WO2004028149A1

WO2004028149A1 - Extraction device, method and computer program product for separation of television signals, teletext information and subtitling

Info

Publication number: WO2004028149A1
Application number: PCT/SE2003/001416
Authority: WO
Inventors: Per-Ola Wester; Andreas Hedin
Original assignee: Telia Ab (Publ)
Priority date: 2002-09-23
Filing date: 2003-09-11
Publication date: 2004-04-01
Also published as: AU2003258999A1; SE0202808D0; SE0202808L

Abstract

The present invention relates to an extraction device (12) at a system (10) for flexible distribution of teletext information. The extraction device (12) can be run to, from an analog and/or digital TV-source (14), separate teletext information (D), TV-signal(s) without teletext information (B) and subtitling (C).

Description

Extraction device, method and computer program product for separation of television signals, teletext information and subtitling

Technical field

The present invention relates according to a first aspect to an extraction device at a system for flexible distribution of teletext information.

According to a second aspect, the present invention relates to a procedure at a system for flexible distribution of teletext information. According to a third aspect, the present invention relates to at least one computer program product to execute the procedure according to the present invention.

Prior art Teletext information, popularly called Teletext/data- TV/datavision, is an old but still used system, which is based on that data is transmitted in the analog TV-system.

With known systems, the teletext information is normally distributed included in the TV-signal. This fact applies to both analog and digital television. This means that the teletext information is transmitted to all customers, whether they are making use of it or not. The system often is experienced as slow by the user since there may be a long period of time before the page of topical interest is transmitted. With existing systems the user only can use Teletext on the channel he/she is watching.

The document WO-00/44 168 describes a system to transmit TV-programs to a plurality of customers, and further information which is connected with the TV- programs . The program is transmitted by use of video signals which have in them included an indication signal which indicates further accessible information. The indication signal can, for instance, include an address to a web site. At a typical user place, a receiver station includes a TV-set of standard type, a control box and a telephone set. The control box interprets the video signals and includes a detector to detect the indication signal. When the indication signal is detected, the control box generates a reproduction/representation, preferably on the TV-set, which indicates the accessibility for the further information. The telephone set effects telephone communication of standard type and also access to Internet to make retrieval of the further information from the Internet site possible. When the address of an Internet site has been received, the control box transmits it to the telephone set. The telephone set then activates a modem, gains access to the Internet site, retrieve the -information and transmits it to the control box. The control box receives the further information and transmits it to the TV-set to be reproduced/represented either together with the TV-program, or replacing the TV-program. One disadvantage with this system is that the user need further hardware, in form of, for instance, the control box. The document US-A1-2001/0044726 describes a procedure and a receiver to provide/distribute a film with speech in optional language. The invention can be implemented in a system including a TV- and/or a video device, an interface and a server device which can be connected to a translator studio. A user can control the TV- or video device and/or the interface by means of a remote control. If a user wants to watch a transmitted film with sound signals in a preferred language, the user can, by means of a language menu presented on a display on the TV- or video device, select the preferred language. The user's selection of language is evaluated in a device to effect identification information corresponding to the selected language and video data for the film which the user intends to watch. The identification information can include the title of the film or any other identification code extracted from, for instance, teletext data. The identification information is transmitted to the server device which, after processing of the identification information, will provide sound translation data to the interface. The television or video device will provide video data received from a broadcast station in synchronization with from the server device received sound translation data, so that the user can watch the film with sound signals corresponding to the by the user selected language. In this system, certainly a solution is used which combines that the information is received as unicast and broadcast, but for a very specific application. A disadvantage in common of the above presented solutions is that they are not very flexible, such as that it is not possible to select the teletext information which is of current interest (for instance only subtitling) .

Summary of the invention

It is an aim of the present invention to solve the above mentioned problems .

According to a first aspect of the invention, an extraction device is effected at a system for flexible distribution of teletext information. The extraction device can be operated in order to from an analog and/or digital TV-source separate teletext information, TV-signals without teletext information and subtitling. One advantage with the extraction device according to the present invention is that it provides the possibility to select the teletext information which is of current interest.

One advantage in this connection is achieved if the extraction device includes at least one conversion device which can be operated to convert the teletext information from the transmitted format into a wanted format.

In this connection one advantage is achieved if the conversion device converts the teletext information into for one thing a format including formatted pages with belonging control codes/characters, and for another a format including formatted pages with subtitling. One advantage in this connection is achieved if the extraction device also includes one to the conversion device connected verification device for verification of the teletext information before transmission. In this connection one advantage is achieved if the extraction device also includes a first filter device connected to the conversion device for letting through of all teletext information, and a second filter device connected to the conversion device for letting through of only the subtitling.

One advantage in this connection is achieved if the first filter device is connected to one in the system included server device.

In this connection one advantage is achieved if the second filter device is connected to one in the system included client terminal.

One advantage in this connection is achieved if the extraction device also includes a teletext receiver connected to the verification device. According to a second aspect of the present invention, a procedure at a system for flexible distribution of teletext information is effected. The procedure includes the step: to, from an analog and/or digital TV-source, separate teletext information, TV-signal (s) without teletext information and subtitling. By the procedure according to the present invention, the possibility is provided to select the teletext information which is of current interest. In this connection one advantage is achieved if the procedure also includes the step: to convert the teletext information from the transmitted format to a wanted format. One advantage in this connection is achieved if the conversion step includes the steps: to convert the teletext information into a format including formatted pages with belonging control codes/characters; and to convert the teletext information into a format including formatted pages with subtitling.

In this connection one advantage is achieved if the procedure also includes the step: to verify the teletext information before transmission . One advantage in this connection is achieved if the procedure after the conversion step(s) also includes the steps : to filter the converted teletext information for letting through of all teletext information; and - to filter the converted teletext information for letting through of only subtitling. In this connection one advantage is achieved if the format including formatted pages with belonging control codes/characters is transmitted/transferred to one in the system included server device.

One advantage in this connection is achieved if the format including formatted pages with subtitling is transmitted to one in the system included client terminal. According to a third aspect of the present invention, at least one computer program product, which can be loaded directly into the internal memory of at least one digital computer, is effected. The computer program product/ products includes software code parts to execute the steps according to the procedure when said at least one product is run on said at least one computer. By this at least one computer program product a flexible solution is achieved which provides possibility to select the teletext information which is of current interest.

It should be emphasized that when the term "include/ including" is used in this application, it shall indicate the existence of said qualities, steps or components, but does not exclude the existence of one or more other qualities, parts, steps, components or groups of them.

Brief description of the drawings Embodiments of the invention now will be described with reference to the enclosed drawings, where: Figure 1 is a block diagram of a system 10 for flexible distribution of teletext information; Figure 2 shows schematically the data flows which exist in the in Figure 1 shown system;

Figure 3 shows a block diagram of an extraction device 12 according to the present invention; Figure 4 shows a flow chart of a procedure at a system for flexible distribution of teletext information according to the present information;

Figure 5 shows a flow chart of a procedure for the in

Figure 1 shown system 10; Figure 6 shows a flow chart of a first use of the in

Figure 1 shown system 10; Figure 7 shows a flow chart of a second use of the in

Figure 1 shown system 10; Figure 8 shows a flow chart of a third use of the in

Figure 1 shown system 10; Figure 9 shows a flow chart of a fourth use of the in Figure 1 shown system 10;

Figure 10 shows a schematic picture of some computer program products according to the present invention.

Detailed description of embodiments

In Figure 1 a block diagram is shown of a system 10 for flexible distribution of teletext information. The system 10 includes an extraction device 12 which separates teletex information, TV-signal (s) without teletext information, and subtitling from an analog and/or digital TV-source 14. The system 10 also includes a server device 16 connected to the extraction device 12, which server device 16 stores the teletext information and metainformation about accessible information. The system 10 also includes a client terminal 18 connected to the extraction device 12 and the server device 16. The client terminal 18 can itself decide if it shall receive the information as only unicast, only broadcast, or as a combination of unicast and broadcast. The system 10 further can include one in the client terminal 18 included selection device 20, by which the user can select one of, or optional combination of, the possible data flows, which can be seen in Figure 2.

In Figure 2 the data flows which exist in the in Figure 1 shown system 10 are schematically shown. The TV- source 14 transmits in ordinary way TV-signals with teletext information A which are received by both the extraction device 12 and the client terminal 18. The extraction device 12 separates the data flow A into three different data flows, namely TV-signals without teletext information B, subtitling C and teletext information D. As can bee seen in Figure 2, the client terminal 18 can receive these data flows B, C and D directly from the extraction device 12. The teletext information D is, in addition, transmitted to the server device 16. By means of the selection device 20 a user can for instance select wanted pages with teletext information, at which the server device 16 to the client terminal 18 transmits selected teletext information and metainformation E. The in Figure 2 shown arrow E is bi-directional because the transmission of the data flow E is preceded by the selection, which occurs in the opposite direction. The server device 16 in addition can transmit information regarding change F to the client terminal 18.

The metainformation is created by the server device 16 by means of activity analysis of the teletext information. Below follows a description of how the in Figure 1 and 2 shown system 10 is working, and different ways in which the system 10 can be used.

The system 10 separates the teletext information D from the TV-signal A. That part of the teletext information which is considered as interesting to all users (subtitling C) is transmitted in traditional broadcast way - the larger amount of information is derived as required from the server device 16 by the client terminal 18. This means that bandwidth can be saved and that all pages are stored on the server device 16 and for that reason can be derived/retrieved immediately. The teletext receiver, that is the client terminal 18, can show information from just any channel. The presentation/showing of teletext information is no longer depending on which channel users are watching.

The system 10 stores the teletext information D on the server device 16 in a format which makes possible correct re-creation of all transmitted information. On the server device 16 is also stored metainformation about which content that is accessible. The receiver by that easily can have a correct information about which information that is accessible, that is, which pages and subpages that are active. That means that the user directly will have indication about whether a page exists or not. The system

10 also makes it possible to get access to the teletext information from other terminals than a TV, for instance an ordinary web browser.

As can be seen in Figure 1 and 2, the system 10 in the main comprises three parts:

• The extraction device 12 extracts the teletext information from an analog or digital TV-source

14, forwards this to the server device 16 or directly to the client terminal 18. The extraction device 12 also can select a subset of information and transmit also this to the client terminal 18, for instance subtitling C. A TV- signal without teletext information B is also transmitted.

• The server device 16 stores the teletext information and metainformation about which pages that are accessible. The client terminal 18 can derive/retrieve metainformation and pages of the teletext information E via unicast (today http) . The server device 16 can transmit information about changes F to the client terminal 18 to eliminate unnecessary reading from the server device by the client terminal 18. • The client terminal 18 presents, to the user, interfaces which are similar to the today existing interfaces. The client terminal 18 can receive its information from a mix of data flows A - F.

By selecting different combinations of data flows, different qualities of the system 10 can be achieved.

Below follows some examples.

By using the data flow E in a traditional system with the data flow A, a rapid page loading is achieved. • By allowing that only the data flows B, C and E are reaching the user/customer, the capacity which would have been needed to transmit teletext information via broadcast can be saved - this without loosing in function. Thus bandwidth is saved.

• By using data flows E or D, a user/customer can access teletext information from another channel than the one the user/customer is watching. In Figure 3 a block diagram of an extraction device 12 according to the present invention is shown. The extraction device 12 includes a teletext receiver 22 for reception of TV-signals with teletext information from an analog and/or digital TV-source 14 (compare Figure 1 and 2) . The extraction device 12 in addition includes one to the teletext receiver 22 connected verification device 24 for verification of the teletext information before transmission. The extraction device 12 also includes one to the verification device 24 connected conversion device 26 operated to convert the teletext information from the transmitted format into a wanted format . According to one preferred embodiment of the extraction device 12 according to the present invention, teletext information is converted by the conversion device 26 into on the one hand a format including formatted pages with belonging control codes/characters, and on the other a format including formatted pages with subtitling. The extraction device 12 also includes a first filter device 28 and a second filter device 30, both connected to the conversion device 26. The first filter device 28 lets all teletext information through, and the second filter device 30 lets only the subtitling through. As can be seen in Figure 3, the first filter device 28 is connected to one in the system 10 included server device 16, and the second filter device 30 is connected to one in the system 10 included client terminal 18.

In Figure 4 a flow chart of a procedure at system 10 for flexible distribution of teletext information according to the present invention is shown. The procedure starts at the block 110. The procedure then continues, at the block 112, with the step: To receive TV-signal (s) by means of the teletext receiver 22 (compare Figure 3) . After that, the procedure continues, at the block 114, with the step: To verify the teletext information before transmission. The procedure then continues, at the block 116, with the step: To convert the teletext information into a format including formatted pages with belonging control codes/characters. After that, the procedure continues, at the block 118, with the step: To convert the teletext information into a format including formatted pages with subtitling. The procedure then continues, at the block 120, with the step: To filter the converted teletext information for letting through of all teletext information. After that, the procedure continues, at the block 122, with the step: To filter the converted telex information for letting through of only subtitling. As can be seen in Figure 3, the result of the filtering 1 is transmitted/transferred to the server device 16, and the result of the filtering 2 is transmitted/transferred to the client terminal 18. The procedure then is finished at the block 124.

In Figure 5 a flow chart of a procedure for flexible distribution of teletext information is shown. The procedure starts at the block 30. The procedure then continues, at the block 32, with the step: To, from an analog and/or digital TV-source 14, separate teletext information D, TV-signal (s) without teletext information B and subtitling C. After that, the procedure continues, at the block 34, with the step: To store the teletext information D and metainformation about accessible information. The procedure then continues, at the block 36, with the step: To, by means of a client terminal 18, receive the information as only unicast, only broadcast, or as a combination of unicast and broadcast. The procedure then is finished at the block 38.

According to one preferred embodiment of the procedure, a user can, via the client terminal 18, select one of, or optional combination of, the following data flows: TV-signal (s) with teletext information A, TV- signal (s) without teletext information B, subtitling C, teletext information D, selected teletext information and metainformation E and information regarding change F. In Figure 6 a flow chart of a first use of the system 10 is shown. The procedure starts at the block 40. The procedure then continues, at the block 42, with the step: To receive TV-signal with teletext information A by means of the client terminal 18 from the TV-source 14. After that, the procedure continues, at the block 44, with the step: To, by means of the client terminal 18, select teletext information. The procedure then continues, at the block 46, with the step: To, by means of the client terminal 18, select teletext information and metainformation E from a storing device. This results in rapid page loading of teletext information. The procedure then is finished at the block 48.

In Figure 7 a flow chart of a second use of the system 10 is shown. The procedure starts at the block 50. The procedure then continues, at the block 52, with the step: To, by means of the client terminal 18, receive TV-signal without teletext information B. After that, the procedure continues, at the block 54, with the step: To, by means of the client terminal 18, receive subtitling C. The procedure then continues, at the block 56, with the step: To, by means of the client terminal 18, select teletext information. After that, the procedure continues, at the block 58, with the step: To, by means of the client terminal 18, receive selected teletext information and metainformation E from a storing device. The procedure then is finished at the block 60. This procedure results in that bandwidth is saved.

In Figure 8 a flow chart of a third use of the system 10 is shown. The procedure starts at the block 70. The procedure then continues, at the block 72, with the step: To, by means of the client terminal 18, receive TV-signal without teletext information B. After that, the procedure continues, at the block 74, with the step: To, by means of the client terminal 18, receive teletext information D from a storing device. The procedure then is finished at the block 76. This procedure makes it possible for a user to get access to teletext information from another channel than the one the user at present moment is watching via the client terminal 18.

It should be emphasized that with the system 10 according to the present invention it will be possible to show teletext information on the client terminal 18 regarding a TV-channel which at the present moment does not transmit any teletext information.

In Figure 9 a flow chart of a fourth use of the system 10 is shown. The procedure starts at the block 80. The procedure then continues, at the block 82, with the step: To, by means of the client terminal 18, receive TV-signal without teletext information B. After that, the procedure continues, at the block 84, with the step: To, by means of the client terminal 18, select teletext information. The procedure then continues, at the block 86, with the step: To, by means of the client terminal 18, receive selected teletext information F from a storing device. The procedure then is finished at the block 88. This procedure makes it possible for a user to get access to teletext information from another channel than the one that the user at the present moment is watching via the client terminal 18. In Figure 10 a schematic picture of some computer program products according to the present invention is shown. In Figure 10 n different digital computers lOOi,..., 100_n are shown, and n different computer program products 102ι,..., 102_n, which can be loaded directly into the internal memory of said computers 100i, ..., 100_n. Each 102ι, ..., 102_n include software code parts to execute some or all steps according to the patent claim 9 when the product/products 102χ, ..., 102_n are run on the computer/ computers 100ι, ..., 100_n. The computer program products

102ι, ..., 102_n can, for instance, be in form of diskettes, RAM- disks, magnetic tape, opto magnetic disks, or any other suitable products. The computer program products in addition can be distributed via some form of computer network.

It should be emphasized that the change of flow F per channel can be used to minimize the data flow E.

The above described system 10 according to the present invention can be applied in many different ways and with many different types of networks. Below some ways are exemplified to apply this system 10.

In this example all transmission/transfer of data is made over computer network (IP) . In this case the system 10 is used to make loading of pages by means of the data flow E more rapid. Updating the client terminal will have from the in the TV-signal included teletext information, that is, via the data flow A.

In another example all teletext information is received via the system 10. In this example the client terminal 18 does not receive the data flow A. On the other hand, the client terminal 18 makes use of the data flow B to receive the TV-signal. In addition, the client terminal 18 receives the data flows C, E and F. The point of it here is that the client terminal 18 does not all the time need to receive all teletext information but only that which the user is interested in (subtitling and selected pages) and that the client terminal can receive teletext pages from a channel which is not the channel the data flows B- and C of which are received. In another example the distribution is made over a combination of computer network and digital TV-network. In a digital TV-network, the data flow A in Figure 2 is divided into the data flows Al and A2, both including TV- signal (s) with teletext information. The data flow Al is passing via the digital TV-network (DVB-T, DVB-C or DVB-S) to the client terminal 18. The data flow A2 is coming in to the extraction device 16 via another network, which can be a computer network or a digital TV-network. In this case the client terminal (for instance a digital TV-receiver) is using the system primarily to increase speed at deriving/ retrieving of pages (the data flow E) . Updating of pages can be given to the client terminal 19 either via the data flow Al or F. The data flows F and E are passing via the back channel of the client terminal 18 (which is capable of bi-directional transmission) . The advantage/gain here is that loading of pages will be more rapid and that the client terminal 18 can receive teletext pages from a channel which is not the channel the flow Al of which is received.

In this example system 10 is used to make possible for the client terminal 18 to show teletext pages from another channel than the one that is transmitted. The client terminal 18 receives the data flows B and C from the channel the TV-signal of which shall be shown, the data flow F from the channel the teletext information of which is wanted and uses the data flow E to get the metainformation and the selected teletext pages. The point of it here is that loading of pages is made more rapid and that the client terminal 18 need not receive teletext pages from a channel which is of no interest. In a traditional system, the client terminal might have to receive an extra A-data flow in order to receive teletext information from another channel than the one the TV-signal of which is shown.

The invention is not limited to the above described embodiments. It will be evident that many different modifications are possible within the scope of the enclosed patent claims .

Claims

PATENT CLAIMS

1. An extraction device (12) at a system (10) for flexible distribution of teletext information, c h a r a c t e r i z e d in that the extraction device (12) is arranged to, from an analog and/or digital TV- source (14), separate teletext information (D) , TV- signal (s) without teletext information (B) and subtitling (C) .

2. An extraction device (12) as claimed in patent claim

1, c h a r a c t e r i z e d in that the extraction device (12) includes at least one conversion device (26) arranged to convert the teletext information from the transmitted format into a wanted format.

3. An extraction device (12) as claimed in patent claim

2, c h a r a c t e r i z e d in that the conversion device (26) converts the teletext information into on the one hand a format including formatted pages with belonging control codes/characters, and on the other a format including formatted pages with subtitling.

4. An extraction device (12) as claimed in patent claim 3, c h a r a c t e r i z e d in that the extraction device

(12) in addition includes one to the conversion device (26) connected verification device (24) for verification of the teletext information before transmission.

5. An extraction device (12) as claimed in patent claim 3 or 4, c h a r a c t e r i z e d in that the extraction device (12) in addition includes a first filter device (28) connected to the conversion device (26) for letting through of all teletext information, and a second filter device (30) connected to the conversion device (26) for letting through of only the subtitling.

6. An extraction device (12) as claimed in patent claim 5, c h a r a c t e r i z e d in that the first filter device (28) is connected to one in the system (10) included server device (16) .

7. An extraction device (12) as claimed in patent claim 5 or 6, c h a r a c t e r i z e d in that the second filter device (30) is connected to one in the system (10) included client terminal (18) .

8. An extraction device (12) as claimed in any of the patent claims 1-7, c h a r a c t e r i z e d in that the extraction device (12) in addition includes a teletext receiver (22) connected to the verification device (24).

9. A procedure at a system (10) for flexible distribution of teletext information, which procedure includes the step: to, from an analog and/or digital TV-source (14), separate teletext information (D) , TV-signal (s) without teletext information (B) , and subtitling (C) .

10. A procedure at a system (10) for flexible distribution of teletext information as claimed in patent claim 9, c h a r a c t e r i z e d in that the procedure also includes the step: to convert the teletext information from the transmitted format into a wanted format .

11. A procedure at a system (10) for flexible distribution of teletext information as claimed in patent claim 9, c h a r a c t e r i z e d in that the conversion step includes the steps : to convert the teletext information into a format including formatted pages with belonging control codes/characters; and to convert the teletext information into a format including formatted pages with subtitling.

12. A procedure at a system (10) for flexible distribution of teletext information as claimed in any of the patent claims 9-11, c h a r a c t e r i z e d in that the procedure also includes the step: to verify the teletext information before transmission.

13. A procedure at a system (10) for flexible distribution of teletext information as claimed in any of the patent claims 10-12, c h a r a c t e r i z e d in that after the conversion step(s) the procedure also includes the steps: - to filter the converted teletext information for letting through of all teletext information; and to filter the converted teletext information for letting through of only subtitling.

14. A procedure at a system (10) for flexible distribution of teletext information as claimed in patent claim 11, c h a r a c t e r i z e d in that the format including formatted pages with belonging control codes/characters are transmitted/transferred to one in the system (10) included server device (16) .

15. A procedure at a system (10) for flexible distribution of teletext information as claimed in patent claim 11, c h a r a c t e r i z e d in that the format including formatted pages with subtitling is transmitted/transferred to one in the system (10) included client terminal (18) .

16. At least one computer program product (102ι, ..., 102_n) which can be loaded directly into the internal memory of at least one digital computer (100ι, ..., 100_n) , including software code sections to execute the steps according to the patent claim 9 when said at least one product (102ι, ..., 102_n) is run on said at least one computer (100ι, ..., 100_n) .