Abstract: A video processing method is provided. In the method, a video bit stream is obtained. Configuration information of the video bit stream is determined. The configuration information includes reference image information. The reference image information indicates (i) whether a video track corresponding to the video bit stream includes a reference image and (ii) whether the video track requires reference to the reference image. The video bit stream and the configuration information are encapsulated to obtain the video track.

Abstract: A method includes receiving a polygon mesh that includes a plurality of vertices; generating a set of candidate predictors, each candidate predictor in the set of candidate predictors corresponding to a respective displacement vector between a vertex from the plurality of vertices to a vertex to be coded; selecting a candidate predictor from the set of candidate predictors; and generating a bitstream that includes at least a candidate predictor index corresponding to the selected candidate predictor.

Abstract: A method and apparatus for encoding or decoding a video sequence includes encoding or decoding the video sequence using a 4:4:4 chroma format, or encoding or decoding the video sequence using a 4:2:2 chroma format, wherein when encoding or decoding the video sequence using the 4:4:4 chroma format, copying an affine motion vector of one 4×4 luma block using an operation other than an averaging operation and associating the affine motion vector to a co-located 4×4 chroma block, and when encoding or decoding the video sequence using the 4:2:2 chroma format, associating each 4×4 chroma block with two 4×4 co-located luma blocks such that an affine motion vector of one 4×4 chroma block is an average of the motion vectors of the two co-located luma blocks.

Abstract: The various implementations described herein include methods and systems for coding video. In one aspect, a method includes receiving a video bitstream including a current coding block of a current image frame and determining that the current coding block is to be predicted in a weighted bi-prediction (WBP) mode. The method further includes in response to the current coding block being predicted in the WBP mode, determining that the current coding block is associated with two bi-prediction blocks and identifying a plurality of distinct weighting factor lists including at least a first list of positive weighting factors and a second list of mixed weighting factors. The method further includes selecting one of the weighing factor lists, identifying a first weighting factor from the weighing factor lists, and reconstructing the current image frame, including determining the current coding block by combining the two bi-prediction blocks based on the first weighting factor.

Abstract: A video decoding method includes performing entropy decoding processing on a code block of a video image frame of a video image frame sequence, to obtain a quantization coefficient block of residual data corresponding to the code block; collecting statistics of quantization coefficients in a target region in the quantization coefficient block, to obtain a quantization coefficient statistical value; selecting a transform matrix combination corresponding to the quantization coefficient statistical value; and performing inverse transform processing on an inverse quantization result of the quantization coefficient block based on the selected transform matrix combination, to obtain reconstructed residual data, the reconstructed residual data being used for video image reconstruction.

Abstract: A method and apparatus that derives a curve of a mesh sequence from a frame of a video bitstream, the curve comprising a plurality of vertices; subdivides the curve by adding a plurality of subdivided vertices; calculates one or more displacement vectors between each of the plurality of vertices on the curve and each of the plurality of subdivided vertices on the subdivided curve; transforms the one or more displacement vectors to output one or more original coefficients; tracks the current frame with a previous frame to obtain a one-to-one correspondence between the plurality of vertices of the current frame and a plurality of vertices of the previous frame; predicts one or more coefficients of each of the plurality of vertices in current frame based on the one-to-one correspondence; performs entropy coding on one or more prediction residues; and encodes the one or more prediction residues.

Abstract: A method for video encoding includes determining that a current block in a first coding tree unit (CTU) of a current picture is to be coded using an affine model in a merge mode, and obtaining, from a line buffer, one or more motion vectors of blocks located at bottom locations in a second CTU above the current block. The line buffer only stores motion vectors of minimum-size blocks located at the bottom locations of the second CTU above the current block and the line buffer does not store (i) a block width or block height of the minimum-size blocks, (ii) affine control point information, and (iii) an affine flag. The method further includes deriving motion vectors of control points of the current block using the affine merge model, and encoding the current block based on the affine merge model and the motion vectors of the control points.

Abstract: A method of video encoding includes determining whether a reference block for a current block is located in a different coding tree unit (CTU) than a CTU of the current block. The method also includes, in response to the reference block being located in the different CTU, (i) determining whether a memory location of a reference sample memory for the reference block is available. The second area is collocated in the different CTU with a position of the first area in the CTU of the current block. In response to the determination that the reference block is located in the different CTU, the method also includes, (ii) in response to a determination that the memory location for the reference block is available, retrieving, from the memory location corresponding to the reference block, one or more samples to encode the current block.

Abstract: A method performed by at least one processor of an encoder comprises: performing, on an input 3D mesh, a symmetry detection process to estimate a partition plane. The method further comprises partitioning the input 3D mesh into a first side and a second side based on the partition plane, where the first side is opposite to the second side, and where a first vertex on the first side is symmetric to a second vertex on the second side. The method further comprises quantizing the first vertex and the second vertex in pairs to reduce a quantization error and symmetry prediction error associated with the first vertex and the second vertex.

Abstract: A method performed by encoder comprises partitioning a mesh into a first side and a second side; determining, for a first vertex located on the first side, whether a first perpendicular line extending from the first vertex intersects with two or more surfaces of the mesh on the second side, each intersection of the first perpendicular line corresponding to an intersected vertex on the second side; based on the determination the first perpendicular line intersects with two or more surfaces of the mesh on the second side, selecting one of the intersected vertices on the second side as a second vertex corresponding to the first vertex based on a shortest distance between each intersected vertex and a predicted vertex on the second side that is symmetric to the first vertex; and generating a new connection in the mesh.

Abstract: A method, computer program, and computer system is provided for video encoding and decoding. Video data including a current picture is received. A virtual reference frame is generated for the current picture based on hierarchical level associated with the current picture and a nearest decoded picture. The video data is decoded based on the generated reference frame.

Abstract: Aspects of the disclosure provide methods and apparatuses for video decoding. In some examples, an apparatus includes processing circuitry. The processing circuitry decodes prediction information of a current block from a coded video bitstream. Based on an intra block copy mode being applied to the current block, the processing circuitry infers a vector resolution flag indicates that a resolution of a block vector is integer-pel, determines the resolution of the block vector based on resolution information that is included in the prediction information, determines the block vector according to the determined resolution, and reconstructs at least one sample of the current block according the block vector.

Abstract: A method and apparatus comprising computer code for mesh coding configured to cause a processor or processors to receive an input dynamic mesh representing a volumetric data of at least one three-dimensional (3D) visual content, wherein the input dynamic mesh comprises a plurality of mesh frames; determine that a mesh frame among the plurality of mesh frames comprises a plurality of texture maps in response to a mesh file associated with the mesh frame indicating that at least two different materials are applied in the mesh frame; determine a material index associated with each triangle face in the mesh frame, wherein a respective material index indicates a texture to be applied to a respective triangle face; and encode material indices associated with the mesh frame of the input dynamic mesh.

Abstract: A method of mesh processing includes receiving coded information of a mesh, the coded information including position connectivity of a plurality of 3D vertices of a mesh in a 3D space, and a correspondence of the plurality of 3D vertices to UV vertices in a UV space for the mesh; determining UV connectivity of the UV vertices; determining, based on the coded information, a first initial UV vertex in a first UV chart in the plurality of UV charts; determining first UV vertices in the first UV chart according to a traversing order of 3D vertices corresponding to the first UV vertices in the first UV chart, the traversing order starting from the first initial UV vertex and traversing each UV vertex in the first UV chart; decoding, from the coded information, prediction residuals of the first UV vertices; and determining first UV coordinates of the first UV vertices accordingly.

Abstract: A method of mesh processing includes receiving coded information of a mesh, the coded information includes position connectivity of a plurality of 3D vertices of a mesh in a 3D space, and a correspondence of the plurality of 3D vertices to UV vertices in a UV space for the mesh. The method further includes generating a reconstructed mesh in the 3D space by the plurality of 3D vertices according to the position connectivity, and determining seam vertices from the plurality of 3D vertices. The method also includes performing a prediction of seam edges in the 3D space based on at least the seam vertices, at least an edge between two seam vertices is predicted to be a seam edge. The method can also include cutting the reconstructed mesh into patch components according to the seam edges and determining UV connectivity of the UV vertices according to the patch components.

Abstract: Media content data of an object is received. Whether a first parameter indicated by a first description of the object in an acoustic scene and a second parameter indicated by a second description of the object in a visual scene are inconsistent is determined. Based on the first parameter indicated by the first description of the object in the acoustic scene and the second parameter indicated by the second description of the object in the visual scene being inconsistent, one of the first description of the object in the acoustic scene and the second description of the object in the visual scene is modified based on another one of the first description and the second description that is not modified, wherein the modified one of the first description and the second description is consistent with the other one of the first description and the second description that is not modified.

Abstract: In some examples, processing circuitry receives at least a first mesh frame associated with a first time instance and a second mesh frame associated with a second time instance. The first mesh frame includes a first two dimension (2D) map with first patches having three-dimension (3D) information mapped to 2D. The second mesh frame includes a second 2D map with second patches having 3D information mapped to 2D. The processing circuitry identifies that a first patch in the first patches is a reference matching patch for a second patch in the second patches. Further, the processing circuitry determines first re-map transform parameters for a temporal alignment of the second patch to the first patch, and generates a new second 2D map that includes a transformed second patch that is transformed from the second patch according to the first re-map transform parameters.

Abstract: A method of video decoding is provided. In the method, a coded video bitstream including a current picture is received. Whether a current block included in the current picture is coded in an intra block copy (IBC) mode is determined. In response to determining that the current block is coded in the IBC mode, a maximum number of IBC predictor candidates associated with the current block is determined as equal to a value of max(M, MaxNumMergeCand). The MaxNumMergeCand is equal to a number of candidates in a merge mode list and the M is a predetermined integer. An IBC predictor candidate list is constructed based on the maximum number of IBC predictor candidates. A block vector associated with the current block is determined based on a block vector predictor included in the IBC predictor candidate list. The current block is reconstructed based on the block vector.

Abstract: A method performed includes encoding a first vertex, a second vertex, and a third vertex of a first face of a polygon mesh; determining a set of adaptive weights that comprise a first weight, a second weight, and a third weight; and performing parallelogram prediction to predict a fourth vertex in a second face of the polygon mesh by applying the first weight to the first vertex, the second weight to the second vertex, and the third weigh to the third vertex, in which the first weight is less than 0.8 and greater than 0, in which the second weight is greater than ?0.8 and less than 0, and in which the third weight is less than 0.9 and greater than 0.

Abstract: This disclosure relates generally to video coding and particularly to intra block copy coding mode. For example, a method is disclosed for reconstructing a video block in a video stream. The method may include extracting at least one syntax element from the video stream, the at least one syntax element being associated with an intra block copy (IBC) prediction of the video block; determining an IBC referencing mode for the IBC prediction of the video block, the IBC referencing mode comprises one of no-IBC mode, a local-referencing IBC mode, a non-local-referencing IBC mode, and a local-and-non-local-referencing IBC mode; and generating reconstructed samples of the video block from the video stream based on the IBC referencing mode.