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Once the type of recording method is selected, the quality of the recordings can be determined
by selecting the video format (e.g., H.264, MPEG-4, Motion JPEG), resolution, compression level
and frame rate. These parameters will affect the amount of bandwidth used, as well as the size
of storage space required.
Network video products may have varying frame rate capabilities depending on the resolution.
Recording and/or viewing at full frame rate (considered as 30 frames per second in NTSC stan-
dard and 25 frames per second in PAL standard) on all cameras at all times is more than what
is required for most applications. Frame rates under normal conditions can be set lower—for
example, one to four frames per second—to dramatically decrease storage requirements. In the
event of an alarm—for instance, if video motion detection or an external sensor is triggered—
a separate stream with a higher recording frame rate can be sent.
11.3.4 Recording and storage
Most video management software use the standard Windows file system for storage, so any
system drive or network-attached drive can be used for storing video. A video management
software program may enable more than one level of storage; for instance, recordings are made
on a primary hard drive (the local hard disk) and archiving takes place on either local disks,
network-attached drive or remote hard drive. Users may be able to specify how long images
should remain on the primary hard drive before they are automatically deleted or moved to the
archive drive. Users may also be able to prevent event-triggered video from being deleted auto-
matically by specially marking or locking them in the system.
11.3.5 Event management and intelligent video
Event management is about identifying or creating an event that is triggered by inputs,
whether from built-in features in the network video products or from other systems such as
point-of-sale terminals or intelligent video software, and configuring the network video surveil-
lance system to automatically respond to the event by, for example, recording video, sending
alert notifications and activating different devices such as doors and lights.
Event management and intelligent video functionalities can work together to enable a video
surveillance system to more efficiently use network bandwidth and storage space. Live camera
monitoring is not required all the time since alert notifications to operators can be sent when
an event occurs. All configured responses can be activated automatically, improving response
times. Event management helps operators cover more cameras.
Both event management and intelligent video functionalities can be built-in and conducted in a
network video product or in a video management software program. It can also be handled by both
in the sense that a video management software program can take advantage of an intelligent
video functionality that is built into a network video product. In such a case, the intelligent video
functionality, such as video motion detection and camera tampering, can be performed by the
VIDEO MANAGEMENT SYSTEMS - CHAPTER 11
