Abstract: A motion vector prediction method based on an affine motion model and a device are provided. The method includes: obtaining one spatial reference block of a to-be-processed picture block; determining a plurality of preset subblock locations of the spatial reference block; obtaining motion vectors corresponding to preset pixel locations of the to-be-processed picture block that are extrapolated from motion vectors corresponding to the preset subblock locations; and obtaining motion vectors corresponding to a plurality of subblock locations of the to-be-processed picture block that are interpolated from the motion vectors corresponding to the preset pixel locations. According to this application, prediction accuracy in coding can be improved, and coding efficiency can be improved.

Abstract: A method of coding is described. The method can include obtaining a bitstream for a current picture, obtaining a value of a first indicator for the current picture according to the bitstream indicating a slice type, and obtaining a value of a second indicator for the current picture according to the bitstream indicating whether a weighted prediction parameter is present in a picture header or slice header of the bitstream. The method can also include parsing a value of the weighted prediction parameter for a current block of a current slice of the current picture from the bitstream. Furthermore, the method can include predicting the current block according to the value of the weighted prediction parameter.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a video signal partitioned into a chroma block and a first neighboring luma block. The mechanism also includes encoding prediction information for chroma samples of the chroma block into a bitstream. The prediction information for the chroma samples is determined via intra-prediction based on down-sampled neighboring luma samples. The down-sampled neighboring luma samples are generated from a single row of luma samples from the first neighboring luma block. A bitstream including the prediction information for the chroma samples is transmitted to support decoding and display of the chroma samples.

Abstract: A picture prediction method is provided, which includes: obtaining initial motion information of a current picture block; determining, based on a matching cost criterion, that positions of a pair of reference blocks are a position of a target forward reference block of the current picture block and a position of a target backward reference block of the current picture block, where positions of each pair of reference blocks include a position of a forward reference block and a position of a backward reference block; and for the positions of each pair of reference blocks, a first position offset and a second position offset are in a mirror relationship; and obtaining a predicted value of a pixel value of the current picture block based on a pixel value of the target forward reference block and a pixel value of the target backward reference block.

Abstract: A video data inter prediction method is provided, which includes: determining a candidate motion information list of a current picture block, where the candidate motion information list includes at least one first candidate motion information group, at least one second candidate motion information group, the first candidate motion information group is a motion information group determined based on motion information of preset locations on a first neighboring picture block of the current picture block and a motion model of the first neighboring picture block, the second candidate motion information group is a set of motion information of at least two sample locations that are respectively neighboring to at least two preset locations on the current picture block; determining target motion information from the candidate motion information list; and performing inter prediction on the current picture block based on the target motion information.

Abstract: A video decoding method, including: parsing a received bitstream to obtain prediction information of a coding unit (CU); obtaining a target transform mode of a residual transform unit (TU); parsing the received bitstream to obtain transform coefficients of the residual TU; applying an inverse quantization to the transform coefficients of the residual TU to obtain dequantized coefficients; applying, based on the target transform mode, an inverse transform to the dequantized coefficients to obtain a residual block of the residual TU; obtaining a prediction block of the CU based on the prediction information; obtaining a video block based on the residual block and the prediction block; and outputting a video sequence including a video frame that includes the video block.

Abstract: An intra-frame decoding method includes obtaining, from a video code stream, prediction mode information of a first signal component of a current block, determining a prediction mode of the first signal component of the current block from a prediction mode set of the first signal component of the current block according to the prediction mode information of the first signal component of the current block, where the prediction mode set of the first signal component of the current block includes at least one of a linear model above (LMA) mode and a linear model left (LML) mode; obtaining a predicted value of a first signal component sampling point of the current block, and obtaining a reconstructed value of the first signal component sampling point of the current block according to the predicted value of the first signal component sampling point of the current block.

Abstract: This disclosure discloses a method for obtaining a candidate motion vector list, an apparatus, an encoder, and a decoder. The method for obtaining a candidate motion vector list comprises: when a first candidate picture block is encoded/decoded and an inter prediction mode is used, determining whether a reference picture of the first candidate picture block is the same as a reference picture of a current block; and constructing a candidate motion vector list of the current block based on a determining result; when the reference picture of the first candidate picture block is different from the reference picture of the current block, the MV of the first candidate picture block is not used to construct the list. Implementing this disclosure can reduce complexity of a motion information derivation process, and improve coding efficiency.

Abstract: This application relates to the field of video coding technologies, and discloses a video coder and a corresponding method, to help improve video coding performance. In this application, encoding and decoding are collectively referred to as coding. A video coding method includes: determining a block split policy of a current picture block based on a size relationship between the width and the height of the current picture block; applying the block split policy to the current picture block to obtain a coding block; and reconstructing the obtained coding block to reconstruct the current picture block.

Abstract: A mechanism for position dependent spatial varying transform (SVT) for video coding. A prediction block and a corresponding transformed residual block are received at a decoder. A type of spatial varying transform (SVT) employed to generate the transformed residual block is determined. A position of the SVT relative to the transformed residual block is also determined. An inverse of the SVT is applied to the transformed residual block to reconstruct a reconstructed residual block. The reconstructed residual block is then combined with the prediction block to reconstruct an image block.

Abstract: The present disclosure provides a chroma block prediction method and a device. The method includes: parsing a bitstream to obtain first indication information; downsampling a first luma block by a first filter when a value of the first indication information is a first value or by using a second filter when a value of the first indication information is a second value, to obtain a second luma block; obtaining a plurality of chroma samples and a plurality of luma samples; obtaining linear model coefficients based on the plurality of chroma samples and the plurality of luma samples; and obtaining a prediction value of the current chroma block based on the second luma block and the linear model coefficients.

Abstract: A method of decoding a coded video bitstream includes obtaining a sequence parameter set (SPS)-level syntax element from the bitstream, wherein that the SPS-level syntax element equaling a preset value specifies that no video parameter set (VPS) is referred to by a SPS, and wherein the SPS-level syntax element being greater than the preset value specifies that the SPS refers to a VPS. The method further includes obtaining, when the SPS-level syntax element is greater than the preset value, an inter-layer enabled syntax element specifying whether one or more inter-layer reference pictures (ILRPs) are enabled to be used for the inter prediction of one or more coded pictures, and predicting one or more coded pictures based on the value of the inter-layer enabled syntax element.

Abstract: The present disclosure provides a generic multi-source heterogeneous large-scale data system, including a sync node config unit, an install & deployment unit, a block & pipelining unit, a unilateral sync unit, a bilateral sync unit and a correctness guarantee unit. The system operates on a middle layer which is above a node database layer and beneath an application logic layer. In a data synchronization process, a client end transmits captured local change information to a server end in accordance with a synchronization task plan; the server end receives and transfers the change information to an asynchronous parallel message processing mechanism to be stored in a corresponding message queue; the server end polls a local message queue for reading to-be-processed change information, and then performs subsequent data change in accordance with rules for heterogeneous data mapping, so as to maintain consistence of synchronized data objects between a source end and a target end.

Abstract: A decoding method includes obtaining an identifier from a bitstream, where the identifier indicates a minimum decoding time interval k between library pictures that is allowed in the bitstream, obtaining, when parsing the bitstream, a decoding moment ti of a current decoded picture and a decoding moment tj of a first decoded picture that is closest to the current decoded picture and that references a new library picture when the current decoded picture is decoded by referencing a library picture, where the new library picture is a library picture that is not decoded or needs to be re-decoded when the first decoded picture is decoded, and determining a preset quantity of library pictures as candidate reference pictures of the current decoded picture based on a relationship between k and a difference between ti and tj.

Abstract: The present disclosure provides a video image decoding method in which a size of an affine motion compensation image sub-block in an affine image block is determined based on a motion vector difference, motion vector precision, a distance between control points in the affine image block, and a size of the affine image block, where the size includes a length in a horizontal direction and a length in a vertical direction, so that a length of the affine image block in a horizontal/vertical direction is an integer multiple of the length of the affine motion compensation image sub-block in the horizontal/vertical direction.

Abstract: Image encoding and decoding methods, apparatuses and computer-readable media are described. An example image encoding method includes: determining N encoded units from adjacent encoded units of a to-be-encoded unit according to a first preset rule, where a motion prediction mode of the N encoded units is the same as that of the to-be-encoded unit; generating an nth motion vector group by using a first preset algorithm and based on a motion vector of an nth encoded unit; determining, from obtained N motion vector groups according to a second preset rule, one motion vector group as an optimal motion vector group; determining a prediction sample value of each sample unit in the to-be-encoded unit by using a second preset algorithm and based on the optimal motion vector group; and encoding a prediction residual of each sample unit and an index identifier of the optimal motion vector group, to obtain a bitstream corresponding to the to-be-encoded unit.

Abstract: The present disclosure provides a video picture coding method, a video picture decoding method, a coding device, and a decoding device. The method includes: determining a distance between control points for an affine picture block; determining a motion vector difference for the affine picture block, motion vectors of the control points being used to determine the motion vector difference; and performing coding processing on the affine picture block over a size that includes a horizontal length and a vertical length, wherein the horizontal length and the vertical length vary based on the distance between the control points, the motion vector difference, and a motion vector precision.

Abstract: A method for decoding a coded video bitstream is provided. The method includes: obtaining a reference layer syntax element by parsing the coded video bitstream, wherein a value of the reference layer syntax element specifying whether a layer with index k is a direct reference layer for a layer with index i; determining whether the layer with index j is a reference layer for the layer with index i based on the value of the reference layer syntax element; and when a condition is satisfied, predicting a picture of the layer with index i based on the layer with index j, wherein the value of a chroma format related syntax element applied to the layer with index i is the same as the value of a chroma format related syntax element applied to the layer with index j.

Abstract: This application provides a video picture prediction method and apparatus, to resolve a problem in a conventional technology that a length of a coded video sequence is increased. The first type of identifier may be added to a bitstream. The first type of identifier is used to indicate whether an affine motion model-based inter prediction mode is enabled for a video picture. For a video picture or a picture block included in the slice for which the affine motion model does not need to be used, a parameter, related to the affine motion model, of the picture block may not need to be transmitted. On a decoder side, during decoding of the picture block, the parameter related to the affine motion model does not need to be parsed. This can reduce load of a decoder, increase a processing speed, and decrease a processing time.