Abstract: There is provided a method of processing video information, the method comprising encoding (430) received video information, the encoded video information having an encoded video bitrate (330), wherein the encoded video bitrate is variable in response to the complexity of the received video information. The method further comprises buffering (440) the encoded video information in a buffer (145), wherein the size of the buffer (145) is controlled in response to the complexity of the received video information.

Abstract: There is provided a method of adapting a Quantization parameter of digitally encoded video, comprising using a look-ahead encoding pass to provide look-ahead bit costs for each macroblock in a picture of interest, calculating an activity metric for each macroblock in the picture of interest, determining at least an accumulated look-ahead bit cost threshold for a low macroblock activity category, wherein the low macroblock activity category comprises macroblocks having an activity metric below a pre-determined level, sorting the macroblocks according to the calculated activity metrics of each macroblock to provide sorted macroblocks, adding sorted macroblocks to the low macroblock activity category in ascending activity order and accumulating bit costs of the added sorted macroblocks up to the determined accumulated look-ahead bit cost threshold, and applying a change in quantization parameter, Qp, to the macroblocks of the picture of interest comprising decreasing the Qp value of the macroblocks in the low ma

Abstract: The present invention relates to a method of and apparatus for compression encoding of a picture in a picture sequence. In particular, the invention relates to a method of and apparatus for compression encoding of a picture in a picture sequence so as to maintain a good picture quality while providing compression coding and decoding with low latency. The invention provides a method of compression encoding a picture in a picture sequence in which the pictures in the picture sequence are coded as prediction coded pictures with a single reference picture and have at least two macroblock sets. One set is a refresh set in which the macroblocks are intra-picture coded. The decoded compression coded picture information used for compression coding picture information is decoded without use of a de-blocking filter.

Abstract: A method of pre-processing a sequence of video picture data comprising I pictures, P pictures and B pictures, where the pictures are arranged as a plurality of Group Of Pictures (GOP) and each of the Group Of Pictures has a first picture and a plurality of Sub Group of Pictures (Sub-GOP). The method uses an analysis of the sequence of video picture data to determine a position of a scene change relative to a position of a start of a new GOP within the sequence of video picture data and then moves the start of the new GOP to coincide with the scene change by extending or decreasing a current GOP length according to whether the scene change and the start of a new GOP are within a predetermined number of pictures of each other. An apparatus for carrying out the method is also provided.

Abstract: There is provided a method of adapting a Quantization parameter of digitally encoded video, comprising calculating spatial activity values of macroblocks in a picture of interest, creating a histogram of the spatial activity values, determining a change of quantization parameter value for a low activity category ?QPLA from a skewness parameter of the histogram. There is also provided an apparatus for carrying out the method, and a computer readable product carrying instructions which when executed carry out the method.

Abstract: A method and apparatus for determining a type of picture encoding of a decompressed video signal by detecting periodic changes of high frequency content of individual fields of the video signal. The determination may be used in particular to align picture types in successive video compression systems in a video compression concatenation chain.

Abstract: There is provided a method of detecting repeated pictures in a sequence of video picture data, each picture of said video picture data comprising a plurality of macroblocks, the method comprising performing hierarchical motion estimation on the video picture data to provide best motion vectors for each macroblock, best motion vector sum of absolute difference values for each macro block and zero motion vector sum of absolute difference values for each macroblock, wherein the hierarchical motion estimation includes a plurality of levels, and said best motion vectors, best motion vector sum of absolute difference values and zero motion vector sum of absolute difference values for each macroblock are provided for at least a top level, providing a noise threshold value based upon the zero motion vector sum of absolute difference values from the top level of the hierarchical motion estimation, accumulating the best motion vector sum of absolute difference values for macroblocks having best motion vector sum of abs

Abstract: There is provided a method of statistically multiplexing a plurality of input video data streams into at least one output data stream having a pre-determined capacity, comprising providing a plurality of bit rate estimates at different quality levels for each input video data stream using a look-ahead encoder, summing together the bit rate estimates of the same quality level for all input video data streams, determining the picture quality of each input video data stream at which the summed bit rate estimates is equal to or less than the output data stream pre-determined capacity. There is also provided an apparatus and system for carrying out the method, and a computer readable product carrying instructions which when executed carry out the method.

Abstract: There is provided a method of processing video information, the method comprising encoding (430) received video information, the encoded video information having an encoded video bitrate (330), wherein the encoded video bitrate is variable in response to the complexity of the received video information. The method further comprises buffering (440) the encoded video information in a buffer (145), wherein the size of the buffer (145) is controlled in response to the complexity of the received video information.

Abstract: The invention relates to the compression coding of video signals. The invention may be applied in some embodiments to the compression coding of three dimensional television (3DTV) signals. The invention provides a method of coding of a video signal, in which the presence of at least a first image area and a second image area in a picture, in which the images in the first image area and in the second image area are substantially identical is determined. In response to a positive determination, picture information in one image area is compression coded without reference to picture information in another image area. The invention also provides a video coder for coding a video signal.

Abstract: A method and apparatus for detecting (51) in a video stream a scene cut (11, 12) between a current field of the video stream and an immediately preceding field includes determining (61) differences for a first plurality of image parameters between values of the image parameters for a current field and for one or more immediately preceding fields. A flag value is set (62) for each parameter indicating whether a possible scene break exists between the current field and the immediately preceding field dependent on the respective differences. The flag values for each parameter are combined (63) to form a combined parameter and a scene break trigger signal generated (64) indicating a scene break between the current field and the immediately preceding field if the combined parameter exceeds a predetermined trigger threshold. A change of criticality is determined (52) at a forthcoming scene cut.

Abstract: There is provided a method of adapting a Quantization parameter of digitally encoded video, comprising calculating spatial activity values of macroblocks in a picture of interest, creating a histogram of the spatial activity values, determining a change of quantization parameter value for a low activity category ?QPLA from a skewness parameter of the histogram. There is also provided an apparatus for carrying out the method, and a computer readable product carrying instructions which when executed carry out the method.

Abstract: There is provided a method of adapting a Quantization parameter of digitally encoded video, comprising using a look-ahead encoding pass to provide look-ahead bit costs for each macroblock in a picture of interest, calculating an activity metric for each macroblock in the picture of interest, determining at least an accumulated look-ahead bit cost threshold for a low macroblock activity category, wherein the low macroblock activity category comprises macroblocks having an activity metric below a pre-determined level, sorting the macroblocks according to the calculated activity metrics of each macroblock to provide sorted macroblocks, adding sorted macroblocks to the low macroblock activity category in ascending activity order and accumulating bit costs of the added sorted macroblocks up to the determined accumulated look-ahead bit cost threshold, and applying a change in quantization parameter, Qp, to the macroblocks of the picture of interest comprising decreasing the Qp value of the macroblocks in the low ma

Abstract: There is provided a method of statistically multiplexing a plurality of input video data streams into at least one output data stream having a pre-determined capacity, comprising providing a plurality of bit rate estimates at different quality levels for each input video data stream using a look-ahead encoder, summing together the bit rate estimates of the same quality level for all input video data streams, determining the picture quality of each input video data stream at which the summed bit rate estimates is equal to or less than the output data stream pre-determined capacity. There is also provided an apparatus and system for carrying out the method, and a computer readable product carrying instructions which when executed carry out the method.

Abstract: There is provided a method of detecting repeated pictures in a sequence of video picture data, each picture of said video picture data comprising a plurality of macroblocks, the method comprising performing hierarchical motion estimation on the video picture data to provide best motion vectors for each macroblock, best motion vector sum of absolute difference values for each macro block and zero motion vector sum of absolute difference values for each macroblock, wherein the hierarchical motion estimation includes a plurality of levels, and said best motion vectors, best motion vector sum of absolute difference values and zero motion vector sum of absolute difference values for each macroblock are provided for at least a top level, providing a noise threshold value based upon the zero motion vector sum of absolute difference values from the top level of the hierarchical motion estimation, accumulating the best motion vector sum of absolute difference values for macroblocks having best motion vector sum of abs

Abstract: A method of pre-processing a sequence of video picture data comprising I pictures, P pictures and B pictures, where the pictures are arranged as a plurality of Group Of Pictures (GOP) and each of the Group Of Pictures has a first picture and a plurality of Sub Group of Pictures (Sub-GOP). The method uses an analysis of the sequence of video picture data to determine a position of a scene change relative to a position of a start of a new GOP within the sequence of video picture data and then moves the start of the new GOP to coincide with the scene change by extending or decreasing a current GOP length according to whether the scene change and the start of a new GOP are within a predetermined number of pictures of each other. An apparatus for carrying out the method is also provided.

Abstract: A method and apparatus for determining a type of picture encoding of a decompressed video signal by detecting periodic changes of high frequency content of individual fields of the video signal. The determination may be used in particular to align picture types in successive video compression systems in a video compression concatenation chain.

Abstract: A method of controlling frame types in a video compression system having I, P and B frames calculates activity figures of the video signal in vertical, vertical temporal and horizontal directions. Video sequences with low complexity in which the vertical activity within a field is less than the vertical-temporal activity within a frame are encoded without using B frames whereas sequences with high complexity, i.e. spatial detail, are encoded using B frames by the use of the invention, disadvantages associated with B frames are reduced by the selected use of B frames.

Abstract: A method and system for detecting and replacing spurious motion vectors in video signal compression includes determining whether a motion vector of a current macroblock is spurious by comparing the motion vector with motion vectors of motion vectors of neighbouring macroblocks; and replacing the motion vector as spurious if the difference exceeds a predetermined threshold. In particular, the method and system seeks to determine (72, 73) whether at least one cluster of motion vectors of neighbouring macroblocks can be formed; and if not, leaves (80) the motion vector of the current macroblock unchanged but if so determining (74) whether the motion vector falls within a cluster. The motion vector may be replaced (81) under certain criteria if the motion vector does not fall within a cluster of motion vectors of neighbouring macroblocks.

Abstract: A method and encoder for compressing a video signal inserts at least one non-referenced frame to coincide with a duration of a flash on detecting the flash in the video signal. On detecting a fade in the video signal, an order in which frames are coded is changed such that referenced frames are positioned immediately before and after the fade and a pyramidal structure of bidirectionally coded frames are used for the duration of the fade.