Abstract: 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.

Abstract: A method of decoding a video sequence coded with subpictures can include receiving a first syntax element corresponding to a coding tree unit (CTU) size in a bitstream at a decoder, receiving a second syntax element corresponding to whether a picture being partitioned into subpictures, in response to the second syntax element indicating the picture is partitioned into the subpictures, receiving third syntax elements indicating a position and a size of each of the subpictures in the picture based on a unit of the CTU size, and reconstructing one or more of the subpictures based on the position and the size of each of the respective subpictures in the picture.

Abstract: Method and apparatus of video encoding video coding for a video encoder or decoder using Neural Network (NN) are disclosed. According to one method, input data or a video bitstream are received for blocks in one or more pictures, which comprise one or more colour components. The residual data, prediction data, reconstructed data, filtered-reconstructed data or a combination thereof is derived for one or more blocks of said one or more pictures. A target signal corresponding to one or more of the about signal types is processed using a NN (Neural Network) and the input of the NN or an output of the NN comprises two or more colour components. According to another method, A target signal corresponding to one or more of the about signal types is processed using a NN and the input of the NN or an output of the NN comprises two or more colour components.

Abstract: 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.

Abstract: 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.

Abstract: Exemplary video processing methods and apparatuses for encoding or decoding a current block by inter prediction are disclosed. Input data of a current block is received and partitioned into sub-partitions and motion refinement is independently performed on each sub-partition. A reference block for each sub-partition is obtained from one or more reference pictures according to an initial motion vector (MV). A refined MV for each sub-partition is derived by searching around the initial MV with N-pixel refinement. One or more boundary pixels of the reference block for a sub-partition is padded for motion compensation of the sub-partition. A final predictor for the current block is generated by performing motion compensation for each sub-partition according to its refined MV. The current block is then encoded or decoded according to the final predictor.

Abstract: Method and apparatus for constrained de-blocking filter are disclosed. According to one method, if a CU is partitioned into multiple sub-CUs, the de-blocking process is also applied to the sub-block boundaries inside the current filtered-reconstructed block. According to another method, if first reference samples used for the de-blocking process of a first boundary are to be modified by the de-blocking process of a second boundary, the first reference samples are replaced by padding samples that are not to be modified by the de-blocking process of the second boundary. According to yet another method, the de-blocking process is applied to a reconstructed block corresponding to a current block to result in a current filtered-reconstructed block regardless whether a boundary of the current block corresponds to an 8×8 sample grid boundaries.

Abstract: 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.

Abstract: Methods and apparatus for Adaptive Loop Filter (ALF) processing of reconstructed video are disclosed. According to one method, clipping values for the ALF processing are determined depending on a bit depth of a center reconstructed pixel. A current ALF output for the current block is derived, where the current ALF output comprises a weighted sum of clipped differences of original differences and each of the original differences is calculated between a first reconstructed pixel at a non-center filter location and the center reconstructed pixel, and each of the original differences is clipped according to a corresponding clipping value to form one clipped difference. In another method, a target clipping value is always signaled at an encoder side or parsed at a decoder side even if the target clipping value is zero. In another method, the clipping values are encoded or decoded using a fixed-length code.

Abstract: A method and apparatus for video coding utilizing a current block, a maximum side of the transform block of the current block corresponds to 64. A scaling matrix is derived from elements of an 8×8 base scaling matrix, where the elements in a bottom-right 4×4 region of the 8×8 base scaling matrix are skipped, either not signaled or set to zero. According to another method, a current block belongs to a current picture in a first color format that has only a first color component. A first scaling matrix is signaled at the video encoder side or parsed at the video decoder side for the first color component of the current block. Signaling any second scaling matrix is disabled at the video encoder side or parsing any second scaling matrix is disabled at the video decoder side for a second or third color component of the current block.

Abstract: A method for signaling subpicture structures for coded video is provided. A video decoder receives data from a bitstream to be decoded as a sequence of video pictures. The video decoder receives from the bitstream subpicture specification for one or more subpictures in the sequence of video pictures. The subpicture specification identifies a position and a size for each subpicture by providing an index that identifies a coding tree unit (CTU) for the subpicture. The video decoder reconstructs each subpicture for the sequence of video pictures according to the subpicture specification.

Abstract: A method and apparatus of Inter prediction for video coding using Multi-hypothesis (MH) are disclosed. If an MH mode is used for the current block: at least one MH candidate is derived using reduced reference data by adjusting at least one coding-control setting; an Inter candidate list is generated, where the Inter candidate list comprises said at least one MH candidate; and current motion information associated with the current block is encoded using the Inter candidate list at the video encoder side or the current motion information associated with the current block is decoded at the video decoder side using the Merge candidate list. The coding control setting may correspond to prediction direction setting, filter tap setting, block size of reference block to be fetched, reference picture setting or motion limitation setting.

Abstract: A method and apparatus of video coding incorporating Deep Neural Network are disclosed. A target signal is processed using DNN (Deep Neural Network), where the target signal provided to DNN input corresponds to the reconstructed residual, output from the prediction process, the reconstruction process, one or more filtering processes, or a combination of them. The output data from DNN output is provided for the encoding process or the decoding process. The DNN can be used to restore pixel values of the target signal or to predict a sign of one or more residual pixels between the target signal and an original signal. An absolute value of one or more residual pixels can be signalled in the video bitstream and used with the sign to reduce residual error of the target signal.

Abstract: A method and apparatus for video coding using block partition are disclosed. According to the present invention, a partition structure corresponding to recursively partitioning a current block into smaller TU (transform unit) blocks until the partition structure reaches a maximum allowed split depth or until a block size of at least one of smaller TU blocks is a supported core transform size, where the current block is partitioned into final smaller TU blocks according to the partition structure. A transform coding process is applied to the current block according to the partition structure, where the transform coding process is skipped for at least one of the final smaller TU blocks. A flag can be signalled for the current block to indicate whether the current block is allowed to skip the transform coding process for said at least one of the final smaller TU blocks.

Abstract: A method of palette management for palette coding in a video coding system receives input data associated with a current block in a high-level picture structure and initializes a palette predictor in the high-level picture structure before a corresponding palette of a first palette-coded block in the high-level picture structure is coded. If a palette mode is selected for the current block, the method applies the palette coding to the current block using a current palette and updates the palette predictor based on the current palette to generate an updated palette predictor for a next block coded in the palette mode.

Abstract: A video coder that uses a shared candidate list to encode or decode multiple blocks of pixels within a shared boundary is provided. The video coder identifies a shared boundary encompassing a plurality of blocks of pixels of a current picture in a video sequence. The video coder identifies one or more prediction candidates as a shared candidate list based on neighbors of a region defined by the shared boundary. The video coder codes one or more blocks of pixels encompassed by the shared boundary by using one or more prediction candidates selected from the shared candidate list.

Abstract: According to a method for Adaptive Loop Filter (ALF) processing of reconstructed video, multiple indicators are signaled in slice at an encoder side or parsed at a decoder side, where the multiple indicators are Adaptive Parameter Set (APS) indices associated with temporal ALF filter sets for the ALF processing. A current indicator is determined from the multiple indicators, where the current indicator is used to select a current ALF filter set. Filtered-reconstructed pixels are derived for the current block by applying the current ALF filter to the current block. In another method, if the ALF processing applied at a target sample requires an outside sample on other side of a target virtual boundary from the target sample, the outside sample is replaced by a padded sample.

Abstract: A method and apparatus of Inter prediction for video coding using Multi-hypothesis (MH) are disclosed. If an MH mode is used for the current block: at least one MH candidate is derived using reduced reference data by adjusting at least one coding-control setting; an Inter candidate list is generated, where the Inter candidate list comprises said at least one MH candidate; and current motion information associated with the current block is encoded using the Inter candidate list at the video encoder side or the current motion information associated with the current block is decoded at the video decoder side using the Merge candidate list. The coding control setting may correspond to prediction direction setting, filter tap setting, block size of reference block to be fetched, reference picture setting or motion limitation setting.

Abstract: Methods and apparatus of video processing for a video coding system using Neural Network (NN) are disclosed. According to this method, a shifted region is determined for the filter region to avoid unavailable reconstructed or filtered-reconstructed video data for the NN processing of the filter region, where boundaries of the shifted region comprises region boundaries derived by shifting target boundaries upward, leftward, or both upward and leftward, and wherein the target boundaries correspond to one or more top boundaries and one or more left boundaries of target processing region including the current block and one or more remaining un-processed blocks. According to another method, the areas outside boundaries of pictures, slices, tiles, or tile groups are padded. In yet another method, a flag is used to indicate whether the NN processing is allowed to cross a boundary between two slices, two tiles or two tile groups.