Tencent America LLC

Qualcomm Incorporated

Tencent Technology (shenzhen) Company Limited

Xiang Li

Shan Liu

Xin Zhao

Guichun Li

Xiaozhong Xu

Liang Zhao

Lien-Fei Chen

Ling Li

Cheung Auyeung

Li Zhang

Meng Xu

Byeongdoo Choi

Yixin Du

Ying Chen

Stephan Wenger

Hongbin Liu

Marta Karczewicz

Jianle Chen

Kai Zhang

Joel Sole Rojals

Li Feng Zhang

Hong Zhang

Krishnakanth Rapaka

Jing Ye

Madhu Peringassery Krishnan

Hsiao-Chiang Chuang

Chao Pang

Cheng-Teh Hsieh

Vadim Seregin

Wei-Jung Chien

Anish Tamse

Yi-Wen Chen

Sungwon Lee

Robert Owen Hughes

Thuong Nguyen Canh

Charles J Bieberich

Michael Robert Turner

Yu-Chen Sun

Lienfei Chen

Zhongzheng Yuan

Qiang Zhang

Feng Zou

Johanna Bakonyi

Delphine Collin

Steven Richard Brunette

Robert Sibley

Lifen Wu

Shuang Liang

Tejashree Joglekar

A method of and an apparatus for controlling intra prediction for decoding of a video sequence are provided. The method may include based on a reference line index signaling a first reference line nearest to a coding unit, among a plurality of reference lines adjacent to the coding unit, applying intra smoothing on one or more first reference lines comprising the first reference line, among the plurality of reference lines, and based on the intra smoothing being applied on the one or more first reference lines, applying a position-dependent intra prediction combination (PDPC) on one or more third reference lines comprising the first reference line, among the plurality of reference lines, while preventing application of the PDPC on one or more fourth reference lines other than the one or more third reference lines, among the plurality of reference lines.

Multi-line intra prediction

In a method for video decoding, prediction information of a current block is decoded from a coded video bitstream. The prediction information is indicative of a reference line selected from multiple reference lines and an intra prediction mode selected from a set of potential intra prediction modes that is associated with the reference line. At least one sample of the current block is reconstructed based on the intra prediction mode and at least one reference sample in the reference line. When the reference line is a non-zero reference line, a first set of potential intra prediction modes associated with the non-zero reference line includes a smaller number of potential intra prediction modes compared to a second set of potential intra prediction modes associated with a zero reference line. The first set of potential intra prediction modes only includes most probable modes.

Intra prediction with multiple reference lines

First affine parameters and second affine parameters for each of one or more affine models associated with a current block are determined. The first affine parameters of the respective affine model are associated with a first motion vector for a first reference picture of the current block. The second affine parameters of the respective affine model are associated with a second motion vector for a second reference picture of the current block. The first affine parameters and the second affine parameters of the respective affine model have opposite signs. Control point motion vectors (CPMVs) of the affine motion of the current block are determined by performing the affine bilateral matching based on the determined first affine parameters and the determined second affine parameters of the one or more affine models. The current block is reconstructed based on the CPMVs of the affine motion of the current block.

Affine models use in affine bilateral matching

Aspects of the disclosure provide a method and an apparatus including processing circuitry that performs template matching (TM) on motion vector resolution (MVR) pairs of a current block by determining a TM cost corresponding to each one of the MVR pairs. The current block is predicted with an affine adaptive motion vector prediction (ΔMVP) mode. Each MVR pair includes a first MVR in a first plurality of MVRs corresponding to a first reference picture and a second MVR in a second plurality of MVRs corresponding to a second reference picture. Each TM cost is determined based on a current template of the current block and a bi-predictor of the respective MVR pair. The bi-predictor is based on a first reference template in the first reference picture and a second reference template in the second reference picture. An MVR pair is selected based on the determined corresponding TM costs.

Template-matching based adaptive motion vector resolution (AMVR) for bi-prediction and an affine mode

A method for video decoding includes determining that an angular intra prediction mode for a current block is a wide angle mode. The method further includes determining a non-wide angle mode that corresponds to the wide angle mode, the non-wide angle mode being spaced apart from the vertical mode or the horizontal mode by an angular distance that is less than or equal to the predetermined threshold. The method further includes, in response to a determination that an intra prediction coding tool and coding tool parameters are specified for the determined non-wide angle mode, performing intra prediction for the current block using the wide angle mode, using the intra prediction coding tool, and using the coding tool parameters specified for the determined non-wide angle mode.

Coding tool parameter selection by mapping wide angle intra prediction modes to non-wide intra prediction modes

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. An apparatus for video decoding includes processing circuitry that decodes prediction information for a current block in a current coded picture. The prediction information indicates a motion vector predictor index (MVP_idx) for selecting a motion vector predictor in a motion vector predictor list. The processing circuitry determines whether the MVP_idx is smaller than a threshold. When the MVP_idx is determined to be smaller than the threshold, the processing circuitry decodes a motion vector difference (MVD) corresponding to the motion vector predictor and reconstructs the current block based on the motion vector predictor and the MVD. When the MVP_idx is determined to be equal to or larger than the threshold, the processing circuitry reconstructs the current block based on the motion vector predictor without the MVD which is not signaled in the coded video sequence.

Methods and apparatuses for video coding

Aspects of the disclosure provide a method and an apparatus including processing circuitry for video decoding. The processing circuitry decodes, from a coded video bitstream, a first syntax element indicating whether a first component in the coded video bitstream is coded based on a second component in the coded video bitstream. The processing circuitry determines whether to decode one or more second syntax elements for a chroma related coding tool based on the first syntax element. The chroma related coding tool is a luma mapping with chroma scaling coding tool or a cross-component adaptive loop filter. The one or more second syntax elements are decoded when the first syntax element indicates that the first component is coded based on the second component. The one or more second syntax elements are not decoded when the first syntax element indicates that the first component is not coded based on the second component.

Signaling presence of chroma component in video bitstream

Video decoding and encoding methods and apparatuses are provided. The decoding method includes: obtaining a first parameter set corresponding to a to-be-decoded video frame; determining an effective quantization matrix (QM) according to syntax elements included in the first parameter set, the effective QM being a QM actually used for inversely quantizing quantized transform coefficients during decoding of the to-be-decoded video frame; and decoding the effective QM.

Video decoding method and apparatus, video encoding method and apparatus, device, and storage medium

Coded information indicates that an adaptive up-sampling filter is applied to a current block in a current picture. A respective class for each of a plurality of subblocks of the current block is determined. A respective filter coefficient set is determined for each of the plurality of subblocks from a plurality of filter coefficient sets of the adaptive up-sampling filter. The respective filter coefficient set is determined based on at least one class corresponding to the respective subblock and a respective sampling rate of reference pixel resampling (RPR) applied on a reference picture of the current picture. The respective sampling rate is associated with one of a plurality of phases of the RPR. The adaptive up-sampling filter is applied to the current block to generate filtered reconstructed samples of the current block based on the determined respective filter coefficient sets without applying a secondary adaptive loop filter (ALF).

Adaptive up-sampling filter for luma and chroma with reference picture resampling (RPR)

In a method, coded information of a current block and neighboring blocks of the current block in a current picture is received from a coded video bitstream. A list of merge candidates of the current block is generated based on the neighboring blocks of the current block. The list of merge candidates of the current block is divided into a plurality of subgroups. Each of the plurality of subgroups includes one or more merge candidates. The one or more merge candidates are ordered within each subgroup by a respective template matching (TM) cost associated with each of the one or more merge candidates. The current block is reconstructed based on a merge candidate selected from the list of merge candidates of the current block.

Grouping based adaptive reordering of merge candidate

In a method of decoding, coded information of a coding unit (CU), a template region, and a plurality of reference regions is received. The coded information includes a first syntax element indicating whether the CU is predicted based on a template matching based multiple reference line (MRL) intra prediction mode. In response to the first syntax element indicating that the CU is predicted based on the template matching based multiple reference line (MRL) intra prediction mode, a plurality of cost values is determined between (i) respective prediction samples of the template region based on samples in each of the plurality of reference regions, and (ii) reconstructed samples of the template region corresponding to the respective prediction samples. A reference region from the plurality of reference regions is determined based on the plurality of cost values. Samples of the CU are reconstructed based on the samples in the determined reference region.

Intra mode selection and signaling

A method for coding video data, executable by a processor, includes receiving video data; entropy-parsing the received video data into one or more components; de-quantizing the one or more entropy-parsed components; performing a joint component secondary transformation (JCST) on the one or more components in accordance with a JCST kernel selected based on one of (i) a prediction mode corresponding to the video data, (ii) a primary transform type of a current block, and (iii) a secondary transform kernel selected for the current block; and decoding the video data based on one or more residual components corresponding to the joint component secondary transformed components.

Mode-dependent joint component transform

One or more intra mode predictors of a current block are determined, where the one or more intra mode predictors are derived based on the neighboring samples of the current block via either a decoder side intra mode derivation (DIMD) or a template-based intra mode derivation (TIMD). Whether a position dependent intra prediction combination (PDPC) is to be applied is determined based on the one or more intra mode predictors. In response to the determining that the PDPC is to be applied, a fusion process is performed on the one or more intra mode predictors to combine the one or more intra mode predictors into a single intra mode predictor. The PDPC is applied based on the single intra mode predictor to generate a modified predictor of the current block. The current block is reconstructed based on the modified predictor generated by the PDPC.

Applying PDPC after fusion of plural intra mode predictors

A method and apparatus for inter prediction performed by at least one processor. The method for inter prediction comprising: receiving a coded video bitstream that includes a current picture, and first and second reference pictures associated with the current picture, the current picture including at least one block encoded in accordance with an inter bi-prediction mode, the at least one block including a first motion vector that points to the first reference picture and a second motion vector that points to the second reference picture; determining whether an out of boundary condition associated with the first motion vector and the second motion vector is satisfied; and adaptively disallowing bi-prediction to have MVs pointing to out of reference picture boundary, for inter bi-prediction mode.

Method and apparatus adaptive constraint on bi-prediction for out-of-boundary conditions

Aspects of the disclosure provide methods, apparatuses, and non-transitory computer-readable storage mediums for video encoding/decoding. In a method, prediction information for a current block is decoded. The prediction information indicates a first intra prediction mode and a secondary transform index, based on which a secondary transform core is determined. A first transform coefficient block is de-quantized from the prediction information. A size of the first transform coefficient block is less than a size of the secondary transform core. A part of a second transform coefficient block is generated based on the first transform coefficient block and the secondary transform core. A size of the second transform coefficient block equals the size of the secondary transform core. A size of the part of the second transform coefficient equals the size of the first transform coefficient block. The current block is reconstructed based on the part of the second transform coefficient block.

Secondary transform application for various block sizes

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Saratoga, CA, United States of America

Xiang Li