Video Monitoring on
Personal Computers
Geoffrey R. Amthor Impact Ideas, Inc. Flowery Branch, Georgia G325-5019-00 Personal Systems October, 1992 Pages 14-20 G325-5019-00
With the IBM video
monitoring
solution, the gap between digital computers and
analog video has been bridged.
Now the two great information revolutions of the
20th century -
computing and
television - can be brought together
seamlessly at the desktop with
single-cable networkability across entire
organizations and at a surprisingly
affordable price. In most
organizations
today, desktop
video
means
walking to a conference room and playing a videotape. While you are viewing
that
tape,
you are out of
touch with your colleagues, perhaps missing spur-of
the-
moment
meetings and
important
phone
calls. The same
situation is
true for live
video.
If
you
are a financial
broker,
you
want to keep in
touch with world events or current market activity. If you
are an
employee
in a large
corporation,
you
want
to keep abreast of events aired on the internal TV
network.
In
both
cases, you face a
choice
of
having a TV on your
desk or shuttling to a conference room to view broadcasts. IBM Video
Monitoring Solution With the IBM
video
monitoring solution, you can have TV in your desktop computer. Everyone
who needs
video
sources, such as
cable TV, broadcast TV, VCRs, videodisc players, internal corporate
TV, and closed circuit
TV,
can do so
conveniently at a desktop computer - whether the
computer
is
a PS/2, PC AT, or
compatible. These video
sources can
be displayed
in
full-screen
mode or in a window alongside computer applications on standard VGA
monitors. IBM's
video
monitoring
solution supports video distribution over token-ring Local Area Networks
(LANs) that
use
the IBM Cabling
System (ICS). Video is one of
many
applications
run
at the
desktop - with no impact on the performance of digital
applications.
Because
the technology
is
affordably
priced,
video
monitoring
can
be deployed across
entire organizations. In token-ring installations, more than 70 channels of video can be passed
simultaneously over the
network. PS/2 TV Figure 1. PS/2 TV The key enabling
product of IBM's
video
monitoring
solution is IBM PS/2 TV, shown in Figure 1. It is packaged in the slim
external enclosure
positioned
directly
beneath the
PS/2
monitor
in the figure. It contains a 181-channel, cable-ready TV tuner that accepts National Television Standards
Committee
(NTSC) broadcast signals from a cable TV source or antenna, as well
as standard baseband
video
input from a VCR,
laser
videodisc
player, or
video camera.
An
internal
speaker,
headphone
jack,
and
a set of video and
audio input/output connectors complete the PS/2 TV unit. PS/2 TV is a
very affordable
enhancement
to desktop
PS/2,
PC AT,
and compatible
systems During
installation, the
PS/2 display
cable
is
routed from the monitor to the PS/2 TV unit, with a second video cable
going from the
PS/2 TV unit to the PS/2 system unit. Similarly, the keyboard
cable is
routed directly to the PS/2 TV unit, with a second
keyboard
cable
routed from the
PS/2 TV
unit
to the standard
keyboard connector in the PS/2 system unit. When the PS/2 TV unit is
inactive, keyboard
and
video signals pass
through the
unit
unimpeded. PS/2 TV is
activated
through either
software
or
a hot-key combination captured by the unit. When activated, PS/2
TV has standard
television controls - channel selection, volume, mute, brightness,
contrast, and color. It provides
three
viewing modes: • The normal
full-screen
computer display •
Full-screen
television • A full-screen
user
application overlaid with a movable Picture-in-Picture (PIP) TV video image, which uses one-ninth of the screen (In its current version, PS/2 TV supports PIP functions only in VGA
display mode; XGA is supported only
in full- screen mode.) Audio is available in any of the modes,
and
it can be muted. Video received can
be recorded onto a VCR
by
using PS/2
TV's video- and
audio-out capabilities. The keyboard is normally used to control PS/2
TV, but under
OS/2
or Windows the
functions can
be
controlled
through
menu selections as
a
concurrent
application. Display modes
can be
changed and
television
parameters
controlled just as with a standard television set. Control is fast and intuitive - a novice can
learn
in minutes. Because PS/2 TV
comes
with its own microcontroller, video places no demands
on the PS/2 system
unit.
Computer
applications run as fast as ever. IBM PS/2 TV
offers an
affordable
enhancement
to
desktop
PS/2s. At
the
time this article
was written, the suggested retail price in the U.S. was $495. Network
Distribution
System While PS/2 TV is
often
used in standalone implementations,
it
also can be
used
as
part
of an
organization-wide strategy
of
accessing networked
video
from
desktops. A basic
distribution system
can
be
installed
simply
by
wiring standard
coaxial
cabling to
each
PS/2
TV unit
in
the organization.
At
the studio headend,
several
video
sources can
be
distributed on their
own programming channel; video source choices include cable TV, satellite, antenna, VCRs, videodisc players, and video cameras. In addition to the video sources, a distribution system is required, typically
consisting of a
combiner,
an
RF video
distribution
amplifier,
and
a
multisplitter. For organizations with existing or
planned
token-ring
networks
using
the
shielded twisted-pair
IBM
Cabling
System,
a novel
approach can
take advantage
of the ICS
cabling and
eliminate
the
need to pull separate coaxial cabling for video signals. This exciting solution is possible because both
4 Mbits and 16
Mbits per
second
token-ring
networks
leave
approximately
500 MHz
of free
bandwidth,
which is
available for
video
transmissions.
In turn, this free bandwidth can easily
support over 70
channels
of video. F-Coupler ![]() Figure 2.
IBM F-Coupler with
Faceplate To distribute
video
over a token-ring network, a filtering device called an IBM
F-Coupler must be
added at
each
endpoint, as shown
in Figure 2.
One
F-Coupler
at
the
headend
merges
data
signals
from the token-ring Multistation Access Unit (MAU) with video, as shown
in Figure 3.
Figure 3.
Example
of PS/2 TV Distribution System The F-Couplers
at the
PS/2 endpoints
separate
those
signals. In
small
installations,
the
headend
F-Coupler
may
be
located in a studio
with the video
sources,
the
video distribution system (combiner, RF video distribution amplifier, and splitter), and the token
ring
MAU.
In larger
installations, the headend F-Coupler would be placed on the token-ring
distribution panel
in
the wiring closet
where video and data signals are received. Because wiring
represents a
significant expense
in a cabling system,
the IBM
F-Coupler affords
an excellent way
to reduce the
investment required to handle data and video transmissions that
previously have
used
separate
cables. The IBM
F-Coupler is a
highly
affordable
distribution
solution.
At the
time this article
was written,
F-Couplers
had
a suggested
retail price
in the U.S. of $85
each.
Each
receiving
F-Coupler
needs a special faceplate (shown in Figure 2). At this writing, faceplates
were available
for
a
suggested retail price
of
$6.85. Video
Monitoring Applications IBM PS/2 TV
enables video
feeds from
sources
such as
cable
TV, VCRs,
videodisc
players, and
closed
circuit
cameras
to be displayed
on
existing
PS/2 monitors
- eliminating the
need for redundant equipment and
allowing video to
be integrated
into
normal
working environments. Combining both pieces of equipment saves desk space and cost. More important, time
is saved
because
users
can
quickly switch
between
video and
computer
information. Now you can
access a
world
of
video sources.
Imagine the applications! Broadcast monitoring: Information sources
such as network
and
cable
news broadcasts can be monitored on
a
workstation. This
function is
valuable to
stockbrokers,
financial
analysts,
journalists,
and
others
who need
to keep abreast of
world
events.
A
small window displays
the live
video
feed while they continue
to
perform
their
normal work
routines. To enhance
concentration
on normal
work,
video can be
delivered silently, or
the program can be
monitored in
audio-only
mode.
When an item of interest arises in the broadcast, the user
can jump into PS/2
TV's dedicated
mode,
complete
with full screen video and audio. The result is easy access to vital information and improved
productivity. Business television: Many corporations today
have private
video studios that
produce internal
programming
comparable
to
that of major television networks. Satellite and mobile uplink facilities are readily available and
reasonably priced.
With the IBM
video
monitoring
solution,
even
small
companies
can broadcast
internal
programming
to the desktops of their workers - allowing them to work at their desk and still receive vital corporate broadcasts
conveniently. Another
excellent
application is business-to-business
television.
IBM customers can use the video monitoring solution to view IBM Field Television Network (FTN) telecasts in their own offices. Training: The cost of training employees
goes far beyond
curriculum materials
and
trainer
fees.
For
live training,
organizations
also
must consider
travel
and
housing
expenses and
the loss of
employee time from
their
day-to-day
positions. For "canned"
training
delivered by
videotape, students
usually
leave their desks
and
go to a conference
room or
training
facility.
With
the IBM video
monitoring
solution,
that
material can
be
delivered directly
to student desktops. For live training, students can still interact with the instructor by telephone - allowing
cost-effective
training
anywhere.
Taped instruction also can be played from a VCR attached directly to
the PS/2 TV at
the
desktop. Video library: While
organizations
often
store large
volumes of videotapes and videodiscs, the process of getting a video to a
requester can be
time-consuming
and
costly.
The
IBM
video
monitoring
solution enables the creation of a centralized video library
where tapes are
loaded
for local
viewing at
desktops. Equipment also is available to further automate the
operation of video
libraries by
providing
remote
control or automated operations. A hybrid digital/analog
video solution also can be
created, where video is
stored
digitally on network servers and converted for analog
transmission to the desktop.
This
analog
transmission avoids clogging network bandwidth with digital video, while
it preserves the
flexibility
of digital
video editing and storage. Manufacturing
and process
monitoring:
Manufacturing
supervisors
can
now
work on their desktop computer applications while keeping an
eye on the
manufacturing line - thanks to IBM PS/2 TV and closed
circuit
television. Intelligent
video
workstations
can be
programmed to
monitor
critical
safety issues and alert an operator when needed. Store
monitoring: Sales
clerks can
ring
up transactions on
PS/2 systems
while
keeping
an eye on store operations - thanks again to the
pairing of
IBM
PS/2 TV and
closed-circuit
cameras. Surveillance monitoring: Multiple PS/2
TV units can be
attached to a
single
PS/2,
allowing several surveillance cameras to display
within windows
on
a single monitor.
Motion
detectors
and other
system peripherals, such as autodialers, can transform a desktop PS/2 into a
comprehensive
security
system. Videoconferencing:
The
same infrastructure
and
equipment used for
one-way video can enable two-way video within a building. By splitting the band of
video frequencies
into forward and reverse channels, a technician can design the
distribution system to
allow
point-to-point
video and voice communication. If the facility has a videoconferencing
suite
that uses
a codec
for land-line
wide-area
videoconferencing, it can be extended to allow an executive to
join a conference
being
conducted on
another
floor
of the
building. Group meetings: Employee
meetings
frequently
involve
large groups
of
people
crowded into a conference room, viewing a videotaped message from management. With
the IBM
video
monitoring
solution, organizations can broadcast live from the executive offices
to workers
watching at
their
desks.
Employees can interact by telephone or video conference link. For those who
missed the meeting,
a
tape can be played
for several
days
from
a library. Employees need only select the appropriate channel on
their workstations. Collaborative
workstations: Multimedia applications and presentations are often created by
a team of workers
who
concentrate on
specific parts
of
the
overall project. Presentation files can be created and stored on a token-ring
network file
server, while
video
segments
can be stored in analog form on a central VCR or
laserdisc
player/recorder.
When
the team
is
supported by the
video monitoring solution, all team members can remotely access both
analog and digital
sources
conveniently
from their
desks. Schools: Schools may
discover
that
video
information is
more effective
when
delivered
to the students ' desks. Instead of displaying video on a
large-screen
television to a classroom of students, schools can deliver important
documentaries and educational
videos
to classroom
PS/2s
equipped
with PS/2 TV. Home: With a
stand-alone PS/2
TV
unit,
home office and
weekend
workers
do not have to
choose between
computer-based
work
and
catching
the weekend
ball game.
They
can
do both,
right
on their
home
PS/2 systems. Installing
and Using PS/2 TV Setting up a
local PS/2
TV unit is a
matter
of
connecting a few cables, selecting a video source, and making a couple of
adjustments. Because
PS/2
TV is an external
device,
it
is
not
necessary to open
the PS/2 system unit for installation. Instead, the installation process
is analogous to
installing
a home VCR
between
video
inputs and the TV
monitor. Several cables
pass
through the PS/2 TV unit: • The keyboard
plugs into
the IBM
PS/2
TV unit, with an
output cable
connected
to
the PS/2 system. • The display
cable is
routed from
the
monitor
to the IBM PS/2 TV unit, with a cable then connected to the IBM PS/2
system unit. • The video source
-
VCR, videodisc player,
antenna, cable
TV,
or closed-circuit
camera -
is
hooked
up
directly to the IBM
PS/2
TV unit. • A power cable
runs from
a wall
transformer
to the IBM
PS/2 TV
unit. • There are video-
and
audio-out
connectors
in the IBM
PS/2 TV
unit
for the attachment
of
a VCR
or
other recording
device. How PS/2
TV Works Once cabled and
configured, the IBM PS/2 TV unit is always ready. As with any
television set,
the
picture
and
sound
are
standing
by
-
waiting for
the user to turn on
the set, select a channel,
and adjust
the
volume. With
PS/2
TV, you make a
few
other decisions too,
such
as selecting a
viewing
size,
placement
of the video
window,
and
any personal fine
tuning. In all
cases,
PS/2
TV's display overlays the VGA signals from the PS/2 system unit, much like a VCR's on-screen programming instructions overlay the TV's
own video display. The PS/2 TV unit
picks
up the video
signal
from
a designated source: antenna, cable, VCR, or
videodisc.
On
user command,
it
then delivers
this
video to the PS/2
display. There
are
three
display options: • Full-screen
computer
application
display
(PC
mode) • Picture-in-Picture
video
window,
overlaying
the
active
computer application • Full-screen video display You can quickly
switch
among these modes
by pressing a
key
or clicking a
mouse. How to
Control PS/2 TV The method of
turning
on the "set," choosing a channel, or making adjustments depends on the
operating system. With
DOS,
a
series
of
keyboard
entries
is
used for volume,
channel
selection,
picture
adjustments,
viewing mode,
and
picture
location. As
each
decision
is made, a
corresponding
on-screen panel
highlights and
guides
interactions.
You also can select a timeout for these panels. When the
keyboard is
used for these
adjustments
and
actions, it is temporarily dedicated to the PS/2 TV unit. Pressing the Num Lock
key twice in
quick
succession
activates
this
dedicated
mode.
When you are
finished,
the
Escape key returns
control to the
PS/2
system
unit.
No software
is
required
for
this keyboard
operation. In a Windows or
OS/2
environment,
there
is an
option
of using these same key
sequences
or
a series
of
menus
and
control
panels to
perform all the PS/2 TV functions. Windows and OS/2 application
software are
provided
with the PS/2
TV. Customizing
PS/2 TV A supplemental Application
Programming
Interface
(API) is
included with
PS/2
TV
for organizations that need the capabilities of the PS/2 TV in a
program-controlled
interactive
environment. The PS/2 TV User's Guide documents the API,
describes how to
code
to it, and gives examples. An organization
may
want to store video
segments
as objects
in a
remote
videodisc
library. By writing a custom program to the optional API, organizations
can provide users
with
automated access
to these segments from
desktops.
You can
simply
select
a video
segment
from
a
menu; in
turn, the customized
environment would
direct the video
distribution system
to
search
for
an open video channel.
After selecting
an
open
channel,
the customized
environment would
then tune the
PS/2 TV unit to the chosen channel and begin video transmission. An automated system
also
could be used
to play Digital
Video Interactive(DVI-) compressed digital video stored on remote CD-ROM or hard disk
servers,
with
"on
the
fly"conversion
to analog signals
for
transmission. How
F-Coupler Works With the IBM F-Coupler,
an
organization can
now
assemble a complete network
for all its
video, audio,
and
data
needs using a single
installation of
a shielded
twisted-pair
IBM
Cabling
System.
Figure 4.
Additional
Bandwidth Available with Shielded Twisted Pair Operating in a 4 Mbits or 16 Mbits per
second
token-ring
environment, approximately
500 MHz of
free
bandwidth
is
available for video
transmissions in
the 50 MHz to 550
MHz
range.
This free
bandwidth, shown conceptually
in Figure
4,
can
easily
support
over 70
channels. Frequency
Division
Multiplexing
(FDM)
techniques
make this greater cable bandwidth
utilization
possible.
Specifically,
the ICS uses
highquality
cable
that can support signal transmissions at the high
frequencies used
for
broadband audio and
video, as well as the data transmissions for which it
has been used
historically. This shielded, twisted-pair cable
contains both aluminum foil and
mesh shield, enabling it to handle the simultaneous
transmission of broadband and
baseband signals. With an IBM
F-Coupler
on each end of the cable, a higher frequency signal
for audio and video is
transmitted on top of the data signal. The headend
F-Coupler combines the two
signals into a single transmission, while the
receiving F-Coupler separates the
signals
and
routes them to
their appropriate ports. Each F-Coupler includes both
a coaxial connector for broadband
signals and a data connector for baseband signals. A
circuit in the F-Coupler is
designed
to isolate the
different signals from each other on their respective
bandwidths, maintaining complete
isolation during transmission. Flexibility
of Use The
ICS/broadband LAN
can be adapted into a variety of configurations,
depending upon the unique needs
of each user. Video signals can originate
from an antenna,
VCR, or video camera. These broadband signals are then
transmitted on coaxial
cable to a multi-splitter (or tap/combiner) that leads
to the CA TV
distribution panel in the wiring closet. It is here
that the video signals are
directed to the F-Coupler. Simultaneously, data
signals also are transmitted on
the IBM Token-Ring network to the wiring closet, where they too are routed to the
F-Coupler. Leaving the
wiring
closet, shielded twisted-pair wiring on the ICS carries both baseband and broadband signals to the end of the cable
drop.
At that
point, the
F-Coupler
at the
faceplate
separates the
signals,
sending the data to the PS/2 workstation while the broadband
transmission
is
directed
to
a
video receiver. Easy
Installation To install this
system,
a technician places one
F-Coupler
on the
ICS
distribution
panel
in
the
wiring
closet
where the
video
and data
signals
are received.
Another
F-Coupler is placed in the
office
or conference room where the signals are to be separated. A special faceplate is required
to enable both
coaxial
cable connection
of the video and a token ring attachment. Technicians
installing
the devices
must
consider
the
total
length of
cable
in
the
network,
as
well as the
length
of cable in
each
node
in the network.
Recommended cable
lengths
can be
obtained
from
the
F-Coupler
Planning
Guide
(GA27-3949)
or other
documentation such as the IBM Cable System Planning and
Installation Guide (GA27-3361). Similarly,
installation
of an
ICS
broadband LAN requires
calculating the
attenuation of the
video signal
as
a function
of
both signal
frequency
and
cable length. This information is available from the F-Coupler Planning Guide. References In addition to basic product
brochures,
the
following in-depth
IBM information materials are available: • Video Monitoring
Solution videotape
(GV21-8205) • F-Coupler
Planning
Guide (GA27-3949) • F-Coupler
Assembly and
Installation Instructions (GA27-3950) • PS/2 TV User's Guide (0571-0238) For more
information
about the IBM video
monitoring
solution,
contact
your
IBM
representative or call the IBM Multimedia Information Center at (800) 426-9402. Geoffrey R. Amthor is president of
Impact Ideas, Inc., a consulting firm
specializing in
multimedia research and communications. Over the
past seven
years,
he has published
numerous articles in IBM publications as
well as others. He has
specialized in multimedia since 1989. impact ideas,
inc. 6713 Crestwood
Peninsula Flowery Branch,
GA
30542 ( 404) 967-9700 |