What are they talking about?!?
Digital/HDTV Terms that Begin with "D"

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D/A
Conversion of digital to analog signals. The device is also referred to as DAC (D/A converter). In order for conventional television technology to display digitally transmitted TV data, the data must be decoded first and then converted back to an analog signal.

DBS
Abbreviation of "Direct Broadcast Satellite" - refers to digital TV transmissions via satellite.

De-interlacing (also called line-doubling)
The process of converting an interlaced-scan video signal (where each frame is split into two sequential fields) to a progressive-scan signal (where each frame remains whole). De-interlacers are found in digital TVs and progressive-scan DVD players. More advanced de-interlacers include a feature called 3-2 pulldown processing. For TVs, de-interlacing is often referred to as "line-doubling" or "upconversion."

Delay
The time difference between a sonic event and its perception at the listening position (sound traveling through space is delayed according to the distance it travels). People perceive spaciousness by the delay between the arrival of direct and reflected sound (larger spaces cause longer delays).

Diffusion
In audio, the scattering of sound waves, reducing the sense of localization. In video, the scattering of light waves, reducing hot spotting, as in a diffusion screen.

Digital Audio Output
A connection found on HDTVs and HDTV tuners for sending the Dolby Digital audio of HDTV broadcasts to an A/V receiver with Dolby Digital decoding. The two most common types of digital output are coaxial and Toslink optical.

Digital Television (DTV)
Refers to all formats of digital television, including high definition television (HDTV), and standard definition television (SDTV). Also referred to as ATV (Advanced TV).

Digital Theatre System (DTS)
Digital Theater Systems. A digital sound recording format, originally developed for theatrical film soundtracks, starting with Jurassic Park. Records 5.1 discrete channels of audio onto a handful of laser discs, CDs, and DVDs. Requires a player with DTS output connected to a DTS processor.

Digital Theatre System ES (DTS ES)
An enhanced version of the 5.1 DTS system. Like Dolby’s Surround EX, a sixth channel is added. In some cases (DTS ES Discrete), the sixth channel is discrete. Software is backwards-compatible with 5.1 systems, but requires an ES or 6.1 processor to obtain additional benefit. Neo:6 is a subset of DTS ES that creates 6.1 from material with fewer original channels.

D-ILA
Direct Drive Image Light Amplifier. This Hughes/JVC technology uses a reflective LCD to create an image. A light source is then reflected off the reflective LCD and is directed through a lens to a screen.

Direct-view TV
The conventional and most common type of TV, which uses a single large (up to 40") CRT to display images. Other TV types include rear-projection and front-projection.

DLP (Digital Light Processing)
A projection TV technology developed by Texas Instruments, based on their Digital Micromirror Device (DMD) microchip. Each DMD chip has hundreds of thousands of tiny swiveling mirrors which are used to create the image — each mirror represents a single pixel. DLP technology is used in both front- and rear-projection systems.

There are two basic types of DLP projector: "single-chip" projectors use a single DMD chip along with a spinning color wheel, while much more expensive "3-chip" projectors dedicate a chip to each basic color: red, green, and blue.

DMD (Digital Micromirror Device)
Texas Instruments engine that powers DLP projectors. Uses an array with tens of thousands of microscopic mirrors that reflect a light source toward or away from the lens, creating an image. Each mirror represents a pixel. See DLP.

DTS
Digital Theater Systems sound. Discrete 5.1 channel surround system similar but not the same as Dolby Digital. Dolby Digital is the DTV standard, but DTS competes with it on DVD and in the movie theaters.

Dolby® EX
An enhancement to Dolby Digital that adds a surround back channel to 5.1 soundtracks. The sixth channel is matrixed from the left and right surround channels. Often referred to as 6.1. Sometimes referred to as 7.1 if the system uses two surround back speakers, even though both speakers reproduce the same signal. Software is backwards-compatible with 5.1 systems, but requires an EX or 6.1 processor to obtain additional benefit.

Dolby® Digital
A discrete multichannel digital audio format that is the official audio standard for HDTV (and DVD). Dolby Digital is normally associated with 5.1-channel surround sound. Though this channel configuration is common, it is only one of several possible variations — a "Dolby Digital" soundtrack can mean anything from 1 to 5.1 channels.

Dolby Pro Logic
An enhancement of the Dolby Surround decoding process. Pro Logic decoders derive left, center, right, and a mono surround channel from two-channel Dolby Surround–encoded material via matrix techniques.

Dolby Pro Logic II
An enhanced version of Pro Logic. Adds improved decoding for two-channel, non-encoded soundtracks and music.
Dome: A type of speaker-driver shape; usually used for tweeters (convex). Concave domes are usually referred to as “inverted domes.”

Dot Crawl
An artifact of composite video signals that appears as a moving, zipper-like, vertical border between colors. Downconvert
A term used to describe the format conversion from a higher resolution input signal number to a lower display number, such as 1080i input to 480i display.

DTS (Digital Theatre System)
See Digital Theatre System.

DTS ES (Digital Theatre System ES)
See Digital Theatre System ES.

DTV (Digital Television)
See Digital Television.

DVD
Officially known as the Digital Video Disc, though marketers unofficially refer to it as the Digital Versatile Disc. DVD uses a 5-inch disc with anywhere from 4.5 Gb (single layer, single-sided) to 17 Gb storage capacity (double-layer, double sided). It uses MPEG2 compression to encode 720:480p resolution, full-motion video and Dolby Digital to encode 5.1 channels of discrete audio. The disc can also contain PCM, DTS, and MPEG audio soundtracks and numerous other features. An audio-only version, DVD-A uses MLP to encode six channels of 24-bit/96-kHz audio.

DVD-A
Digital Versatile Disc-Audio. Enhanced audio format with up to six channels of high-resolution, 24-bit/96-kHz audio encoded onto a DVD, usually using MLP lossless encoding. Requires a DVD-A player and a controller with 6-channel inputs (or a proprietary digital link) for full compatibility.

DVD-R
A recordable DVD format similar to CD-R in that it is a write-once medium. Backed by Pioneer, Panasonic, Toshiba, and others.

DVD-RW
A recordable DVD format similar to CD-RW in that it is re-recordable medium. Backed by Pioneer, Panasonic, Toshiba, and others.

DVD+R
A recordable DVD format similar to CD-R in that it is a write-once medium. Backed by Sony, Philips, Yamaha, HP, and others.

DVD+RW
A recordable DVD format similar to CD-RW in that it is re-recordable medium. Backed by Sony, Philips, Yamaha, HP, and others.

DVD-RAM
A recordable DVD format similar to CD-R in that it is a write-once medium. Backed by Pioneer, Panasonic, Toshiba, and others.

DVI (Digital Visual Interface)
A multi-pin computer-style connection intended to carry high-resolution video signals from digital set-top boxes (HDTV-capable DIRECTV, DISHNetwork, and cable boxes, plus a few DVD players) to HDTV monitors with a compatible connector. The signals are encrypted with High-bandwidth Digital Content Protection (HDCP) to prevent recording.

Dynamic Range
The difference between the lowest and the highest levels; in audio, it’s often expressed in decibels. In video, it’s listed as the contrast ratio.