Abstract: Aspects of the disclosure provide methods and apparatuses for video encoding. In some examples, an apparatus includes processing circuitry that identifies a reference sub-block in a previously reconstructed block of a picture. The processing circuitry determines whether reconstructed samples of the reference sub-block are included in an intra block copy search range according to a position of a current sub-block in a current block of the picture. The processing circuitry determines whether the reference sub-block is valid based on the reconstructed samples of the reference sub-block being determined as included in the intra block copy search range according to the position of the current sub-block. The processing circuitry further encodes the current sub-block based on the reconstructed samples of the reference sub-block in response to the reference sub-block being determined as valid.

Abstract: A method for video encoding includes determining a parameter corresponding to the coded video bitstream based on a calculated maximum number of candidates. The parameter is in a range from 0 to 5-sps_sbtmvp_enabled_flag, where the sps_sbtmvp_enabled_flag equal to 1 specifies that subblock based temporal motion vector predictors are used. The sps_sbtmvp_enabled_flag equal to 0 specifies that the subblock based temporal motion vector predictors are not used. In response to a current block being in a subblock based prediction mode, the method includes encoding samples of the current block based on a candidate selection from a constructed subblock based merge candidate list of the current block. The constructed subblock based merge candidate list of the current block is constrained by the maximum number of candidates in the subblock based merge candidate lists.

Abstract: Aspects of the disclosure provide methods for video encoding/decoding and processing circuitry. In some embodiments, the processing circuitry receives a block in an I slice from a video. In response to a slice type parameter indicating the I slice and at least a width or height of the block being greater than 64, the processing circuitry sets a current mode type parameter to MODE_TYPE_INTRA. The processing circuitry then determines whether a skip mode is possible for the block in the I slice based on at least one of the width or the height of the block being greater than 64 and the current mode type parameter. When neither the width nor the height of the block is greater than 64 and the current mode type parameter is not MODE_TYPE_INTRA, the processing circuitry determines to output the skip mode flag into a coded video bitstream for the block.

Abstract: Aspects of the disclosure provide a method and an apparatus including processing circuitry for video decoding. The processing circuitry can decode prediction information of a chroma coding block (CB) from a coded video bitstream. The prediction information indicates an intra block copy (IBC) mode for the chroma CB and the chroma CB includes one or more chroma units. The processing circuitry can determine a chroma block vector (BV) for one of the one or more chroma units based on at least one luma unit collocated with the one of the one or more chroma units. The at least one luma unit is coded in the IBC mode. The processing circuitry can reconstruct at least one sample in the one of the one or more chroma units based on the chroma BV. The at least one luma unit and the chroma CB can be associated with separate luma-chroma coding trees.

Abstract: A method for video encoding includes determining a corresponding motion vector for each of multiple control points of a base predictor. The method further includes determining a corresponding motion vector difference for each of the multiple control points of the base predictor based on the determined motion vector for each respective control point. The method further includes generating prediction information of the current block to be included in a coded video bitstream. The prediction information includes (i) a usage flag indicative of the affine merge mode with offset, (ii) offset parameters defining the determined corresponding motion vector difference for each of the one or more of the control points, and (iii) a zero motion vector difference flag for the multiple control points of the base predictor. The zero motion vector difference flag indicates whether offset parameters for the respective control point are provided in the prediction information.

Abstract: A method of video encoding in an encoder is described. A triangle merge list of a current coding block in a set of coding blocks is constructed based on a number of triangular merge mode candidates. The number of triangular merge mode candidates in the triangle merge list is less than or equal to a maximum number of triangular merge mode candidates. A first syntax element that indicates the maximum number of triangular merge mode candidates is generated. Further, a coded video bit stream that includes the first syntax element is generated.

Abstract: A video bitstream comprising coding information of a current block in a current picture is received. The coding information indicates that the current block is coded by a flip mode in which locations of samples of the current block are adjusted within the current block. A reference block is determined from a plurality of candidate reference blocks in a reconstructed region of the current picture for the current block based on template matching (TM) costs. The TM costs indicate differences between a template of the current block and respective templates of the plurality of candidate reference blocks. A reconstruction block of the current block is determined based on the determined reference block. The current block is reconstructed by adjusting locations of samples of the reconstruction block within the reconstruction block based on the flip mode.

Abstract: Aspects of the disclosure provide method and apparatus for video coding. In some examples, an apparatus includes receiving circuitry and processing circuitry. The processing circuitry decodes, from a coded video bitstream, a syntax element for an adjusted version of an initial quantization parameter (QP) value at a picture level for a picture. The adjusted version is in a range with an upper boundary that is changed with a maximum QP value. Then, the processing circuitry determines the initial QP value of a segment (such as a slice, a tile, a group of tiles and the like) in the picture based on the syntax element and determines a QP value for a block in the segment according to the initial QP value of the segment and adjustments associated with the block. Then, the processing circuitry performs an inverse quantization on quantized data of the block according to the determined QP value.

Abstract: A video bitstream is received. The video bitstream includes a current block comprising a plurality of subblocks and a template region of the current block comprising a plurality of template subblocks adjacent to at least one of a top side and a left side of the current block. A motion vector (MV) located in a center position of the current block is determined. The MV is determined based on at least one MV of the plurality of subblocks of the current block. A MV for each of the plurality of template subblocks is determined based on the MV located in the center position of the current block and a respective MV of a corresponding subblock of the plurality of subblocks that is adjacent to the respective template subblock. The current block is reconstructed based on the determined MVs for the plurality of template subblocks.

Abstract: Aspects of the disclosure include methods and apparatuses for video coding. One of the apparatuses includes processing circuitry that receives a bitstream of a current block in a current picture. The current block is coded with a directional nearest neighbor prediction (DNNP) mode. The processing circuitry selects a prediction value for a sample in the current block from a top-left value, a top value, or a left value based on one or more difference values between respective paired values of (i) the top-left value associated with a top-left reference sample that is a top-left neighbor of the current block, (ii) the top value associated with a top reference sample that is a top neighbor of the sample in the current block, and (iii) the left value associated with a left reference sample that is a left neighbor of the sample in the current block. The processing circuitry reconstructs the current block using the selected prediction value for the sample in the current block.

Abstract: A method of video encoding includes receiving a merge sharing region including a plurality of coding blocks, constructing a shared merge candidate list for the merge sharing region, and encoding a current inter coded coding block in the merge sharing region based on the shared merge candidate list. The method also includes determining whether to update a history-based motion vector prediction (HMVP) table with motion information of the current inter coded coding block based on whether the current inter coded coding block is inter coded with a merge/skip mode. The method further includes updating the HMVP table with the motion information of the current inter coded coding block when the HMVP table is determined to be updated with the motion information of the current inter coded coding block.

Abstract: A method, computer program, and computer system for encoding or decoding video data, and indicating, with a syntax element, types of slices for all slices of a coded picture, the syntax element being coded using an unsigned integer.

Abstract: Aspects of the disclosure provide a method and an apparatus for video encoding. Whether a block size cbSize of a chroma block in luma samples is less than or equal to a minimum allowed chroma quaternary tree (QT) leaf node size MinQtSizeC in luma samples such that cbSize <=MinQtSizeC is determined. In response to the block size cbSize of the chroma block in luma samples being less than or equal to the minimum allowed chroma QT leaf node size MinQtSizeC in luma samples, a QT split is determined as disallowed for the chroma block. Partition information indicating that a chroma coding tree structure in a dual tree is applied to the chroma block is generated, the partition information further indicating the block size cbSize of the chroma block in luma samples and the minimum allowed chroma QT leaf node size MinQtSizeC in luma samples.

Abstract: A method for video decoding in a decoder is provided. Coding information of a current block (CB) from a coded video bitstream is decoded. The coding information includes weighted prediction information that indicates a weighted prediction for the CB. A determination is made as to whether to apply a prediction refinement with optical flow (PROF) on the CB based on the weighted prediction information. The CB is reconstructed based on the weighted prediction and whether the PROF is determined to be applied on the CB.

Abstract: A method of controlling intra prediction for decoding or encoding of a video sequence, is performed by at least one processor and includes obtaining intra prediction modes including directional modes respectively corresponding to angular prediction directions, a first amount of one or more of the directional modes being excluded from the intra prediction modes based on a second amount of the intra prediction modes and a third amount of most probable modes (MPMs). The method further includes selecting, as the MPMs, two or more of the intra prediction modes from which the one or more of the directional modes are excluded, and selecting, for decoding the video sequence, one of the intra prediction modes from which the one or more of the directional modes are excluded.

Abstract: A data decoding method, performed by a computer device, is provided. The data decoding method includes obtaining coded data corresponding to a current to-be-decoded unit, obtaining a coding mode restriction type corresponding to the current to-be-decoded unit by decoding the coded data, determining a candidate coding mode set corresponding to the current to-be-decoded unit according to the coding mode restriction type, the candidate coding mode set comprising a block copy intra-frame coding mode, selecting a target coding mode from the candidate coding mode set, and decoding the current to-be-decoded unit according to the target coding mode, thereby obtaining corresponding decoded data.

Abstract: An apparatus for video decoding includes processing circuitry. The circuitry can be configured to receive a current block that is affine coded and included in a current coding tree unit (CTU), and determine an inherited affine candidate based on regular motion information of two minimum blocks in a rightmost column of minimum blocks of a left neighboring CTU of the current CTU when the current block is adjacent to a left boundary of the current CTU.

Abstract: Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes receiving circuitry and processing circuitry. In some embodiments, processing circuitry decodes, prediction information for a block in an I slice from a coded video bitstream, and determines, whether an intra block copy (IBC) mode is possible for the block in the I slice. In response to a slice type parameter indicating I slice and at least a width or height of the block being greater than 64, the processing circuitry sets a current mode type parameter to MODE_TYPE_INTRA. Further, in an embodiment, the processing circuitry decodes a flag that indicates whether a skip mode is applied on the block from the coded video bitstream. Then, the processing circuitry reconstructs the block at least partially based on the flag.

Abstract: An apparatus for video decoding, includes processing circuitry configured to determine an affine model for a current block coded with an interweaved affine mode. Based on the affine model, a first prediction block corresponding to a first pattern for partitioning the current block into first sub-blocks and a second prediction block corresponding to a second pattern for partitioning the current block into second sub-blocks can be generated. The first and second prediction blocks include interpolated samples having an intermediate bit-depth larger than an input bit-depth of the current block. Co-located first and samples in the first and second prediction blocks with a precision corresponding to the intermediate bit-depth are weighted averaged to obtain averaged samples. The averaged samples are rounded to the input bit-depth to obtain corresponding third samples in a final prediction block of the current block.

Abstract: A method for video encoding includes determining whether coding of a current block in an IBC prediction mode is performed in an explicit mode or an implicit mode based on whether a difference exists between a block vector and a corresponding block vector predictor. The current block is part of a current picture to be coded. The method further includes constructing a block vector predictor candidate list for the current block, the block vector predictor candidate list having a first number of block vector predictor candidates in the implicit mode, and having a second number of block vector predictor candidates in the explicit mode. The method further includes selecting a block vector predictor candidate from the constructed block vector predictor candidate list and encoding the current block according to the selected block vector predictor candidate.