APPARATUS AND METHOD FOR RECEIVING AND FILTERING TRANSMITTED PROGRAMS

Abstract: The invention relates to an apparatus and a method for transmitting or receiving programs. Along with the programs, additional data pertaining to the programs is transmitted or received. The additional data comprises a format descriptor and a topic descriptor, which specify respectively a format of a program, for example movie or magazine, and a topic of said program, for example sports or politics. The user is allowed to select programs in accordance with conditions upon the format descriptor and the topic descriptor.

Description: APPARATUS AND METHOD FOR RECEFVFNG AND FILTERFNG TRANSMITTED PROGRAMS FIELD OF THE INVENTION The invention relates to an apparatus for receiving a plurality of programs, comprising data decoder means for receiving program information related to at least one respective program of said plurality of programs. The invention further relates to an apparatus for transmitting a plurality of programs, comprising data generator means for transmitting program information related to at least one respective program of said plurality of programs The invention further relates to a method of transmitting a plurality of programs, comprising a step of transmitting program information related to at least one respective program of said plurality of programs. The invention further relates to a method of receiving a plurality of programs, comprising a step of receiving program information related to at least one respective program of said plurality of programs. BACKGROUND OF THE INVENTION The development of, in particular, digital television will dramatically increase the number of programs which can be received simultaneously, making it more difficult for viewers to select a suitable program. Recently, features have been introduced to help the user make a choice, e.g. by filtering the received programs in accordance with user supplied preferences. For example, some known TVs enable a user to restrict the information presented by an electronic program guide (EPG) to programs of a specific category. Information about a program's category may be supplied by the content provider, e.g. included in a dedicated teletext page or as part of the service information (SI) of a digital broadcast stream. It is important to classify the content of a tv program in a short way. Usually a topic or genre descriptor is used for this. The notions topic and genre are used indifferently hereinafter. Often the set of possible values used for a genre is either very limited or unlimited (free). Naturally, allowing only a small number of values reduces the usefulness of the descriptor. It becomes too coarse to accurately describe the subjective notion of genre. On the other hand using a very large set or unlimited set maybe useful for humans to assess their interest in a certain program, but it is cumbersome for automatic retrieval. Searching for a particular type of program is hard when the number of possible descriptions for a genre is unlimited. Intelligent agents that automatically search for a program that might be of interest to the user based on its user-profile would certainly benefit from a limited set of possible values for a genre. OBJECT AND SUMMARY OF THE INVENTION It is an object of the invention to provide an apparatus having improved means for filtering receivable programs in accordance with user supplied preferences. To this end, the apparatus according to the invention is characterized in that the data decoder means are adapted to extract from said program information a format descriptor representative of a format of said respective program, for example movie or magazine, and a topic descriptor representative of a topic of said respective program, for example sport or politics. By using two descriptors, one to describe the genre, the other to describe the format of a program, the invention reduces the number of values required for the proper description of programs, without the disadvantages mentioned hereinbefore. With the systems of the prior art the two program aspects are intermingled, whereby either a genre description is intrinsically linked to a certain program format, or distinct genre descriptions are required to describe programs about the same topic but having different formats. The system proposed by the invention is more comprehensible to the user, because the total number of descriptive values is reduced, and said values relate to clearly distinguishable aspects of the receivable programs. A further embodiment of the apparatus according to the invention comprises format selection means for selecting a first subset of said plurality of programs in accordance with a first user-supplied condition upon said format descriptor, and topic selection means for selecting a second subset of said plurality of programs in accordance with a second user- supplied condition upon said topic descriptor. This embodiment enables the user to select programs in accordance with a particular program format or in accordance with a particular topic. The selected programs may be presented in an EPG. For example, the user could select only programs having a documentary format, irrespective of the topic of the programs. On the other hand, the user could select only programs dealing with crime, irrespective of the format of the programs. A further embodiment of the apparatus according to the invention comprises intersection means for creating a third subset of said plurality of programs by selecting programs which are common to the first and second subset. In this way the user is enabled to select programs which comply with conditions upon both the format descriptor and the topic descriptor. The invention thus provides a very easy way of accurately selecting programs. In a further embodiment the program information includes multiple topic descriptors. Generally, the format of a program is uniquely defined and does not change in the course of the program, but several topics may be dealt with in one program. By allowing multiple topic descriptors, such programs can be described properly, which again leads to improved means for filtering the receivable programs. In a further embodiment the topic descriptor comprises an ordered list of topic subdescriptors, each of said topic subdescriptors being more general than the succeeding topic subdescriptor and being logically implied by said succeeding topic subdescriptor. Even though the use of a separate format descriptor drastically reduces the list of possible genres the list may still be rather large. Therefore the description of the genre of a program could be structured into multiple layers, e.g. the three layers Area, Genre and Sub-genre. This makes it possible to still provide information if a detailed choice is not possible. If, for example, a certain sport is not in the list it is still possible to say that it is a sport. Since the list is subject to changes in, for example, fashion, culture or viewing habits, the list could be made adaptable (note however, that changes in the two highest levels will be rather infrequent). The invention is particularly suitable for radio and television receivers and settop-boxes. BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects of the invention will be apparent from and elucidated by way of a non-limitative example with reference to a drawing in which: Figure 1 shows a diagram of a television transmitter and receiver as an embodiment of the apparatuses according to the invention, Figure 2 shows a more detailed diagram of a digital television receiver as an embodiment of the apparatus according to the invention. DESCRIPTION OF EMBODIMENTS Figure 1 shows a diagram of a television transmitter 1 and television receiver 2 as an embodiment of the apparatuses according to the invention. The transmitter 1 comprises a content database 3, containing the audio and video content of television programs. The transmitter 1 further includes a format information database 4 and a topic information database 5, containing information about, respectively, the format and topics of the programs in the content database 3. The information for the format information database 4 and the topic information database 5 is entered by an operator by means of input means 8. A data generator 6 combines and codes the information from the format information database 4 and the topic information database 5. An adder circuit 7 combines the audio/video signals from the content database 3 and the information from the data generator 6 into a broadcast signal, which is transmitted through the atmosphere or a network 16. The television receiver 2 comprises a separator circuit 10 which is capable of separating the audio/video signals and the additional information generated by the data generator 6. The audio/video information is further processed by the signal processor 11 to be presented on a presentation device (not shown in figure 1). The additional information is decoded by a data decoder 12 and stored in a format information database 13 and a topic information database 14. A program selector 15 is capable of filtering information related to receivable programs, using information from databases 14 and 15, for example to be presented to the user in an EPG by means of the signal processor 11. Figure 2 shows a more detailed block diagram of the television receiver 2. Digital broadcast streams, modulated upon radio frequency (RF) signals, are received from the ether by an antenna 21 or, alternatively, from a cable network. The broadcast streams may be formatted, for example, in accordance with the Digital Video Broadcasting (DVB) standard. A tuner 22 comprises a standard analog RF receiving device which is capable of receiving said RF signals and selecting one of them to be output to a demodulator 23. Which signal tuner 22 selects is dependent upon control data received from a central processing unit (CPU) 25. The demodulator 23 converts the analog signal into a digital packet stream, based on control signals received from the CPU 25. This packet stream is then output to a demultiplexer 24, which selects packets belonging to a particular program in accordance with control data received from the CPU 25, and decomposes the packet stream into elementary video, audio or data streams. In an alternative embodiment of the invention, the packet stream is output from demodulator 23 directly to the CPU 25. In this embodiment, the CPU 25 performs the tasks of the demultiplexer 24, thereby eliminating the need for the demultiplexer 24. A video processor 28 decodes the video stream received from the demultiplexer 24 or from the CPU 25. In preferred embodiments of the invention, the video processor 28 is an MPEG-2 decoder; however, any decoder may be used as long as the decoder is compatible with the type of coding used to code the video data. Decoded video data is then transmitted to a display screen 29. An audio processor 26 decodes the audio stream received from the demultiplexer 24. Again, any decoder may be used as long as the decoder is compatible with the type of coding used to code the audio data. Decoded audio data is then transmitted to a speaker system 27. The demultiplexer 24 outputs the elementary data stream to the CPU 15. The elementary data stream has two types of data: control data and content data. Content refers to, e.g., interactive programs; control refers to tables in the multiplex which specify matters like the structure of the multiplex, the (RF) frequencies at which the channels are modulated, and the addresses where the various content components and the (other) tables in the multiplex can be found. The CPU 25 comprises one or more microprocessors capable of executing program instructions retrieved from a read-only memory (ROM) 32. These program instructions comprise parts of software modules including, inter alia, a command module 33, an EPG module 34, a format filter 35 (embodying the format selection means), a topic filter 36 (embodying the topic selection means) and a filter combination module 37 (embodying the intersection means). Data processed by said software modules, e.g. DVB-SI data and user profile information, may be stored in a non- volatile memory 31. The command module 33 is capable of controlling functions of the TV-set, like tuning, and transmitting data to the video processor 28 to be displayed on the screen 29. A user command unit 30 receives user commands, e.g. through a remote control (not shown), and transmits them to the command module 33 to be processed. For example, when the user enters a channel number, the command module 33 controls the tuner 22 and the demultiplexer 24 to select the corresponding broadcast stream and data packets therein, and sends graphical data to the video processor 28 to present feedback on the screen 29, e.g. the preset number, the channel name being displayed for a few seconds. Digital broadcast streams comprise information for describing the structure of the broadcast stream and generating navigation user-interfaces. For example, a DVB broadcast stream comprises Program Specific Information (PSI, part of the MPEG specifications) and SI information, necessary, inter alia, for decoding the program information and generating an electronic program guide. Specifications of the DVB standard are widely available and well known to those of ordinary skill in the art. The EPG module 34 interprets the DVB-SI data received from the demultiplexer 24 to collect information about the programs available in the received broadcast streams. The format filter 35 extracts from this information the format descriptors specifying the format of the various programs. In response to conditions supplied by the user by means of the user command unit 30, the format filter 35 selects only the information pertaining to the programs whose format meets said conditions. For example, if the user supplies a condition 'format = movie', the format filter 35 selects the information pertaining to movies, irrespective of their topic. Similarly, the topic filter 36 extracts from the EPG information the topic descriptors specifying the topic(s) of the various programs. In response to conditions supplied by the user, the topic filter 36 selects only the information pertaining to the programs whose topics meet said conditions. For example, if the user supplies a condition 'topic = crime', the topic filter 36 selects the information pertaining to programs about crime, irrespective of their format. The selections obtained by means of the format filter 35 and the topic filter 36 may be combined by means of the filter combination module 37, preferably by making an intersection of the two selections. The resultant selections may be further processed by the EPG module 34. The format descriptor and the topic descriptor may take values from a predefined set of values corresponding to various formats and topics respectively. These sets of values may be defined in many ways, differ in the number of values and possibly in the number of layers. A preferred embodiment of the format descriptor is shown in the following table: Format descriptor Movie TV Drama Series Soap opera Docu-drama Documentary Informative/Educational News Magazine Reportage Event / Performance Show Trailer Special A preferred embodiment of the topic descriptor, comprising a three-layered structure, is shown in the following table: The three layers Area, Genre and Sub-genre make it possible to provide information even if a detailed choice is not possible. If, for example, a certain sport is not in the list it is still possible to say that it is a sport. Since the list is subject to changes in, for example, fashion, culture or viewing habits, the list could be made adaptable (note however, that changes in the two highest levels will be rather infrequent). Adding a new value to the list at a later stage could cause software not to recognise the new value. Therefore the higher levels always should be specified, not just the lowest level. For example, "Sports.SportsEvent.OlympicGames" instead of just "OlympicGames" even though the latter already is a unique value. Although the invention has been described with reference to particular illustrative embodiments, variants and modifications are possible within the scope of the inventive concept. Thus, for example, the various software modules may be implemented and combined in several ways or located in different devices, e.g. a set-top box or a video recorder. The word 'comprising' does not exclude the presence of elements or steps other than those listed in a claim. In summary, the invention relates to an apparatus and a method for transmitting or receiving programs. Along with the programs, additional data pertaining to the programs is transmitted or received. The additional data comprises a format descriptor and a topic descriptor, which specify respectively a format of a program, for example movie or magazine, and a topic of said program, for example sports or politics. The user is allowed to select programs in accordance with conditions upon the format descriptor and the topic descriptor. Further aspects of the invention are disclosed in the following Appendix.

Claims: CLAIMS: 1. An apparatus for receiving a plurality of programs, comprising data decoder means for receiving program information related to at least one respective program of said plurality of programs, the data decoder means being adapted to extract from said program information a format descriptor representative of a format of said respective program, for example movie or magazine, and a topic descriptor representative of a topic of said respective program, for example sports or politics. 2. An apparatus as claimed in Claim 1, comprising format selection means for selecting a first subset of said plurality of programs in accordance with a first user-supplied condition upon said format descriptor, and topic selection means for selecting a second subset of said plurality of programs in accordance with a second user-supplied condition upon said topic descriptor. 3. An apparatus as claimed in Claim 2, comprising intersection means for creating a third subset of said plurality of programs by selecting programs which are common to the first and the second subset. 4. An apparatus for transmitting a plurality of programs, comprising data generator means for transmitting program information related to at least one respective program of said plurality of programs, the data generator means being adapted to include in said program information a format descriptor representative of a format of said respective program, for example movie or magazine, and a topic descriptor representative of a topic of said respective program, for example sports or politics. 5. A method oftransmitting a plurality of programs, comprising a step of transmitting program information related to at least one respective program of said plurality of programs, a step of including in said program information a format descriptor representative of a format of said respective program, for example movie or magazine, and a step of including in said program information a topic descriptor representative of a topic of said respective program, for example sports or politics. 6. A method as claimed in Claim 5, further comprising a step of including into said program information further topic descriptors representative of further topics of said respective program. 7. A method as claimed in Claim 5 or 6, wherein said topic descriptor comprises an ordered list of topic subdescriptors, each of said topic subdescriptors being more general than the succeeding topic subdescriptor and being logically implied by said succeeding topic subdescriptor. 8. A method of receiving a plurality of programs, comprising a step of receiving program information related to at least one respective program of said plurality of programs, a step of extracting from said program information a format descriptor representative of a format of said respective program, for example movie or magazine, and a step of extracting from said program information a topic descriptor representative of a topic of said respective program, for example sports or politics. 9. A method as claimed in Claim 8, further comprising a step of extracting from said program information further topic descriptors representative of further topics of said respective program. 10. A method as claimed in Claim 8 or 9, wherein said topic descriptor comprises an ordered list of topic subdescriptors, each of said topic subdescriptors being more general than the succeeding topic subdescriptor and being logically implied by said succeeding topic subdescriptor. 11. A method as claimed in any one of Claims 8 to 10, comprising a step of selecting a first subset of said plurality of programs in accordance with a first user-supplied condition upon said format descriptor, a step of selecting a second subset of said plurality of programs in accordance with a second user-supplied condition upon said topic descriptor, and a step of creating a third subset of said plurality of programs by selecting the programs common to the first and the second subset. 12. A signal for representing a plurality of programs, comprising program information related to at least one respective program of said plurality of programs, said program information comprising a format descriptor representative of a format of said respective program, for example movie or magazine, and a a topic descriptor representative of a topic of said respective program, for example sports or politics.

Inventors: MEULEMAN PETRUS G, STIENSTRA MARCELLE A, MEULEMAN, PETRUS, G., STIENSTRA, MARCELLE, A.
Applicants: KONINKL PHILIPS ELECTRONICS NV, KONINKLIJKE PHILIPS ELECTRONICS N.V.
Application year: 2000
Main classification: H04N7
IPC codes: H04H1, H04N5, H04N7