User guide

274
Appendix C, Matrox RT.X100 Xtreme Glossary
crossfade See dissolve.
cube effect A Matrox effect that lets you
map video or graphics to the faces of 3D
shapes such as cubes and slabs.
cut A direct switch from one video and/or
audio source to another.
D
D-9 Originally known as Digital-S. A
professional variant of the DV format
developed by JVC that uses a data rate of 50
Mb/sec (5.96 MB/sec), which is double the
data rate of most other DV formats. Video is
sampled at 4:2:2 for both NTSC and PAL
sources to give enhanced chroma resolution.
It uses a 1/2” metal particle tape.
Digital8 A consumer camcorder video
format developed by Sony. Digital8
camcorders use the DV format to record
digital video and audio onto 8mm and Hi-8
tapes via any device that has an IEEE-1394
interface.
Digital-S See D-9.
digital signal A signal representing video
or audio information as binary digits that can
be easily regenerated with no noise or
distortion. See also analog signal.
Digital Video See DV.
digitize To convert analog information,
such as a video signal from a VTR or camera,
into digital information that can be processed
and stored by a computer.
Direct memory access (DMA) A
technique used to rapidly transfer data
between an attached device, such as a disk
drive, and the computer's main memory
without needing to pass the data through the
central processing unit (CPU).
DirectX A Microsoft-developed program
that enables interfaces to support advanced
hardware features without being written
specifically for each hardware model.
DirectShow (formerly called ActiveMovie) is
part of DirectX.
display card A card that has its own
memory and processor to handle graphics and
enhance display capabilities. Also called
graphics accelerator card or graphics card.
dissolve A transition in which one image
smoothly fades to another image. It is
characterized by the gradual ending of one
image occurring simultaneously with the
gradual beginning of another. Also called
crossfade.
driver Software that controls a device, such
as a display card, and enables it to work with
other software.
drop-frame time code For NTSC video,
time code is normally produced by a
generator that counts at 30 frames per second.
NTSC color signals, however, actually have a
display frequency rate close to 29.97 frames
per second. Drop-frame time code
compensates for this time difference by
dropping two frames from the count every
minute except for every tenth minute so that
the time code matches clock time.
DV Digital Video. A standard digital bit
stream and compression format (known as the
Blue Book standard) used to record video and
audio onto a digital tape. DV is intra-frame
based, saving each frame separately, and uses
a fixed 5:1 compression ratio to reduce the
size of video files. DV’s data rate is fixed at
25 Mb/sec (2.98 MB/sec). Video is sampled
at 4:1:1 for NTSC sources or 4:2:0 for PAL
sources. See also DVCAM, DVCPRO,
DVCPRO50, and D-9.
DVCAM A professional variant of the DV
format developed by Sony that records a 15
micron track on a metal evaporated (ME) tape
at a data rate of 25 Mb/sec (2.98 MB/sec).
Video is sampled at 4:1:1 for NTSC sources
or 4:2:0 for PAL sources.