Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/41—Structure of client; Structure of client peripherals
  • H04N21/426—Internal components of the client ; Characteristics thereof
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/45—Management operations performed by the client for facilitating the reception of or the interaction with the content or administrating data related to the end-user or to the client device itself, e.g. learning user preferences for recommending movies, resolving scheduling conflicts
  • H04N21/4508—Management of client data or end-user data
  • H04N21/4532—Management of client data or end-user data involving end-user characteristics, e.g. viewer profile, preferences
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/45—Management operations performed by the client for facilitating the reception of or the interaction with the content or administrating data related to the end-user or to the client device itself, e.g. learning user preferences for recommending movies, resolving scheduling conflicts
  • H04N21/454—Content or additional data filtering, e.g. blocking advertisements
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/16—Analogue secrecy systems; Analogue subscription systems
  • H04N7/162—Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing
  • H04N7/163—Authorising the user terminal, e.g. by paying; Registering the use of a subscription channel, e.g. billing by receiver means only

Definitions

• the invention relates to a method of and apparatus for enabling the inhibition of television programme display in dependence on the programme content.
• V-chip V-chip
• the broadcaster rates each programme in four censorship categories.
• the values for each category are then transmitted simultaneously as part of the extended data services (EDS) of the Closed Captioning (CC) system.
• EDS extended data services
• CC Closed Captioning
• the parent sets a threshold for each category. If a rating exceeds the pre-authorised value, the V-chip; suppresses the video and audio signals. As the reaction of the V-chip decoder is near instantaneous, the system can easily handle channel hopping. Moreover, the parent does not have to worry about missing content warnings in TV guides or at the start of programmes.
• the Electronic Industries Association defines the four censorship categories and the number of data bits required to transmit the code: • MPAA rating (equivalent to film classifications, e.g. 18, PG, etc.) - 3 bits violence content advisory level - 2 bits (which allows for a scale of 0 to 3) sexual content advisory level - 2 bits mature content advisory level - 2 bits.
• CC data can be recorded and reproduced by a VHS VCR during play-back of a programme.
• recorded and pre-recorded tapes could also contain censorship data.
• the CC signal would occupy valuable teletext transmission capacity (one line would be permanently lost) and different encoding systems would be required 25 Secondly, it would be very expensive for broadcasters in terms of the duplicate transmission equipment and data bridges (in cable amplifiers) required for both teletext and CC signals.
• the invention provides a method of enabling an authorised person to disable the sound and/or visual display of a television programme or a part thereof in dependence on the programme content, the method including the steps of; i) classifying the whole and/or instantaneous content of a television programme, ii) generating code words representing the allocated classification, and iii) inserting the code words in a teletext signal multiplexed with the television signal representing the programme in both a machine readable and a displayable form.
• classification code words in both displayable and machine readable form use can be made of the classification of programmes by a viewer having a receiver which includes a teletext decoder but which does not include automatic means for disabling the display in response to codes set into the automatic means by the user and compared with the transmitted codes.
• the measure according to the invention of inserting the classification codes into both the displayable portion of the teletext data and ensuring that these codes can be detected and acted upon by automatic means it is possible to disable the sound and/or visual display either automatically, if automatic means is included in the receiver, or by action of a supervising viewer if no automatic means is incorporated in the receiver provided only that it includes a teletext decoder.
• the viewer can call up the programme classification page and monitor the classification of the programme currently being transmitted even if automatic disabling of the display is not available with the receiver being used.
• An advantage of using the teletext transmissions to convey the code is that in many countires the infrastructure is already in place for inserting the teletext signal into the transmitted signal and that a large number of television receivers now incorporate teletext decoders. Thus there is a viewer demand for the teletext service and an editing facility can be relatively easily added to both at the receiver and at the programme originating source.
• the programme provider monitors the content of the programme and provides an appropriate indication of its content by means of a code inserted in an associated teletext signal
• the person in control of the television set can then use this code to determine whether or not such programmes should be displayed (visually and/or orally)
• teletext packets to convey the code it is possible to produce a visual display of the codes in addition to the automatic inhibition of display, if automatic means are provided, or to produce purely a visual display of the codes if a receiver having only a basic teletext decoder is used
• Teletext pages are transmitted in sequence and consequently priority can be given to certain pages
• the repetition rate could be matched to the degree of the content, i e when high classification codes are present the page is sent more frequently Consequently the classification can easily be changed frequently if desired
• This enables the occasional occurrence of possibly offensive events to be edited out while still allowing viewing of the programme as a whole
• news and current affairs programmes may include distressing or offensive scenes, such as incidents from war zones, as relatively short portions of the programme as a whole
• the packet may be transmitted more frequently to enable even shorter events, such as a single word, to be deleted
• the displayable codes may be displayed at pre-determined positions on a teletext page, the machine readable codes then being the codes producing the displayable codes at the predetermined positions
• the machine readable codes may be concealed from display In this way if row 1 is used there is still an undisplayed row between the page heading and the text on the display page
• the machine readable codes may be contained in an extension packet associated with the displayed page
• the machine readable codes may be protected by an error correction code With the method where the displayed codes and machine readable codes are identical they are protected only by a parity check Current teletext decoders will automatically perform this parity check on all received characters in a page If, however, the machine readable codes are concealed from display it is possible to provide a greater degree of error protection for those codes
• the machine readable codes in the extension packets, which will not be displayed can be Hamming coded Similarly if the machine readable codes are concealed on a given row of a page these can also be given greater error protection than displayed codes without confusing the viewer
• This page may be transmitted on a given page number which page number may be stored in non-volatile memory in the receiver so that it can be accessed by pressing a single button on a remote control unit
• the frequency transmission of the current programme page may be increased when any change of classification code takes place
• the frequency of transmission of the current programme page may increase as the level of classification increases
• the time taken to access a page decreases as the frequency of transmission increases, that is the page is transmitted at shorter time intervals
• the time taken for it to appear will be less than or equal to the interval between successive transmissions of that page
• a higher classification code is transmitted the viewer will have a shorter maximum time to wait before receiving and displaying the page
• the method may include the further step of generating error correction bits for insertion in the packet with the code words
• the code words are protected by means of a Hamming code, the code words being 4/8 Hamming coded
• One or more classification criteria may be each encoded using code words comprising two bits and an individual criterion may apply to the whole programme or to individual events within a programme
• the classification criteria may include one or more of, violent content, sexual content, distressing content, mature language
• the use of two bit code words for each criterion allows the setting of four possible levels for that criterion For example taking the criterion of violent conduct the code 00 could represent zero violent content, the code 01 a low level of violent conduct, the code 10 a medium level of violent conduct, and the code 11 a high level of violent conduct
• One of the code words may represent the region of origin of the programme, and the region of origin may be represented by a four bit code
• the indication of the region of origin of the programme may be useful in view of the sensibilities of different cultures Thus what is offensive to one nationality or religious group may not be to another and consequently the possibility of modifying the meaning of a particular code depending on the programme origin and the sensibilities of the controlling authority for the TV receiver could be useful Thus certain communities may have a greater or lesser tolerance of sexual or violent conduct and by providing a region of origin code the level may be accordingly increased or decreased at the location of the receiver
• an extension packet containing the code words may be inserted in the closest field blanking period to the beginning and/or end of an event which changes the classification within the programme which is being classified
• Normally packet 8/30 format 1 is transmitted approximately once per second In order to enable individual words, for example, to be disabled this is not sufficiently accurate but by causing the packet to be transmitted also in the closest field blanking interval it will be within 20 milliseconds of the occurrence of the offending word which will be sufficient to enable the word to be suppressed
• auxiliary channel for example that for the proposed Audetel service which provides an audio assistance signal for describing action in a scene
• the invention further provides a method of disabling the sound and/or visual display of a television programme, the method comprising the steps of, iv) establishing the authority of the user to define the programme or parts thereof which are to be disabled, v) entering into a memory within the television receiver code words corresponding to programme content it is desired to suppress, vi) receiving television signals including displayable code words and machine readable code words located in a teletext signal multiplexed with the television signals, the code words representing the programme classification, vii) comparing the received code words with the entered code words, and
• the reception of television signals having an undesirable content for a potential audience, for example children, can be controlled using this method
• the classification applied to the programme being viewed can be monitored by displaying a particular teletext page which contains the classification codes in a form intelligible to a viewer
• the machine readable code words may be located in an extension packet of the teletext signal This may be a page related extension packet such as packet 26 or a non-page related extension packet such as packet 8/30 format 1
• a television set or video recorder equipped with a teletext decoder which is capable of detecting and decoding extension packets can be used to ⁇ o monitor the classification of a programme according to its content and if a user enters a classification which it is desired to suppress then means can be provided to disable the output of a
• Step iv) of the method may be accomplished by entering a Personal i s Identification Number (PIN)
• step iv) of the invention may be accomplished by monitoring a physiological characteristic of the authorised person
• a relatively simple method of establishing authority is to issue a PIN which is known only to the authorised user The entered PIN is then
• the classification codes may be updated
• the code words may be entered using a remote control unit
• Remote control units are frequently provided with television sets and are invariably provided with television sets capable of receiving and displaying teletext data They have a numeric keypad and thus can be used for entering
• An on screen display message which informs the viewer of the reason the sound or visual display is disabled may be generated.
• Such a message will prevent a viewer from thinking there is a fault in the television set which is causing the display or sound to cease.
• the messages may, for example, be of the form "sound inhibited because of mature language", or "display inhibited because of distressing event.”
• An inhibited sound may be replaced with an alternative sound.
• the alternative sound may be defined by the received signal.
• a range of sounds might replace the original words.
• the replacing sound may depend on the length of the passage to be replaced.
• alternative non-objectionable words might be transmitted in an auxiliary channel to replace the words not allowed by the selected classification.
• Such alternative words may be transmitted, for example, using any spare capacity in the proposed Audetel service.
• the invention further provides a television signal programme source including a teletext signal insertion arrangement, means for classifying television signals to be transmitted according to the programme content they convey, means for generating code words representing the classification allocated to the programme or part thereof, and means for inserting the code words within the teletext signal in both displayable form and machine readable form.
• a television signal programme source including a teletext signal insertion arrangement, means for classifying television signals to be transmitted according to the programme content they convey, means for generating code words representing the classification allocated to the programme or part thereof, and means for inserting the code words within the teletext signal in both displayable form and machine readable form.
• the teletext signal may be as defined in the World System Teletext Standard and the machine readable code words may be inserted in extension 5 packet
• the extension packet may be packet 8/30 format 1
• This extension packet is normally transmitted at approximately one second intervals and is not page related It is decoded by many teletext decoders and includes information as to the programme provider, first page to be acquired, and a real time clock There are four bytes within this packet ⁇ o which according to the invention are used for transmitting programme classification codes
• Means may be included for changing the classification within the duration of a single programme
• the first 15 is to prevent the reception of a whole programme deemed to be unacceptable and the second is to allow viewing of a programme but to delete possibly offending events
• the length of events which can be excluded depends on the frequency of transmission of the codes
• Packet 8/30 format 1 is normally transmitted once per second and thus events can be deleted easily in multiples 20 of a second
• Means may be provided for error correcting the code words
• the words maya be protected by means of a Hamming code
• the code words may be 4/8 Hamming coded 25
• the code words may comprise words defining the level of one or more of the following categories, sexual exphcitness, violence, mature language, 30 distressing images or sounds
• news programmes may portray high levels of violence in particular reports such as from war zones They may also contain distressing content, for example pictures of starving people as a result of famine
• distressing content for example pictures of starving people as a result of famine
• Other examples of material which may be distressing to some viewers include the display of operations in medical programmes
• the code words may further include a code word indicating the region of origin of the programme
• the invention still further provides a record carrier containing data representing a television programme, classification code words representing allocated classifications for the whole and/or instantaneous content of the programme, and an associated teletext signal, wherein the code words are contained in the teletext signal in both displayable and machine readable form
• a record carrier containing data representing a television programme, classification code words representing allocated classifications for the whole and/or instantaneous content of the programme, and an associated teletext signal, wherein the code words are contained in the teletext signal in both displayable and machine readable form
• the teletext signal may conform to the World System Teletext Standard and the machine readable code words may be inserted in an extension packet
• the extension packet may be packet 8/30 format
• the teletext signal may be converted into a multilevel code to reduce the bit frequency of the teletext signal, in which case, the record carrier may be
• the invention yet further provides a television receiver suitable for receiving and displaying television signals from such a television signal source or record carrier, the television receiver comprising a teletext decoder, means for extracting the machine readable code words representing the classification allocated to the currently received programme, means for displaying the displayable classification codes, means for entering information representing any programme classification which represents programmes whose display it is desired to inhibit, means for comparing the entered and received classification, and means for allowing or disabling display of the programme in dependence on the result of the comparison
• codes corresponding to programmes or parts of programmes which it is desired to suppress are entered into a television receiver
• Corresponding codes are received via the teletext signal and can be compared, within the receiver, with the entered codes to enable control of the display and audio output of the receiver
• the codes are included in teletext extension packets which are not page related such as packet 8/30 format 1 , it is not necessary to have a teletext decoder permanently looking for a particular page Instead the teletext decoder can perform its normal function of acquiring user selected pages and it will automatically acquire the non page related extension packets
• Authorization means may be provided for allowing only an authorised 5 person to enter the programme classification
• the authorization means may comprise means for entering a PIN means for comparing the entered PIN with a stored PIN, and means for allowing the entry of programme codes if the stored and entered PINs are identical ⁇ o
• This provides an easy secure means for ensuring that only an authorised person, for example a parent, can alter the classification codes It does however, have the disadvantage that the code may be forgotten or compromised In the first case it is then difficult to change the classification and in the second case an unauthorised person may be able to change the
• the authorization means may comprise means for monitoring a physiological characteristic of the authorised person means for storing the monitored characteristic, means for requesting a change in the acceptable programme content, means for monitoring the characteristic in
• Various physiological characteristics may be used, for example fingerprints, facial characteristics
• Means may be provided for generating an on screen display message to inform the viewer why the sound and/or display has been disabled This prevents the viewer form assuming there is a fault in the receiver when a programme cannot be received or is interrupted due to its classification
• Means may be provide for replacing unsuitable words with an alternative audio signal
• the alternative audio signal may represent alternative
• the alternative words may be received as part of the television signal
• objectionable words may be replaced, for example, by a bleep signal
• they may be replaced by an alternative unobjectionable word
• An auxiliary channel which could be used is the proposed Audetel channel for transmitting audio assistance messages for the blind or partially sighted
• Means may be provided for disabling the sound and visual display if no 15 classification code is received with the televison signal
• Figure 1 shows a television system for carrying out a method according to the invention
• Figure 2 shows in block schematic form a television programme source according to the invention
• Figure 3 shows a scheme for code words for classifying programmes, the code words being inserted into a teletext extension packet
• Figure 4 shows in block schematic form a television receiver according to the invention
• Figure 5 illustrates a process for programming the television receiver to operate according to the method of the invention
• Figure 6 illustrates possible on-screen display messages when the method is invoked
• Figure 7 illustrates display screens where both displayable classification codes and machine readable codes are included in a display page
• FIG. 1 is a block schematic diagram of a system in which methods according to the invention may be carried out
• the system shown in Figure 1 comprises a television signal source 1 , a television transmission medium 2, and a plurality of television receivers 3-1 to 3-n
• the television signal programme source may be a normal television broadcast equipment, either terrestrial broadcast or satellite broadcast or could be the programme source for a cable television network
• the television programme source includes a teletext inserter and means for entering programme classification codes into a teletext signal in both displayable and machine readable form
• the codes in machine readable form may be sent within a display page of the teletext signal or may be sent in extension packets which will not be displayed Alternatively the machine readable codes sent within the display page may be concealed from the viewer
• the transmission medium 2 may take any convenient form for example it could be radio waves as broadcast by a terrestrial transmitter or a satellite transmitter or could be a cable network for a cable TV system
• the television receivers 3-1 to 3-n are connected to the programme source via the transmission medium 2
• the television programme source comprises a source of video and audio signals 10 which may for example be a television camera whose video output is fed via a teletext inserter 11 to a transmission network 12
• the audio output from the television signal source 10 is fed via a line 13 to a further input of the transmission network 12
• a conventional teletext editing system 14 is connected to the teletext inserter 11 and has a further input which is fed from a TV access control equipment 15
• the TV access control equipment 15 is arranged to insert into the teletext signal code words classifying the content of the television programme being created by the signal source 10 These code words are in both displayable and machine readable form
• the TV access control equipment 15 has a first input 16 which receives data from a TV programme scheduling system This data will for example provide an overall indication of the content of the programme which can be used to inhibit display of that programme at a receiver
• the information may for example define the levels of violence, sexual content, mature language or distressing content which may occur in the programme
• the TV access control equipment 15 has a first input 16
• the codes generated by the TV access control equipment 15 or received by it and passed to the teletext editing system are then inserted into the teletext signal
• the machine readable codes may also be the displayable codes or may be sent separately either at different positions on the display page or in extension packets which may or may not be page related
• the machine readable codes may be inserted into selected bytes of the packet 8/30 format 1 or in selected triplets of packet 26
• Figure 3 shows the content of packet 8/30 format 1 modified to enable the machine readable codes to be inserted
• packet 8/30 format 1 modified to enable the machine readable codes to be inserted
• it comprises a clock run in period and framing code and bytes containing information identifying it as packet 8/30, as format 1 , defining an initial page, a network identity, a time offset, modified julian date and coordinated universal time
• There are then four bytes available which are, according to the invention, used to transmit classification codes for the programme
• the allocation of two bits for each of the programme content classifications allows four possible levels to be set for that particular content
• the code 00 could mean no content of that type, the code 01 a low level content, the code 10 a medium level content, and the code 1 1 a high ⁇ o content level
• a parent could decide that programmes having a low or medium sexual content level could be viewed by children so long as the individual events containing sexual content were i s inhibited
• they would set the acceptable programme level to 01 , while they may wish to eliminate incidents having sexual content altogether and thus set the event within the programme code to 00
• the same considerations apply to violent content within a programme
• the distressing content classification is likely to be only of limited duration within a programme The
• the region of programme origin code is considered useful in that different areas and countries have different moral codes and consequently what may be classified as a low level of violence in one region may be classified as a medium or even high level of violence in another region
• the same considerations may well apply to sexual content and also distressing or mature language content It would be possible within the receiver to modify the codes
• the present invention therefor provides that the classification code for
• each programme is also inserted in a displayable form on a selected teletext page and that in some embodiments a machine readable version is associated with the selected page
• a machine readable version is associated with the selected page
• This particular embodiment has the disadvantage that it reduces the editorial freedom of the page editor and may limit the amount of information which can be displayed on the page
• the second embodiment is illustrated in Figure 3b and includes in row 1 the classification codes preceded by a conceal character ( C L ) Row 1 is often displayed as a blank row to separate the main body of the text from the page header and in these circumstances may be used to contain the machine readable classification codes without imposing significant editorial restrictions In addition by concealing the codes it is possible to adopt proceedures to increase the reliability of the data It will be appreciated that in the first example the classificaiton codes are protected only by a single parity bit In this example the rating values may be transmitted as data which passes the 8/4 Hamming check Single bit errors can then be detected and corrected and double bit errors detected and rejected
• Table 1 shows the rating value, transmitted value, and displayed character for embodiment 1 which is illustrated in Figure 7a while Table 2 shows the rating value, transmitted value, and the displayed charcter (in the absence of the conceal character) for embodiment 2 which is illustrated in Figure 7b where the values are transmitted using the 8/4 Hamming check
• the machine readable ratings data is sent via triplets in extension packets 26
• the data in the triplets in packet 26 are protected by 24/18 Haming code which allows single bit errors to be identified and corrected and double bit errors to be identified and rejected
• the recently issued Enhanced Teletext Specificaiton has a number of unallocated triplets If the row address triplet with mode value 01 1 10 was allocated for this purpose eleven bits could be used for rating data
• This embodiment could be used to extend the PDC protocol for video recorders
• Teletext TV listings pages carry machine readable data in packets 26 which can be loaded into a VCR to control the recording of a programme in conjunction with data broadcast in packet 8/30 format 2 to define the identity of the current programme
• By adding the ratings data to the PDC data it is possible to check the rating when an attempt to record a programme is made and to inform the viewer whether the rating of the programme is such that the recording facility will be inhibit
• a fourth possibility is to transmit the machine readable code in packet 8/30 format 1 as proposed in UK Patent Application No 9619878 3 (PHB341 10) and to display it in viewable form on the selected page
• PHB341 UK Patent Application No 9619878 3
• a viewer with a teletext decoder but without a control system for inhibiting the display will be able to monitor visually the rating of the programme and decide whether to manually switch off the television receiver or prevent recording by a VCR
• the machine readable code may be sent for example in extension packet 8/30 format 1 which is not associated with any particular page while the displayable codes are sent on the selected page
• extension packet 8/30 format 1 which is not associated with any particular page
• the displayable codes are sent on the selected page
• a viewer with a teletext decoder but without a 5 control system for inhibiting the display will be able to monitor visually the rating of the programme and decide whether to manually switch off the television receiveer or prevent recording by a VCR
• While there is no direct association between the selected page and packet 8/30 format 1 it is clear that the broadcaster will update both at the same time ⁇ o
• One advantage of sending the machine readable codes within the dsiplay page is that some broadcasting authorities have no facilities for transmitting extension packets and hence if they are to broadcast the machine readable codes they have to be sent within the display page
• FIG. 4 shows in block schematic form an embodiment of a television i s receiver according to the invention
• the television receiver comprises an aerial 20 which feeds a conventional tuner 21 and IF and demodulator block 22
• a combined video and blanking signal is available at the output of the block 22 and is fed to a teletext decoder 23 and a colour decoder 24
• the output of the colour decoder 24 is fed to a video selector 25
• a control processor 27 controls in conventional fashion the operation of the television receiver It receives control instructions from a remote control unit 28 which the viewer uses to select a particular channel for display and
• the processor 27 will receive from the teletext decoder 23 the codes which are present in the packet 8/30 format 1 , that is the codes representing the content of sexual matter, violent matter, distressing matter or mature language It will also store within a non volatile memory 29 codes, which have been entered
• the processor 27 will compare the received codes with the stored codes and depending on the output of that comparison will produce a signal on line 30 which is fed to the video selector 25 via the ORgate 26 and which in appropriate circumstances will cause the video display to be blanked It will also feed a signal via a line 31 to an audio selector 32 which will cause the audio output to be muted in appropriate circumstances
• the audio selector produces an output which is fed to the standard audio circuits represented by block 33 and to a loudspeaker 34, while the video selector 25 produces an output which is fed to standard video circuits 35 and to a display device 36
• the audio selector 32 has a further input fed from a terminal 37 to which an alternative audio source may be connected This may be for example a tone generator which replaces any offending words by a bleep or it may be connected to an auxiliary channel for example an Audetel channel to provide alternative words for the offensive words
• the Audetel channel is a channel proposed for use for providing an audio assistance signal which provides a description of the scene to help the following of a programme by persons unable to see the display screen clearly or at all, for example blind or partially sighted persons There will normally be some spare capacity on this channel which will enable an alternative word for possibly offensive words to be transmitted by the broadcaster or to be encoded within any programme source since Audetel will be idle while there is dialogue
• Figure 4 shows a television receiver but the invention could equally well be applied to a video recorder In that case the outputs of the audio and video selector circuits 32 and 25 would be fed to record heads on the video recorder Thus only programmes having the authorised codes would be recorded on the video recorder
• An alternative arrangement for a video recorder would be to allow recording of the received television programme regardless of the classification codes associated with it, but to record those codes on the tape so that on replay the television receiver is able to react to the output from the video recorder in the same way that it would react to a a broadcast programme In this way a programme can be recorded for viewing by a number of different persons each of whom may have a different allowable classification level for particular content Thus a whole programme may be played back through one television receiver, but only a restricted version through another
• Figure 5 A-E illustrates an on screen display sequence which enables a person to enter the codes into a television receiver
• On initial switch on the on screen display sets out a message which invites the user to enter a personal identification number This is assuming that authorization is checked by means of a PIN
• the PIN may be burnt into a memory by the manufacturer who then informs the buyer of the number of the PIN so that the owner can initiate the selection of the classification
• An alternative is to set the PIN to all zeros at the factory and for a routine to be entered into when the set is first switched on to change the PIN to any number that the user desires Subsequently when it is desired to change the classification a key to request this is pressed on the remote control unit This brings up the on screen display message which invites the user to enter the PIN This is shown as screen 1 in Figure 5A
• Screens 13 to 15 illustrate the programming of the mature language content which is acceptable Again this only excludes the specific events rather than the programme as a whole since the occurrence of possibly offensive words is likely to be only a small proportion of the programme as a whole especially if programmes having excessive sexual or violent content are already excluded
• Screens 16 and 17 illustrate the programming of the region of origin It enables the user to exclude programmes from certain regions if desired This may be desirable for example where a particular country is transmitting propaganda material which may not contain excessive sexual content or violent content or even distressing content or mature language, but the authorised person may wish to prevent reception of programmes of such a nature
• An alternative use for the region of origin codes is to modify the effective codes for sexual, violent, distressing content or mature language depending on the source of the programme
• region A it may be desired that the level of sexual content accepted is moderate level only because what is considered moderate in region A may be considered to be high in the region where the receiver is located
• This code of changing may be programmed permanently into the 5 receiver or may be settable by the user
• Screen 18 is
• Figure 6 shows examples of on screen messages which are displayed when the access control system is in operation
• the first screen shows that the programme is not available and states that it is due to high levels of
• the third screen shows similarly that the display is temporally blanked due to distressing content
• the fourth screen shows the picture displayed with a message superimposed upon it stating that the sound has been muted because of mature language
• Teletext services provide information on a wide variety of subjects, including TV listings and TV programme-related material Frequently the Teletext service provider will also be the TV programme provider and thus will have detailed knowledge of the content of the TV programmes Warning information regarding the suitability and content of a particular programme can be broadcast as part of a TV listings page, or as part of a page providing a detailed description of a particular programme Further, it is possible to transmit this information when it relates to the current "on-air" programme on a dedicated page number so that the viewer only has to remember one page number to check the details of the current programme Which ever method is employed, the suitability and content information can be available all the time the programme is being broadcast
• Teletext page - a Magazine Inventory Page (MIP) - This page indicates the function and content of the other pages in the magazine in which the MIP is transmitted
• An eight bit value (transmitted as two 8/4 Hamming coded bytes) is sent for each possible three-digit page number (mOO - mFF)
• One such category is TV programme related warning page (code 7AH) This is a single page (i e it is not a rotating page) and it is intended to give a visual, readable indication of the suitability and content of a programme
• a suitable decoder can search the Magazine Inventory Pages on each channel and note in non-volatile memory the page number of the TV programme related warning page Thus there would be no need to expect user interaction to configure the system as set up is automatic for channels broadcasting a MIP containing appropriate data A check may be made at periodic intervals to establish that the stored page number is still valid Once the page number is established any or all of the techniques outlined previously (single button access, display on update, display on appearance and display on channel change) can be offered
• the system outlined so far provides human-readable information on a standard teletext page about the suitability and content of a TV programme
• the invention extends this to allow access to a programme to be restricted
• machine-readable data to be transmitted, in some embodiments as part of the page, so that receiving equipment can be controlled
• the machine readable data should preferably include error protection to ensure reliable data as a viewer would soon become annoyed if spurious blanking of a programme occurred
• Such data can define ratings for the content of the programme in a number of categories, e g mature language, sexual, violent content, etc
• the information presented visually is defined in a qualitative manner
• the ratings data can be interpreted by a suitably equipped TV and the display of picture and sound can be inhibited if threshold limits are exceeded In this way a parent can prevent a child from watching a particular programme, or type of programme, the parent deems unsuitable Further, by incorporating a suitable decoder in a VCR, the recording of programmes considered unsuitable can be prevented
• the TV or VCR would have a user interface which allows the parent to set or change the thresholds having first entered an identification code (PIN number) It will be some considerable period of time before all TV and VCR receivers have the ability to be controlled in this way However, it is desirable to provide the suitability and content information to as many receivers as soon as possible and this is readily achieved by linking the access control data to a visual description on a Teletext page
• the machine-readable data can be added to the TV warning page in a number of ways For example as codes embedded within the display part of the page (packets 1 -23), or in page-related extension packets (packets 24-28)
• the latter method is likely to be more robust as the coding scheme employed by some of the extension packets is more heavily protected against transmission path errors through the use of Hamming coding
• some transmission systems are not capable of carrying extension packets and in that case the parity protected data of the normal display packets has to be used
• a normal teletext page uses packet 0 to convey Hamming protected control data for the page number and various display attributes of the page It also includes text to appear at the top of the page, usually defining the page number, date and service provider in a directly displayable form, plus the local time Conventionally, the rest of the directly displayable part of the page is transmitted via packets 1 to 23, with packet 24 used in some transmission schemes to provide an extra display row to simplify navigation around the database
• the location of the various codes used to convey the different ratings can be defined
• a suitable decoder would know from where to read the data to determine whether the programme is allowed to be presented on the TV screen or recorded via the VCR
• a code of practice between broadcasters and manufacturers to establish the format and layout of the page would be desirable in implementing the invention
• the language rating can be found in packet 20 at column 21
• the sexual content rating in packet 21 at column 21 the violent content rating in packet 22 at column 21
• the display data is also the machine-readable data and no additional codes have to be transmitted
• row 1 is often displayed as a blank row to separate the main body of the text from the page header and could be allocated for this purpose
• Figure 7b illustrates how the ratings presented visually in rows 20 to 30 23 are entered in sequence after the Conceal control attribute ( C L ) in row 1
• the value adopted for a particular rating is the value that would be displayed on the screen if the transmitted code was displayed on TV screen via the display circuits for the Teletext decoder
• values between 10 and 15 could be presented in a hexadecimal format (e g A to F) and values in the range 16 to 255 by two hexadecimal coded values ⁇ o It should be noted that this embodiment allows a number of categories to be included until the complete row has been filled New categories can be added at the right hand end of the sequence at a later date and compatibility will be maintained with earlier decoders
• the minimum requirements for the page are a page header and
• a decoder should be designed to inspect several successive receptions of the data and integrate the result before concluding the ratings for the current programme
• This reliability of the data on the allocated packet can be improved by transmitting the ratings values as data which passes the 8/4 Hamming check 5 Single bit errors can be then be detected and corrected and double bit errors detected and rejected
• the Hamming decoded value represent the ratings value
• Conceal attribute (transmission code 98H) may be inserted after each element i s if this was the chosen method of hiding the data
• Transmitted value 64H,98H 49H,98H 73H,98H 49H 98H,02H, 98H Simpler decoders have no option than acquire the data and check it as if it was parity coded They would then need to apply the received data to a 20 look-up, or reference table, to establish the actual ratings values More sophisticated decoders, where the processing and checking performed on any byte is more flexible, could perform Hamming 8/4 checking straight away
• allocating the row address triplet with mode value of 30 01 1 10 can supply 1 1 bits for rating data
• Teletext TV listings pages can carry machine-readable data in packets 26 that can be loaded into a VCR to control programme recording in conjunction with a packet 8/30, format 2 broadcast to define the identify the current programme
• a VCR can check the rating when a programming request is made and inform the viewer if the programme will not be able to be recorded because of the thresholds currently set in the VCR

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• 1996
  • 1996-11-14 GB GBGB9623717.7A patent/GB9623717D0/en active Pending
• 1997
  • 1997-11-10 CN CN97192824A patent/CN1123223C/zh not_active Expired - Fee Related
  • 1997-11-10 KR KR1019980705365A patent/KR19990077223A/ko not_active Application Discontinuation
  • 1997-11-10 EP EP97909547A patent/EP0876730A2/de not_active Withdrawn
  • 1997-11-10 WO PCT/IB1997/001420 patent/WO1998021891A2/en not_active Application Discontinuation
  • 1997-11-10 JP JP10522337A patent/JP2000503511A/ja active Pending

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