Glossary
GLOSSARY
2:2 pull-down
The process of transferring 24-frames/sec film format into video by repeating each frame (used for PAL DVD’s) as two video fields.
(AD)
3:2 pull-down
Method used to map the 24 fps of film onto the 30 fps (60 fields) or 25 fps (50 fields), so that one film frame occupies three video
fields, the next two, etc. It means the two fields of every other video frame come from different film frames making operations
such as rotoscoping impossible, and requiring care in editing. Some sophisticated equipment can unravel the 3:2 sequence to
allow frame-by-frame treatment and subsequently re-compose 3:2. The 3:2 sequence repeats every five video frames and four film
frames, the latter identified as A-D. Only film frame A is fully on a video frame and so exists at one time code only, making it the
editable point of the video sequence.
Artefacts
Undesirable elements or defects in a video picture. These may occur naturally in the video process and must be eliminated in
order to achieve a high-quality picture. Most common in analog are cross color and cross luminance. Most common in digital are
macroblocks, which resemble pixelation of the video image.
Aspect ratio
Relation between the horizontal & vertical dimension in which the window will be displayed, e.g. 4 by 3 or 16 by 9. Can also be
expressed as a decimal number, such as 1.77. The larger the ratio or decimal, the wider are less square the image.
Color space
A color space or color standard is a mathematical representation for a color. For example the RGB color space is based on a
Cartesian coordinate system.
Color temperature
The coloration (reddish, white, bluish, greenish, etc.) of white in an image, measured using the Kelvin (degrees K) temperature
scale. Higher temperatures output more light.
Common address
Projector will always execute the command coming from a RCU programmed with that common address.
Default Gateway
A router that serves as an entry point into and exit point out of a network. For example, a local network (LAN) may need a gateway
to connect it to a wide area network (WAN) or to the Internet.
DHCP
Dynamic host configuration protocol. DHCP is a communications protocol that lets network administrators manage centrally and
automate the assignment of IP addresses in an organization’s network. Using the Internet Protocol, each machine that can connect
to the Internet needs a unique IP address. When an organization sets up its computer users with a connection to the Internet,
an IP address must be assigned to each machine. Without DHCP, the IP address must be entered manually at each computer
and, if computers move to another location in another part of the network, a new IP address must be entered. DHCP lets a network
administrator supervise and distribute IP addresses from a central point and automatically sends a new IP address when a computer
is plugged into a different place in the network.
DMX
DMX-512 Lighting protocol over RS-485 interface. Carries information of 512 channels from a lighting controller to lighting devices.
Standardized by USITT.
HDCP
High-bandwidth Digital Content Protection (HDCP) is a form of digital copy protection developed byIntel Corporation to protect digital
audio and video content as it travels across DisplayPort, Digital Visual Interface (DVI), High-Definition Multimedia Interface (HDMI),
Gigabit Video Interface (GVIF), or Unified Display Interface (UDI) connections. The specification is proprietary, and implementing
HDCP requires a license.
HEPA
High Efficiency Particulate Absorbing
R59770057 CLM HD8 15/03/2010
219