Abstract: An inter-prediction method and apparatus are provided. An initial motion vector is obtained for a current block. Search space positions are determined according to the initial motion vector. Matching costs for the search space positions are checked according to a checking order to select a target search space position with a minimal matching cost. A refining motion vector of the current block is determined based on the initial motion vector and the target search space position. A central search space position is determined first according to the checking order, and the central search space position is pointed to by the initial motion vector.

Abstract: The present disclosure provides apparatuses and methods for splitting an image into coding units. An image is divided into coding tree units (CTUs) which are hierarchically partitioned. Hierarchical partitioning includes multi-type partitioning such as binary tree or quad tree splitting. For CTUs completely within the image and CTUs on the boundary, respective multi-type partition depths are chosen. The present disclosure provides for multi-type partitioning flexibility in a boundary portion of the image.

Abstract: The present disclosure provides a method of coding implemented by a decoding device, the method comprising: obtaining a value of a splitting mode index for a current coding block; obtaining a value of an angle index for the current coding block according to the value of the splitting mode index value and a pre-stored table; setting a value of an index partIdx according to the value of the angle index; and storing motion information for the current coding block according to the value of the index partIdx.

Abstract: A method for deblocking a chroma block edge between a first chroma block of a first image block and a second chroma block of a second image block. The method includes a decision process which includes: determining a first chroma quantization parameter for the first chroma block based on a first luma quantization parameter of a first luma block of the first image block and a chroma QP mapping table for the first chroma block; determining a second chroma quantization parameter for the second chroma block based on a second luma quantization parameter of a second luma block of the second image block and a chroma QP mapping table for the second chroma block; determining an averaged and rounded chroma quantization parameter based on the first chroma quantization parameter and the second chroma quantization parameter; and determining a threshold parameter based on the averaged and rounded chroma quantization parameter.

Abstract: Apparatuses and methods for encoding and decoding a video are provided. The method includes determining whether at least one of two blocks of an image in a video is predicted with a combined inter-intra prediction (CIIP), where the two blocks include a first block (block Q) and a second block (block P). There is a boundary between the two blocks. The method further includes setting a boundary strength (Bs) for the boundary to a first value when at least one of the two blocks is predicted with the CIIP, and performing deblocking filter based on the Bs.

Abstract: A method for coding implemented by a decoding device or an encoding device includes: obtaining a first prediction mode for a first sub-block, obtaining a second prediction mode for a second sub-block; obtaining a first prediction value for a sample in the current block according to the first prediction mode, obtaining a second prediction value for the sample in the current block according to the second prediction mode; obtaining a value of an indicator, the value of the indicator indicating a blending operation which is performed for the sample in the current block; and obtaining a combined prediction value for the sample in the current block, according to the value of the indictor, the first prediction value, and the second prediction value. The blending operation adaptively performs around a separation line dividing the current block into at least the first sub-block and the second sub-block.

Abstract: The present disclosure relates to apparatuses and methods for determination of motion parameters (e.g. motion vectors) for motion prediction of a coding block, and is applicable to video encoding and/or decoding. The motion parameter is selected from motion parameters, which include motion parameters associated with a set of respective image samples not included in the coding tree unit, where the set of image samples are located at a predetermined position relative to an extended boundary of the coding tree unit. The apparatuses and methods of the present disclosure may facilitate reducing on-chip buffer requirements for motion prediction.

Abstract: A method for constructing a Most Probable Mode (MPM) list for intra prediction, the method comprising: determining whether a left neighboring block of a current coding block is available or not; determining whether an above neighboring block of the current coding block is available or not; using a Planar mode, a DC mode, a vertical mode (VER_IDX), a horizontal mode (HOR_IDX), an intra prediction mode corresponding to the vertical mode with an offset ?4, an intra prediction mode corresponding to the vertical mode with an offset 4, to obtain a value of an intra prediction mode for the current coding block when one of conditions is satisfied. The MPM list is used to obtain an index value corresponding to a prediction mode of a picture block, so as to improve coding efficiency.

Abstract: A deblocking filter of an image processing device is provided. The deblocking filter is used in an image coding process, for deblocking a block edge between a first coding block and a second coding block of an image. The first block has SA samples perpendicular to the block edge by N samples parallel to the block edge, and the second block has SB samples perpendicular to the block edge by N samples parallel to the block edge. No more than IA samples of the first coding block are used as first filter input values, and no more than IB samples of the second coding block are used as second filter input values. No more than MA samples of the first coding block are modified as first filter output values, and no more than MB samples of the second coding block are modified as second filter output values.

Abstract: The present disclosure relates to image encoding/decoding applying decoder side intra-prediction mode determination (DIMD). In order to reduce the computational complexity, DIMD for a current coding block based on a template of a neighboring reconstructed coding block is not performed if the border between the current and the reconstructed coding block concurs with a border between coding tree blocks.

Abstract: The present disclosure relates to a method and device of decoding video data. The device and method use a mapping process to simplify the calculation procedure for intra prediction, to improve coding efficiency. The decoding of encoded data comprises: obtaining an indication indicating whether the intra-prediction mode for a picture block is in a set of most probable modes, MPM, or not; if the indication indicates that the intra prediction mode for the picture block is not in the set of MPMs, generating a mapping relationship between at least one intra prediction mode in the first set of intra prediction modes and at least one intra prediction mode in the set of non-MPMs; decoding the encoded data to obtain an intra prediction mode codeword for the picture block; and obtaining the intra prediction mode for the picture block according to the mapping relationship and the intra prediction mode codeword.

Abstract: Embodiments provide an apparatus and method of partitioning of an image or an image slice. In particular, on an image processing apparatus, the image or image slice is split into an integer number of coding tree units in both vertical and horizontal directions. Boundary coding tree units are then at least partially forced-split so that at least one resulting coding unit is a result of binary-tree partitioning, i.e., includes a coding unit which is longer on one side than on the other side. The longer side is parallel or concurrent to the image or image slice boundary. Recursively partitioning coding units that span the picture boundary without the requirement for signaling partition information in a bitstream can be achieved.

Abstract: An apparatus and a method for filtering reconstructed images, in particular, video images, with adaptive multiplicative filters. The efficiency of the filtering operation is increased by restricting the allowable values of the filter coefficients to those that have only a limited number of “ones” in the binary representation.

Abstract: A coding apparatus configured to select an intra prediction mode for a current block, encode the selected intra prediction mode using truncated binary coding every time the selected intra prediction mode is a remaining mode, and encode the selected intra prediction mode using N bits when the selected intra prediction mode is included in a first portion from remaining modes and using N+1 bits when the selected intra prediction mode is included in a second portion of the remaining modes.

Abstract: A system and method for processing a video stream are provided. When coding or decoding a video stream a de-blocking filtering may be applied for reducing discontinuities caused by use of a block-based video coding. The de-blocking filtering is performed using a filter grid. The size of the filter grid is chosen adaptively based on the processing parameters. The adaptive size of the filtering grid is determined based on the number of samples used and modified in de-blocking filtering of an edge of a coding block. The filtering grid may be used both for vertical and horizontal edge filtering.

Abstract: A method of coding, implemented by a decoding device, includes obtaining a bitstream wherein at least one bit in the bitstream representing a syntax element for a current block, wherein the syntax element specifies the clipping index of the clipping value for an adaptive loop filter (ALF); parsing the bitstream to obtain a value of the syntax element for the current block, wherein the syntax element is coded using a fixed length code; applying adaptive loop filtering on the current block, based on the value of the syntax element for the current block. Herein fixed length code means that all possible values of the syntax element are signaled using the same number of bits.

Abstract: An in-loop deblocking filter apparatus (120) for processing a current row or column of samples into a filtered row or column of samples. The current row or column of samples comprises a plurality of samples from a first sample block and a horizontally or vertically neighboring second sample block of a reconstructed picture of a video stream. The samples of the current row or column of samples have sample values pN?1?p0, q0?qN?1 wherein N is an even integer greater than 2. If a first condition or a second condition is satisfied, the current row or column is processed by: determining a filtered sample value q0? by applying a (2N?1)-tap filter to the sample values pN?2, . . . , p0, q0, . . . , qN?1 of the current row or column; and/or determining a filtered sample value p0? by applying a (2N?1)-tap filter to the sample values pN?1, . . . , p0, q0, . . . , qN?2 of the current row or column.

Abstract: The present invention relates to the performance of motion vector refinement in a search space for multi-reference inter-prediction. Two or more reference pictures are selected, one of those used for motion vector refinement. Based on an initial estimate of a motion vector to the reference picture for motion vector refinement, a search space in this reference image is constructed. Using template matching, the first motion vector is refined. The second motion vector to another reference picture is calculated using its initial estimate, the initial estimate of the first motion vector and the refined first motion vector.

Abstract: The present disclosure relates to means to enable reduction of memory access in motion vector determination and/or refinement for a prediction block. In particular, the present disclosure relates to means to enable reduction of memory access in motion vector determination and/or refinement performed on a sub prediction block basis. In other words, a prediction block is split into sub prediction blocks for which at least the motion vector refinement is performed individually. The memory access window which limits the samples accessible during the motion vector determination and refinement of the sub prediction blocks does not exceed the memory access window for performing the motion vector determination and/or refinement for the prediction block.

Abstract: The present disclosure provides a method of coding implemented by a decoding device, the method comprising: obtaining a splitting mode index value for a current coding block; obtaining an angle index value angleIdx for the current coding block according to the splitting mode index value and a table that specifies the angle index value angleIdx based on the splitting mode index value; setting an index value partIdx according to the angle index value angleIdx; and decoding the current coding block according to the index value partIdx.