1.
Brief Introduction
Terms and Definitions
VSP 168HD User Manual 20
“MPEG”:
Motion Picture Expect Group. A standard committee under
the auspices of the International Standards Organization working on
algorithm standards that allows digital compression, storage and
transmission of moving image information such as motion video,
CD-quality audio, and control data at CD-ROM bandwidth. The MPEG
algorithm provides inter-frame compression of video images and can
have an effective compression rate of 100:1 to 200:1.
“NTSC”:
The color video standard used in North America and some
other parts of the world created by the National Television Standards
Committee in the 1950s. A color signal must be compatible with
black-and-white TV sets. NTSC utilizes an interlaced video signals,
525 lines of resolution with a refresh rate of 60 fields per second (60
Hz). Each frame is comprised of two fields of 262.5 lines each, running
at an effective rate of 30 frames per second.
“PAL”:
Phase Alternate Line. A television standard in which the phase
of the color carrier is alternated from line to line. It takes four full
pictures (8 fields) for the color-to-horizontal phase relationship to
return to the reference point. This alternation helps cancel out phase
errors. For this reason, the hue control is not needed on a PAL TV set.
PAL, in many transmission forms, is widely used in Western Europe,
Australia, Africa, the Middle East, and Micronesia. PAL uses 625-line,
50-filed (25 fps) composite color transmission system.
“Operator”:
Refers to the person who uses the system.
“PIP”:
Picture-in-Picture. A small picture within a larger picture created
by scaling down one of the images to make it smaller. Each picture
requires a separate video source such as a camera, VCR, or
computer. Other forms of PIP displays include Picture-by-Picture
(PBP) and Picture-with-Picture (PWP), which are commonly used with
16:9 aspect display devices. PBP and PWP image formats require a
separate scaler for each video window.
“Polarity”:
The positive and negative orientation of a signal. Polarity
usually refers to the direction or a level with respect to a reference (e.g.
positive sync polarity means that sync occurs when the signal is going
in the positive direction).
“RJ-45”:
Registered Jack-45. A connector similar to a telephone
connector that holds up to eight wires used for connecting Ethernet
devices.
