GB2278980A

GB2278980A - A video subscriber system

Info

Publication number: GB2278980A
Application number: GB9312181A
Authority: GB
Inventors: Peter Stephen Cuthew; Richard Stephen John Gavens
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-06-12
Filing date: 1993-06-12
Publication date: 1994-12-14
Also published as: GB9312181D0

Abstract

A video subscriber system comprises a central data unit 10 having a digital compressor 12 and a subscriber console 15 having a decompressor 19 Audio/visual signals are compressed by the digital compressor 12 and transmitted via a telecommunications network 14 to a subscriber console 15 where the signals are decompressed by the decompressor 19 to provide video information which may be viewed on a display unit 20. The system enables feature films, for example, to be transmitted from a central library to remotely located subscribers in a time period shorter than the length of the film itself. <IMAGE>

Description

A Video Subscriber System This invention relates to a video subscriber system in which a subscriber is provided with video material for viewing at a subscriber station.

In WO 90/15497 there is disclosed an audio subscriber system in which audio signals are transmitted on demand in real time from a transmitting station to a receiving station. An application of the system is the transmission to subscribers of customised sound programmes selected from a store. The transmission of each sound programme will be of only a few minutes duration.

However, if such a system were to be adapted for transmission of visual signals in addition to audio signals, for example for the purpose of transmitting to a subscriber a feature film, the system would be uneconomic because of the duration of the transmission from the transmitting station to the subscriber's receiving station.

According to the present invention, there is provided a subscriber system comprising a transmitting station for transmitting audio/visual signals and a receiving station for receiving the signals wherein the transmitting station includes means for compressing video information to provide the signals and the receiving station includes means for decompressing the signals to provide the video information so that the information is viewable on a screen.

The video information can be compressed for example by selectively signalling only variable information. When, for example, an image varies in time only in respect of movement of a foreground object relative to a scene, digital information indicative of the scene is invariable during the period. Therefore, only digital information indicative of the variable information need be transmitted subsequent to initial transmission of digital information indicative of the scene.

However, it will be appreciated that other methods could equally be used to compress the video information.

Following is a description, by way of example only and with reference to the accompanying drawing of one method of carrying the invention into effect.

The drawing is a block diagram of one embodiment of a subscriber system in accordance with the present invention.

Referring now to the drawing, there is shown a central data unit 10 including a video station 11 for generating analogue audio/visual signals of a video emission, a digital compressor 12 for converting the signals to digital signals and to compress the digital signals and a mass storage unit 13 for storing the compressed digital signals. The central data unit 10 is connected via a telecommunications network 14 to one of a plurality of subscriber consoles 15.

Each subscriber console 15 includes a control unit 16 for transmitting signals to and receiving signals from the telecommunications network 14, a storage unit 17 communicating with the control unit 16, a control panel 18 for controlling operation of the control unit 16 and a decompressor 19 connected to the control unit 16. The decompressor 19 is connectable to a display unit 20.

The video station 11 is adapted to process video information from a primary source, such as a feature film or a video recording, and generates audio/visual signals indicative of the video information. The signals are compressed in the compressor 12 and digital compressed signals are generated indicative of the audio/visual signals and the compressed signals are stored in the mass storage unit 13.

Access to the mass storage unit 13 is available to subscribers on demand, the accessibility being facilitated by operation of the control panel 18 of a subscriber's console 15 whereby the control unit 16 of the console 15 is interactively connected via the telecommunications network 14 to the mass storage unit 13.

The selected compressed digital signals are transmitted from the mass storage unit 13 of the central data unit 10 via the telecommunications network 14 to the control unit 16 of the subscriber's console 15 whereupon the received signals are directed by the control unit 16 to the storage unit 17.

The information stored in the storage unit 17 is accessed by the control unit 16 when the subscriber operates the control panel 18 to view the information on the display unit 20, the information being directed to the display unit 20 through the decompressor 19 of the subscriber's console 15 which reestablishes the video information to the format of the primary source prior to processing at the video station 11 of the central data unit 10.

It will be appreciated that the information stored in a storage unit 17 of a subscriber's console 15 may be accessed at any time by operation of the control panel 18 of the console 15. The digital signals stored in the storage unit 17 will be modified only when the control unit 17 is operated by the control panel 16 to access further digital information from the mass storage unit 13'of the central data unit 10 via the telecommunications network 14.

It will also be appreciated that the duration of transmission of the compressed digital signals could be substantially reduced by utilising the extra unused wires provided to each user of the telecommunications network. In order to establish a link via the telecommunications network only two wires are required. The digital compressed information could therefore be divided into a number of segments and each segment transmitted separately via the plurality of wires available.

Claims

1. A subscriber system comprising a transmitting station for transmitting audio/visual signals and a receiving station for receiving the signals wherein the transmitting station includes means for compressing video information to provide the signals and the receiving station includes means for de-compressing the signals to provide the video information so that the information is viewable on a screen.

2. A system as claimed in Claim 1 wherein the transmitting station and the receiving station are in communication one with another by means of a communications link.

3. A system as claimed in Claim 2 wherein the communications link is a telecommunications network.

4. A system as claimed in any one of the preceding Claims wherein the receiving station includes means for interactively communicating with the transmitting station.

5. A system as claimed in Claim 4 wherein the said means is a keyboard.

6. A subscriber system substantially as hereinbefore described and as illustrated in the accompanying drawing.