Hfi Innovation Inc.

Mediatek Corporation

Shih-Ta Hsiang

Tzu-Der Chuang

Ching-Yeh Chen

Yu-Wen Huang

Chih-Wei Hsu

Lulin Chen

Olena Chubach

Chih-Ming Fu

Chen-Yen Lai

Shan Liu

Shaw-Min Lei

Chia-Ming Tsai

Man-Shu Chiang

Zhi-Yi Lin

Xiaozhong Xu

Jian-Liang Lin

Yi-Wen Chen

Jicheng An

Yu-Chen Sun

Yu-Pao Tsai

Chia-Yang Tsai

Mohammed Golam Sarwer

Yu-Lin Chang

Chi-Ling Wu

Chia-Ping Chen

A method and apparatus of context initialization for entropy coding. According to one method, previous context states derived from one or more previous slices for an arithmetic entropy coder are determined, where the previous context states are stored in multiple context state buffers and different context state buffers are used to store the previous context states for different temporal sublayers. Target context states are determined from the previous context states for the current slice in a current temporal sublayer indicated by a current temporal ID, wherein a target context state buffer storing the target context states is determined according to the current temporal ID. A current set of context states for the arithmetic entropy coder is initialized using the target context states. The input data is encoded or decoded using the arithmetic entropy coder after said initializing the current set of context states for the arithmetic entropy coder.

Method and apparatus of entropy coding for scalable video coding

Encoding methods and apparatuses comprise determining parameters of a specific process for a current slice, signaling in one or more Adaptive Parameter Sets (APSs), performing the specific process using the parameters, signaling an APS ID of each signaled APS in a slice header, and encoding the current slice. Each APS is classified into a category according to a type of data carried by the APS. The APS ID of each signaled APS is counted in a category associated with the specific process and is independent of other categories. Decoding methods and apparatuses comprise parsing an APS ID of each referenced APS from a slice header of a current slice for a specific process, determining parameters from each referenced APS according to the parsed APS ID and a category associated with the specific process, performing the specific process on the current slice and decoding the current slice.

Methods and apparatuses of syntax signaling and referencing constraint in video coding system

Video processing methods and apparatuses include receiving input video data associated with a current picture, signaling or parsing a first syntax element, wherein the first syntax element indicates whether to infer or predict subpicture information of a current layer of the current picture from a target layer; signaling or parsing a second syntax element to determine information about the target layer for obtaining the subpicture information of the current layer of the current picture, and encoding or decoding the current layer of the current picture using the subpicture information of the current layer of the current picture.

Methods and apparatuses of inter coding for pictures partitioned into subpictures in video coding systems

A method and apparatus for joint sign prediction of transform coefficients. At the encoder side, a maximum number is determined according to coding context of the current block. A set of jointly predicted coefficient signs associated with a set of selected transform coefficients is determined where a total number of the set of jointly predicted coefficient signs is equal to or smaller than the maximum number. Joint sign prediction for the set of jointly predicted coefficient signs is determined by selecting one hypothesis from a group of hypotheses corresponding to combinations of the set of jointly predicted coefficient signs that achieves a minimum cost.

Method and apparatus for sign coding of transform coefficients in video coding system

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 method and apparatus for signaling or parsing picture partition information are disclosed. The current picture is partitioned into one or more slices and one or more tiles according to the picture partition information. A control syntax is determined, where the control syntax is signaled from the video bitstream at the encoder side or parsed from the video bitstream at the decoder side unless the picture partition information indicates that a rectangular slice mode is selected, each sub picture is allowed to contain more than one rectangular slice, and the current picture contains only one rectangular slice in the current picture. In-loop filtering is applied across slice boundaries if the picture partition information indicates multiple slices existing in the current picture and the control syntax indicates the in-loop filtering being enabled.

Method and apparatus for signaling slice partition information in image and video coding

Video processing methods and apparatuses in a video encoding or decoding system for processing out-of-bounds nodes in a current picture. An out-of-bounds node is a coding tree node with a block region across a current picture boundary. The video processing method or apparatus determines an inferred splitting type, applies the inferred splitting type to split the out-of-bounds node into child blocks, adaptively splits each child block into one or multiple leaf blocks, and encodes or decodes the leaf blocks in the out-of-bounds node inside the current picture. The inferred splitting type for partitioning out-of-bounds nodes in an inter slice, picture, or tile is the same as the inferred splitting type for partitioning out-of-bounds nodes in an intra slice, picture, or tile.

Methods and apparatuses of processing video data of out-of-bounds nodes

Method and apparatus of video coding are disclosed. According to one method, in the decoder side, a predefined Intra mode is assigned to a neighboring block adjacent to the current luma block when the neighboring block satisfies one or more conditions. An MPM (Most Probable Mode) list is derived based on information comprising at least one of neighboring Intra modes. A current Intra mode is derived utilizing the MPM list. The current luma block is decoded according to the current Intra mode According to another method, a predefined Intra mode is assigned to a neighboring block adjacent to the current luma block if the neighboring block is coded in BDPCM (Block-based Delta Pulse Code Modulation) mode, where the predefined Intra mode is set to horizontal mode or vertical mode depending on prediction direction used by the BDPCM mode.

Method and apparatus of luma most probable mode list derivation for video coding

A video system that applies constraints on block partitioning is provided. The system receives a partitioning control parameter from a bitstream specifying a maximum block size for enabling ternary-tree split that is constrained to be 64 or smaller. The system receives data from a bitstream for a block of pixels to be decoded as a current block of a current picture of a video. The system splits the current block into one or more partitions recursively, wherein ternary split is disallowed for a partition of the current block unless the partition is less than or equal to the maximum block size. The system reconstructs the one or more partitions of the current block.

Signaling block partitioning of image and video

Method and apparatus for signaling or parsing constrained active entries in reference picture lists for multi-layer coding are disclosed. For the decoder side, when the current picture is a RADL (Random Access Decodable Leading) picture, reference picture list 0 or reference picture list 1 of the current picture is mandatorily required to contain no active entry corresponding to a RASL (Random Access Skipped Leading) picture with pps_mixed_nalu_types_in_pic_flag equal to 0 or a picture that precedes an associated IRAP (Intra Random Access Point) picture in decoding order, and wherein an active entry in the reference picture list 0 or the reference picture list 1 of the RADL picture can refer to a RASL picture with the pps_mixed_nalu_types_in_pic_flag equal to 1 and a referenced RASL picture either belongs to the same layer or a different layer than a layer containing the current picture which is the RADL picture.

Method and apparatus for video coding with constraints on reference picture lists of a RADL picture

A method and apparatus for decoding prediction residues in a video coding system operate by receiving input data associated with a current residual block, wherein the input data correspond to coded quantized-transform coefficients associated with the current residual block to be decoded at a decoder side, and wherein the current residual block is divided into one or more sub-blocks. This method further signals a plurality of syntax elements representing coded quantized transform coefficients at the encoder side or parsing the plurality of syntax elements representing the coded quantized transform coefficients at the decoder side, wherein at least two of the plurality of syntax elements are coded in a CABAC regular mode and all syntax elements coded in the CABAC regular mode are signalled or parsed in one coding pass. The method further encodes or decodes the current residual block according to the plurality of syntax elements.

Method and apparatus of transform coefficient coding

Video processing methods and apparatuses in a video coding system include receiving input video data of a current block in a current picture, determining whether a transform skip mode is enabled for the current picture, signaling or parsing a syntax element associated with a size constraint for enabling the transform skip mode in a SPS referred to by the current picture when the transform skip mode is enabled, determining whether the transform skip mode is applied to the current block when the current block satisfies the size constraint, processing residues of the current block according to the transform skip mode when the transform skip mode is applied to the current block, and encoding or decoding the current block. An enabling flag is signaled in a high-level syntax set or parsed from the high-level syntax set to determine whether the transform skip mode is enabled for the current picture.

Methods and apparatuses for transform skip mode information signaling

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

A method for performing transform skip mode (TSM) in a video decoder is provided. A video decoder receives data from a bitstream to be decoded as a plurality of video pictures. The video decoder parses the bitstream for a first syntax element in a sequence parameter set (SPS) of a current sequence of video pictures. When the first syntax element indicates that transform skip mode is allowed for the current sequence of video pictures and when transform skip mode is used for a current block in a current picture of the current sequence, the video decoder reconstructs the current block by using quantized residual signals that are not transformed.

Signaling coding of transform-skipped blocks

A method for for signaling high-level information in image and video coding is provided. A video decoder receives data from a bitstream to be decoded as a current picture of a video. The video decoder parses a picture header of the current picture that includes a set of one or more slice information syntax elements in the picture header for indicating presence of one or more types of slices that are present in the current picture. The video decoder reconstructs the slices of the current picture by using the set of slice information syntax elements.

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Hsinchu, Taiwan

Shih-Ta Hsiang