Cisco Technology, Inc.

Tandberg Telecom As

Gisle Bjontegaard

Arild Fuldseth

Mattias Ahnoff

Techniques for direct mode video coding/decoding techniques. According to one embodiment, various blocks in B frames may use motion vectors from different reference frames (P frames or B frames), according to what is referred to herein as a patchwork motion field. Different blocks of a given frame may use motion vectors inherited from different frames for purposes of computing a predicted block for the given frame.

Motion compensation using a patchwork motion field

Video transform coefficient encoding and decoding methods are provided. A two-dimensional array of quantized transform coefficients are obtained for a block of a video frame. The two-dimensional array of quantized transform coefficients are converted to a one-dimensional array of integer samples using a scan pattern, wherein each sample is represented with a level that is an absolute value of the sample and a sign bit if the level is greater than zero. The one-dimensional array of samples is converted to a bit-stream by processing the one-dimensional array of samples in sequential order. A switch is adaptively made between multiple coding modes, where each coding mode is characterized by how consecutive coefficients are jointly coded as a single event. For each mode, a switch may be adaptively made between various variable length code (VLC) tables.

Transform coefficient coding using level-mode and run-mode

A block of size N&#xd7;M of a video frame can be either split into smaller blocks in n different ways (e.g. horizontal, vertical, quad, etc.), or alternatively it can be coded using one out of m different coding modes (e.g. intra, inter, bi-prediction, etc.). Since splitting into smaller sub-blocks and coding the N&#xd7;M block in one of the m possible ways are mutually exclusive, there are n+m distinct possibilities for processing the block further. The n+m possible ways of processing the N&#xd7;M blocks are assigned a code (e.g., a number) and coded with a codeword derived from a VLC table. This achieves efficient combined coding of split information and other block-level parameters.

Combined coding of split information and other block-level parameters for video coding/decoding

A video decoding method is provided. The method includes receiving an encoded bit stream representative of a video signal, the encoded bit stream including information indicating partitioning of a frame of the video signal into blocks such that at least one rectangular block of any size occurs at any position of the frame. Information is obtained from the encoded bit stream, the information signaling at least one video coding parameter for the at least one rectangular block. The encoded bit stream of the video signal is decoded in accordance with the information for the at least one rectangular block. An analogous video encoding method is also provided.

Block-based video coding using a mixture of square and rectangular blocks

A video coding/decoding system, method and computer program product employ an integer transform matrix for transforming to/from transform coefficients and residual pixel data in moving pictures by a set of semi-orthonormal basis vectors. The basis vectors are derived from conventional DCT or KTL matrixes, but relaxes to some extent the requirements for orthogonality, norm equality and element size limitation. In this way improved coding efficiency and lower complexity compared to previously used integer transforms are possible.

Integer transform video compression system, method and computer program product

A video decoding method including: receiving an encoded block of data; decoding the encoded block of data to generate decoded data; and performing a sample adaptive offset on a whole or part of the decoded data, wherein a pixel B to be modified as part of the sample adaptive offset is adjacent to pixels A and C, and the pixel B is modified as part of the sample adaptive offset if (B&#x2266;A and B&#x2266;C) or (B&#x2267;A and B&#x2267;C).

Digital video compression system, method and computer readable medium

A method including: obtaining video information at a video decoder apparatus, the video information including largest coding units of video data and filtering information, each of the largest coding units having a common size; obtaining, at the video decoder apparatus, an adaptive loop filter on/off indicator for each of the largest coding units, wherein each of the largest coding units includes a respective adaptive loop filter on/off indicator; and performing, by the video decoder apparatus, adaptive loop filtering to the largest coding units if the respective adaptive on/off indicators are on.

Video compression using an adaptive loop filter

A method for scanning MacroBlocks in video compression and selecting alternative sized Large Macroblocks accordingly. The scanning pattern is divided into scanning fragments with a size corresponding to different possible Large Macroblocks. This allows for varying the size of the selected Macroblocks, based on minimizing distortion and/or bit rate consumption.

Method, apparatus, and computer readable medium for video compression

The invention is related to decoding of block wise coded video pictures. The determination of using de-blocking filtering between coded blocks is based on alternative characteristics compared to the characteristics used in H.264/AVC.

Deblocking filter

A pre-processing of video data before coding and transmission, for a method for noise reduction in High-Density video images. A low implementation-complex filter filters raw pixel data output of a video camera with a low pass property for both spatial and temporal noise and the filter is adapted based on the high frequency content of the picture, leaving most of the image content unaffected by the filtering process.

Method related to noise reduction

A method for representing video data related to a macroblock of a video image in a coding procedure wherein certain, video data or combinations of video data is represented in predefined events associated with indexed positions in a Variable Length Code (VLC) table including codes assigned to each indexed position, including: determining, with a processor, that a first event among said predefined events occurs during the coding procedure; coding, with the processor, the first event with a code assigned to a position x in the VLC table being associated with the first event, the VLC table being stored in a memory device; determining, with the processor, whether x&#x3e;0, wherein 0 denotes a position at a top of the VLC table; and rearranging, with the processor, the VLC table by associating a second event currently associated with a position x&#x2212;1 with the position x, and associating the first event with the position x&#x2212;1.

Variable length coding (VLC) method and device

A method including: calculating a prediction of a first block of pixels in a second video frame with a temporal position between a first and a third video frame from a first motion vector of pixel position components relative to spatial pixel positions of the first block referring the first video frame and a third motion vector of pixel position components relative to spatial pixel positions of the first block referring the third video frame, wherein a second block of pixels in the third video frame spatially collocated with the first block is predicted from a second motion vector of pixel position components relative to spatial pixel positions of the second block referring the first video frame.

Method for pixel prediction with low complexity

A method including: obtaining, with the video processing apparatus, video frames, the video frames including macroblocks; comparing, with a video processing apparatus, a current macroblock in a current frame stored in a current frame buffer with a corresponding reference macroblock in a reference frame stored in a reference frame buffer; and setting, with the video processing apparatus, a flag value for said current macroblock if the comparing indicates that the current macroblock and the corresponding reference macroblock are substantially different.

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Oppegard, Norway

Gisle Bjontegaard