Hfi Innovation Inc.

Mediatek Corporation

Zhi-Yi Lin

Tzu-Der Chuang

Ching-Yeh Chen

Chih-Wei Hsu

Chia-Ming Tsai

Chun-Chia Chen

Yu-Wen Huang

Shih-Ta Hsiang

Man-Shu Chiang

Chen-Yen Lai

Yu-Chi Su

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

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 coding system receives input data related to a current block in a current picture at a video encoder side or a video bitstream corresponding to compressed data including the current block at a video decoder side; determines one or more MVs (motion vectors) associated with a target Inter coding tool for the current block at the video encoder side or at the video decoder side, applies a same conversion process to said one or more MVs to generate one or more converted MVs at the video encoder side or at the video decoder side when the target Inter coding tool belongs to at least two tools of a group; and encodes the current block or motion information of the current block using said one more converted MVs at the video encoder side.

Method and apparatus of motion-vector rounding unification for video coding system

Methods and apparatus of video coding using sub-block based affine mode are disclosed. According to this method, control-point motion vectors (MVs) associated with the affine mode are determined for a block. A sub-block MV is derived for a target sub-block of the block from the control-point MVs for the block. A prediction offset is determined for a target pixel of the target sub-block using information comprising a pixel MV offset from the sub-block MV for the target pixel according to Prediction Refinement with Optical Flow (PROF). The target pixel of the target sub-block is encoded or decoded using a modified predictor. The modified prediction is generated by clipping the prediction offset to a target range and combining the clipped prediction offset with an original predictor.

Method and apparatus of sample clipping for prediction refinement with optical flow in video coding

A method and apparatus of video coding, where according to one method, input data related to a current block in a current picture are received at a video encoder side or compressed data comprising the current block are received at a video decoder side. A first syntax at a high level in a video bitstream regarding residual coding type is signaled at the encoder side or parsed at the decoder side. A target coding mode is determined for the current block based on information comprising a value of the first syntax. The current block is encoded at the encoder side or decoded at the decoder side according to the target coding mode. The high level may correspond to a slice header or a picture header.

Method and apparatus of residual coding selection for lossless coding mode in video coding

A method and apparatus of encoding or decoding for a coding system, where bi-directional CU (coding unit) weighting (BCW) is enabled for the coding system to allow using multiple pairs of weights, are disclosed. According to this method, a Merge candidate list is generated for the current block, where current bi-directional CU weights for a bi-directional predictor of the current block associated with a target Merge candidate in the Merge candidate list are set to a pre-define pair of weights when the target Merge candidate corresponds to a selected Merge candidate. In another method, current bi-directional CU weights for a bi-directional predictor associated with a target Merge candidate in the Merge candidate list are inherited from the target Merge candidate when the target Merge candidate corresponds to a selected Merge candidate.

Method and apparatus of video coding using bi-directional CU weight

According to one implementation, a method receives input data related to a current block in a current picture at a video encoder side or receiving a video bitstream comprising coded data of the current block at a video decoder side. When hen the MIP mode is applied to the current block, the method checks availability for a target reference boundary region comprising left reference boundary samples and top reference boundary samples, wherein the left reference boundary samples and the top reference boundary samples are checked jointly for the current block. The method further performs a padding process if an unavailable sample exists in the target reference boundary region, wherein the unavailable sample is padded with a default value or a sample value of an available sample and derives a reduced predictor, and encodes or decodes the current block using a MIP predictor derived from the reduced predictor.

Method and apparatus of matrix-based intra prediction for video coding

Video processing methods include receiving input data of a current block in a current slice, determine determining whether one or more components of the current block satisfy one or more predefined criteria during partitioning, and applying a mode constraint to the current block only if the one or more components of the current block satisfy the one or more predefined criteria, wherein the mode constraint restricts all blocks within the current block to be processed by a same prediction mode when the current block is split into a plurality of blocks. The methods adaptively split the current block into one or more blocks, and pare one or more prediction mode syntax elements of a first block in the current block according to a constrained mode of the current block. The methods further encode the current block with the mode constraint.

Method and apparatus of encoding or decoding video blocks with constraints during block partitioning

An intra prediction method comprises receiving input data of a current block in a current picture, deriving reference samples of the current block from boundary samples, selecting a matrix for the current block, generating intermediate predicted samples by multiplying the reference samples and the matrix, and clipping the intermediate predicted samples before up-sampling. The intra prediction method further comprises performing an up-sampling process on the clipped intermediate predicted samples to generate predicted samples for the current block, and encoding or decoding the current block according to the predicted samples of the current block.

Method and apparatus of matrix based intra prediction in image and video processing

The techniques described herein relate to methods, apparatus, and computer readable media configured to encode or decode video data. A current block of video data is coded using affine prediction. A first set of candidates of a candidate list for the current block is generated, including determining one or more inherited candidates and deriving one or more constructed candidates. After generating the first set of candidates, it is determined whether the candidate list is full. Upon determining the candidate list is not full, the candidate list is filled by generating a second set of candidates of the candidate list, including one or more of generating one or more zero motion vector candidates, generating one or more additional derived candidates based on the plurality of associated neighboring blocks of the current block, and generating a temporal motion vector candidate based on a temporal collocated picture.

Methods and apparatus for generating affine candidates

Method and apparatus of video coding are disclosed. According to one method, the left reference boundary samples and the top reference boundary samples are checked jointly. According to another method, selected original left reference boundary samples and selected original top reference boundary samples at specific positions are used for predictor up-sampling. According to yet another method, the horizontal interpolation and the vertical interpolation are in a fixed order regardless of a shape of the current block, size of the current block or both.

A method and apparatus of video coding for a video encoding system or video decoding system are disclosed. According to one method, the current block region is partitioned into one or more leaf blocks using quadtree (QT) partition and/or 1D (one-dimensional) partition by firstly signalling or parsing a first syntax element to indicate whether the current block region is split into multiple smaller blocks. According to a second method, a target syntax model from multiple syntax models is determined. The current block region is partitioned into one or more leaf blocks using QT partition and/or 1D partition and signalling block partition information according to the target syntax model at an encoder side, or the block partition information is parsed according to the target syntax model and the current block region is partitioned into one or more leaf blocks at a decoder side.

Methods and apparatus for signaling coding unit partitioning of video data

An image or video processing method comprises receiving input data of a current block, mapping an MIP mode index to a default mode, and encoding or decoding the current block by referencing the default mode. Another image or video processing method comprises receiving input data of a current block coded or to be coded by an MIP mode, and parsing or signaling a transpose flag for the current block indicating whether transposing is applied in coding the current block. Reference samples of the current block are prepared from neighboring boundary samples according to the transpose flag. A matrix is selected to be multiplied to the reference samples to generate predicted samples. A transposing process is adaptively applied to the current block according to the transpose flag, and the predicted samples are used to encode or decode the current block.

A method and apparatus use an Inter coding tool and OBMC (Overlapped Block Motion Compensation). According to one implementation, a method of video coding using OBMC (Overlapped Block Motion Compensation) operates by receiving input data associated with a current block, wherein the input data correspond to pixel data to be coded at an encoder side or coded data to be decoded at a decoder side, applying the OBMC to the current block depending on one or more constraints, and signaling an OBMC syntax conditionally at the encoder side or parsing the OBMC syntax conditionally at the decoder side for the current block, wherein the OBMC syntax indicates whether the OBMC is applied to the current block.

Growing community of inventors

Hsinchu, Taiwan

Zhi-Yi Lin