Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
  • H04N5/445—Receiver circuitry for the reception of television signals according to analogue transmission standards for displaying additional information
  • H04N5/45—Picture in picture, e.g. displaying simultaneously another television channel in a region of the screen
• • 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
  • H04N21/42607—Internal components of the client ; Characteristics thereof for processing the incoming bitstream
  • H04N21/4263—Internal components of the client ; Characteristics thereof for processing the incoming bitstream involving specific tuning arrangements, e.g. two tuners
• • 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
  • H04N21/431—Generation of visual interfaces for content selection or interaction; Content or additional data rendering
  • H04N21/4312—Generation of visual interfaces for content selection or interaction; Content or additional data rendering involving specific graphical features, e.g. screen layout, special fonts or colors, blinking icons, highlights or animations
  • H04N21/4316—Generation of visual interfaces for content selection or interaction; Content or additional data rendering involving specific graphical features, e.g. screen layout, special fonts or colors, blinking icons, highlights or animations for displaying supplemental content in a region of the screen, e.g. an advertisement in a separate window
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/44—Receiver circuitry for the reception of television signals according to analogue transmission standards
  • H04N5/445—Receiver circuitry for the reception of television signals according to analogue transmission standards for displaying additional information
• • 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
  • H04N21/41—Structure of client; Structure of client peripherals
  • H04N21/426—Internal components of the client ; Characteristics thereof
  • H04N21/42661—Internal components of the client ; Characteristics thereof for reading from or writing on a magnetic storage medium, e.g. hard disk drive
• • 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
  • H04N21/434—Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream
  • H04N21/4347—Demultiplexing of several video streams
• • 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
  • H04N21/47—End-user applications
  • H04N21/482—End-user interface for programme selection

Definitions

• the present invention relates to television display unit and methods of processing television signals.
• Picture-in-Picture is a feature that allows the display of a smaller second video stream or still picture sequence in a corner of the main video picture. This second picture can e.g. be used to monitor one video stream while watching another.
• PiP has been possible technically since the 1980's namely even when only analogue television signals were available. Even though it has proven to be a highly desirable feature, it has never reached mainstream products due to the associated cost. In particular, in an analogue TV, an expensive extra tuner, extra memory and an additional signal processing block is required to make the feature possible.
• An object of the present invention may be to provide a television display unit enabling picture-in-picture capability at lost cost.
• the present invention provides a television display unit comprising a receiver for a plurality of channels of television signals, means for displaying signals of a television channel, means for inputting signals of another television channel, means for displaying one channel as a reduced image additional to the main display in the on-screen-display plane.
• the present invention may provide PiP with limited tuner capability.
• the television display unit may include any one or more of the following features:-
• • means to effect real-time decoding for displaying one channel as a rendered image in the on-screen-display plane. • means to effect time-sharing of the signals for decoding.
• • conversion means comprises quantisation means for the pixel values and means to add a palette entry for each palette colour not yet in the palette.
• conversion means comprises means to run length encode the pixels to produce groups of comparable value.
• • conversion means comprises means to reduce the quantization level until attainment of a required colour level.
• • conversion means comprises means to map the pixels to the palette colours.
• the present invention also provides remote control apparatus to operate a television display unit of the present invention.
• the present invention also provides a method of operating a television display unit comprising displaying signals of a television channel, inputting signals of another television channel, displaying one channel as a reduced image additional to the main display in the on-screen-display plane.
• Another aspect of the present invention provides a computer program product directly loadable into the internal memory of a digital computer, comprising software code portions for performing the steps of the method of the present invention when said product is run on a computer.
• Another aspect of the present invention provides a computer program for performing the steps of the method of the present invention when said product is run on a computer.
• the present invention also provides a carrier, which may comprise electronic signals, for a computer program embodying the present invention.
• the present invention also provides electronic distribution of a computer program of the invention.
• a description is now given, by way of example only, reference being made to the accompanying drawings, in which:- Figure 1 is a television display unit embodying the present invention; Figure 2 shows stages in a conversion process.
• the present invention involves a CPU on a MPEG video decoder to provide Picture-in-Picture (PiP) functionality, by decoding MPEG frames in software and rendering the decoded frame on top of the video plane.
• PiP Picture-in-Picture
• the television display unit reduces the frame rate of the PIP video, while eliminating the main cost factors, namely:
• Tuner in television receivers with only one tuner, PiP is provided for a limited amount of channels, only those channels in the same transport stream (or TS) multiplex.
• Television receivers with PVR functionality i.e. with hard-drive
• PVR as a second video source
• Television receivers with a broadband modem can use streaming video streams as additional sources.
• television receivers with more than one tuner allow for unlimited TV PiP functionality.
• DVB Video distribution uses a large number of separate frequencies (transponders) to send digital streams down from a satellite. On one such frequency, a limited amount of bandwith is available (typically 30-60 Megabit per second).
• the stream that is send on one frequency is called a transport stream (TS) and contains a multiplex of a number of programs, typically 4-10 programs (e.g. BBC1 , BBC2, etc).
• TS transport stream
• Some broadcasters buy a transponder in a satellite and use the one TS to send all their programs out in the same TS on the same frequency.
• the palette is built by progressing through the pixels and adding a palette entry for each pixel color that is not yet in the palette.
• the quantization limits the total amount of different colors in the total picture, so that most of the pictures have less than 256 different colors. In the initial implementation, if a picture has more than 256 colors, it is not displayed and the next one is taken.
• a further-refined implementation as shown in Figure 2 consists of the following steps:
• the pixels are mapped to the palette colors (bitmapping) so that pixel values are replaced by palette indices, operation 36.
• bitmapping bitmap
• the palette is ordered in Y, U, V, e.g. color 100 90 70 is larger than 90 100 100 because the Y value is larger, so it is higher up in the palette. It is also possible to do the pixel mapping right after quantization, after steps 2 and after 4 (in the refinement loop).
• the total error is maintained for each of the colors in the palette by calculating the color error for each and every pixel and adding it to the total of the particular color.
• This total error is the sum of the errors of all the pixels (or better: runlength groups of pixels) that have been assigned a particular color.
• Data compression is the reduction of redundancy in data representation, carried out for decreasing data storage requirements and data communication costs.
• a typical video codec system is presented in Figure 1.
• the lossy source coder performs filtering, transformation (such as Discrete Cosine Transform (DCT), sub-band decomposition, or differential pulse-code modulation), quantization, etc.
• the output of the source coder still exhibits various kinds of statistical dependencies.
• the (lossless) entropy coder exploits the statistical properties of data and removes the remaining redundancy after the lossy coding.
• the DCT is used as a lossy coding technique.
• the DCT algorithm processes the video data in blocks of 8 8, decomposing each block into a weighted sum of 64 spatial frequencies.
• the data is also organized in 8 8 blocks of coefficients, each coefficient representing the contribution of a spatial frequency for the block being analyzed.
• the matrix is transformed into a vector of coefficients, and further compressed by an entropy coder which consists of two major parts: Run-Length Coder (RLC) and Variable-Length Coder (VLC).
• RLC represents consecutive zeros by their run lengths; thus the number of samples is reduced.
• the RLC output data are composite words, also referred to as source symbols, which describe pairs of zero-run lengths and values of quantized DCT coefficients. When all the remaining coefficients in a vector are zero, they are all coded by the special symbol end-of-block.
• Variable length coding also known as Huffman coding, is a mapping process between source symbols and variable length codewords.
• variable length coder assigns shorter codewords to frequently occuring source symbols, and vice versa, so that the average bit rate is reduced.
• coded data is sent through a continuous stream of bits with no specific guard bit assigned to separate between two consecutive symbols.
• decoding procedure must recognize the code length as well as the symbol itself.
• the MPEG encoder in the headend has used VLC to code symbols into a string of variable length bit-strings (e.g. symbols can be 2,3,4,5,16 bits long and are not byte aligned in the final stream). Even though they are not byte aligned, one can still find out where a new symbol starts because each symbol is unique.
• VLC variable length bit-strings
• VLD variable length decoding
• the microdecoder is specifically optimised for the PiP task. More specifically, it only decodes a few coefficients per DCT block, resulting in a reduced resolution for the output picture. It decodes I frames and only 3 out of the total of 64 coefficients in a DCT block, giving a factor 4 of reduction in resolution in both horizontal and vertical direction. There is no fundamental restriction for doing just I frames and the number of used coefficients/resolution can be changed according to the constraints.
• the decoder performs the following actions:
• a VLD operation must be performed for all coefficients that follow the third coefficient in the particular DCT block (even though they are not used in the IDCT and their value does not influence the pixel values), because of the way that MPEG works since the star of the next DCT block is not byte-aligned in any way. The only way to find the start of the next DCT block is to read away all VLD words of the previous DCT block.
• a filtering operation (post processing) is used on the picture in the frame buffer, in order to improve visibility of the PiP picture at normal viewing distances.
• the picture in the resulting frame buffer is rendered onto the OSD plane (or Video/Still plane depending on the decoder).
• the result of this VLD is not essential (it only being necessary to read the bits away to get to the next VLD word) to develop a faster VLD function.
• the speed improvement is obtained by reading away the bits in the VLD word as soon as the size of this VLD word is known, and omit looking up the runlength/value pair in a VLD table. This step is important for achieving a software decode performance to enable implementation at low cost.
• the PiP picture has a reduced resolution and uses a lower frame-rate, sometimes it may be difficult to see what the image content actually represents. This is partly caused by the fact that the original video content was intended for a viewing distance of 3-5 times the image size.
• a post-processing filter is used to adjust the contrast and brightness of the PiP picture, and thereby help recognition.
• increasing the contrast can lead to unwanted effects. It is therefore desirable to adjust contrast/brightness differently on an image-segment by image-segment basis. For example, for a picture with a beach, a sea and a blue sky, there could be a different contrast/brightness adjustment for beach, sea and sky.
• the PiP image is displayed on top of the normal video in the OSD (i.e. On Screen Display) plane.
• OSD On Screen Display
• the order of the display planes is fixed and higher image planes conceal underlying planes.
• the still-picture plane is behind the video plane and the video plane is behind the OSD plane.
• the OSD plane is used for display of the PiP which requires the true- colour PiP Image (YUV) to be converted into a bitmap and mapped onto the available OSD palette (256 colours for the most popular chips).
• YUV true- colour PiP Image
• the palette must be selected and optimised on a picture-by-picture basis depending on the different colours in the picture. A few colours in the palette can be reserved to allow for specific OSD graphics to be displayed in another part of the screen while showing PiP.
• the television receiver includes the following features:-
• Emulating a multi-screen decoder by decoding frames from a number of different streams, by decoding a single frame from one stream, then one from another stream, etc, then display the frames.
• Feature 5 may allow a viewer to watch a time-delayed version of a TV program coming from the PVR, while monitoring the live feed in a PiP window.
• a viewer may start to watch a soccer match 30 minutes late, may catch up by fast forwarding selected parts of the beginning of the match, but in the meantime monitor the live match in the PiP in order to see whether there are any new goals).
• a break for advertisements occurs during the television program,
• PiP is often used by viewers for monitoring (in the PiP window) the main program while the other TV channels for more interesting content. This could mean that offering PiP actually may result in a reduction of the exposure of viewers to commercials, which is bad for the service provider.
• viewing behaviour can be limited or restricted so that only switching between the specified channels (e.g. those of the service provider) is encouraged. This operates as follows: 1 . A viewer is watching a movie on SKY Movies.
• PiP In a low-cost box with a single tuner and no PVR, PiP is only available for channels in the same TS multiplex. If all programs in the multiplex are owned by the same service provider, then the "loyalty PiP" strategy as outlined above is a useful feature that results directly from the single-tuner restriction.
• Figure 1 shows a television receiver 1 having input circuitry 2 including tuners 3 and 4, hard disk unit HDD 5, all of which can input to demultiplex unit 6 and to the television monitor 7.
• the MicroDecoder unit 8 receives real-time MPEG2 video data from the demux 6 or MDD units. It decodes the MPEG2 video stream, performs postprocessing to optimize the picture quality and outputs the video pictures to a TV or to a companion device via a wireless link. For display on a TV, the video data is rendered onto an OSD plane.
• the video data Before output to a companion device 9 via a wireless link 10, the video data is re-encoded using a proprietary compression scheme in order to minimise the data rate on the wireless link and maintain the picture quality.
• Operation of the PiP facility is by use of a remote control unit 11 with appropriate command signals for microdecoder unit 8 and ancillary equipment.
• the microdecoder unit 8 is a MPEG2 video decoder with software capability, and frame-rate and resolution are targeted at monitoring of secondary video streams.
• the memory footprint and processing load are highly optimised for deployment in low-cost set-top boxes.
• the decoder 8 has flexible real-time requirements in order to allow for easy integration with existing STB software and comes with associated chip-specific MPEG frame- capture and rendering modules.
• the decoder 8 enables monitoring of secondary live video channels e.g. for monitoring main channel when switching during a commercial, or monitoring major events other channels, allowing for second channel monitoring, multi channel monitoring or Mosaicing for advanced channel surfing.
• It allows monitoring of secondary video streams while using a PVR, e.g. for monitoring a channel that is being recorded while watching another channel. Monitoring the live video feed while watching a time shifted version, browsing PVR content while watching a live video channel, building a mosaic for browsing PVR content.
• the MicroDecoder unit 8 fully complies with the MPEG2 video standard including different image sizes and frame rates, filed+frame coding, both can patterns, different quantization matrices, yet it was designed for seamless integration with existing STB software.
• the television receiver includes acquisition and rendering modules for specific decoder architectures, or a decoding core, optimised in assembly for a specific processor, or integration of the MicroDecoder with existing STB SW "set-top box" software, for systems for several middleware standards like OpenTV, NDS, Microsoft TV and MediaHighway.
• the PiP facility is not available for channel providers other than that of the principal channel currently being viewed. In this way, the viewer is encouraged to check only those channels associated with the same channel provider, in this instance C2 to C4 because he still wants to monitor C1.
• Sky Sports has a single tuner box with ST chip.
• Sky could upgrade the SW in their boxes (remotely) to offer a feature that allows a viewer to watch one Sky Sports channel (say Sky Sports 1 or SP1) while monitoring any of the 2 other Sky Sports channels in a PiP window.
• SP2+SP3 PiP While PiP is on, channel up/down only changes between SP1 , 2, and 3.
• a person is watching a program on Channel 1 (hereinafter known as C1).
• the chip looks for an action being a reduction to PiP followed within a specified period, for example 5 seconds, by at least one switching.
• the chip detects that C1 is in an ad break or a programme break.
• there is provided a statistical analysis for example, if the viewer watches C1 continuously for 25 minutes, one can deduce that there is something of interest, and so a channel change after that period of time would probably be during a commercial break, or just a switch to check for anything else. If the user is switching fast (e.g. there being less than 10 seconds between channel changes), the user is actually checking on what is presently on all the other channels.
• C1 can either be kept as the main image, or as one of the PiPs while highlighted in some way, for example with a white boarder.
• a commercial break starts while watching a soccer match on Sky Sports 1.
• the user presses the PiP button once to indicate that he wants to keep monitoring this channel.
• the main screen keeps displaying SP1 and there is no PiP picture yet.
• the user changes channels and the SP1 PiP appears on those channels that are in the same multiplex. Pressing PiP while a PiP window is present on the screen (e.g. in SP2) will disable the active PiP and remove the window.

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• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Business, Economics & Management (AREA)
• Marketing (AREA)
• Controls And Circuits For Display Device (AREA)
• Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)

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• 2002
  • 2002-12-13 GB GBGB0229245.6A patent/GB0229245D0/en not_active Ceased
• 2003
  • 2003-11-27 JP JP2004560016A patent/JP2006510292A/ja not_active Withdrawn
  • 2003-11-27 CN CNA2003801059892A patent/CN1726700A/zh active Pending
  • 2003-11-27 AU AU2003283658A patent/AU2003283658A1/en not_active Abandoned
  • 2003-11-27 EP EP03775639A patent/EP1574051A1/en not_active Withdrawn
  • 2003-11-27 US US10/538,105 patent/US20060109380A1/en not_active Abandoned
  • 2003-11-27 WO PCT/IB2003/005546 patent/WO2004056101A1/en not_active Ceased
  • 2003-11-27 KR KR1020057010674A patent/KR20050088428A/ko not_active Withdrawn

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