Abstract: The present disclosure relates to adaptive filtering, e.g. adaptive loop filtering, which may be used during encoding and decoding of video pictures. In particular, the present disclosure provides for determining a zero coefficients map, in which each bit indicates whether or not a respective filter coefficient of a supporting region is to be included into the bitstream for an adaptive filter. An indication of the zero coefficients map is included into the bitstream before at least one filter coefficient of the adaptive filter indicated by the zero coefficients map as to be included into the bitstream. The provision of a zero coefficients map enables an efficient signaling and allows for flexible filter shapes that are particularly suitable for the content at hand.

Abstract: A motion information storing method comprises: determining a distance between a sample set in the current block and the common boundary; and comparing the distance with a threshold to determine whether third motion information is stored for the sample set, wherein the third motion information is derived by the first motion information and the second motion information.

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: The present disclosure relates to motion vector determination using template or bilateral matching and predictor generation based on the motion vector. The template or bilateral matching and/or the predictor generation use interpolation filtering. The interpolation filtering operation accesses integer sample positions within a window, and further uses padded sample values for integer sample positions outside the window, which are based on at least one sample within said window, and uses the accessed integer sample position values as well as the padded sample values to perform the template or bilateral matching and/or predictor generation.

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: Signalling of syntax elements in a sequence parameter set of a video bitstream is addressed. Particularly, it is provided a method of decoding a video bitstream wherein a sequence parameter set, SPS, is coded that contains syntax elements that apply to a video sequence, the method comprising obtaining a value of a first syntax element from the SPS used to specify whether a decoded picture buffer, DPB, parameters syntax structure is present in the SPS and obtaining a value of a second syntax element from the SPS, at least when determining that the value of the first syntax element specifies that the DPB parameters syntax structure is present in the SPS, used to specify the presence of a DPB syntax element in the DPB parameters syntax structure, wherein the DPB syntax element is applied to a temporal sublayer except for the highest temporal sublayer in the video sequence.

Abstract: An apparatus and method for marking availability of a candidate coding block for merge estimation of a current coding block within a coding tree unit (CTU). The candidate block may be marked as unavailable if a splitting depth of the current coding block is equal to or larger than a predetermined threshold and a first location of the candidate block and a second location of the current block are included in a same merge estimation region (MER). Otherwise, the candidate block is marked as available. A candidate block may be marked as unavailable also, when a parent block “parentCurr” of the current block and a parent block “parentCand” of the candidate block, with both parent blocks obtained by splitting, are the same block and when the size of the parentCand is smaller than a threshold.

Abstract: A method of coding implemented by a decoding device, comprising obtaining a video bitstream; decoding the video bitstream to obtain an initial intra prediction mode value for chroma component of a current coding block; determining whether a ratio between a width for luma component of the current coding block and a width for chroma component of the current coding block is equal to a threshold or not; obtaining a mapped intra prediction mode value for chroma component of the current coding block according to a predefined mapping relationship and the initial intra prediction mode value, when it's determined that the ratio is equal to the threshold; obtaining a prediction sample value for chroma component of the current coding block according to the mapped intra prediction mode value.

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: A device for encoding and a device for decoding a picture, respectively, and corresponding methods relating to the field of picture coding are provided. The devices are respectively configured to partition the picture into one or more slices, each slice comprising one or more tiles, and one or more slices holding coded picture data. Further, the devices are configured to encode the one or more slices holding coded picture data, thereby improving coding and decoding of pictures with uncoded buffer space.

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: It is provided a method of decoding a video bitstream implemented by a decoding device, the video bitstream including coded data for a plurality of pictures. The decoding method comprises: parsing an enabling flag for decoder motion vector refinement (DMVR) from a sequence parameter set of the video bitstream; parsing a disabling flag for DMVR from a syntax structure of a lower hierarchic syntax structure level than the sequence parameter set (SPS) level of the video bitstream; and performing DMVR based inter bi-prediction for a current block within at least one region of the current picture to obtain predicted sample values of the current block when at least one pre-defined condition is fulfilled, and wherein the at least one pre-defined condition comprises that the parsed value of the disabling flag specifies that DMVR based inter bi-prediction is enabled for at least one region of the current picture.

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.