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: 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 picture in a reference list. A plurality of intermediate vectors associated with one of the plurality of reference pictures is determined. The plurality of intermediate vectors includes an initial vector and a plurality of intermediate motion vectors (MVs). The initial vector is associated with the current picture. Each of the plurality of intermediate MVs is defined between two respective reference pictures of the plurality of reference pictures. A candidate motion vector predictor (MVP) is determined for the current block based on a sum of the plurality of intermediate vectors. The current block is reconstructed based on an MVP candidate list that includes the candidate MVP.

Abstract: A method of decoding of a video or picture bitstream implemented by a decoding device, the bitstream including a current sequence parameter set (SPS) comprising syntax elements that apply to a video sequence, the method comprising: obtaining a first syntax element used to determine a maximum number of temporal sublayers that is allowed to be present in each coded layer video sequence) referring to the current SPS, wherein a value of the first syntax element is in a range of 0 to a first value, wherein the first value is a value of a second syntax element used to determine the maximum number of temporal sublayers that is allowed to present in a layer in each coded video sequence referring to a video parameter set, when the second syntax element is referred to by the SPS; decoding the bitstream based on the value of the first syntax element.

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: A method of coding, implemented by a decoding device, includes obtaining a bitstream, wherein at least one bit in the bitstream represents 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: A partitioning method comprises determining whether a current block of a picture is a boundary block and whether the size of the current block is larger than a minimum allowed quadtree leaf node size; and if the current block is the boundary block and the size of the current block is not larger than the minimum allowed quadtree leaf node size (MinQTSize), applying forced binary tree (BT) partitioning to the current block. A method comprises making a determination that a current block of a picture is a boundary block and that a size of the current block is less than or equal to a minimum allowed quadtree (QT) leaf node size (MinQTSize); and applying, in response to the determination, forced binary tree (BT) partitioning to the current block.

Abstract: A video decoder is provided for the decoding of a video bitstream encoded in a temporal interpolated prediction (TIP) mode. First and second motion vectors pointing to respective reference frames, or reference pictures within those frames, are generated for a block of a current picture. The motion vectors are then refined by application of a decoder-side motion vector refinement (DMVR) process, based on a bilateral matching process, and the refined motion vectors are used to decode the block. The refinement may more specifically involve consideration of candidates for the refined motion vectors, selected by the bilateral matching. The refinement may be applied at both block and sub-block divisions of the current picture.

Abstract: This disclosure describes a set of advanced video coding technologies and is particular related to an intra warp prediction of a sample in a video block where the sample is intra predicted using a weighted sum of basis functions of pixel coordinate position of the sample. A set of weighting coefficients for the weighted sum may be predefined or may be derived by an encoder and signaled in a bitstream containing the video block at various coding levels.

Abstract: The present disclosure provides methods and devices of processing a block according to a merge candidate list, the method comprising: constructing a first list according to motion information of neighboring blocks of a current block; obtaining prediction information of the current block; when the prediction information of the current block indicates that a sub-block prediction is applied to the current block, obtaining a uni-prediction candidate for the current block according to the first list; using, the uni-prediction candidate for the current block to perform inter prediction of the current block. According to embodiment of the present disclosure, the regular merge list can be directly used and there is no need to explicitly generate the uni-prediction merge candidate list for sub-block prediction.

Abstract: A method of coding implemented by a decoding device is provided. The method includes parsing a bitstream to obtain a flag from a picture header of the bitstream, wherein the flag indicates whether a current picture is I picture. when the flag indicates that the current picture is I picture, a syntax element designed for inter prediction is inferred to a default value; or when the flag indicates that the current picture is P or B picture, obtaining a syntax element designed for inter prediction from the picture header.

Abstract: Coded information of a current block and neighboring blocks of the current block is received, where the current block is predicted in an intra directional mode. The intra directional mode of the current block is determined to be associated with an angle that is one of smaller than 90 degrees and larger than 180 degrees. In response to the intra directional mode of the current block being associated with the angle, whether a delta angle associated with the current block is a pre-defined delta angle is determined. In response to the delta angle associated with the current block not being the pre-defined delta angle, a single direction intra prediction and not a bi-direction intra prediction is applied to the current block. A sample of the current block is reconstructed based on an adjacent reference sample on a reference line that is determined according to the single direction intra prediction.

Abstract: A decoding method and a decoder for decoding a current block of a video frame is provided, wherein the decoding method comprises determining a list of Most Probable Modes (MPMs) for the current block. When at least one condition is satisfied, the list of MPMs includes a DC mode, a Vertical mode, a Horizontal mode, an intra prediction mode corresponding to a value of the Vertical mode with a first offset, and an intra prediction mode corresponding to the value of the Vertical mode with a second offset. The decoding method further includes obtaining a MPM flag and a MPM index for the current block from a bitstream of the video, and obtaining an intra prediction mode for the current block for reconstructing the current block.

Abstract: An example method of video encoding includes receiving video data comprising first block. The method also includes determining that the first block is to be encoded using first and second reference blocks and signaling a high-level syntax (HLS) flag in a video bitstream that indicates whether an implicit masked blending mode is enabled for the first block. When the HLS flag having a first value, encoding the first block using a first set of weighting factors for reference values from the first reference block and the second reference block. When (i) the HLS flag having a second value and (ii) at least one of the first reference block and the second reference block is at least partially outside of a corresponding reference boundary, encoding the first block using a second set of weighting factors for the reference values from the first reference block and the second reference block.

Abstract: It is provided a method of prediction coding of a current block, comprising: obtaining an intra prediction mode of a left neighbor block of the current block and an intra prediction mode of an above neighbor block of the current block; constructing a Most Probable Mode (MPM) list of intra prediction modes for the current block, the MPM list comprising at least 5 entries of intra prediction modes as follows: {ang, 2+((ang+61)%64), 2+((ang?1)%64), 2+((ang+60)%64), 2+((ang) %64)} when at least a first condition is fulfilled, where ang represents the intra prediction mode of the left neighbor block or the intra prediction mode of the above neighbor block.

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: A computing system receives a video bitstream that includes a current block and a syntax element indicating that the current block is to be predicted in a blending mode. The current block is encoded using information from first and second reference blocks. When a portion of the current block corresponds to a first area that (i) is within corresponding reference boundaries in both of the first and second reference blocks or (ii) is not within the corresponding reference boundaries in both of the first and second reference blocks, the system reconstructs the portion by averaging reference values from the first and second reference blocks. When the portion of the current block corresponds to a second area that is within the corresponding reference boundaries in only one of the first and second reference blocks, the system derives weighted reference values and reconstructs the portion by combining the weighted reference values.

Abstract: This disclosure relates generally to video coding/decoding and particularly for providing extension to block adaptive weighted prediction (BAWP) with multiple motion vectors. One method includes receiving a coded video bitstream; identifying, from the coded video bitstream, a first motion vector corresponding to a first reference block and a second motion vector corresponding to a second reference block; obtaining a first scaling factor corresponding to the first motion vector and a second scaling factor corresponding to the second motion vector by parsing the coded video bitstream; generating a first predicted block based on the first scaling factor and the first reference block according to a first linear equation; generating a second predicted block based on the second reference block according to a second linear equation; and reconstructing the current block based on the first predicted block and the second predicted block.

Abstract: An example method of video coding includes receiving a video bitstream comprising a plurality of blocks, including a current block. The method also includes identifying a current subblock in the current block and deriving a subsampled subblock by sub-sampling the current subblock. The method further includes deriving, using the subsampled subblock, a set of subblock motion vectors for the current subblock, and deriving a set of refined subblock motion vectors from the set of subblock motion vectors. Additionally, the method includes reconstructing the current subblock using the derived set of refined subblock motion vectors.

Abstract: The various implementations described herein include methods and systems for decoding a current coding block. In one aspect, a method includes retrieving one or more motion vector (MV) candidates from a reference MV bank. The method includes, in accordance with a determination that a first condition is satisfied, inserting the one or more MV candidates from the reference MV bank into the MVP list associated with the current coding block after derived MV candidates is inserted into the MVP list. The method includes, in accordance with a determination that the first condition is not satisfied, inserting the one or more MV candidates from the reference MV bank into the MVP list associated with the current coding block before the derived MV candidates is inserted into the MVP list. The method includes predicting the current coding block based on the MVP list.

Abstract: A method of filtering a sample value of a picture and a video decoding apparatus are disclosed, the method comprises: obtaining a reconstructed sample value for a block of the picture; obtaining filter coefficients for adaptive loop filtering according to a bitstream; obtaining a sum value according to the filter coefficients and the reconstructed sample value for the block; rounding the sum value according to a vertical position of a sample in the block, to obtain a rounded sum value; obtaining a filter reconstructed sample value for the block according to the rounded sum value.