Tencent America LLC

Other

Tencent Technology (shenzhen) Company Limited

Apple Inc.

Guichun Li

Shan Liu

Xiaozhong Xu

Xiang Yang Li

Xiang Li

Xin Zhao

Lien-Fei Chen

Meng Xu

Liang Zhao

Jing Ye

Byeongdoo Choi

Ling Li

Han Gao

Hong Zhang

Yixin Du

Alexandros Michael Tourapis

Anish Tamse

Arash Vosoughi

Bin Zhu

Alican Nalci

Hilmi Enes Egilmez

Thuong Nguyen Canh

Linfeng Guo

Lien-fei Chen

Dzung T Hoang

Van Luong Pham

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.

Directional nearest neighbor prediction mode

Processing circuitry receives coded information of a motion vector difference (MVD). The processing circuitry calculates cost values associated with value combinations for a plurality of bits in coding bits of the MVD, at least one of the plurality of bits is a bit in a codeword for indicating a magnitude for the MVD. The processing circuitry determines a combination of prediction values for the plurality of bits from the value combinations, the combination of prediction values is associated with a lowest cost value in the cost values. The processing circuitry decodes the coded information of the MVD to obtain one or more indicators for the combination of prediction values, the one or more indicators indicates whether the plurality of bits is correctly predicted by the combination of prediction values. The processing circuitry determines the MVD based on the combination of prediction values and the one or more indicators.

Method and apparatus for motion vector coding

Processing circuitry receives a video bitstream comprising a current coding block in a picture coded in a template-based multiple reference line intra prediction (TMRL) mode. The processing circuitry determines combinations of reference lines and intra prediction modes for the current coding block. A first combination in the combinations includes a first reference line and a first intra prediction mode. For the first combination, the processing circuitry calculates template entry delta values respectively associated with entries of a template of the current coding block based on the first reference line and the first intra prediction mode, and calculates a first template matching cost value by unequal weighting of the template entry delta values. The processing circuitry sorts the combinations according to template matching cost values respectively associated with the combinations, selects a specific combination from the sorted combinations, and reconstructs the current coding block according to the specific combination.

Template matching for multiple reference line intra prediction

In a method of video decoding at a video decoder, a bitstream of a coded video associated with a current coding block that is partitioned into a first part and a second part along a partition edge for prediction in a geometric partitioning mode is received. A weight index at a sample position of the current coding block is determined based on a look up table. The weight index is used to derive a blending weight for blending two prediction signals corresponding to the first part and the second part of the current coding block. A stored motion vector type for a first motion storage unit in a motion field of the current coding block is determined based on a motion index of the first motion storage unit. A motion vector of the first motion storage unit is stored based on the stored motion vector type.

Weight derivation for geometric partitioning mode

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes processing circuitry. The processing circuitry receives a coded video bitstream including a current picture. The current picture includes a current block. The processing circuitry determines, based on decoded information from the coded video bitstream, that the current block in the current picture is coded in an affine bi-prediction mode. The current block is predicted by a plurality of control point motion vectors. The processing circuitry refines the plurality of control point motion vectors by applying bilateral matching motion refinement, and reconstructs the current block according to the refined plurality of control point motion vectors associated with the current block.

Method for affine motion refinement

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.

Motion vector derivation of subblock-based template-matching for subblock based motion vector predictor

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. The processing circuitry extracts, from a bitstream, a signal indicative of an application of a template matching based block vector refinement for coding a current block in a current picture referencing (CPR) mode. The processing circuitry derives a first refined block vector associated with the current block according to the template matching based block vector refinement. The first refined block vector includes a first block vector refinement offset applied on a first block vector associated with the current block. The processing circuitry reconstructs the current block according to a first reference block in a same picture as the current block, the first reference block being indicated by the first refined block vector.

Block vector refinement method for intra block copy

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. The processing circuitry receives a bitstream carrying a plurality of pictures, and determines at least a motion compensation padding (MCP) block that is located in an MCP area outside of a picture and next to a picture boundary of the picture. The processing circuitry derives, according to a plurality of candidates with positions located at the picture boundary within the picture, a motion vector of the MCP block for motion compensated boundary padding, and reconstructs at least a sample in the MCP block according to the derived motion vector for the motion compensated boundary padding.

On motion compensated picture boundary padding

Processing circuitry for video decoding receives coded information of a current block in a current picture from a coded video bitstream, the coded information is indicative of applying local illumination compensation (LIC) on the current block in the current picture. The processing circuitry derives, parameters of an LIC model, according to a first template of a current block and a second template of a reference block in a reference picture. The reference block is pointed based on a motion vector for the current block. The first template includes a subset of reconstructed neighboring samples that are above and left to the current block, and the second template includes collocated samples to the subset of the reconstructed neighboring samples. The processing circuitry applies the LIC model on the current block according to the reference block to generate compensated samples of the current block.

Local illumination compensation

Processing circuitry receives coded information of a current block indicative of applying LIC on the current block according to at least a first reference block in a first reference picture. The processing circuitry determines, for a sample in the current block, at least a first reference sample in the first reference block, the first reference sample is co-located to the sample in the current block. The processing circuitry calculates a weighted sum of a plurality of terms and an offset for the LIC according to a plurality of parameter values for a plurality of parameters used in the LIC, and reconstructs the sample accordingly. The plurality of parameter values includes at least a first weighting value for a first weighting that is applied to a non-linear term of the first reference sample of a kth power, k is a power index value and is not equal to 1.

Local illumination compensation for bi-prediction

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes processing circuitry. The processing circuitry extracts, from a bitstream, merge with motion vector difference (MMVD) candidate information for a current block in a current picture. The processing circuitry generates a first MV refinement offset associated with a first motion vector for the MMVD candidate based on a refined step size and a plurality of refinement positions. The processing circuitry derives a first refined motion vector (MV) value associated with a MMVD candidate according to the MMVD candidate information and the generated first MV refinement offset. The processing circuitry reconstructing the current block according to a first reference block in a first reference picture, the first reference block is indicated by the derived first refined MV value.

MMVD candidate refinement methods

A method and an apparatus are provided. The apparatus includes processing circuitry that receives a coded video bitstream comprising a current picture that includes a current block. The processing circuitry determines, based on a syntax element in the coded video bitstream, that the current block including a plurality of subblocks is coded in a subblock-based temporal motion vector prediction (SbTMVP) mode. The processing circuitry determines a plurality of displacement vector (DV) predictor (DVP) candidates and receives a base index indicating a DVP in the plurality of DVP candidates and a DV offset of the current block. The processing circuitry determines a DV based on the DVP and the DV offset. The DV indicates a block collocated with the current block in a collocated reference picture. The processing circuitry reconstructs a subblock in the plurality of subblocks based on motion information of a corresponding subblock in the collocated block.

Subblock level temporal motion vector prediction with multiple displacement vector predictors and an offset

Aspects of the disclosure provide a method and an apparatus including processing circuitry that adds merge candidates into a merge candidate list of a current block in a current picture. The merge candidates include available merge candidates including one or more of spatial motion vector predictors (MVP(s)), temporal MVP(s), non-adjacent MVP(s), history-based MVP(s), and pairwise average MVP(s). Whether the merge candidate list includes all available SMVP, TMVP, NA-MVP, HMVP, and PAMVP, and no merge candidate in the merge candidate list has a zero motion vector (zero MV) are determined. If the merge candidate list includes all available SMVP, TMVP, NA-MVP, HMVP, and PAMVP, and no merge candidate in the merge candidate list has the zero MV, the merge candidate having the zero MV is added to the merge candidate list. Merge candidates in the merge candidate list including the merge candidate having the zero MV are reordered using template matching.

Zero motion vector in adaptive reordering of merge candidates (ARMC)

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. The processing circuitry determines, a use of an inherited context initialization in a context-based adaptive binary arithmetic coding (CABAC) for decoding a current portion of a video sequence carried by a bitstream. The processing circuitry decodes, from the bitstream, a syntax value that indicates a decoded portion in the video sequence for a context inheriting, and initializes context models for the CABAC based on stored context states associated with the decoded portion. Further, the processing circuitry decodes, the current portion from the bitstream according to the context models that are initialized based on the stored context states associated with the decoded portion.

CABAC inherited context initialization

Method, apparatus, and non-transitory storage medium for fusing sub-block motion vector predictors into one sub-block motion vector predictor during video coding and decoding is provided. The method may include deriving a first displacement vector for a sub-block of a current block identifying a co-located sub-block of a co-located picture, and based on the identified co-located sub-block, determine whether the co-located sub-block overlaps with one or more sub-blocks associated with a motion field grid in the co-located picture. Based on determining that the co-located sub-block overlaps with the one or more sub-blocks, the method may include, retrieving two or more sub-block motion vectors respectively associated with the one or more sub-blocks. A final motion vector predictor for the sub-block of the current block may be derived based on the two or more sub-block motion vectors retrieved.

Growing community of inventors

Milpitas, CA, United States of America

Guichun Li