Specific embodiments of the present invention will now be described with reference to the accompanying drawings, in which:
The received signals comprise digitally encoded data. In this example, the data is compressed using the Digital Video Broadcast/Moving Pictures Expert Group 2 (DVB/MPEG 2) standard which permits both programme data and additional data (for example interactive service data) to be transmitted in a single channel. DVB/MPEG 2 enables high compression ratios to be achieved. The hard disk 13 receives and stores compressed data. The data is decompressed only after retrieval from the hard disk 13.
Satellite (and indeed cable) programmes are usually scrambled to prevent unauthorised access by non-authorised subscribers. The receiver 3 therefore has a conditional access control circuit 14 which co-operates with a smart card 14a to determine whether the viewer has subscribed to a particular channel and is therefore authorised to access the channel. Parental control over channel access is also provided, at least in part, by the access control circuit 14. The receiver 3 further comprises a descrambling circuit 15 which is controlled by the access control circuit 14 to enable the descrambling of the signal by authorised subscribers.
Descrambled data is supplied to a transport/demultiplexer 16 which separates the data into video data, audio data, user services data, programme scheduling data, etc. for distribution to various locations within the receiver 3. The receiver 3 also comprises a video decompression and processing circuit 18 utilizing a dedicated video Random Access Memory (RAM) 17, and an audio decompression and processing circuit 19, operating according to the MPEG 2 standard, for example. The video and audio decompression and processing circuits 18 and 19 receive demultiplexed signals directly from the transport/demultiplexer 16, or from the hard disk 13. Decompressed video signals are input to a SCART interface 20 for direct input to a television set (TV) 2 and to a Phase Alternation Line (PAL) encoder 21 where they are encoded into the PAL format for modulation by a Ultra High Frequency (UHF) modulator 22 for output to the UTHF input of the TV 2 if so desired.
The receiver 3 is controlled by a processor 23 which communicates with the various units of the receiver via a bus 24. The processor 23 has associated with it Read Only Memory (ROM) 25 (optionally including a Compact Disc—Read Only Memory (CD-ROM) drive 25a), Random Access Memory (RAM 26) and a flash (non-volatile and writable) memory 27.
The processor 23 controls operation of the receiver 3 by tuning the tuners 10a and 10b to receive signals for the desired channels by controlling the demultiplexing, descrambling and decompression so that the desired programme and/or interactive service data is displayed on the screen of the TV 2, and by controlling the hard disk 13 to record desired television programmes or to play back previously recorded television programmes. Viewer selection of desired programmes and customer services is controlled by viewer manipulation of a remote control unit 28, which in response to such viewer manipulation transmits control signals to a receiver 29 for input to the processor 23. The remote control unit 28 also allows the viewer to control of the operation of the hard disk 13 to record television programmes, to play back recorded television programmes and to program the recording of television programmes, etc.
The receiver 3 further comprises a high-speed data interface 30 and a Recommended Standard 232 (RS232) interface 31 providing a serial link. The high-speed data interface 30 and the RS232 interface 31 may be connected to a Personal Computer (PC) and/or a games console and/or other digital equipment (not shown). The high speed data interface 30 enables the receiver 3 to be connected to other devices (not shown), for example to enable reception of services transmitted via other media such as broadband cable, external storage media or digital terrestrial broadcast. The receiver 3 further comprises a modem interface 32 for connecting a telephone network.
Operation of the receiver 3 is controlled by software that makes the processor 23 responsive to control signals from the remote control unit 28, additional data in the received signals and/or data stored in the memory units 25 to 27. Interaction between hardware and software in the receiver 3 is described in detail in our international patent application published as WO 01/11865. Operation of the receiver 3 in receiving and decoding data representing television programmes and data defining scheduling and other information related to the programmes is described in detail in our international patent application published as WO 96/37996. Operation of the receiver 3 in providing interactive services is described in our international patent application published as WO 97/23997.
Within the Digital Video Broadcasting (DVB) standard for digital television broadcast there exists a standard for the transmission of schedule information such that it can be decoded and presented correctly to subscribers in the form of an Electronic Programme Guide (EPG). This DVB standard is known generally as the SI standard and can be found in the specification: ETS 300 468, ETSI Digital Broadcasting Systems for Television, Sound and Data Services; Specification for Service Information (SI) in Digital Video Broadcasting (DVB) Systems 2nd edition. Guidelines for using the specification are given in ETSI ETR 211-DVB SI Guidelines. The receiver 3 is designed to support the SI specification.
In addition to operating data for use in controlling access to channels, additional data in a channel can include brief programme schedule data representative of so-called event information tables (EITs) defining the scheduling of programmes in each channel. The programme schedule data is used by the receiver 3 to control the operation of the hard disk 13. When the receiver 3 is programmed to record a selected television programme, the receiver 3 operates the hard disk 13 to start and to stop the recording in accordance with the programme schedule data which comprises the start and the end time of the selected television programme. Since the programme schedule data is updated regularly, the recording is started and stopped in accordance with the updated programme schedule, thus guaranteeing that a selected television programme is actually recorded even in case of a change of programme schedule, because such change is reflected in the programme schedule data in each channel.
The programme schedule data may be stored in the RAM 26 and, once stored, the scheduling information is available effectively instantaneously for controlling the operation of the hard disk 13. As discussed above, the programme schedule data is transmitted regularly so that the receiver 3 will be updated substantially continuously. The information is brief to enable each channel to carry the progranne schedule data without excessive overheads in terms of bandwidth requirements in each channel and memory requirements in the receiver.
In addition, a dedicated EPG channel transmits more detailed programme scheduling information. The information transmitted via this dedicated channel is updated more frequently and covers a longer period of time (e.g. one week). As a consequence, an up-to-date television programme schedule of a complete week will always be available. As explained in greater detail below, the receiver 3 is arranged to display the programme scheduling information on the TV 2. Also, a viewer can interact with the receiver 3 to program recordings of television programmes, view a desired part of the available programme schedule, etc., on the basis of the information received via the dedicated EPG channel.
Accordingly, while the programme schedule data in each channel is used by the receiver 3 to operate the hard disk 13 to record a selected television programme in a selected channel at the correct up-to-date time, the programme scheduling information in the dedicated EPG channel is used to display the programme schedule for several of the channels over a predetermined period of time (which in turn is used for programming the receiver 3 as described below).
Since the tuners 10a and 10b can be tuned to receive different channels, it is possible for a first television progranme in one channel to be displayed on a TV and recorded on the hard disk 13, while at the same time a second television programme in another channel is also recorded on the hard disk 13.
The hard disk 13 of the receiver 3 is similar to conventional hard disks used in computer systems for storing large amounts of data. The hard disk 13 has a capacity of many gigabytes (e.g. 40 gigabytes) and receives video and audio data for storage in the compressed form in which it is received, for example, in accordance with the DVB/MPEG 2 standards as discussed above. This allows for the storage of several hours of television programmes (e.g. 20+ hours) on the hard disk 13. The hard disk 13 comprises two storage areas, one for the storage of television programme data, and the other for storing “metadata” which is used to control the hard disk 13, as discussed in greater detail in our earlier patent publications mentioned above. The processor 23 controls the operation of the hard disk 13. More-specifically, the processor 23 controls the recording and playback of television programmes to and from the hard disk 13. Other processors (not shown) can be used to control the hard disk 13 as appropriate, but the control is described in this document with reference to only processor 23 to facilitate understanding.
http ://www1.sky.com/products/skyplus/Sky+PVR1.pdf
the contents of which are incorporated herein by reference.
To avoid repetition, where the same references are used in
A satellite dish 4 receives signals from the satellite television broadcast network and provides these to first and second satellite dish inputs 4a, 4b. Terrestrial television broadcast signals are received by terrestrial aerial 9 and provided to a terrestrial aerial input 9a. The UHF modulator 22 provides a primary RF interface 22a for connection to a primary TV 2a, optionally as in this case via an external video recorder 5, and a secondary RF interface 22b for connection to a secondary TV 2b. The SCART interface 20 includes a video recorder SCART socket 20a and a TV SCART socket 20b. A Separate Video (S-Video) connector 36 provides an alternative output to the primary TV 2a, if this has an S-Video input. Left and right channel audio outputs 33a, 33b, and optical digital audio output 34, for connection to external audio reproduction equipment 35, output the audio signals from the channel to which the receiver 3 is tuned.
An arrangement of the receiver 3 in a first embodiment of the invention is shown in
A secondary TV 2b is at the secondary location 42b and is connected to the receiver 3 through the secondary RF interface 22b by means of a connector 44. The connector 44 may be a coaxial cable, or a wireless audio/video sender. A remote control extender 40 receives the IR control signals from the remote 28 and relays them to the receiver. The remote 28 can be carried between the primary location 42a and the secondary location 42b, or different remotes could be used at each location.
The arrangement as described thus far is known per se, and may use a known wired extension system, such as the tvLINK® system, or a wireless extension system such as the video sender with remote control extender as described above.
In a wired extension system, the remote control extender 40 receives IR signals from the remote 28, and converts them to modulated electrical signals in the connector 44. The coaxial cable which carries UHF signals from the receiver 3 also carries the modulated electrical signals from the remote control extender 40 to the receiver. A schematic diagram of this type of remote control extender 40 is shown in
In a wireless extension system, audio and video signals output by the receiver 3 are transmitted in a frequency channel which does not interfere with terrestrial radio and TV channels. This channel is received and converted to a signal for input to the secondary TV 2b. The remote control extender 40 converts IR signals from the remote 28 to signals which are transmitted in a frequency channel which is received and converted to control signals for input to the receiver 3. A schematic diagram of a wireless extension system is shown in
From the above discussion, it is apparent that control signals received directly from the remote 28 by the receiver 3 are input at the IR receiver 29, while control signals received via an extender are input at the secondary RF interface 22b. In this embodiment, the receiver sets the picture format mode automatically according to the input at which the control signals are received. If the control signals are input at the IR receiver 29, this indicates that the user is at the primary location 42a and wants to watch the primary TV 2a. Therefore, a picture format mode suitable for the primary TV 2a is selected. If control signals are input at the secondary RF interface 22b, this indicates that the user is at the secondary location 42b and wants to watch the secondary TV 2b. Therefore, a picture format mode suitable for the secondary TV 2b is selected. The receiver 3 stores primary and secondary picture format modes suitable for the primary TV 2a and the secondary TV 2b respectively. These stored modes may be set and modified by the user or by an installation engineer.
As described above, the receiver 3 stores and executes software which controls the operation of the receiver 3, including setting the picture format mode. In the first embodiment, the software includes a computer program for performing a method illustrated by the flowchart in
The computer program may be stored on a carrier and loaded into memory, such as the flash memory 27, on the receiver 3. The program may be downloaded as a satellite broadcast signal and applied as a patch or update to software already resident on the receiver 3. The scope of the present invention includes the program, the carrier carrying the program and the broadcast signal.
The decoded control signal may include an indication of which input received the control signal, or the program may perform an operating system call to detect whether the IR receiver 29 and/or the input at the secondary RF interface 22b is active. If both inputs are active, or a control signal was received from the other input within a predetermined short time, such as 30 seconds, this may indicate that different users are trying to watch the primary TV 2a and the secondary TV 2b simultaneously. In this case, the program may maintain the format currently set.
An additional problem occurs when the receiver 3 is set to tune to a channel automatically at a predetermined time. For example, a user may select from the EPG a programme to be viewed at a later time, and may select an ‘autoview’ option for that programme. The receiver 3 obtains the corresponding channel and time information for the selected programme, and automatically tunes to the channel at the start time of the programme. In this case, the receiver 3 has no information to indicate whether the user wants to watch the programme on the primary TV 2a or the secondary TV 2b. The receiver 3 therefore selects the primary format when displaying an Autoview programme, and prevents a change to the secondary format while the programme is shown, in case the programme is being recorded on the external video recorder 5 The primary format is maintained after the Autoview programme has finished, but may subsequently be changed in response to a control signal received on the secondary RF interface 22b. In other words, the program described with reference to
The receiver 3 may display a reminder shortly before tuning to a channel in Autoview mode. The reminder can be removed by pressing a button on the remote 28. The format is not changed in response to the control signal cancelling the reminder display.
The method of setting the primary and secondary location settings will now be illustrated with reference to the screenshots shown in
The effect of either type of extension system is that a user can control the same receiver 3 when viewing either the primary TV 2a or the secondary TV 2b. The location of the receiver 3 is only important because it contains the IR receiver 29. The receiver 3 may be at a third location if some means is provided for conveying control signals to that location. For example, an infrared repeater could be used to receive IR signals from the remote 28 at the first location 42a, convert the signals to electrical signals in a cable leading to the third location, and reconstruct the IR signals for emission to the IR receiver 29.
The first embodiment relates to automatically selecting the aspect ratio of the picture format output by the receiver 3, but alternatives to this embodiment may also fall within the scope of the present invention. A similar technique could be used to change other video settings which differ between a primary and a secondary display. For example, one or both of the displays may be a digital display having a native resolution. If the receiver 3 were to include a digital video output, it would be desirable to set the digital video signal to match the native resolution of the digital display. The picture format setting which is automatically selected in the first embodiment could then be a resolution setting instead of an aspect ratio.
A similar technique could also be used automatically to select audio settings, where common settings are applied to primary and secondary audio outputs, but different settings are desirable for audio reproduction apparatus connected to the primary and the secondary audio outputs.
Although the first embodiment is advantageously applied to a television receiver, it could also be applied to other sources of video and/or audio signals which is not able to apply settings independently to outputs to multiple devices. In particular, the first embodiment can be applied to live TV broadcasts, buffered live TV broadcasts where the displayed broadcast is buffered and delayed relative to the received broadcast, and to pre-recorded programmes, such as those previously recorded on the hard disk 13. Hence, the first embodiment could also be applied to a device which plays pre-recorded programmes but does not receive broadcasts, such as a video or DVD player.
A second embodiment of the invention addresses the problem of listening to radio stations received by a television broadcast receiver. An arrangement of the receiver 3 in this embodiment is shown in
A wireless audio base station 55 is connected to the stereo audio output 33 of the receiver and transmits a wireless audio signal to a wireless audio receiver 60 which plays the audio signal. A user can change channel using a keypad 65 to generate control signals. The control signals are transmitted back to the base station 55 and control the receiver 3 to retune to a different channel.
The receiver 3 outputs on the audio output 33 the audio content of the channel to which the receiver is tuned; the channel may be a television channel or a radio channel. Hence, the wireless audio receiver 60 can be used to listen to a television channel, but not to view the video content. The receiver 3 may also output audio signals, such as background music, in an interactive mode where no broadcast event is tuned to. Any audio signals output by the receiver 3 are relayed to the wireless audio receiver 60.
EPG data is output to the base station 55 by the receiver 3 and is transmitted to the audio receiver 60, where it is displayed on a liquid crystal display (LCD) 61. The user can change the EPG data and select programmes for listening using the keypad 65. This allows the user to receive radio stations wirelessly from the receiver, and to view EPG text information and messages, without requiring a video display.
The base station 55 includes a processor 57 which performs control and data processing functions. The processor 57 receives EPG data from the RS232 interface 31 of the receiver, and outputs the data to a modulator 58. The modulator 58 also receives audio signals from the audio output 33 which are FM converted and transmitted together with the data via an antenna.
The audio receiver 60 includes a demodulator 63, which receives the FM signal via an antenna and outputs the audio signal a loudspeaker 66. If the audio signal is a stereo signal, the left and right channels are output to separate loudspeakers 66a, 66b. The EPG data is decoded from the received signal and output to a processor 62, which controls the LCD 61 to display the EPG data as text.
The processor 62 receives and decodes control signals initiated by key presses on the keypad 65. In response to some control signals, the processor may vary the EPG data display. Other control signals are output to a modulator 64, where they are modulated and upconverted to a modulated control signal which is transmitted via an antenna.
The modulated control signal is received, down-converted and demodulated by a demodulator 59 in the base station 55. The demodulated control signals are processed by the processor 57 and output to a control interface 56, where they are input to the second RF interface 22b of the receiver 3.
In one example, the signal transmitted by the base station is at 864 MHz and carries the EPG data at a data rate of 2.4 kbit/s, as well as the audio FM signal. The control signal transmitted by the wireless audio receiver 60 is at 433.92 MHz and has a data rate of 1.2 kbit/s.
The input and output connections between the receiver 3 and the wireless audio base station 55 are shown in
The audio receiver includes an internal battery (not shown), for portability. The battery is preferably rechargeable. Instead of, or in addition to the keypad 65, there may be provided an infrared remote control which sends control signals to an infrared receiver on the audio receiver 60.
As mentioned above with reference to
In the second embodiment, EPG data from the receiver 3 is transmitted from the base station 55 to the audio receiver 60 using a text-based message protocol. No video data is included in the EPG data. In other words, the EPG text is encoded using a character code, rather than as an image. One advantage of using a character code is that the data rate requirement for the wireless link between the base station 55 and the audio receiver 60 is low. Another advantage is that the audio receiver can display the EPG data using a simple text display, such as the LCD 61. This display can be light, with a low power consumption, and therefore aids the portability of the audio receiver.
The character code may encode alphanumeric characters and graphic symbols. The code is converted by the processor 62 and/or the LCD 61 to a bitmap representing the corresponding characters or symbols. However, the character code itself does not define the bitmap which will be displayed, in contrast to a video signal or an image signal, which defines the state of each pixel to be displayed.
The display may show the channel number, channel name, and the event name, and optionally further information on the event. When the user changes channel, details of the new channel and new current event are displayed. The channel may be changed by pressing the channel up or channel down key, or by entering a three digit channel identity number using the numeric keys on the keypad 65. Each digit is transmitted to the receiver 3 as it is entered, and the receiver 3 echoes the digit back to the audio receiver 60 using the message protocol. When all three digits have been entered, the receiver 3 tunes to the corresponding channel and outputs the channel number, channel name, and the event name for that channel.
In a specific example, the message protocol consists entirely of ASCII (American Standard Code for Information Interchange) characters formatted as variable length message using the format shown in Table 1 below:
Each message begins with Start_Byte and Message_Length, and contains a variable number of fields, each prefaced with Message_Tag_Main, Message_Tag_Sub and Field_Length and containing Field_Data. Checksum is a checksum of the whole message. The message tag indicates what type of EPG data is contained in the message field, while Message_Tag_Sub has a definition which is dependent on the corresponding Message_Tag_Main. The audio receiver 60 decodes the EPG messages and displays the data content in a manner dependent on the message tag.
The software resident on the receiver 3 outputs EPG data on the RS232 interface 31 selectively, either in response to control signals received from the base station 55 via the second RF interface 22a, or automatically to output information indicating the status of the receiver 3 and/or the current time. To maximize the response time of the system, the receiver 3 may initially output only the most important information, such as the channel name, wait for any further control signals, and then output the event name.
The receiver 3 also generates and outputs the message tags, which are passed by the base station 55 to the audio receiver 60. The receiver 3 does not output all of the available EPG data, but only the EPG data which may be required for display on the audio receiver 60. However, the base station 55 may filter messages according to their message tags. For example, the receiver 3 may output a message indicating the current date and time, which is suppressed by the base station 55 in a mode in which time and date are not displayed on the audio receiver 60.
Alternatives to the second embodiment may nevertheless fall within the scope of the present invention. For example, some or all of the functionality of the base station 55 could be integrated within the receiver 3.
Although the second embodiment is advantageously applied to a television receiver, it could also be applied to an audio-only receiver or an audio storage or reproduction device, such as a compact disc (CD) player.
The receiver 3 may receive the audio signal and/or EPG data from any suitable television or audio broadcast, whether via a satellite, terrestrial or cable broadcast or a media stream over a network, such as the Internet. The EPG data may be obtained from another source than the audio signal. For example, the EPG data could be downloaded from a network address, such as an Internet address.
Number | Date | Country | Kind |
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0401830.5 | Jan 2004 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB05/00304 | 1/28/2005 | WO | 00 | 11/9/2007 |