Multiplex Method and Associated Functional Data Structure for Combining Digital Video Signals

Abstract

Functional data structure for coding a set of digital images. Each of the images is compressed into at least-one first data stream portion, which comprises a portion of the macroblocks reduced by physical redundancies, and-one second data stream portion, which describes the redundancies. For the intraprediction macroblocks, the first data stream portion can be reduced by colour value statements with correlations to colour values from rows of pixels outside and at one edge of the intraprediction macroblock and for which, in the case of pixels outside the compressed image, a colour value default is assumed. The second data stream can comprise intrapredictors for describing the correlations, with coding of an area which is divided into first areas, each of which is occupied by the macroblocks of one of the digital images, and a second area which spaces apart the first areas and is occupied by default colour value pixels.

1 - 15 . (canceled) 
     
     
         16 . A method for coding a set of at least two compressed digital images received from at least two video participants in a multipoint control unit, wherein the compressed digital images are chronologically synchronous images of different chronological image sequences in different data sets of the at least two video participants, the method comprising:
 dividing the compressed digital images from the video participants into macroblocks of pixels coded with color value statements that include intraprediction macroblocks that occurs in an area that is divided into first spaces and a second space, each of the first spaces being occupied by the macroblocks of a respective one of the compressed digital images, the second space spacing the first spaces from each other, the second space being occupied by pixels with a default color value for intraprediction to avoid decompression errors during intraprediction and wherein all the pixels of the second space have the default color value; and   wherein each of the compressed digital images is compressed into at least:
 a first data stream portion having at least one portion of the macroblocks that is reduced by at least physical redundancies, and 
 a second data stream portion assigned to the first data stream portion that describes the redundancies; and 
   wherein for each of the intraprediction macroblocks, the first data stream portion is reduced by color value statements with correlations to color values from at least one line of pixels that are arranged outside of the intraprediction macroblock on an edge of that intraprediction macroblock and wherein pixels outside the compressed image assume the default color value; and   the second data stream portion comprises intrapredictors to describe the correlations.   
     
     
         17 . The method of  claim 16 , wherein the macroblocks have quadratic areas of the same size, each of which having the same number of pixels. 
     
     
         18 . The method of  claim 16 , wherein the at least one line of pixels is at a top edge or a left edge. 
     
     
         19 . The method of  claim 16 , wherein the digital images are chronologically synchronous images of different chronological image sequences that are data sets of I-frames of video image recordings. 
     
     
         20 . The method of  claim 19 , wherein the first data stream portion is reduced by physical and chronological redundancies. 
     
     
         21 . The method of  claim 20 , wherein the first data stream portion is reduced by at least one of: a compression via a frequency analysis, a compression based on quantisation, a compression based on entropic coding, and a compression based on discrete cosine transformation. 
     
     
         22 . A non-transitory storage medium comprising coding software that defines steps of a method for coding a set of at least two compressed digital images from at least two video participants that are received by a multipoint control unit, the compressed digital images being chronologically synchronous images of different chronological image sequences in different data sets of the at least two video participants, the coding software being stored in the storage medium such that, when the coding software is executed by the multipoint control unit, the multipoint control unit performs a method comprising:
 dividing the compressed digital images from the video participants into macroblocks of pixels coded with color value statements that include intraprediction macroblocks that occurs in an area that is divided into first spaces and a second space, each of the first spaces being occupied by the macroblocks of a respective one of the compressed digital images, the second space spacing the first spaces from each other, the second space being occupied by pixels with a default color value for intraprediction to avoid decompression errors during intraprediction and wherein all the pixels of the second space have the default color value; and   wherein each of the compressed digital images is compressed into at least:
 a first data stream portion having at least one portion of the macroblocks that is reduced by at least physical redundancies, and 
 a second data stream portion assigned to the first data stream portion that describes the redundancies; and 
   wherein for each of the intraprediction macroblocks, the first data stream portion is reduced by color value statements with correlations to color values from at least one line of pixels that are arranged outside of the intraprediction macroblock on an edge of that intraprediction macroblock and wherein pixels outside the compressed image assume the default color value; and   the second data stream portion comprises intrapredictors to describe the correlations.   
     
     
         23 . A multipoint control unit, comprising:
 a receiving unit configured to receive compressed digital images from devices of multiple video participants via a telecommunication network, the compressed digital images being chronologically synchronous images of different chronological image sequences in different data sets received from the devices of the video participants;   a non-transitory storage medium having encoding software stored thereon that configures the multipoint control unit to encode the received compressed digital images, the encoding performed by the multipoint control unit via the encoding software comprising:
 dividing the compressed digital images into macroblocks of pixels coded with color value statements that include intraprediction macroblocks that occur in an area that is divided into first spaces and a second space, each of the first spaces being occupied by the macroblocks of a respective one of the compressed digital images, the second space spacing the first spaces from each other, the second space being occupied by pixels with a default color value for intraprediction to avoid decompression errors during intraprediction, wherein all the pixels of the second space have the default color value, 
 wherein each of the divided digital images are compressed into at least:
 a first data stream portion having at least one portion of the macroblocks that is reduced by at least physical redundancies, and 
 a second data stream portion assigned to the first data stream portion that describes the redundancies, and 
 for each of the intraprediction macroblocks, the first data stream portion is reduced by color value statements with correlations to color values from at least one line of pixels that are arranged outside of the intraprediction macroblock on an edge of that intraprediction macroblock and wherein pixels outside the compressed image assume the default color value and the second data stream portion comprises intrapredictors to describe the correlations; and 
 
   a sending unit configured to send data encoded by the multipoint control unit via the telecommunications network.   
     
     
         24 . The multipoint control unit of  claim 23 , wherein the default color value is a luminance value or a chrominance value. 
     
     
         25 . The multipoint control unit of  claim 23 , wherein the macroblocks have quadratic areas of the same size, each quadratic area having the same number of pixels. 
     
     
         26 . The multipoint control unit of  claim 23 , wherein the at least one line of pixels is at a top edge or a left edge. 
     
     
         27 . The multipoint control unit of  claim 23 , wherein the data sets are comprised of I-frames of video image recordings. 
     
     
         28 . The multipoint control unit of  claim 27 , wherein the first data stream portion is reduced by physical and chronological redundancies. 
     
     
         29 . The multipoint control unit of claim of  claim 28 , wherein the first data stream portion is reduced by at least one of: a compression via a frequency analysis, a compression based on quantisation, a compression based on entropic coding, and a compression based on discrete cosine transformation. 
     
     
         30 . The multipoint control unit of  claim 23 , wherein the encoding of the digital images is performed such that decompression errors in intrapredictions is prevented. 
     
     
         31 . The multipoint control unit of  claim 23 , wherein the reduction of the at least one portion of the macroblocks of the first data stream portion is performed in accordance with video encoding standard H.264. 
     
     
         32 . The multipoint control unit of  claim 23 , wherein the multipoint control unit is a server of a video conference system. 
     
     
         33 . The multipoint control unit of  claim 23 , wherein the multipoint control unit is a central server of a video conference system. 
     
     
         34 . The multipoint control unit of  claim 23 , wherein the encoding performed by the multipoint control unit is performed without first decompressing the compressed digital images. 
     
     
         35 . The multipoint control unit of  claim 23 , wherein the second space separates every two of the first spaces at a distance corresponding to one of the macroblocks.