D
DAC -
Digital-to-analog converter.
data
object -
In an application, an element of a
data structure (such as a file, an array, or an operand) that is needed
for program execution and that is named or otherwise specified by the allowable
character set of the language in which the program is coded.
data
stream -
All data transmitted through a data
channel.
data streaming -
Real-time,
continuous flowing of data.
DCP -
See device control panel.
decode -
(1) To convert data by reversing the effect of previous
encoding. (2) To interpret a code. (3) To convert encoded text into plaintext
by means of a code system. (4) Contrast with encode.
default
video window -
(1) Refers to where video is
displayed when an application does not indicate an application-defined window
with the MCI_WINDOW message. This is provided by and managed for the application
by MMPM/2. (2) See also application-defined window.
default
window -
See default video window.
delta
frame -
Refers to one or more frames occurring
between reference frames in the output stream. Unlike a reference frame,
which stores a complete image, a delta frame stores only the changes in
the image from one frame to the next. See reference frame.
destination
rectangle -
An abstract region which defines
the size of an image to be created when recording images for software motion
video playback. The ratio of this rectangle's size to that of the source
rectangle determines the scaling factor to be applied to the video.
destination
window -
See destination rectangle.
device
capabilities -
The functionality of a device,
including supported component functions.
device
context -
The device status and characteristics
associated with an opened instance of an Media Control Interface device.
device control panel (DCP) -
An integrated set of controls that is used to control a device or media
object (such as by playing, rewinding, increasing volume, and so on).
device
controls -
See standard multimedia device
controls.
device driver -
(1)
A file that contains the code needed to use an attached device. (2) A program
that enables a computer to communicate with a specific peripheral device;
for example, a printer, a videodisc player, or a CD drive.
device
element -
A data object, such as a file, utilized
by a compound device.
device object -
An object that provides a means for communication between a computer and
the outside world. A printer is an example of a device object.
device
sharing -
(1) The ability to share a device
among many different applications simultaneously. If a device is opened
shareable, the device context will be saved by the operating system when
going from one application to another application. (2) Allowing a device
context to be switched between Media Control Interface devices.
device-specific
format -
The storage or transmission format
used by a device, especially if it is different from an accepted standard.
dialog -
In an interactive
system, a series of related inquiries and responses similar to a conversation
between two people.
digital -
(1)
Pertaining to data in the form of numeric characters. (2) Contrast with
analog.
digital audio -
(1)
Material that can be heard that has been converted to digital form. (2)
Synonym for digitized audio.
digital signal
processor (DSP) -
A high-speed
coprocessor designed to do real-time manipulation of signals.
digital
video -
(1) Material that can be seen that has
been converted to digital form. (2) Synonym for digitized video.
digital video effects (DVE) -
An
online editing technique that manipulates on-screen a full video image;
activity for creating sophisticated transitions and special effects. Digital
video effects (DVE) can involve moving, enlarging, or overlaying pictures.
Digital Video Interactive (DVI) -
A
system for bringing full-screen, full-motion television pictures and sound
to a regular PC. DVI is a chip set and uses delta compression; that is,
only the image-to-image changes in each frame are saved rather than the
whole frame. Data (video footage) is compressed into a form that reduces
memory requirements by factors of 100 or greater. This compressed data
is stored on optical discs and can be retrieved at a rate of 30 frames per
second. (The DVI technology was developed by RCA and then sold to Intel.
IBM has chosen this technology for future use in the PS/2.)
digital-to-analog
converter (DAC) -
(1) A functional unit that
converts data from a digital representation to an analog representation.
(2) A device that converts a digital value to a proportional analog signal.
digitize -
To convert
an analog signal into digital format. (An analog signal during conversion
must be sampled at discrete points and quantized to discrete numbers.)
digitized audio -
Synonym
for digital audio.
digitized video
-
Synonym for digital video.
digitizer
-
A device that converts to digital format any
image captured by the camera.
direct manipulation
-
A set of techniques that allow a user to
work with an object by dragging it with a pointing device or interacting
with its pop-up menu.
direct memory access
-
The transfer of data between memory and input and
output units without processor intervention.
direct-read-after-write
(DRAW) disc -
A videodisc produced directly
from a videotape, one copy at a time. A DRAW disc usually is used to check
program material and author applications before replicated discs are available.
disc -
Alternate
spelling for disk.
discard stop -
In data streaming, requests that the data stream
be stopped and the data remaining in the stream buffers be discarded.
disk
-
A round, flat, data medium that is rotated
in order to read or write data.
display image
-
A collection of display elements or segments
that are represented together at any one time on a display surface. See
also background image and foreground image.
dissolve
-
To fade down one picture as the next fades
up. Synonym for crossfade.
dithering
-
When different pixels in an image are prebiased
with a varying threshold to produce a more continuous
gray scale despite a limited palette. This technique is used to soften a
color line or shape. This technique also is used for alternating pixel
colors to create the illusion of a third color.
DLL
-
dolly
-
A wheeled platform for a camera; a camera
movement where the tripod on which the camera is mounted physically moves
toward or away from the subject.
DOS IOProc
-
An internal I/O procedure, provided by the MMPM/2
system, that supports DOS files.
double-click
-
In SAA Advanced Common User Access, to press
and release a mouse button twice within a time frame defined by the user,
without moving the pointer off the choice. See click. See also drag
select.
drag select -
In
SAA Advanced Common User Access, to press a mouse button and hold it down
while moving the pointer so that the pointer travels to a different location
on the screen. Dragging ends when the mouse button is released. All items
between the button-down and button-up points are selected. See also click,
double-click.
DRAW disc -
Direct-read-after-write
disc.
drop-frame time code -
A
nonsequential time code used to keep tape time code matched to real time.
Must not be used in tapes intended for videodisc mastering.
DSP
-
Digital signal processor.
DTMF
-
Dual-tone modulation frequency.
dual
plane video system -
Refers to when graphics
from the graphics adapter are separate from the analog video. That is,
there is a separate graphics plane and video plane. The analog video appears
behind the graphics, showing through only in the areas that are transparent.
Since graphics and video are separate, capturing the graphics screen will
only obtain graphics, and capturing the video screen will only obtain video.
This is also true for restoring images. See also single plane video
system.
dual-state push button -
A push button that has two states, in and out. It is used for setting and
resetting complementary states, such as Mute and Unmute.
dual-tone
modulation frequency (DTMF) -
dub -
To copy
a tape; to add (sound effects or new dialog) to a film; to provide a new
audio track of dialog in a different language. (Often used with "in" as
"dub in".)
DVE -
DVI -
dynamic icon -
An
icon that changes to convey some information about the object that it represents.
For example, a folder icon can show a count, indicating the number of objects
contained within the folder. Also, a tape player icon can show an animation
of turning wheels to indicate that the machine playing.
dynamic
linking -
In the OS/2 operating system, the
delayed connection of a program to a routine until
load time or run time.
dynamic link library (DLL)
-
A file containing executable code and data
bound to a program at load time or run time, rather than during linking.
The code and data in a dynamic link library can be shared by several applications
simultaneously.
dynamic resource allocation
-
An allocation technique in which the resources
assigned for execution of computer programs are determined by criteria applied
at the moment of need. (I) (A)
dynamic resource
-
A multimedia program unit of data that resides
in system memory. Contrast with static resource.
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