Multiplex method and associated functional data structure for combining digital video signals
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 color value statements with correlations to color 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 color 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 color value pixels.
1. A method for coding a set of at least two compressed digital images received from at least two video participants of a video conference 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 and are divided into macroblocks of pixels coded with color value statements, including intraprediction macroblocks; wherein the coding occurs in an area which is divided into first areas, each of which is occupied by the said macroblocks of one of the compressed digital images, and a second area by which the first areas are spaced in parallel from each other, wherein the second area is occupied by pixels with a color value default for the intraprediction, to avoid decompression errors during intrapredictions, wherein all the pixels of the second area have this color value default and the second area in each case spaces apart two of the first areas in parallel by a distance corresponding to at least one of the quadratic macroblocks; the method comprising:
compressing each of the images into at least a first data stream portion which comprises at least one portion of the macroblocks, said portion being reduced by at least physical redundancies for transmission of the compressed images to video conference participants as a compilation of the different chronologically synchronous images received from the at least two video participants, and a second data stream portion assigned to the first data stream portion, said second data stream portion describing the reduced physical redundancies,
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 which are arranged outside and on an edge of the intraprediction macroblock and for which the color value default is used in the case of pixels outside the compressed image, and the second data stream portion comprises intrapredictors to describe the correlations to the color values; and
wherein the color value default is a pre-selected color value that separates the first areas from the second area so that all pixels in the second area have a same color value for separation of the different digital images received from the at least two video participants that are compressed into the first data stream portion during the compressing of each of the images so that the first data stream portion is decompressible and decodable for displaying the at least two digital images of the compilation of the different chronologically synchronous images.
2. The method according to claim 1 , wherein the macroblocks have quadratic areas of the same size, each of which have the same number of pixels.
3. The method according to claim 1 , wherein the at least one line of pixels is arranged on a top or a left edge of the intraprediction macroblock.
4. The method according to claim 1 , wherein the digital images are chronologically synchronous images of different chronological image sequences.
5. The method of claim 4 , wherein the compressing is performed such that the first data stream portion is reduced by physical and chronological redundancies.
6. The method according to claim 5 , wherein the compressing is performed such that the first data stream portion is reduced by via a frequency analysis, a discrete cosine transformation, quantisation, or entropic coding.
7. The method according to claim 1 , wherein the digital images frames of video image recordings.
8. A non-transitory computer readable medium having a program stored therein such that when a multipoint control unit runs the program, the multipoint control unit performs the method of claim 1 .
9. The multipoint control unit of claim 8 , wherein the multipoint control unit is a server of a video conference system or a central server of a video conference system.
10. The multipoint control unit of claim 8 , wherein the encoding performed by the multipoint control unit is performed without first decompressing the compressed digital images.
11. A method for coding a set of at least two digital images received from at least two video participants in a multipoint control unit without decompressing the digital images, wherein the 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 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 without decompressing the digital images, each of the first spaces being occupied by the macroblocks of a respective one of the 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
compressing each of the digital images into at least:
a first data stream portion having at least one portion of the macroblocks that is reduced by at least physical redundancies for transmission of the compressed digital images to video conference participants as a compilation of the different chronologically synchronous images received from the at least two video participants, 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 have the default color value;
wherein the default color value is a pre-selected color value and each and every pixel in the second space has a same color value to separate the first spaces from the second space for separation of the different digital images received from the at least two video participants that are compressed into the first data stream portion during the compressing of each of the images so that the first data stream portion is decompressible and decodable for displaying the at least two digital images of the compilation of the different chronologically synchronous images; and
the second data stream portion comprises intrapredictors to describe the correlations.
12. The method of claim 11 , wherein the first data stream portion is reduced by physical and chronological redundancies.
13. The method of claim 12 , wherein the second space separates every two of the first spaces at a distance corresponding to one of the macroblocks.
14. A multipoint control unit, comprising:
a receiver configured to receive digital images from devices of multiple video participants via a telecommunication network, the 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 digital images, the encoding performed by the multipoint control unit via the encoding software comprising:
dividing the 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 without decompressing the compressed digital images, each of the first spaces being occupied by the macroblocks of a respective one of the 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,
compressing each of the divided digital images into at least:
a first data stream portion having at least one portion of the macroblocks that is reduced by at least physical redundancies for transmission of the compressed images to video conference participants as a compilation of the different chronologically synchronous images received from the at least two video participants, 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 have the default color value and the second data stream portion comprises intrapredictors to describe the correlations;
wherein the default color value is a pre-selected color value and each and every pixel in the second space has a same color value to separate the first spaces from the second space for separation of the different digital images received from the at least two video participants that are compressed into the first data stream portion during the compressing of each of the images so that the first data stream portion is decompressible and decodable for displaying the at least two digital images of the compilation of the different chronologically synchronous images; and
a transmitter configured to send data encoded by the multipoint control unit via the telecommunications network; and
wherein the encoding performed by the multipoint control unit is performed without first decompressing the compressed digital images.
15. The multipoint control unit of claim 14 , wherein the default color value is a luminance value or a chrominance value.
16. The multipoint control unit of claim 14 , wherein the second space separates every two of the first spaces at a distance corresponding to one of the macroblocks.
17. The multipoint control unit of claim 16 , wherein the at least one line of pixels is at a top edge or a left edge.
18. The multipoint control unit of claim 14 , wherein the data sets are comprised of I-frames of video image recordings.
19. The multipoint control unit of claim 14 , wherein the first data stream portion is reduced by physical and chronological redundancies.
20. The multipoint control unit of claim 14 , wherein the encoding of the digital images is performed such that decompression errors in intrapredictions is prevented.