Matrox Electronic Systems Matrox RT.X2 - Manual (Page 205)

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Glossary of terms
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
process that contains all the information
required to reproduce a complete image. It
allows random access points within a video
stream, and acts as a reference point for B-
frames and P-frames to be built. I-frames are
editable because they contain enough data to
construct an entire video frame, unlike B-
frames or P-frames.
impressionist effect A Matrox effect that
lets you choose from many different patterns
to make your image appear similar to an
impressionist painting.
insert editing Recording new video
and/or audio material onto a prerecorded (or
striped) tape. Insert edits can be made in any
order, unlike assemble edits, which must be
made sequentially.
inter-frame compression A video
compression method that compares a series of
frames in a video sequence and removes the
redundant data. Inter-frame compression
treats all the frames in the sequence as an
interdependent group. As a result, most of the
frames can’t be edited independently. Also
called temporal redundancy reduction.
Contrast with intra-frame compression. See
also GOP.
interlaced scanning A method of
creating a video image by drawing only the
odd numbered lines on the screen in one pass,
then the even numbered lines in the next pass.
Two passes are therefore required to create a
complete frame of video. NTSC and PAL
displays are interlaced. See also progressive
scanning.
interleave A technique used to incorporate
the video and audio portions of a video clip
into one file. See also AVI.
intra-frame compression A video
compression method that removes redundant
information from within a frame. Intra-frame
compression treats each frame of a video
segment independently. Several video
compression formats use the intra-frame
method. These include Motion-JPEG, DV,
and MPEG-2 I-frame. Also called spatial
redundancy reduction. Contrast with inter-
frame compression. See also I-frame (Intra-
frame).
IRE unit An arbitrary unit designated by
the Institute of Radio Engineers to define the
amplitude of a video signal. 1 IRE is equal to
approximately 7 mV.
J
JPEG (pronounced “jay-peg”) Joint
Photographic Experts Group. A compression
and storage standard used for still, digital
images. See also Motion-JPEG.
K
key effect See alpha key, chroma key, and
luma key.
keyframe A particular frame at which one
or more effect settings have been defined.
Settings applied at a keyframe remain active
on the clip until a later keyframe is defined to
turn off or change the settings.
L
lens flare effect A Matrox effect that lets
you choose from many different patterns to
simulate the light refractions caused by
shining a bright light into the lens of a camera
when taking a photo.
LTC Longitudinal Time Code. Time code
that is generally encoded as an audio signal
onto a linear audio track of a tape. This type