Alibaba Group Holding Limited

Alibaba (china) Co., Ltd.

Alibaba Innovation Private Limited

Alibaba Group Holding Limtted

Atibaba Group Holding Limited

Ru-Ling Liao

Yan Ye

Jie Chen

Jiancong Luo

Mohammed Golam Sarwer

Xinwei Li

Xuan Huang

Zhao Wang

Yamei Chen

Mohammad Golam Sarwer

Changyue Ma

A VVC-standard encoder and a VVC-standard decoder are provided, implementing a residual sign prediction method utilizing a sorting order of residual coefficients and an expanded region of a TB. As sign prediction accuracy is higher for larger transform coefficient levels, a VVC-standard encoder and a VVC-standard decoder sort transform coefficient signs of a TB in a one-dimensional array, based on corresponding QIdx values instead of the residual coefficient level value. The first n signs according to corresponding QIdx values, ordered from largest to smallest, are predicted using a residual sign prediction method, and the rest of the signs are signaled by EP bins. A sign prediction area is also extended, without limitation to an upper-left 4×4 region within the transform block, but to a region up to 32×32 in size; a VVC-standard encoder signals the maximum dimensions of the region to a VVC-standard decoder in syntax structures of the block.

Residual sign prediction of transform coefficients in video coding

The present disclosure provides methods and apparatuses for signaling subpicture partitioning information. An exemplary method includes: determining, according to a subpicture information present flag signaled in a bitstream, whether the bitstream comprises subpicture information; and in response to the bitstream comprising the subpicture information, signaling in the bitstream at least one of: a number of subpictures in a picture, a width, a height, a position, and an identifier (ID) mapping of a target subpicture, a subpic_treated_as_pic_flag, and a loop_filter_across_subpic_enabled_flag.

Method and apparatus for signaling subpicture partitioning information

A method for performing motion compensation includes: receiving a first wrap-around motion compensation flag associated with one or more pictures, and a second wrap-around motion compensation flag associated with a sequence of pictures; and determining whether the first wrap-around motion compensation flag is equal to a first value or a second value based on the second wrap-around motion compensation flag or a luma coding tree block size: when the second wrap-around motion compensation flag is equal to the second value, determining the first wrap-around motion compensation flag equal to the second value, or when the luma coding tree block size in unit of minimum coding block plus 1 is greater than a picture width in unit of minimum coding block minus 1, determining the first wrap-around motion compensation flag is equal to the second value.

Methods for performing wrap-around motion compensation

The present disclosure provides systems and methods for processing video content. The method can include: partitioning, along a partitioning edge, a plurality of blocks associated with a picture into a first partition and a second partition; performing inter prediction on the plurality of blocks, to generate a first prediction signal for the first partition and a second prediction signal for the second partition; and blending the first and second prediction signals for edge blocks associated with the partitioning edge.

Block partitioning methods for video coding

The present disclosure provides methods for performing training and executing of a multi-density neural network in video processing. An exemplary method comprises: receiving a video stream comprising a plurality of pictures; processing the plurality of pictures using a first branch of a first block in the neural network, wherein the neural network is configured to reduce blocking artifacts in video compression of the video stream and the first branch comprises one or more residual blocks; and processing the plurality of pictures using a second branch of the first block in the neural network, wherein the second branch comprises a down-sampling processing, an up-sampling processing, and one or more residual blocks.

Neural network based in-loop filtering for video coding

A VVC-standard encoder and a VVC-standard decoder are provided, implementing a decoder-side chroma intra prediction mode gradient-based derivation method, which improves coding efficiency of chroma intra prediction, thereby saving on signaling cost. A VVC-standard decoder configures one or more processors of a computing system to derive one of multiple possible chroma intra prediction modes by computing gradients of adjacent luma samples and chroma samples of a current chroma block. With minimal increase in signaling cost, the VVC-standard coding and decoding processes are enhanced to base intra prediction modes for chroma blocks on collocated luma block-adjacent reconstructed luma samples adjacent reconstructed chroma samples, enabling prior computational work done on coding and decoding adjacent blocks to be referenced. In this fashion, coding gains can be achieved in matching texture characteristics of the current chroma block based on a texture gradient including adjacent blocks.

Decoder-side chroma intra prediction mode gradient-based derivation

The present disclosure provides a computer-implemented method for encoding video. The method includes: receiving a video frame for processing; generating one or more coding units of the video frame; and processing one or more coding units using one or more palette predictors having palette entries, wherein each palette entry of the one or more palette predictors has a corresponding reuse flag, and wherein a number of reuse flags for each palette predictor is set to a fixed number for a corresponding coding unit.

Methods for palette prediction

The present disclosure provides a computer-implemented method for decoding video. The method includes receiving a bitstream including a coding unit of a video frame, the coding unit being coded in a skip mode or a direct mode; determining whether the coding units has a width greater than a threshold width or a height greater than a threshold height; in response to the coding unit having the width greater than the threshold width or the height greater than the threshold height, enabling a motion vector angular prediction process to store one or more motion vector angular prediction candidates in a candidate list storing a plurality of motion candidates associated with the coding unit; and performing an inter prediction to the coding unit according to the candidate list and an index parsed from the bitstream.

Method and apparatus for encoding or decoding video

The present disclosure provides a computer-implemented method for encoding video. The method includes: determining whether a coded video sequence (CVS) contains equal number of profile, tier and level (PTL) syntax structures and output layer sets (OLSs); and in response to the CVS containing equal number of PTL syntax structures and OLSs, coding the bitstream without signaling a first PTL syntax element specifying an index, to a list of PTL syntax structures in the VPS, of a PTL syntax structure that applies to a corresponding OLS in the VPS.

Methods for coding or decoding video parameter set or sequence parameter set

The present disclosure provides a video data processing method for cross-component sample adaptive offset (CCSAO). The method includes determining an index based on a vertical coordinate of a chroma sample within a picture; determining a luma sample based on the index; classifying the chroma sample based on a reconstructed value associated with the luma sample; determining an offset based on the classification; and adding the offset to a reconstructed value associated with the chroma sample.

Methods, apparatus, and non-transitory computer readable medium for cross-component sample adaptive offset

Methods and apparatuses video processing include: in response to receiving a video sequence, encoding first flag data in a parameter set associated with the video sequence, wherein the first flag data represents whether gradual decoding refresh (GDR) is enabled or disabled for the video sequence; when the first flag data represents that the GDR is disabled for the video sequence, encoding a picture header associated with a picture in the video sequence to indicate that the picture is a non-GDR picture; and encoding the non-GDR picture.

Methods and systems for performing gradual decoding refresh processing on pictures

During video encoding or decoding, cross-component prediction can be used to predict a chroma sample from collocated reconstructed luma samples. The prediction can be based on a gradient of the collocated reconstructed luma samples, a down-sampled value of the collocated reconstructed luma samples, or a combination thereof. An exemplary method includes: determining a first value associated with a chroma sample, by applying a first gradient pattern to reconstructed values of a first plurality of luma samples; determining a second value associated with the chroma sample, by applying a down-sampling filter to reconstructed values of a second plurality of luma samples; and predicting the chroma sample based on the first value and the second value.

Cross component prediction of chroma samples

The present disclosure provides methods for picture processing. The method can include: receiving a bitstream comprising a set of pictures; determining, according to the received bitstream, whether a virtual boundary is signaled at a sequence level for the set of pictures; in response to the virtual boundary being signaled at the sequence level, determining a position of the virtual boundary for the set of pictures, the position being bounded by a range signaled in the received bitstream; and disabling in-loop filtering operations across the virtual boundary.

Methods for signaling virtual boundaries and wrap-around motion compensation

The present disclosure provides video processing method and apparatus. An exemplary method includes: determining whether a coding block comprises samples outside a picture boundary; and in response to the coding block being determined to comprise samples outside a picture boundary, performing quad tree splitting of the coding block regardless of a value of a first parameter, wherein the first parameter indicates whether the quad tree is allowed to be used to split the coding block.

Methods and apparatuses for block partitioning at picture boundary

The present disclosure provides intra prediction methods for video or image coding. An exemplary method includes: performing an intra predicting process for a target block, wherein performing the intra predicting process comprises: determining an intra prediction mode for the target block; in response to the intra prediction mode is an angular mode, determining a filtered value by applying an N-tap interpolation filter to a plurality of reference samples surrounding the target block based on the angular mode, wherein N is an integer greater than 4; and determining a predicted value of a sample of the target block based on the filtered value.

Growing community of inventors

Beijing, China

Ru-Ling Liao