Abstract:
A method for chroma intra prediction mode decoding includes decoding a chroma intra prediction mode for a current chroma block according to a codeword set corresponding to a chroma intra prediction mode set, wherein the codeword set comprises at least one codeword with a first length type and at least one codeword with a second length type. If a codeword is one of said at least one codeword with the first length type, the chroma intra prediction mode is decoded as a Luma-based chroma prediction Mode (LM) or a Direct Mode (DM). The method also includes determines the chroma intra prediction mode based on an intra prediction mode of a current luma block if the chroma intra prediction mode is the DM.
Abstract:
An apparatus and method for sample adaptive offset (SAO) to restore intensity shift of processed video data are disclosed. In an encoder side, the processed video data corresponding to reconstructed video data, deblocked-reconstructed video data, or adaptive loop filtered and deblocked-reconstructed video data are partitioned into regions smaller than a picture. The region partition information is signaled in a video bitstream located in a position before intensity offset values syntax. At the decoder side, the processed video data is partitioned into regions according to the partition information parsed from the bitstream at a position before intensity offset values syntax. Region-based SAO is applied to each region based on the intensity offset for the category of the region-based SAO type selected.
Abstract:
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.
Abstract:
A method for specifying layout of subpictures in video pictures is provided. A video decoder receives data from a bitstream to be decoded as a current picture of a video. For a current subpicture of a set of subpictures of the current picture, the video decoder determines a position of the current subpicture based on a width and a height of the current picture and a previously determined width and height of a particular subpicture in the set of subpictures. The video decoder reconstructs the current picture and the current subpicture based on the determined position.
Abstract:
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.
Abstract:
Video data processing methods and apparatuses receive input data associated with a current split node partitioned from a parent node by a splitting type, determine a depth of the current split node according to the splitting type, and compare the depth of the current split node with a maximum delta QP signaling depth. A video decoding system derives a delta QP from one or more syntax elements signaled in a TU associated with the current split node according to the comparing result, reconstructs a final QP for the current split node based on a reference QP and the delta QP, and decodes one or more TUs associated with the current split node using the final QP. The depth is counted in a way considering different splitting types and splitting partitions.
Abstract:
Various schemes pertaining to pre-encoding processing of a video stream with motion compensated temporal filtering (MCTF) are described. An apparatus determines a filtering interval for a received raw video stream having pictures in a temporal sequence. The apparatus selects from the pictures a plurality of target pictures based on the filtering interval, as well as a group of reference pictures for each target picture to perform pixel-based MCTF, which generates a corresponding filtered picture for each target picture. The apparatus subsequently transmits the filtered pictures as well as non-target pictures to an encoder for encoding the video stream. Subpictures of natural images and screen content images are separately processed by the apparatus.
Abstract:
Video processing methods and apparatuses implemented in a video encoding or decoding system with conditional secondary transform signaling. The video encoding system determines and applies a transform operation to residuals of a transform block to generate final transform coefficients, and adaptively signals a secondary transform index according to a position of a last significant coefficient in the transform block. A value of the secondary transform index is determined according to the transform operation. The video decoding system parses last significant coefficient position syntax of each transform block in the current block from a video bitstream to determine a position of a last significant coefficient for each transform block, and infers inverse secondary transform is not applied to the current block according to the positions of the last significant coefficients; otherwise, the video decoding system determines an inverse transform operation by parsing a secondary transform index from the video bitstream.
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:
Video processing methods comprise receiving input data of a current block in a current picture having a plurality of Virtual Pipeline Data Units (VPDUs), wherein each VDPU is a fixed size, performing a decoding process to decode Coding Units (CUs) in the current VPDU and generate decoded samples of the current VPDU, wherein each CU coded in a Current Picture Referencing (CPR) mode is decoded by fetching decoded samples in a reference block stored in a CPR referring buffer, and updating the CPR referring buffer by storing the decoded samples of the current VPDU when finishing the decoding process of the current VPDU, wherein the CPR referring buffer is updated one VPDU by one VPDU.