Classifications

• • G—PHYSICS
  • G09—EDUCATION; CRYPTOGRAPHY; DISPLAY; ADVERTISING; SEALS
  • G09G—ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION
  • G09G5/00—Control arrangements or circuits for visual indicators common to cathode-ray tube indicators and other visual indicators
  • G09G5/003—Details of a display terminal, the details relating to the control arrangement of the display terminal and to the interfaces thereto
  • G09G5/006—Details of the interface to the display terminal
• • 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]
  • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
  • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
  • H04N21/236—Assembling of a multiplex stream, e.g. transport stream, by combining a video stream with other content or additional data, e.g. inserting a URL [Uniform Resource Locator] into a video stream, multiplexing software data into a video stream; Remultiplexing of multiplex streams; Insertion of stuffing bits into the multiplex stream, e.g. to obtain a constant bit-rate; Assembling of a packetised elementary stream
  • H04N21/23602—Multiplexing isochronously with the video sync, e.g. according to bit-parallel or bit-serial interface formats, as SDI
• • 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
  • H04N21/4342—Demultiplexing isochronously with video sync, e.g. according to bit-parallel or bit-serial interface formats, as SDI
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/12—Systems in which the television signal is transmitted via one channel or a plurality of parallel channels, the bandwidth of each channel being less than the bandwidth of the television signal
  • H04N7/122—Systems in which the television signal is transmitted via one channel or a plurality of parallel channels, the bandwidth of each channel being less than the bandwidth of the television signal involving expansion and subsequent compression of a signal segment, e.g. a frame, a line

Definitions

• the present invention relates to a system and method for lossless reduction of bandwidth of a data stream transmitted via a digital multimedia link.
• This multimedia data is processed digitally, and to complete the digital infrastructure the data should be transmitted and displayed digitally without any loss known from analog transmission and display technologies.
• One method for transmission of multimedia data such as video data, audio data and so on, is a method which uses the format MPEG to transmit data using a data compression method in order to minimize the required bandwidth.
• a system for lossless reduction of bandwidth of a data stream transmitted via a digital multimedia link comprising coding means for coding at least one control signal such that at least one control word is generated each time said at least one control signal changes, multiplexer means for multiplexing payload data and said at least control word such that there is provided said data stream comprising said payload data if no blanking period of said payload data is present and said at least one control word if said blanking period of said payload data is present, data transmission means for transmitting said data stream, demultiplexer means for receiving said data stream transmitted by said data transmission means for demultiplexing said payload data and said at least one control word from said data stream such that said payload data and said control word are separated from each other, and decoding means for decoding said at least one control word such that said at least one control signal is recovered.
• said transmission means comprises a transmit FIFO and a receive FIFO, said data stream being input to said transmit FIFO before being transmitted and said transmitted data stream being input to said receive
• a system wherein said payload data and said at least one control signal are provided synchronous to a system clock of an payload data input interface.
• said payload data is at least one of pixel data and audio data.
• said coding means is a run-length coding means and said decoding means is a run-length decoding means.
• a method for lossless reduction of bandwidth of a data stream transmitted via a digital multimedia link comprising the steps of coding at least one control signal such that at least one control word is generated each time said at least one control signal changes, multiplexing payload data and said at least control word such that there is provided said data stream comprising said payload data if no blanking period of said payload data is present and said at least one control word if said blanking period of said payload data is present, transmitting said data stream, receiving said data stream for demultiplexing said payload data and said at least one control word from said data stream such that said payload data and said control word are separated from each other, and decoding said at least one control word such that said at least one control signal is recovered.
• said payload data is at least one of pixel data and audio data.
• said coding is a run-length coding and said decoding is a run-length decoding.
• Fig. 1 is a block diagram of a system for lossless bandwidth reduction of a pixel data stream according to an embodiment of the present invention
• Fig. 2 is a time chart of states of various signals used in the system according to the embodiment of the present invention.
• Fig. 3 is a time chart of fill levels of FIFOs used in the system according to the embodiment of the present invention.
• MULTIMEDIA LINK from the assignee of the present application, simultaneously filed herewith, representative's file number IN0424.
• the present invention is not limited to such application and, therefore, there is merely given a short abstract of the technology described in the aforementioned application in order to enhance intelligibility of the background of the present invention.
• a reliable, long distance, serial Gigabit/s and digital multimedia link which is due its serial nature highly scalable.
• bandwidth can be increased by adding additional links or decreased by reducing links and on the other hand the bandwidth of different types of multimedia data such as video data, audio data and sideband data and so on can be amended in a respective link to change the bandwidth for such data in the respective link.
• Such multimedia link is a high-speed serial and long-distance link for video data, audio data and other digital data as sideband data which supports video formats ranging from VGA with 18 bit color depth up to SXGA with 24 bit color depth and even UXGA with 18 bit color depth.
• a pixel stream as it is output from a graphic controller or the like or as it is input at a LCD display or the like comprises predetermined number of n bits for pixel color data and up to three pixel control signals which are used for horizontal and vertical synchronization. Pixel color data bits and pixel control signals are valid at each pixel clock edge. When the pixel control signals indicate a so-called blanking period the pixel color data bits carry no meaningful information.
• a bandwidth of such a pixel stream is a product of pixel clock frequency and a sum of the pixel color data bits and the pixel control signals.
• the following table 1 shows an overview of different video formats from VGA to UXGA according to VESA and the required bandwidth.
• serial data transmission system disclosed in the aforementioned application from the assignee of the present application advantageously provides up to two serial links and a net link bandwidth slightly above 1 GBit/s per serial link.
• formats SXGA and UXGA require a bandwidth which exceeds the available net link bandwidth even for a two link setup as is obvious from table 1.
• the basic concept of the present invention is to replace the pixel control signals by control words which just indicate a change of status of the control signals and to suppress any pixel color data during a blanking period.
• the resulting pixel data stream now comprises pixel color data during a period of no blanking followed by a sequence of few control words when the blanking period occurs. This saves for VESA pixel formats approximately 20 % of the required bandwidth for the native pixel stream as shown in Fig. 1.
• Fig. 1 is a block diagram of a system for lossless bandwidth reduction of a pixel data stream according to an embodiment of the present invention.
• reference sign 1 denotes a pixel data input interface, reference sign
• reference sign 2 denotes a run-length coding means
• reference sign 3 denotes a multiplexer means
• reference sign 4 denotes a transmit FIFO (first-in first-out memory)
• reference sign 5 denotes a serial data transmission means
• reference sign 6 denotes a receive FIFO
• reference sign 7 denotes a demultiplexer means
• reference sign 8 denotes a run-length decoding means
• reference sign 9 denotes a pixel data output interface.
• the pixel data input interface 1 is connected to the run-length coding means 2 and drives one input of the multiplexer means 3.
• the run-length coding means drives another of the multiplexer means 3.
• the output of the multiplexer means 3 is connected to an input of the transmit FIFO 4.
• An output of the transmit FIFO 4 is connected to an input of the given serial data transmission means 5.
• An output of the serial data transmission means 5 is connected to an input of the receive FIFO 6.
• An output of the receive FIFO 6 is connected to an input of the demultiplexer means.
• One output of the demultiplexer means 7 is directly connected to the pixel data output interface 9 and another output of the demultiplexer means 7 is connected with an input of the run-length decoding means 8.
• An output of the run- length decoding means 8 is also connected to the pixel data output interface 9.
• Pixel color data and pixel control signals are provided synchronous to a pixel clock at the pixel data input interface 1.
• the run-length coding means 2 generates pixel control words each time one of the pixel control signals changes.
• the multiplexer means 3 merges pixel color data provided directly from the pixel data input interface 1 and pixel control words generated by the run-length coding means 2.
• the resulting serial data stream shows a variable bandwidth with maximum bandwidth when the pixel color data is transmitted and a bandwidth close to zero when the pixel control words are transmitted. To leverage the bandwidth for a constant serial data transmission the transmit FIFO 4 is used.
• Fig. 3 is a time chart of fill levels of FIFOs used in the system according to the embodiment of the present invention.
• a receive FIFO 6 stores a certain offset level of the pixel color data and the pixel control words.
• the pixel color data is forwarded directly to the pixel data output interface 9 and the pixel control words are decoded within the run- length decoding means 8.
• This run-length decoding means 8 drives the pixel control signals according to the control words generated at a transmitter side by the run-length coding means 2. This pixel control signals are then forwarded to the pixel data output interface 9.
• the embodiment of the present invention has been described with respect to pixel data and pixel control signals. However, it is also possible to apply the present invention to any types of data having payload data and control signals as mentioned above with respect to the pixel data.
• the present invention can advantageously applied on different multimedia data such as at least one of pixel data and audio data and so on.
• a serial data transmission means the present invention is also applicable to another data transmission means such as a parallel data transmission means or the like because the manner of bandwidth reduction is independent from the data transmission means used in an respective application of the present invention.

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• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Physics & Mathematics (AREA)
• Computer Hardware Design (AREA)
• General Physics & Mathematics (AREA)
• Theoretical Computer Science (AREA)
• Television Systems (AREA)

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• 2003
  • 2003-09-22 EP EP03757881A patent/EP1665790A1/de not_active Ceased
  • 2003-09-22 WO PCT/EP2003/010523 patent/WO2005029857A1/en active Application Filing
  • 2003-09-22 AU AU2003273916A patent/AU2003273916A1/en not_active Abandoned

Patent Citations (2)

Non-Patent Citations (1)

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