AMX VTX, Instruction Manual

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VTX Video Teleconferencing System - Preliminary Glossary 47
H.320
H.320 is a narrow-band visual telephone systems and terminal equipment.
H.320 is an umbrella standard. H.320 (video H.261) supports image sizes CIF (352
pixels x 288 pixels) and QCIF (176 pixels x 144 pixels). The desktop video
conferencing products which support CIF are usually of better quality than those
who support QCIF. Some products use Indeo instead of H.320. It's image quality is
far less than H.320 products.
ISDN
Integrated System Digital Network.
NTSC
National Television Standards Committee, the video standard in North and
Central American and Japan.
NT 1
Network Termination type 1. The NT 1 is a device that converts the two-wire
line (or U-interface) coming from your telephone company into a 4-wire line (or S/T-
interface). The NT 1 is physically connected between the ISDN board of your video
teleconferencing system and your ISDN phone line. The NT 1 supports network
maintenance function such as loop testing. Check to see if your ISDN equipment
requires an external NT 1 to operate.
PAL
Phase Alternation Line, the video standard in Europe.
QCIF
Quarter Common Intermediate Format.
Room-based video teleconferencing
Video teleconferencing appropriate for
large groups (compare to Desktop Video teleconferencing).
SECAM
Systemem Electronic Pour Couleur Avec Memoire, a PAL variant used in
France, Russia, and parts of Africa as the video standard.
SPID
Service Profile ID. SPIDs are used to identify which sort of services the switch
provides to their IDSN device. Currently, they are used only for circuit-switched
service (in contrast to packet-switched).
SVHS
An analog video format that captures and stores 400 lines of information. It
stores the color information in two-channel Y/C video (compared to VHS and 8mm,
which store all color information in one channel).
SVideo
SVideo is a higher quality method for delivering luminance and
chrominance signals. The quality is improved by eliminating the need for the
filtering processes that degrade video output. The method is simple - don't combine
the signals in the first place. If the signals are always separate, never combined, then
no filtration is required. The resulting image, captured in the computer's memory, is