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CORRESPONDING COPENDING APPLICATIONS
The following applications are relevant to this application.
U.S. patent application Ser. No. 07/633,640, filed Dec. 21, 1990 for
apparatus for distributing video programs; U.S. patent application Ser.
No. 07/633,641, filed Dec. 21, 1990 for system for transferring television
programs.
BACKGROUND OF THE INVENTION
This invention is concerned with video telecommunication systems, and more
particularly is concerned with a system for distributing video
programming.
Pay-Per-View (PPV) networks can transmit on satellite broadcast, or local
distribution systems. Pay-Per-View (PPV) networks generally provide only
one channel of programming, with some PPV networks providing multiple
channels.
It is desirable to provide a PPV system which has the capacity to
distribute a plurality of programs using commercially available equipment
and any transmission system having at least a corresponding number of
channels.
SUMMARY OF THE INVENTION
Briefly, there is provided a system for distributing video programs over a
transmission medium having a plurality of channels. A stored database
represents a predetermined schedule including timing instructions. A
computer is programmed to provide real time outputs in response to the
timing instructions. A bus has an input coupled to the computer and
provides video player control signals in response to the real time
outputs. A recorded media contains programs. A plurality of video players
are used for playing the recorded media, each video player having a
control port coupled to the bus and responsive to the control signals.
Each video player has an output to provide video signals coupled to a
separate corresponding channel. Scrambling means are interposed between
the output of a video player and the corresponding channel for scrambling
the television signal. Access means enables downstream access to a channel
and unscrambles a video signal on an accessed channel. Access means
provides downstream access to a channel and unscrambles a television
signal on an accessed channel. The access means provides access to the
first and second channels thereby allowing return to the same point of a
program after a pause equal to the staggered time interval.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a schematic representation of a system for distributing video
programming, including a video server; and
FIG. 2 is a block diagram of a video server.
DETAILED DESCRIPTION OF THE INVENTION
Referring first to FIG. 1, there is seen a schematic representation of a
system 10 for distributing video programming. System 10 includes a video
server 11 interfaced to the headend 12 of a transmission system 13 having
a plurality of channels, and a downstream converter 14.
FIG. 2 is a block diagram of the video server 11, which includes, among
other elements, a serving computer 15 and software, a control bus 16 and a
plurality of video players 17.
The serving computer 15 performs all scheduling and control functions (e.g.
start, stop, rewind, etc.) for the video players 17 and gathers video
player usage data. The serving computer 15 is loaded with a scheduling
database representing a predetermined schedule data including timing
instructions. The serving computer 15 is programmed to provide real time
outputs in response to these timing instructions. The scheduling database
may be provided to the serving computer 15 on magnetic memory 19 or
transferred directly from a scheduling computer 20. The program schedule
database includes a five-digit event code (for each program showing),
title, rating, channel, starting times, dates, run time, and price.
The serving computer 15 also monitors the status of the video players 17,
and operates promotional channel video players 18. Operations are
controlled through a menu. A printer 21 prints a hardcopy listing the
program to be placed in each video player 17. An operator display provides
video player status monitoring. A status screen indicates whether a video
playback machine is playing, rewinding, waiting to start playing, not in
use, setting-up, or has failed. Provision of an alarm during video player
failure is included. Monitors (not shown) show what is on a selected
channel.
Commercial parallel bus 16 provides a communications path between an output
port of serving computer 15 and video players 17 and 18, allowing the
serving computer 15 to automatically operate the control features of the
video players. Bus 16 includes one or more bus controller panels which
provide control signals in response to the real time outputs of the
computer 15. These in turn operate video player parallel decoders, each of
which can control several video players.
Video players 17 are used for playing recorded media containing programs in
television format or for coupling a line feed from a live program. The
video players 17 may be any controllable player means such as video
cassette recorders (VCRs) or disk players. Pre-recorded video cassette
format is the most abundant medium for video storage. Video cassette
players may be software controlled for automatic rewind and playback of
tapes. Optical disks are another storage medium. An attractive feature of
optical disk players is the capability of multiple playing heads reading a
disk.
Each video player has a control port coupled to the bus 16 and is
responsive to the control signals. Each video player also has an output
providing television signals for coupling to a separate corresponding
channel via the headend of the transmission system.
The video players 17 play video selections starting at pre-selected times.
Each player can be set for different start times. At the start time, the
medium is played at the start of the active program, which is not
necessarily the beginning of the medium. At the end of the program the
medium is automatically rewound, if necessary, and set to the program
start.
At least two of the video players 17 loaded with duplicate recorded media
and controlled to play at staggered overlapping time intervals.
The medium is changed in the video server upon one of two circumstances.
The first is that the schedule dictates that a different program will
start at a certain time and on a certain channel and the existing video
medium should be removed and a new medium inserted. The second
circumstance occurs if the medium degrades with usage and has been played
a specified number of times. It is then replaced with a fresh copy.
During a pause such as rewinding, the input from another source cuts
through the video player and becomes the player output which is shown on
the channel. This enables the viewer's channel to show another video
source such as a promotional or text channel during times when the player
is not showing a program. Arrangements for a promotional channel are
described below.
The video players 17 have stereo audio capacity. Since it is desirable to
operate audio through balanced pairs for common mode rejection, two audio
outputs are connected to a pair of unbalance-to-balance buffer amplifiers.
Each video player's output signal is coupled to a corresponding channel at
headend 12.
Each video player output is coupled to a corresponding channel on the
transmission system. The video output of the video server is connected
through scrambling means in the headend 12. Each signal is scrambled at
the headend before being placed on the transmission system.
Video server 11 provides a promotional channel. The promotional channel
operates similar to a program, except each promotional segment is shorter
in length than a program and is played continuously on one of two
promotional video players 18 and it is not scrambled. The two players
alternately playing identical preview segments. As one is playing, the
other is rewinding. The promotional channel appears to play continuously.
The switch from one video player to the other is set at a regular interval
which does not interfere with controller operations of the other channels.
The promotional channel continuously shows promotional programming such as
program previews, event promotions, order instructions, and programming
information. A short promotional segment may be repeated back-to-back on a
recorded medium so that the medium does not have to be rewound as
frequently thereby reducing wear. Information on the promotional channel
is changed as required, e.g. monthly, according to programming schedule.
The promotional channel operations are software controlled by the serving
computer 15.
A character generator 22 is coupled to the serving computer 15 for
providing a menu in television format representing a programming schedule.
Server computer 15 continuously synchronizes the menu information with the
video servers. The output of the character generator 22 is coupled
unscrambled though headend 12 to a channel designated for text.
The output of the character generator 22 is also connected into the input
of the first promotional video player. The output of the first promotional
video player is connected into the input of the second promotional video
player. The output of the second promotional video player is connected to
a channel designated for promotionals. If both promotional video players
18 are in a non-play condition, then the character generator 22 output is
automatically connected into the promotional channel.
Amplification of the promotional channel output signal is provided if the
promotional channel output signal is also fed to the plurality of program
video players 17. A distribution amplifier is used to distribute the
promotional channel to the video input of each program video player if
such a feature is desired.
Perusing FIG. 1, the programs and promotions are distributed on separate
channels of the transmission system 13. Such a transmission system may be
broadcast, satellite, cable, or fiber. Headend 12, includes a scrambler 23
which scrambles the program channels.
Converter 14, i.e. access means, enables downstream access to a channel.
The appropriate channel must be unscrambled for a subscriber at the start
of the program.
The preferred ordering system is impulse pay-per-view. Converter 14 is
enabled by the customer to access, i.e. descramble, the television signal
on an accessed channel. Converter 14 may also be enabled to descramble two
channels carrying the same program at a staggered interval, thereby
allowing return to the same point of a program after a pause equal to the
staggered time interval. For example, the subscriber orders a program
beginning at 8:00 p.m. The appropriate channel is unscrambled as well as
the channel having the same program to the next starting time of 8:15
p.m. so that the viewer may return to the same point in a program after a
break.
Sometime after the end of the program the channel is again scrambled. The
run time of the program can be used to indicate the time to scramble a
channel, although it is preferred to leave the channel unscrambled up
until the start of the next program because promotional channel
information is shown at the end of the program. The channel is then again
scrambled to prevent the customer to see the next showing on the channel.
The ordering process allows ordering from a choice of different programs
which start at various times. The ordering process is capable of
processing orders, both ordering and cancelling service, in advance or up
until some time into the event.
The ordering system also allows authorization prior to service delivery.
Two types of authorization may be provided for authorization based on
credit limitation or parental control. Accurate records, correlated by
program, are kept by the converter until transferred for analysis. Records
include data on customer, events ordered and cancelled (program title,
start day and time), time and day of order transaction, blockage in
ordering or receiving service, and price of program.
Preferably, a downstream controller 24 located in the headend 12, daily
polls each set-top converter 14 which has collected billing data and
requests it to call a pre-assigned number to access via the public
switched telephone network to upstream controller 25, also located at the
headend 12, and up-load its billing data to upstream controller 25.
Upstream controller 25 then stores and formats the billing data from
converter 14 and periodically transfers this data to a billing computer
26. Billing computer 26 receives information for each transaction on the
customer, the event code ordered, and any other necessary data. Billing
computer 26 already has program schedule data to identify event code with
title, rating, channel, starting times as well as date, run time, and
price. Billing computer 26 prints a bill 27 which includes the program
title, date, time and price.
The system is adapted for transferring television programs from the video
server 11, i.e. a transmitter, over the transmission system 13 to a
downstream video recorder 28 coupled to the converter 14. Downstream
recorder 28 records the program in response to control signals from the
downstream controller 23 of video server 11. The downstream control
signals may be sent on cable, fiber, or telephone lines, but preferably
the same media the television signals are sent on.
The preferred embodiment of the invention has been described. Variations
and modifications of the invention will now be apparent to those skilled
in the art in light of these teachings. Accordingly, the scope of the
invention is to be determined by the following claims and not by the
details of the foregoing description.
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