D

DAM

Abbreviation for Digital Asset Management.

Data

Information transmitted as binary code. In the case of component video each pixel is a vector quantity and includes information for all color components Y', R-Y' and B-Y.' High quality standard definition for a moving color picture requires a data rate of 200 million bits per second. [BAVC]

Data Compression

A technique that provides for the transmission or storage, without noticeable information loss, of fewer data bits than were originally used when the data was created. [BAVC]

Database

1. The most common data-structuring model is 'relational,' where data is organized in related or linked tables that can be accessed or reassembled in many different ways. Object-oriented databases are also common. [Getty] 2. A collection of information concerning a certain topic organized in a logical fashion for easy access and speedy retrieval. [IMAP]

Decibel (dB)

Unit of measurement for sound levels. [BAVC]

Decoder

A device used to recover the component signals from a composite (encoded) source. Decoders are used in displays and in various processing hardware where component signals are required from a composite source, such as composite chromakeying of color correction equipment, etc. [BAVC]

Degauss

Erase a videotape completely by exposing the tape to a magnetic field.[BAVC]

Demagnetization

A process that erodes audiovisual signals or data encoded onto magnetic tape. This degradation is a natural phenomenon whose speed varies with the type and condition of the tape. [Variable Media]

Derivative file

A file derived or created from another file, rather than created during an original digitization process. Differs from a copy insofar as the derivative file may be altered in some way from the original. [Getty]

Derivative master

A high-quality 'working' image file that is derived from an archival master image file, then subjected to some form of processing, such as color correction. May also be known as a submaster. [Getty]

Desktop

1. The background image and icons that represent the highest-level folder on a personal computer. 2. Said of applications or activities that operate on a personal computer, as in "desktop publishing". [Variable Media]

Deterioration

The degradation of videotape, most typically with the binder, which is responsible for holding the magnetic particles on the tape and facilitating tape transport. If the binder loses integrity - through softening, embrittlement, loss of cohesiveness, or loss of lubrication - the tape may become unplayable. Sticky tape and sticky shed are commonly used terms to describe the phenomenon associated with deterioration of the magnetic tape binder. [BAVC]

DHTML

A new version of HTML, developed by Netscape and expanded by the W3C (the World Wide Web Consortium). Combines JavaScript's ability to move or rewrite page elements with the CSS method of defining document layout and style to create dynamic Web sites. Unlike closed formats such as Flash, users can directly view the source code of DHTML documents. [Variable Media]

Diacetate

Also referred to as cellulose diacetate. The type of basefilm used for making audio tapes until the 1960s. It is related in chemical composition to cellulose acetate. [AMIA]

Diagonal screen

One corner of a screen to the opposite corner. A 9FT high, 12FT wide, screen has a diagonal of 15FT. If the screen is 12x12, it would still rate 15FT diagonal since that would be the diagonal usable. [Projector People]

Digital

Electronic technology that generates, stores, and transmits data in terms of a limited number of discrete states, most commonly as binary data in which two possible states, positive or nonpositive, are represented by 1 or 0, respectively. Because there are only two possible values, the accuracy of binary digital data at any given point is relatively easy to test, and therefore digital technology facilitates the creation of accurate copies. [Getty]

Digital Asset Management

A system that enables the management of digital objects, such as image files, from ingest to archiving and supports continued retrieval. Off-the-shelf DAM software may offer templates and other devices or strategies to facilitate ingest, metadata capture, and searching. May also be called media asset management (MAM). [Getty]

Digital coaxial

Digital coaxial is the most common type of digital audio connection. A digital coaxial connector appears very similar to a RCA connector, but it transmits digital data instead of analog signals. The electrical signal pulses through a copper wire at the heart of the coaxial cable, which is shielded from interference by an aluminum foil casing. [EAI]

Digital preservation

The specific problems and methods of preserving digital, as opposed to analog, assets because of their vulnerability to format obsolescence and media decay. Various strategies have been developed to respond to this, including documentation, the gathering of preservation metadata, the use of open standards, redundant storage, refreshing, migration, emulation, technology preservation, re-creation, and digital archaeology. [Getty]

Digital projector

A Digital projector is a device that converts image data from a computer or digital video source to a bright image, which is then imaged on a distant wall or screen using a lens system. [EAI]

Digital recording

A recording in which binary numbers represent quantized versions of the voltage signals from the recording microphone or the video camera. On playback, the numbers are read and processed by a digital-to-analog converter to produce an analog output signal. [AMIA]

Digital video

System of recording video images using sequences of binary numbers to encode brightness, colour and timing information necessary to reconstruct the moving image. [ScreenSound Australia]

Digital-to-analog

The process in which a series of discrete binary integers is converted to a continuous analog signal. Sometimes referred to as D-to-A. [AMIA]

Digitization

The process of deriving digital objects from analog originals by converting their sampled values to binary code. Also known as analog-to-digital.[Getty]

Disc

Commonly the term used for optical media, such as Compact Discs, as well as analog sound recordings, such as LPs and transcription discs. [AMIA]

Disk

The term used for magnetic media in non-tape format, such as a computer hard disk or a floppy disk. [AMIA]

Display Device

A display device is a presentation device for visual information. In the case of moving images, a display device typically takes the shape of a monitor or projector. [EAI]

Dissolve

A video transition in which the existing image is partially or totally replaced by superimposing another image. One image fades in as the other fades out. [BAVC]

Distribution amplifier

Amplifier that allows one video or audio signal to be sent to several pieces of equipment simultaneously. [BAVC]

DLP projector (Digital Light Processing)

Digital Light Processing (DLP) is a technology used in projectors and projection televisions. Originally developed by Texas Instruments, with DLP the image is created by microscopic mirrors laid out in a matrix on a semiconductor chip. Each mirror represents one pixel in the projected image. [EAI]

Drop-frame time code

SMPTE time code format that continuously counts 30 frames per second but drops 2 frames from the count every minute except for every tenth minute (drops 108 frames every hour) to maintain synchronization of time code with clock time. This is necessary because the actual frame rate of NTSC video is 29.94 frames per second rather than 30 frames. [BAVC]