Hfi Innovation Inc.

Mediatek Corporation

Mediatek Singapore Pte. Ltd.

Tzu-Der Chuang

Ching-Yeh Chen

Yu-Wen Huang

Chih-Wei Hsu

Shan Liu

Chun-Chia Chen

Yu-Chen Sun

Chen-Yen Lai

Zhi-Yi Lin

Xiaozhong Xu

Man-Shu Chiang

Wang-Lin Lai

Shih-Ta Hsiang

Jing Ye

Chia-Ming Tsai

Jungsun Kim

Yi-Wen Chen

Yu-Ling Hsiao

Jian-Liang Lin

Olena Chubach

Shaw-Min Lei

Han Huang

Yu-Chi Su

Lulin Chen

Ding-Yun Chen

Zhenzhong Chen

Cheng-Yen Chuang

Han-Liang Chou

Chia-Yang Tsai

Chia-Yun Cheng

Wang Lin Lai

Chih-Yao Chiu

Chih-Ming Fu

Yu-Cheng Lin

Chih-Hsuan Lo

Zhi Zhou

Kung-Nien Yang

Jan Klopp

Shih-Chun Chiu

Yu Wang

Weijia Zhu

Chih-Ming Wang

Mei Guo

Xianguo Zhang

Mohammed Golam Sarwer

Ping Chao

Yu-Ting Shen

Zhen-Yen Lai

Methods and apparatus for video coding system utilizing Rate-Distortion Optimized Quantization (RDOQ) are provided. According to one method, a rate for a level belonging to a level set of a current quantized transform coefficient is estimated for a current coefficient group (CG) based on neighboring quantized coefficients of the current quantized transform coefficient and the current CG. A best level for the current quantized transform coefficient is selected from the level set for a best RD-cost. In another method, a TB is partitioned into M regions and M best regions are derived for the M regions according to RDOQ. At least two alternative region RD-costs are generated for each of the M best regions based on a relative position between each of the M best regions and a last significant region in the TB. TB RD-cost for the TB is selected according a last non-zero best region position.

Method and apparatus for hardware-friendly rate-distortion optimized quantization in video coding

A method and apparatus for block partition are disclosed. If a cross-colour component prediction mode is allowed, the luma block and the chroma block are partitioned into one or more luma leaf blocks and chroma leaf blocks. If a cross-colour component prediction mode is allowed, whether to enable an LM (Linear Model) mode for a target chroma leaf block is determined based on a first split type applied to an ancestor chroma node of the target chroma leaf block and a second split type applied to a corresponding ancestor luma node. According to another method, after the luma block and the chroma block are partitioned using different partition tress, determine whether one or more exception conditions to allow an LM for a target chroma leaf block are satisfied when the chroma partition tree uses a different split type, a different partition direction, or both from the luma partition tree.

Method and apparatus of luma-chroma separated coding tree coding with constraints

A video encoder receives raw pixel data to be encoded as a current block of a current picture of a video into a bitstream. The video encoder identifies multiple candidate bi-prediction positions for the current block, including a center position, a first set of offset positions, and a second set of offset positions. The first set of offset positions and the second set of offset positions interleave each other. The encoder computes distortion values for each of the candidate bi-prediction positions based on several possible weighting parameter values. The distortion values for the center position are based on each of the several possible weighting parameter values. The distortion values for the first set of offset positions are based on a first subset of the possible weighting parameter values. The distortion values for the second set of offset positions are based on a second subset of the possible weighting parameter values.

Shared architecture for multiple video coding modes

Method and apparatus of Inter prediction for video coding are disclosed. When a sub-block motion compensation coding tool is selected for the current block, the method generates sub-block MVs (motion vectors) associated with multiple sub-blocks, which are included or contained in the current block, according to the sub-block motion compensation coding tool, constrains the sub-block MVs within a range to form constrained sub-block MVs, and applies motion compensation to the current block using the constrained sub-block MVs or applies motion compensation to the current block using one sub-block MV within the range around the primary MV in a second list if a corresponding sub-block MV in a first list is outside the range. In another method, motion compensation is applied to the current block only using reference pixels of reference sub-blocks within a primary reference block.

Method and apparatus of motion vector constraint for video coding

The techniques described herein relate to methods, apparatus, and computer readable media configured to receive compressed video data, wherein the compressed video data is related to a set of frames. A decoder-side predictor refinement technique is used to calculate a new motion vector for a current frame from the set of frames, wherein the new motion vector estimates motion for the current frame based on one or more reference frames. An existing motion vector associated with a different frame from a motion vector buffer is retrieved. The new motion vector is calculated based on the existing motion vector using a decoder-side motion vector prediction technique, such that the existing motion vector is in the motion vector buffer after calculating the new motion vector.

Pattern-based motion vector derivation for video coding

Methods and apparatus for video coding using Adaptive Loop Filter (ALF) processing are disclosed. According to one method, the ALF virtual boundary processing is always applied to the bottom CTU row regardless whether the bottom CTU row is for a picture or a sub-picture. In another method, the ALF padding process is unified for different boundary types belonging to the target boundary belongs to a boundary-type group comprising two or more of slice boundary, tile boundary, VR360 face boundary, and sub-picture boundary. In yet another method, the ALF VB processing has a fixed priority for a corner region that both horizontal and vertical virtual boundaries can be applied.

Method and apparatus for adaptive loop filtering at picture and sub-picture boundary in video coding

Video encoding or decoding methods and apparatuses include receiving input data associated with a current block in a current picture, determining a preload region in a reference picture shared by two or more coding configurations of affine prediction or motion compensation or by two or more affine refinement iterations, loading reference samples in the preload region, generating predictors for the current block, and encoding or decoding the current block according to the predictors. The predictors associated with the affine refinement iterations or coding configurations are generated based on some of the reference samples in the preload region.

Methods and apparatuses of sharing preload region for affine prediction or motion compensation

A method for video encoding and decoding using Low-Frequency Non-Separable Transform (LFNST) mode and apparatus thereof are disclosed. The input data correspond to primary transformed data at the encoder and the input data correspond to coded data of the current CU at the decoder. A CU is partitioned into one or more transform blocks (TBs). An LFNST syntax is determined at an encoder side or at a decoder side if one or more conditions are satisfied. The LFNST syntax indicates whether the LFNST mode is applied to the current CU and/or which LFNST kernel is applied when the LFNST mode is applied. The conditions comprise the CBF indications for the target TBs being false. The current CU is encoded or decoded according to the LFNST mode as indicated by the LFNST syntax.

Methods and apparatus for secondary transform signaling in video coding

Various schemes pertaining to video coding parallelization techniques are described. An apparatus receives video data. The apparatus subsequently calculates a plurality of figures of merits (FOMs), each of the FOM representing how well a particular coding tool may perform in encoding the video data. The apparatus further determines a coding tool that may be suitable for encoding the video data by comparing the FOMs. In determining the coding tool, the apparatus utilizes time-interleaving techniques to parallelly process the video data. The video data may include an array of coding blocks, and the apparatus may receive the video data using a snake-like processing order scanning through the array of coding blocks.

Video encoding parallelization with time-interleaving cache access

A method and apparatus of prediction for video coding are disclosed. According to one method, a luma Intra prediction mode is determined for a corresponding luma block collocated with the current chroma block, where a predefined mode is assigned to the luma Intra prediction mode when the corresponding luma block collocated with the current chroma block satisfies one or more conditions. A chroma Intra prediction mode is determined for the current chroma block according to the luma Intra prediction mode. The current chroma block is then encoded or decoded according to the chroma Intra prediction mode. According to another method, a predefined mode is assigned to Intra prediction mode for the current block when the current block satisfies one or more conditions. The current block is then encoded or decoded according to the Intra prediction mode.

Method and apparatus of chroma direct mode generation for video coding

A methods and apparatus for adaptive data dependency between corresponding blocks partitioned from separate partition trees according to an embodiment of the present invention are disclosed. The data dependency between different tree structures is allowed when the tree structures are mutually inclusive. When the splitting is not used in one tree or when splitting is used in one tree and the same splitting or no split is used in the other tree, the data dependency between different tree structures is allowed. When the splitting in different tree structures are different, then the data dependency between different tree structures is disallowed. For each leaf CU in chroma tree, it should include one or more complete luma leaf CUs or it is completely included in one luma leaf CU, when the data dependency between different tree structures is allowed. Otherwise, then the data dependency between different tree structures is disallowed.

Method and apparatus of luma-chroma separated coding tree coding and constraints

Video processing methods and apparatuses in a video encoding or decoding system for processing a video picture partitioned into blocks with one or more partition constraints. The video encoding or decoding system receives input data of a current block and checks whether a predefined splitting type is allowed to partition the current block according to first and second constraints. The first constraint restricts each sub-block partitioned from the current block to be completely contained in one pipeline unit, and the second constraint restricts each sub-block partitioned from the current block to contain one or more complete pipeline units. The pipeline units are non-overlapping units in the video picture designed for pipeline processing. The current block is not partitioned by the predefined splitting type if any sub-block partitioned by the predefined splitting type violates both the first and second constraints. The system encodes or decodes the current block.

Methods and apparatuses of processing video pictures with partition constraints in a video coding system

A video coding system generating candidates for Merge Mode with Motion Vector Difference (MMVD) with reduced resource usage is provided. The system receives data to be encoded or decoded as a current block of a current picture of a video. The system identifies multiple MMVD candidates for different offset positions based on a merge candidate of the current block. The system generates reference samples for the identified MMVD candidates. The system reconstructs the current block or encodes the current block into a bitstream by using the generated reference samples. The system processes the MMVD candidates in separate groups: a first group of vertical MMVD candidates and a second group of horizontal MMVD candidates. The system generates the reference samples for the identified MMVD candidates by applying a vertical filter to source reference samples of horizontal MMVD candidates and then applying a horizontal filter to outputs of the vertical filter.

Mmvd mode separation and interpolation reordering

In a method and apparatus for video coding using Low-Frequency Non-Separable Transform (LFNST) mode, a coding unit (CU) is partitioned into one or more transform blocks (TBs). A syntax is determined at an encoder side or at a decoder side, where the determining step is performed by signaling the syntax at the encoder side or by parsing the syntax at the decoder side if one or more conditions are satisfied. The syntax indicates whether the LFNST mode is applied to the current CU and/or which LFNST kernel is applied when the LFNSF is applied, and the conditions comprise a target condition corresponding to that all target TBs in a target TB set have a TS mode indication as false, and the target TB set is selected from the TBs in the current CU. The current CU is encoded or decoded according to the LFNST mode.

Methods and apparatus for restricted secondary transform and signaling thereof in image coding

A method and apparatus for video coding using a coding mode belonging to a mode group comprising an Intra Block Copy (IBC) mode and an Intra mode are disclosed. According to the present invention, for both IBC and Intra mode, a same default scaling matrix is used to derive the scaling matrix for a current block. In another embodiment, for the current block with block size of M×N or N×M, and M greater than N, a target scaling matrix is derived from an M×M scaling matrix by down-sampling the M×M scaling matrix to an M×N or N×M scaling matrix.

Method and apparatus of the quantization matrix computation and representation for video coding

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Zhubei, Taiwan

Tzu-Der Chuang