Axis Communications 243SA - Manual (Page 79)

79 AXIS 243SA - Glossary
the coding format used by standard commercial DVD
movies.
MPEG-4 - MPEG-4 is a group of audio and video coding
standards and related technology. The primary uses for
the MPEG-4 standard are web (streaming media) and CD
distribution, conversational (videophone), and broadcast
television.
Most of the features included in MPEG-4 are left to
individual developers to decide whether to implement
them or not. This means that there are probably no
complete implementations of the entire MPEG-4 set of
standards. To deal with this, the standard includes the
concept of "profiles" and "levels", allowing a specific set
of capabilities to be defined in a manner appropriate for a
subset of applications.
Multicast - Bandwidth-conserving technology that
reduces bandwidth usage by simultaneously delivering a
single stream of information to multiple network
recipients. See also Unicast.
Multiplexer - A multiplexer is a high-speed switch that
provides full-screen images from up to 16 analog
cameras. Multiplexers can playback everything that
happened on any one camera with no interference from
the other cameras on the system.
Network camera (Network video camera) - A network
camera is a camera and computer combined in one
intelligent unit. It captures and sends live video directly
over an IP network such as a LAN, intranet or the
Internet. Users can view and/or manage the camera using
a standard web browser or application software from any
local or remote computer on a network. The camera
allows multiple authorized viewers from different
locations to simultaneously access images. A network
camera is sometimes known as an IP camera.
Network connectivity - The physical (wired or wireless)
and logical (protocol) connection of a computer network
or an individual device to a network, such as the Internet
or a LAN.
Network video - Network video (often referred to as
IP-Surveillance for specific applications within security
surveillance and remote monitoring) is a system that gives
users the ability to monitor and record video over an IP
network (LAN/WAN/Internet).
NTSC (National Television System Committee) - NTSC is
an analog color encoding system used in television
systems in Japan, the United States and other parts of the
Americas. NTSC defines the video signal using 525 TV
lines per frame, at a refresh rate equal to 30 frames per
second. See also PAL.
NVR (Network Video Recorder) - A dedicated Network
Video Recorder (NVR) can be used to gather data streams
from remote network cameras and video servers and store
them on a hard disk. An NVR can be a standard networked PC, or a dedicated video recording hard disk
server with its own software application.
PAL (Phase Alternating Line) - PAL is an analog color
encoding system used in television systems in Europe and
in many other parts of the world. PAL defines the video
signal using 625 TV lines per frame, at a refresh rate equal
to 25 frames per second. See also NTSC.
PEM (Privacy Enhanced Mail) - An early standard for
securing electronic mail. The PEM-format is often used
for representing an HTTPS certificate or certificate
request.
Ping - Ping is a basic network program used
diagnostically to check the status of a network host or
device. Ping can be used to see if a particular network
address (IP address or host name) is occupied or not, or if
the host at that address is responding normally. Ping can
be run from e.g. the Windows Command prompt or the
command line in Unix.
Pixel (Picture Element) - A pixel is one of the many tiny
dots that make up a digital image. The color and intensity
of each pixel represents a tiny area of the complete image.
PoE (Power over Ethernet) - Power over Ethernet
provides power to a network device via the same cable as
used for the network connection. This is very useful for
IP-Surveillance and remote monitoring applications in
places where it may be too impractical or expensive to
power the device from a power outlet.
PPP (Point-to-Point Protocol) - A protocol that uses a
serial interface for communication between two network
devices. For example, a PC connected by a phone line to a
server.
PPTP (Point-to-Point Tunneling Protocol) - A protocol
(set of communication rules) that allows corporations to
extend their own corporate network through private
"tunnels" over the public Internet. In this way a
corporation can effectively use a WAN (Wide Area
Network) as a large single LAN (Local Area Network). This
kind of interconnection is known as a virtual private
network (VPN).
Pre/post alarm images - The images from immediately
before and after an alarm. These images are stored in a
buffer for later retrieval.
Progressive scan - Progressive scan, as opposed to
interlaced video, scans the entire picture, line by line
every sixteenth of a second. In other words, captured
images are not split into separate fields as in interlaced
scanning.
Computer monitors do not need interlace to show the
picture on the screen, but instead show them
progressively, on one line at a time in perfect order i.e. 1,
2, 3, 4, 5, 6, 7 etc., so there is virtually no "flickering"
effect. In a surveillance application, this can be critical
when viewing detail within a moving image, such as a