Specifications

Chapter 1  Features 3
Encoder Output
The multiplexer video encoder produces a single video signal con-
taining field by field samples from all camera inputs. The signal is
provided in both composite and S-Video formats (color models
only) for connection to a video recorder. Encoder operation is
continuous and independent of display and decoder functions. All
inputs are sampled in camera number order until motion is de-
tected, when active cameras are sampled more often.
The encoder uses Vertical Interval Signaling (VIS) techniques to
encode system information onto video output to the VCR. Time,
date, camera title, camera number and alarm status information
are placed on the 16 horizontal lines preceding the first active video
line. This technique improves vertical synchronization recovery
and improves graphics degraded by poor tape recorder
performance.
Decoder Output
The multiplexer decoder processes the video output by the VCR
during playback, recovering the video from each camera originally
recorded. The decoder digitizes the playback video and recovers
the VIS information encoded onto each field. The recovered field
is written to the video display memory if required for display.
The call monitor displays full screen images of cameras associated
with alarms or images from any selected camera. It is based on
switched analog camera video.
Color demodulation is based on luminance and color difference
processing. Demodulation circuitry operates on a line by line ba-
sis and will correctly demodulate chroma information conform-
ing to the NTSC (PAL) video standard.
A graphic generator with two interlaced bit mapped pages pro-
vides the alphanumeric and graphic overlays required for on-screen
menus, camera titles and system messages.