of these lines is made up of 1280 separate pixels.
- 480i (480 interlaced): form of standard-definition digital TV (SDTV) that approximates the quality of analog TV, but is not considered HDTV.
- 480p (480 progressive): form of SDTV that is discernibly cleaner and slightly sharper than analog TV; not considered HD.
- 720p (720 progressive): HDTV standard that comprises 720 vertical pixels and 1280 horizontal pixels; 720p is not inferior to 1080i because while it has fewer lines, it has the advantages of progressive scanning, making it better able to handle motion.
- 1080i (1080 interlaced): HDTV standard that specifies an interlaced resolution of 1920x1080.
- 1080p (1080 progressive): refers to the 1920x1080 progressive scan HDTV format; also called Full HD, True HD or Ultra HD. |
| Response Time |
A screen’s signal reaction speed; quicker response times translate to smoother and more fluid images; articulated in terms of milliseconds (ms), such as 8ms. |
| S-Video (Separated-Video) |
4-pin connector jack or cable that provides a sharp, clear picture by transmitting the color and brightness portions of a video signal separately to reduce interference; generally outperforms composite video connections, but doesn’t look as sharp as component video or HDMI connections. |
| Surround Sound |
True Surround Sound: commonly referred to as 5.1, which refers to how digital sound is recorded on 6 separate tracks: front left, front right, front center, rear left and rear right, with an extra track reserved for very low bass.
Simulated Surround Sound: sometimes referred to as 2.1; a sound system that simulates the panning of a full surround sound system while using a TV’s 2 built-in speakers and a subwoofer for bass. |
| Upconvert |
In DTV, the conversion from a lower-resolution input signal number to a higher one. |
| Vertical Resolution |
Number of horizontal lines or pixels that can be resolved from the top of an image to the bottom; the analog NTSC TV standard is 480 lines; digital TV signals have vertical resolution that ranges from 480 lines for standard-definition TV, to 720 or 1080 lines for high-definition TV. |
| Viewing Angles |
Refers to the angle from which you can still view the picture on the screen; TVs with wide viewing angles don’t require you to be positioned directly in front of the set to view an ideal picture; usually referred to in degrees, for example 178 Degrees. |
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