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Appendix
Glossary of Terms
Analog video
: a video signal that is recorded and played back using changes in magnetic levels recorded
on
a tape or disk, e.g., the video we see when we watch a VHS videocassette.
Animation
: a video or film sequence that gives the illusion of motion by presenting a series of images or
photographs.
Balanced audio
: a 3 wire circuit for audio, with the 2 legs of the circuit balanced with respect to ground,
usually terminating in a 1/4 phone or XLR connector, having excellent noise rejection capability.
bit:
the smallest unit of computer memory.
Black burst
: video signal used to synchronize the scan timing of multiple devices.
BNC
: a connector with a secure locking feature, used for video signals.
Brightness
: the darkness or lightness of an image or color; see also, luminance
CD
: compact disc, an optical recording system popular for audio and data.
CD-ROM
: a subset of CD standards (ROM stands for read only memory); holds about 700 MB of data.
Chroma
: the color component of a video signal.
Chroma key
: a color-based video matte (overlay) system that drops all areas of a selected color, often green
or blue, from one image and replaces them with the corresponding areas of a second image.
Component video
: video system where the color and luma components of the video signal are kept
separate (as Y.U.V. or RGB, etc) to maintain highest image quality.
Composite
:
1)
the combination of several images into one;
2)
video system where the color (chroma) and
brightness (luma) signals are combined into one waveform.
Compression
: translating data into a more compact form by discarding redundant information, then
reconstructing the data to its original form; can be either lossless or lossy.
Color correction
: the use of filters, processing amplifiers, and other software and/or hardware devices to
correct a video image
dB
: a unit of measurement for audio signal levels.
Digital video
: a method of representing still or moving images by number values instead of by varying
magnetic levels (analog video).
Dub
: a copy.
DV
: a digital video format recorded at 25 Mbps using (roughly) 5:1 compression.
DVCAM
: Sonys version of native DV format in a professional sized tape format.
EBU:
European Broadcasters Union, the professional standard setting organization for European television.
Field
: for a video signal, a set of lines produced by one sweep down the screen. For interlaced video (what
we watch on TV), it takes two such fields to make one frame (complete image).
Filter
:
1)
A partially transparent material that passes or blocks certain light colors;
2)
An electronic circuit or unit that passes or blocks signals of a particular type or frequency;
3)
Any circuit or device (hardware or software) that shapes or conditions a signal or information.
FireWire
: Apple Computers trademarked name for IEEE1394.
Frame
:
1)
to compose a shot in video or film, to make the image fit into the frame of the screen;
2)
a complete video image.
Frame synchronizer
: a digital buffer that stores a frame of video, compares the sync information to a
reference, and releases the frame at a specific time to adjust for timing errors.
Glossary
: a list of difficult or specialized words for reference.
GPI
: General Purpose Interface, a simple trigger device.
Hue:
a specific color; one of the 3 attributes of color, see also saturation, brightness.
IEEE1394
: a low cost digital interface that can transport data at up to 400 Mbps.
