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field
One-half of the horizontal lines
needed to make a complete scan of an
interlaced video frame. In the NTSC system,
two consecutive fields of 262.5 lines each
create a frame of 525 scan lines. In the PAL
system, two consecutive fields of 312.5 lines
each create a frame of 625 scan lines.
FireWire Apple Computer's original
implementation of the technology that would
be standardized as IEEE-1394 in 1995.
Flex CPU effect See CPU-based effect.
frame A single video image. An interlaced
video frame is comprised of two consecutive
fields (the odd and even fields).
G
garbage matte effect
used to crop unwanted objects from a
foreground image in a chroma or luminance
key effect. You define the shape of the
garbage matte, and only the underlying image
is shown outside the matte.
GOP Group of Pictures. The sequence of I,
B and/or P-frames produced during MPEG or
MPEG-2 compression. This sequence of
frames contains all of the information
required to reproduce a complete video
segment. The longer the GOP, the less
editable it is.
GPU Graphics processing unit. A processor
that is used primarily for computing 3D
functions, such as processing 3D DVEs and
lighting effects. Because the calculations
required to process these effects are
CPU-intensive, the GPU lifts this burden from
the CPU to allow it to perform more
efficiently. A high-performance display card
is sometimes referred to as a GPU.
graphics card See display card.
Appendix D, Matrox Axio Glossary
An effect often
graphics overlay Text or a graphics
image that's superimposed on video. Also
called super.
H
hardware-accelerated effect An effect
that requires the assistance of dedicated
hardware to play back in real time. Compare
with CPU-based effect.
HD Short for HDTV.
HDTV High Definition Television. A
digital television format with image
resolutions up to 1080 vertical scan lines.
HDTV has a 16:9 aspect ratio. Also called
HD. See also SDTV.
HDV A high-definition video format that
uses MPEG-2 video compression at a data
rate of about 19 Mb/sec for HDV-1 or
25 Mb/sec for HDV-2, and records to standard
DV format digital video cassettes.
hue The tint or tone of a color. For
example, the difference between the color
green and red is its hue.
I
IBP compression See MPEG-2 IBP.
IEEE-1394 An international standard data
transfer protocol created by Apple Computer
under the FireWire trademark and
standardized by the Institute of Electrical and
Electronics Engineers (IEEE). It enables
simple, low-cost, realtime data transfer
between computers and consumer and
prosumer electronics products, such as DV
camcorders and DV decks. Commonly
referred to as 1394.
I-frame compression See MPEG-2
I-frame.
I-frame (Intra-frame) A frame created
during the MPEG or MPEG-2 compression
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