Glossary

artifact

In video systems, an unnatural or artificial effect when the system reproduces an image.

bezel

The frame that holds the front cover and attaches to the front of the chassis.

B-Y signal

One of the color difference signals used on the NTSC and PAL systems derived by subtracting luminance (Y) from the blue camera signal (B). The color mixture is close to blue.

chassis

The metal framework of the workstation that contains its working parts.

choose

The action of pressing the left mouse button to bring up a popup menu, moving the cursor to highlight the command that you want to run, and releasing the button.

composite video

A color encoding method or a video signal that contains all of the color, brightness, and synchronizing information in one signal. The chief composite television standard signals are NTSC, PAL, and SECAM. The OCTANE Digital Video board uses the NTSC and PAL standards.

connector

The hardware at the end of a cable that fastens the cable to an outlet, port, or other connector.

console

The window that appears as a stowed icon each time you log in; IRIX reports all status and error messages to this window.

cover

The molded plastic piece that fits over the chassis. The bezel and front cover attach to the cover.

chrominance signal

The high-frequency portion of the video signal that is the color carrier.

framelocking

The software command that causes a workstation to write to the graphics screen at a specified time interval, causing screen graphics to be synchronous with throughput from a video source.

front cover

The pulldown door that allows you to access the power button and drives.

genlock

Synchronizing with another video signal serving as a master timing source. The master timing source can be a composite video signal, a video signal with no active video (only sync information), or, for video studio, a device called a house sync.

luminance

The video signal that describes the amount of light in each pixel.

NTSC

National Television Systems Committee. A color television standard used in North America and parts of South America and Asia for timing format encoding all color, brightness, and synchronizing information in one signal. The NTSC format uses 525 horizontal lines per frame, with two fields per frame of 262.5 lines each. Each field refreshes at 60 Hz.

PAL

Phase Alternated by Line. A color-television timing standard used by most countries in Europe, Australia, and parts of Asia. The PAL standard uses a total of 625 lines per frame, with two fields per frame of 312.5 lines per frame. Each field refreshes at 50 Hz. See also YIQ and YUV.

pull straps

The straps you pull to remove the graphics board set from the chassis.

R-Y signal

A color difference signal obtained by subtracting the luminance signal from the red camera signal. The color mixture is close to red.

SMPTE 259M

A standard delineating the serial transmission of 10-bit 4:2.2 component video signals or 4fsc NTSC composite digital signals. SMPTE 259M is a standard of the Society of Motion Picture and Television Engineers. For more information on this standard, see http://SMPTE.org.

S-Video, S-VHS

Video format in which the Y (luminance) and C (chrominance) portions of the signal are kept separate. Also known as Y/C.

standoffs

Spacers that are used to stack and attach the graphics and video boards to each other.

texture mapping

The process of applying an image to a 3D object to add realism in the rendering.

Video Panel

A software control panel used for selecting video input; adjusting video signal levels and timing characteristics; and selecting filtering, processing, and other options.

wrist strap

A flat cable that you wrap around your wrist and attach to a metal part of the workstation whenever you work with internal components of the workstation. This prevents electrical shocks to yourself and the components.

Y signal

The brightness of a video channel.

Y/C

Video format in which the Y (luminance) and C (chrominance) portions of the signal are
kept separate. Also known as s-video.

YIQ

The NTSC color system uses YIQ as its color space. Y stands for the image's black and white portion (luminance component). The color portion is I and Q which behaves as a color wash laid over the black and white components. See also YUV and PAL.

YUV

A color space (color component encoding format) used by the PAL video standard, in which Y is the luminance signal, and U and V are the chrominance signals. The YUV format derives colors from the RGB format. See also YIQ and PAL.