Abstract: A video bitstream including coded information of a current block in a current picture is received. The coded information includes prediction samples of the current block. The prediction samples are obtained by a matrix multiplication of a matrix of coefficients and reference samples of the current block. A transform set is determined for the current block based on which of a subset of intra prediction modes is applied to the current block when one of the subset of the intra prediction modes is applied to the current block. The subset of intra prediction modes is derived based on the prediction samples of the current block. The current block is reconstructed based on the prediction samples and the transform set.

Abstract: In a method of video decoding, prediction information of a current coding block indicates that the current coding block is coded using a subblock-based temporal motion vector prediction (SbTMVP) mode. A plurality of displacement vector (DV) candidates is obtained. A template of the current coding block is compared with each of multiple templates, each template of the multiple templates being located at a position specified by a corresponding one of the plurality of DV candidates. A cost value associated with each one of the plurality of DV candidates is calculated based on the comparison of the template of the current coding block with each of the multiple templates. A list of the DV candidates is reordered based on the calculated cost values. The current coding block is predicted based at least on a selected DV candidate from the reordered list of the DV candidates.

Abstract: Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, processing circuitry receives a coded video bitstream including a current picture. The current picture includes a chroma block in a chroma separate tree, the chroma block being collocated in a same luma area with one or more luma blocks. The processing circuitry decodes, from the coded video bitstream, a syntax element that indicates a current picture referencing (CPR) mode for the chroma block, and determines, in response to the CPR mode, a chroma block vector for the chroma block according to one or more luma block vectors associated with the one or more luma blocks. The chroma block vector indicates a reference chroma block in the current picture. The processing circuitry reconstructs the chroma block based on the reference chroma block in the current picture.

Abstract: Processing circuitry determines a use of at least two prediction models on different samples in a current block. The processing circuitry generates predicted values of first samples in the current block according to a first prediction model and generates predicted values of second samples in the current block according to a second prediction model that is different from the first prediction model. The processing circuitry determines whether to apply a filter on a current sample in the current block based on whether one or more adjacent neighboring samples use a different prediction model from the current sample. Then, in response to a determination of applying the filter, the processing circuitry reconstructs the current sample based on a filtering output from the filter with predicted values of the current sample and the one or more adjacent neighboring samples being inputs of the filter.

Abstract: An example method of video coding includes receiving a video bitstream comprising a current block and a syntax element and identifying an intra prediction mode for the current block. The method also includes parsing the syntax element to determine whether to change the intra prediction mode when deriving a transform set index, and deriving the transform set index for the current block based on the intra prediction mode and the parsed syntax element. The method further includes selecting a first transform set from a plurality of transform sets according to the transform set index, and reconstructing the current block using the first transform set.

Abstract: A method for video decoding includes decoding prediction information of a current block indicating that local illumination compensation (LIC) is applied to the current block and an adjustment parameter used to adjust at least one parameter of the LIC. The method includes determining at least one of (i) a final scaling parameter ?f of the current block based on the adjustment parameter and an initial scaling parameter ?i that is included in the at least one parameter of the LIC and (ii) a final offset parameter ?f of the current block based on the adjustment parameter and an initial offset parameter ?i that is included in the at least one parameter of the LIC. The method includes determining an updated predictor of the current block based on (i) the at least one of ?f and ?f and (ii) the predictor and reconstructing the current block based on the updated predictor.

Abstract: A method for video decoding includes receiving coded information of a current block indicating inter prediction for the current block. Whether a current intermediate vector pointing to a first block in a first reference picture from a second block in a second reference picture is valid for deriving one of a chain-based MV and a chain-based MVP for the current block is determined based on one or more of reference picture information of the first reference picture, reference picture information of the current block, a position of the first block, and history information associated with at least one previously derived intermediate vector that is associated with the current block and the second block. When the current intermediate vector is valid, the one of the chain-based MV and the chain-based MVP is determined based on the current intermediate vector and the at least one previously derived intermediate vector.

Abstract: Some aspects of the disclosure provide a method of video decoding. For example, bitstream is received. The bitstream includes coded information of a sequence of pictures in a video. Training data for an online transform kernel derivation for a current block is collected based on one or more reconstructed blocks in the sequence of pictures. A transform kernel for the current block is derived based on the training data. The current block is reconstructed based on the transform kernel.

Abstract: A method for video encoding includes adjusting an orientation of a first picture from an original orientation to an adjusted orientation. The method includes encoding, in a bitstream, the adjusted first picture in the adjusted orientation. The method includes generating unified intermediate coding information of the first picture based on a unified orientation of a plurality of pictures in a picture buffer. The plurality of pictures in the picture buffer is oriented in the unified orientation. The unified intermediate coding information is stored in one or more intermediate coding information buffers associated with the first picture. The unified orientation is one of (i) the original orientation and (ii) the adjusted orientation. The method includes encoding, in the bitstream, a second picture based on the unified intermediate coding information of the first picture.

Abstract: A method for video decoding includes selecting a set of filter shapes from a plurality of sets of filter shapes associated with extrapolated filter-based intra prediction based on reconstructed information of a current block. The plurality of sets of filter shapes includes a first set of filter shapes and a second set of filter shapes. The method includes predicting, based on the selected set of filter shapes, a current sample in the current block using the extrapolated filter-based intra prediction. The first set of filter shapes only includes above-left positions that are above and to the left of a current position of the current sample. The second set of filter shapes includes one or more of (i) above-right positions that are above and to the right of the current position and (ii) below-left positions that are below and to the left of the current position.

Abstract: Some aspects of the disclosure provide a method of video decoding. For example, a bitstream is received, the bitstream includes coded information of a sequence of pictures in a video. Further, to apply a coding tool on a current block in a current picture in the sequence of pictures is determined, the coding tool is based on boundary gradient computation. Direction information of the current block is determined, and at least a boundary gradient associated with a sample of the current block is computed based on the direction information of the current block. A reconstructed block of the current block is generated by applying the coding tool that is based on at least the boundary gradient associated with the sample.

Abstract: A video bitstream is received. The video bitstream includes coded information of a current block in a current picture and of a plurality of reference pictures of the current block in a reference list. The coded information indicates that the current block is coded in an affine mode. A first control point motion vector (CPMV) of a first control point of the current block is determined. The first CPMV is associated with a sum of a plurality of intermediate vectors. The plurality of intermediate vectors includes an initial CPMV and an intermediate motion vector (MV). The initial CPMV is between the current picture and an initial reference picture of the plurality of reference pictures. The intermediate MV is between two respective reference pictures of the plurality of reference pictures. The current block is reconstructed based on the first CPMV of the first control point of the current block.

Abstract: The various implementations described herein include methods and systems for coding video. In one aspect, a method includes receiving a video bitstream comprising a plurality of blocks that includes a current block; identifying a block vector for the current block; determining a minimum-cost position in a predetermined area of a location indicated by the block vector; deriving a sub-pixel position based on the minimum-cost position; and reconstructing the current block using the sub-pixel position.

Abstract: An example method of video decoding includes receiving a video bitstream comprising a plurality of blocks, including a current block. The method includes obtaining a reference block for the current block. The method includes obtaining a set of reference template samples for the reference block. The method includes determining a direction for the current block based on the set of reference template samples. The method further includes decoding the current block using the direction.

Abstract: A non-transitory computer-readable storage medium storing instructions which when executed by a processor cause the processor to perform a method of encoding a bitstream. A first collocated block in a first collocated picture is determined based on a first motion shift candidate of a current block in a current picture. First motion information of a current template of the current block is determined based on one or more pieces of motion information of the first collocated block. The first motion information indicates one of a first reference template and a first subblock reference template in a first reference picture. The one of the first reference template and the first subblock reference template is determined based on the first motion information. A first template matching cost is determined based on the current template and the one of the first reference template and the first subblock reference template.

Abstract: Aspects of the disclosure provide a method and an apparatus for video encoding/decoding. The apparatus includes processing circuitry for: receiving prediction information of a current coding block in a current picture from a coded video bitstream, the prediction information indicating that the current coding block is coded using a subblock-based temporal motion vector prediction (SbTMVP) mode; deriving multiple displacement vector (DV) candidates by applying multiple DV offset candidates to a fixed DV predictor of the current coding block; comparing a template of the current coding block with each of multiple templates, each template of the multiple templates being located at a position specified by a corresponding one of the multiple DV candidates; calculating a cost value associated with each one of the multiple DV offset candidates based on the comparing; and reordering DV offset indices of the multiple DV offset candidates based on their calculated cost values.

Abstract: Example methods for decoding and encoding using classifiers for determining transformation information are described herein. An example method of video decoding includes receiving a video bitstream comprising a plurality of blocks that includes a current block. The method also includes applying a classifier to coded information for the current block to determine a transform kernel for the current block. The method further includes reconstructing the current block by applying the transform kernel to perform an inverse transform for the current block.

Abstract: A method includes receiving a bitstream indicating an adjustment factor to a linear formula used in a formula-based inter prediction of a current block in a current picture based on a reference block in a reference picture. The formula-based inter prediction generates a prediction sample of the current block based on the linear formula applied to one or more reconstructed samples in the reference block. The adjustment factor is applied on an initial slope parameter to determine an adjusted slope parameter. An adjusted offset parameter is calculated according to the adjusted slope parameter and a first weighted average of a plurality of first samples in a reference template of the reference block. An adjusted linear formula is generated based at least on the adjusted slope parameter and the adjusted offset parameter. At least a reconstructed sample of the current block is determined according to the adjusted linear formula.

Abstract: A method of video decoding includes receiving motion vector (MV) offset information of a current block in a current picture from a coded video bitstream. The current block includes a plurality of subblocks to be coded with a subblock-based temporal motion vector prediction (SbTMVP) mode. Motion information of a subblock in the plurality of subblocks is determined based on motion information of a corresponding subblock in a collocated block in a collocated reference picture. The collocated block is collocated with the current block and is indicated by a displacement vector (DV) of the current block. Updated motion information of the subblock in the plurality of subblocks is determined based on the motion information of the subblock in the plurality of subblocks and an MV offset of the current block indicated by the MV offset information. The subblock in the plurality of subblocks is reconstructed based on the updated motion information.

Abstract: In method of video processing in an encoder, a candidate list that comprises a plurality of motion vector (MV) candidates for predicting a current block is determined. The plurality of MV candidates in the candidate list is modified according to a motion information based diversity assessment of the plurality of MV candidates. The modifying the plurality of MV candidates prioritizes a subset of MV candidates with a larger difference in motion information. An index indicating a selected MV candidate from the modified candidate list is encoded in a video bitstream. The current block is encoded based on the selected MV candidate.