Abstract: Embodiments of this application provide an encoding and a device. The encoding method includes: obtaining an image; generating feature maps of C channels based on the image, the feature maps including feature values of feature points; generating estimated information matrices of the C channels based on the feature maps of the C channels; grouping the C channels into N channel groups; for at least one target channel group in the N channel groups, determining, based on at least one feature value of at least one encoded feature point corresponding to the target channel group and an estimated information matrix corresponding to the target channel group, at least one probability distribution parameter of a to-be-encoded feature point corresponding to the target channel group; determining, based on the at least one probability distribution parameter, probability distribution of the to-be-encoded feature point; and encoding the to-be-encoded feature point based on the probability distribution.

Abstract: This application provides a chroma block prediction method and apparatus. The method includes: obtaining chroma values of chroma samples; obtaining, luma values of luma samples corresponding to the chroma samples; obtaining, from the luma values, a first luma set and a second luma set; grouping the chroma values into a first chroma set and a second chroma set; determining a scaling coefficient in a linear model based on an average value of luma values in the first luma set, an average value of luma values in the second luma set, an average value of chroma values in the first chroma set, and an average value of chroma values in the second chroma set; determining, based on the scaling coefficient, an offset factor in the linear model; and determining prediction information of the chroma block based on the scaling coefficient and the offset factor.

Abstract: Embodiments of this application disclose a picture reconstruction method and apparatus for a video picture. The picture reconstruction method includes: obtaining a prediction mode of a current coding unit, and/or obtaining a prediction partition mode of the current coding unit, where the current coding unit includes a luma coding block and a chroma coding block, and the prediction partition mode is a mode of splitting the current coding unit into prediction blocks or prediction units; obtaining a transform block of the current coding unit based on the prediction partition mode and/or the prediction mode; and generating a reconstructed picture block of the current coding unit based on the transform block. According to the method in the embodiments of this application, video coding efficiency can be improved.

Abstract: Inter prediction method and apparatus are disclosed to resolve problems in the conventional technology that prediction samples obtained in an inter prediction mode are spatially discontinuous, prediction efficiency is affected, and prediction residual energy is relatively high. The method includes: parsing a bitstream to obtain motion information of a to-be-processed picture block; performing motion compensation on the to-be-processed picture block based on the obtained motion information, to obtain a prediction block of the to-be-processed picture block, where the prediction block of the to-be-processed picture block includes a prediction value of a target sample; and performing weighting calculation on one or more reconstructed values of one or more reference samples and the prediction value of the target sample, to update the prediction value of the target sample, where the reference sample(s) have a preset spatial position relationship with the target sample.

Abstract: Embodiments of this application disclose an intra prediction method for a video sequence. The method includes: obtaining a size and a split mode of a chroma coding tree node; determining, based on the size and the split mode of the chroma coding tree node, whether to allow cross-component linear model (CCLM) intra prediction to be performed on a chroma coding unit included in the chroma coding tree node; determining a prediction mode of the chroma coding unit depending on whether to allow CCLM to be performed on the chroma coding unit; and processing the chroma coding unit based on the prediction mode of the chroma coding unit to obtain prediction samples of the chroma coding unit.

Abstract: This application discloses a method for constructing an MPM list, a method for obtaining an intra prediction mode of a chroma block, and an apparatus. In a specific implementation, a MIP mode is used for a current block, and the method for constructing an MPM list includes: obtaining intra prediction mode information of a neighboring block; determining, based on the intra prediction mode information of the neighboring block, whether an intra prediction mode of the neighboring block is the MIP mode; and skipping using the intra prediction mode of the neighboring block for MPM list construction of the current block if the intra prediction mode of the neighboring block is not the MIP mode; or using the intra prediction mode of the neighboring block for MPM list construction of the current block if the intra prediction mode of the neighboring block is the MIP mode.

Abstract: A picture prediction method includes receiving a bitstream; parsing the bitstream to obtain a prediction mode of a current block; when the prediction mode of the current block is a combined intra and inter prediction mode, selecting an execution manner of a triangular prediction unit mode according to a preset policy; determining motion information of the current block according to the execution manner of the triangular prediction unit mode; performing a motion compensation process based on the motion information, to obtain an inter prediction sample; obtaining an intra prediction sample according to the prediction mode of the current block; and combining the inter prediction sample and the intra prediction sample to obtain a prediction picture of the current block.

Abstract: The present disclosure discloses a video decoding method and a video decoder. The method includes: parsing coding tree split information to obtain a current node; determining coordinates of an upper-left corner of a region covered by a current quantization group based on a depth N of the current node; obtaining a QP delta of a current CU in the region covered by the current quantization group; and obtaining a reconstructed picture of the current CU based on the QP delta of the current CU.

Abstract: A video processing method includes: obtaining prediction information of a CU; obtaining, when the CU comprises only one residual TU and a size of the residual TU is less than a size of the CU, a TU partitioning mode of the CU and a residual position of the residual TU, wherein the TU partitioning mode and the residual position are used to determine a horizontal transform type and a vertical transform type; obtaining transform coefficients of the residual TU based on the horizontal transform type and the vertical transform type; and generating a bitstream that is for storing or transmitting and that includes the prediction information, a first flag that indicates the TU partitioning mode, a second flag that indicates the residual position, and the transform coefficients.

Abstract: A picture partitioning method and apparatus are described. The method includes determining a split mode of a current node, where the current node includes a luma block and a chroma block. The method further includes determining, based on the split mode of the current node and a size of the current node, that the chroma block of the current node is not further split. In accordance with the chroma block of the current node not being further split, the method includes splitting the luma block of the current node based on the split mode of the current node. In accordance with the chroma block of the current node not being further split, the method may be used to split only the luma block of the current node, thereby improving encoding and decoding efficiency, reducing a maximum throughput of a codec, and facilitating implementation of the codec.

Abstract: A method comprising obtaining a bitstream, the bitstream comprises a transform unit syntax and a coding unit syntax, the transform unit syntax includes a value of a first flag and a value of a second flag related to, respectively, a first chroma transform block and a second chroma transform block of a current transform unit or a current sub-transform unit within the current transform unit, the first or second flag specifies whether the first or second chroma transform block contains at least one transform coefficient levels not equal to 0, the coding unit syntax includes a value of a third flag specifying whether a transform tree structure is present or not; and deriving a value of a fourth flag based on the values of the first, second, and third flags, the fourth flag specifies whether a luma transform block contains at least one transform coefficient levels not equal to 0.

Abstract: A method for encoding the region enhancement layer includes obtaining reconstructed pixels of a base layer of a target region; inputting the reconstructed pixels into a correction network to obtain correction information of the target region; inputting the correction information and original pixels of the target region into an encoding network to obtain a residual feature map of an enhancement layer of the target region; and encoding the residual feature map to obtain an enhancement layer bitstream of the target region.

Abstract: Inter prediction method and apparatus are disclosed to resolve problems in the conventional technology that prediction samples obtained in an inter prediction mode are spatially discontinuous, prediction efficiency is affected, and prediction residual energy is relatively high. The method includes: parsing a bitstream to obtain motion information of a to-be-processed picture block; performing motion compensation on the to-be-processed picture block based on the obtained motion information, to obtain a prediction block of the to-be-processed picture block, where the prediction block of the to-be-processed picture block includes a prediction value of a target sample; and performing weighting calculation on one or more reconstructed values of one or more reference samples and the prediction value of the target sample, to update the prediction value of the target sample, where the reference sample(s) have a preset spatial position relationship with the target sample.

Abstract: Techniques are described of a linear model prediction mode. A set of reconstructed neighboring luma samples are determined. Two pairs of luma value and chroma value are determined according to N reconstructed neighboring luma samples, N reconstructed neighboring chroma samples, M reconstructed neighboring luma samples, and M reconstructed neighboring chroma samples. The minimum value of the N reconstructed neighboring luma samples is not less than the maximum luma value of the remaining reconstructed neighboring luma samples of the set of reconstructed neighboring luma samples. The maximum value of the M reconstructed neighboring luma samples is not larger than the minimum luma value of the remaining reconstructed neighboring luma samples of the set of reconstructed neighboring luma samples. M>1 and N>1. Linear model parameters are determined based on the two pairs of luma value and chroma value, and a predictive block is determined based on the linear model parameters.

Abstract: Embodiments of this application disclose a decoding method includes: obtaining a bitstream including picture data; parsing the bitstream to obtain node split mode information of a first-level coding tree and node split mode information of a second-level coding tree, if the split mode corresponding to the first node is no further splitting, parsing the bitstream to obtain encoding information of the first node; and decoding and reconstructing, based on the encoding information of the first node, a coding unit corresponding to the first node, to obtain a picture corresponding to the picture data.

Abstract: An intra prediction method by using cross component liner prediction mode (CCLM), includes: determining a luma block corresponding to a current chroma block; obtaining luma reference samples of the luma block based on determining L available chroma reference samples of the current chroma block, wherein the obtained luma reference samples of the luma block are down-sampled luma reference samples; calculating linear model coefficients based on the luma reference samples and chroma reference samples that correspond to the luma reference samples; and obtaining a prediction for the current chroma block based on the linear model coefficients and values of a down-sampled luma block of the luma block.

Abstract: When probability estimation is performed in encoding and decoding processes, probability distribution of an unquantized image feature is estimated based on a hyperprior feature of the unquantized image feature via a first probability distribution estimation network, and then probability distribution of a quantized image feature is obtained through quantization. Alternatively, probability distribution of a quantized image feature is directly estimated based on a hyperprior feature of an unquantized image feature via a second probability distribution estimation network.

Abstract: A method of decoding includes partitioning a rectangular transform tree node (TTN) using either a vertical binary tree split or a horizontal binary tree split to generate square child TTNs when a maximum transform unit (TU) size for the TTN is smaller than either dimension of the TTN. The method further includes partitioning the child TTNs using a quadtree split to generate transform units (TUs) when the first child TTN dimension and the second child TTN dimension are larger than the maximum TU size, determining that the child TTNs are TUs when the first child TTN dimension and the second child TTN dimension are less than or equal to the maximum TU size, applying the TUs to transform coefficients to generate residuals, and generating a reconstructed block based on the residuals.

Abstract: A video processing method includes: obtaining prediction information of a CU; obtaining, when the CU comprises only one residual TU and a size of the residual TU is less than a size of the CU, a TU partitioning mode of the CU and a residual position of the residual TU, wherein the TU partitioning mode and the residual position are used to determine a horizontal transform type and a vertical transform type; obtaining transform coefficients of the residual TU based on the horizontal transform type and the vertical transform type; and generating a bitstream that is for storing or transmitting and that includes the prediction information, a first flag that indicates the TU partitioning mode, a second flag that indicates the residual position, and the transform coefficients.

Abstract: A prediction mode determining method and apparatus are described. A prediction mode status of a child node of a target node is determined based on an area and a split manner of the target node, where the prediction mode status includes intra prediction mode only and inter prediction mode only. Further, a prediction mode of the child node is determined based on the prediction mode status of the child node. In this way, a same prediction mode is used for all child nodes obtained by splitting the target node. This facilitates pipeline processing of hardware, increases a subsequent processing speed, and improves video coding efficiency.