Tencent America LLC

Sony Corporation

Sony Electronics Inc

Vweb Corporation

Cheung Auyeung

Shan Liu

Xiang Yang Li

Xiang Li

Xin Zhao

Ali Jezu Tabatabai

Liang Zhao

Jun Xu

Ling Li

Sho Long Chen

Stanley H Siu

Jing Ye

Takao Yamazaki

Huipin Zhang

Wei Liu

Ohji Nakagami

Jeongnam Youn

Sundararam Dwarakanath

Zhongzheng Yuan

Jeongnam Young

Aspects of the disclosure provide a method and an apparatus for video coding. In some examples, an apparatus includes processing circuitry that receives a bitstream. The bitstream includes coded information representing a current bin of a syntax element for a block in a picture. The syntax element corresponds to one of an index of a first prediction mode and an index of a second prediction mode. The processing circuitry determines a context model to decode the coded information. The context model is shared with the index of the first prediction mode and the index of the second prediction mode. The processing circuitry decodes the coded information according to the determined context model to obtain the current bin of the syntax element, and reconstructs the block based on the decoded current bin of the syntax element.

Context model reduction

In a method of processing visual media data, a conversion is performed between a visual media file and a bitstream of visual media data according to a format rule. The bitstream includes at least one syntax element that corresponds to transform coefficients of a transform block in a current picture. The format rule specifies that a context model index is based on a sum of an offset value and a base value. The offset value is based on an output of a monotonically non-decreasing function performed on a sum of a group of partially reconstructed transform coefficients. A context model, for the at least one syntax of a current transform coefficient, from a plurality of context models is indicated by the context model index.

Reducing context models for entropy coding of transform coefficients

A method of video decoding performed in a video decoder is disclosed. A first syntax element indicating whether a video is monochrome or includes color components that are encoded separately is generated. A second syntax element that indicates whether joint coding of chroma residuals is enabled based on whether the video is monochrome or includes color components that are encoded separately is generated. Further, a coded video bitstream that includes the first syntax element is generated. The coded video bitstream includes the second syntax element based on whether the video is monochrome or includes color components that are encoded separately. The first syntax element and the second syntax element are different syntax elements.

Signaling of coding tools for encoding a video component as monochrome video

Aspects of the disclosure include methods, apparatuses, and non-transitory computer-readable storage mediums for video encoding/decoding. An apparatus includes processing circuitry that decodes prediction information of a current block that is a part of a current picture in a video bitstream. The prediction information indicates a reference block for the current block. The processing circuitry generates filter coefficients of a filter operation based on neighboring reconstructed samples of the current block and neighboring reconstructed samples of the reference block that are co-located with the neighboring reconstructed samples of the current block. The filter operation compensates local changes to the current picture, such as illumination change or motion blur. The processing circuitry determines a prediction block for the current block based on the filter operation being performed on the reference block of the current block. The processing circuitry reconstructs the current block based on the prediction block of the current block.

Method and apparatus for video coding

In a method of video encoding, whether a sequence of pictures are monochrome or include three color components that are coded separately is determined. Responsive to the sequence of pictures being monochrome or including three color components that are coded separately, a value of a first syntax element is set to indicate that the sequence of pictures are monochrome or include three color components that are coded separately. The value of the first syntax element is encoded in a bitstream of a coded video. A value of a second syntax element is inferred to disable a coding tool that uses multiple color components of a picture as input or depends on a chroma component of the picture based on the first syntax element indicating that the sequence of pictures include three color components that are coded separately. The inferred value indicates active color transform (ACT) is disabled.

Disabling coding tool for active color transform

Processing circuitry decodes information of a coding block in a current picture from a bitstream. The information indicates a bi-prediction mode without weight signaling. Weights associated with the bi-prediction mode are not signaled in the bitstream. Further, the processing circuitry determines a first motion vector associated with a first reference picture and a second motion vector associated with a second reference picture, and determine a first reference template in the first reference picture based on a current template of the coding block and the first motion vector and a second reference template in the second reference picture based on the current template and the second motion vector. The processing circuitry also calculates a weight for use in the bi-prediction mode based on the first reference template, the second reference template and the current template, and reconstructs the coding block using the bi-prediction with the calculated weight.

Bi-prediction without signaling cu-level weights

Aspects of the disclosure provide methods and apparatuses for video processing. In some examples, an apparatus for video processing includes processing circuitry. The processing circuitry determines gating weights associated with expert modules based at least partially on a quantization parameter (QP) value. The expert modules are configured to process an input block that includes an image block being reconstructed based on the QP value. The processing circuitry then weights the expert modules based on the gating weights to generate an output image block corresponding to the image block.

An apparatus includes processing circuitry that calculates, for each of a plurality of sign prediction hypotheses, a cost of the respective sign prediction hypothesis by performing sign prediction on a subset of a plurality of transform coefficients based on a subset of samples in at least one of a topmost row or a leftmost column of a current block. A number of samples in the subset of samples is a constant number and less than a total number of samples in the at least one of the topmost row or the leftmost column of the current block. The processing circuitry selects one of the plurality of sign prediction hypotheses with a minimal cost among the costs of the plurality of sign prediction hypotheses. Further, the processing circuitry coded the current block according to the selected sign prediction hypothesis.

Sign prediction

According to an embodiment, a method of selecting a Rice parameter for encoding a video bitstream using at least one processor includes obtaining an absolute level corresponding to a current transform block; determining whether transform skip is enabled; generating a lookup variable based on the absolute level and the determination of whether the transform skip is enabled; obtaining the Rice parameter from a lookup table based on the lookup variable; and encoding a residual subblock based on the Rice parameter.

Unification of rice parameter lookup table

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. Processing circuitry decodes prediction information of a block from a coded video bitstream. The prediction information is indicative of a matrix based intra prediction for the block. The processing circuitry determines entries of a vector based on neighboring samples of the block. An entry can be determined based on one or more neighboring samples of the block. The processing circuitry converts the entries into a reduced bit form with a number of bits satisfying a requirement of using a first multiplication tool that processes fewer bits than a second multiplication tool. Then, the processing circuitry multiplies, using the first multiplication tool, the entries of the vector in the reduced bit form with entries of a matrix to calculate a subset of prediction samples of the block, and determines other prediction samples of the block based on the subset.

A method of decoding an encoded video. The method includes obtaining the encoded video bitstream and determining whether a chroma array type of a video sequence included in the encoded video bitstream is a first chroma array type indicating that the video sequence includes multiple color planes and that the multiple color planes are jointly. In addition, based on determining that the chroma array type is not the first chroma array type, the method further includes setting a value of at least one syntax element to zero without parsing the at least one syntax element from the encoded video bitstream, and based on the value of the at least one syntax element being zero, decoding the video sequence without applying at least one tool corresponding to the at least one syntax element.

Signaling of video coding tools supporting various chroma format

A method, computer program, and computer system is provided for video coding. Video data comprising a reference frame and residual blocks is received. Transform coefficients associated with the residual blocks are identified. The video data corresponding to the one or more residual blocks is encoded based on an extended dynamic range associated with the transform coefficients.

Method to extend the range of rice parameter for residual coding in transform skip mode

Aspects of the disclosure provide methods and apparatuses for video processing. In some examples, an apparatus for video processing includes processing circuitry. The processing circuitry converts a picture in a subsampled format in a color space into a non subsampled format in the color space. Then, the processing circuitry clips values of a color component of the picture in the non subsampled format before providing the picture in the non subsampled format as an input to a neural network based filter.

In a method for video decoding, coded information of a current block is received. Dimension information and partition information of the current block is determined based on the coded information, where the dimension information indicates at least one of a height, a width, and a size of the current block, and the partition information indicates a binary tree depth of a coding unit partition of the current block. A partition mode of the current block is determined as one of an intra sub-partition mode and a coding unit partition based on (i) comparisons between values of the height, the width, and the size of the current block and respective threshold values, or (i) a ratio between the value of the height and the value of the width of the current block. The current block is decoded based on the determined partition mode of the current block.

A method of video decoding in a decoder is provided. In the method, a coded video bitstream is received. For a scan position in the transform block, an offset value is determined based on a template magnitude for a template of the scan position. The offset value is constrained based on a first number of context models for each frequency region. For the scan position, a base value is determined based on the first number and the scan position. A context model index is determined based on a sum of the offset value and the base value. A context model is selected from a plurality of context models based on the context model index. A value of a syntax element at the scan position is determined based on the context model. A transform coefficient at the scan position is determined based on the value of the syntax element.

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Sunnyvale, CA, United States of America

Cheung Auyeung