Systems and techniques are provided for coding video data. In some examples, a process may include obtaining a first plurality of prediction candidates associated with video data. The process may further include determining a first group of prediction candidates at least in part by applying a first grouping method to the first plurality of prediction candidates. The process may include reordering the first group of prediction candidates and selecting a first merge candidate from the reordered first group of prediction candidates. The process may further include adding the first merge candidate to a candidate list.

In a method, coded information of a current block and neighboring blocks of the current block in a current picture is received from a coded video bitstream. A list of merge candidates of the current block is generated based on the neighboring blocks of the current block. The list of merge candidates of the current block is divided into a plurality of subgroups. Each of the plurality of subgroups includes one or more merge candidates. The one or more merge candidates are ordered within each subgroup by a respective template matching (TM) cost associated with each of the one or more merge candidates. The current block is reconstructed based on a merge candidate selected from the list of merge candidates of the current block.

In a method, coded information of a current block and neighboring blocks of the current block in a current picture is received from a coded video bitstream. A list of merge candidates of the current block is generated based on the neighboring blocks of the current block. The list of merge candidates of the current block is divided into a plurality of subgroups. Each of the plurality of subgroups includes one or more merge candidates. The one or more merge candidates are ordered within each subgroup by a respective template matching (TM) cost associated with each of the one or more merge candidates. The current block is reconstructed based on a merge candidate selected from the list of merge candidates of the current block.

Encoder and method for encoding of pixel values of a digital image comprising multiple lines of pixels to accomplish lossless compression of the digital image. For each of said multiple lines the encoder obtains unencoded pixels values of the line. Further, for each of said multiple lines, the encoder determines, for each of one or more pixels of the line, which encoding to be used for encoding of the unencoded pixel value of the pixel (x) in said lossless compression of the digital image. The determination being based on how said unencoded pixel value relates to unencoded pixel values of other, closest neighboring pixels (N1, N2) of said line.

An image decoding method performed by a decoding device, according to the present document, comprises the steps of: receiving a bitstream including residual information of a current block; deriving a specific number of context-encoding bins for context syntax elements for a current sub-block of the current block; decoding the context syntax elements for the current sub-block included in the residual information on the basis of the specific number; deriving transform coefficients for the current sub-block on the basis of the decoded context syntax elements; deriving residual samples for the current block on the basis of the transform coefficients; and generating a reconstructed picture on the basis of the residual samples.

An image decoding method performed by a decoding device, according to the present document, comprises the steps of: receiving a bitstream including residual information of a current block; deriving a specific number of context-encoding bins for context syntax elements for a current sub-block of the current block; decoding the context syntax elements for the current sub-block included in the residual information on the basis of the specific number; deriving transform coefficients for the current sub-block on the basis of the decoded context syntax elements; deriving residual samples for the current block on the basis of the transform coefficients; and generating a reconstructed picture on the basis of the residual samples.

Different implementations are described, particularly implementations for video encoding and decoding based on wherein the partitioning tree structure is partially shared between luma and chroma blocks are presented. According to an implementation, a single partitioning tree structure is shared between luma and chroma blocks from a root node of the partitioning tree down to a switching node and a dual partitioning tree structure is determined for luma and chroma blocks from the switching node down to a leaf node of the partitioning tree. Thus, this implementation optimizes the coding efficiency by allowing separated trees for smaller blocks, while limiting the complexity of decoding pipeline.

Different implementations are described, particularly implementations for video encoding and decoding based on wherein the partitioning tree structure is partially shared between luma and chroma blocks are presented. According to an implementation, a single partitioning tree structure is shared between luma and chroma blocks from a root node of the partitioning tree down to a switching node and a dual partitioning tree structure is determined for luma and chroma blocks from the switching node down to a leaf node of the partitioning tree. Thus, this implementation optimizes the coding efficiency by allowing separated trees for smaller blocks, while limiting the complexity of decoding pipeline.

A loop filtering method and apparatus are provided. The method includes: obtaining a first pixel matrix, where a value of a pixel at a corresponding location in the first pixel matrix corresponds to a luminance value of a pixel at a corresponding location in a first picture block; obtaining a second pixel matrix, where a pixel at a corresponding location in the second pixel matrix corresponds to a quantization step value corresponding to the luminance value of the pixel at the corresponding location in the first picture block; performing filtering processing on an input pixel matrix by using a filtering network to obtain an output pixel matrix, where the filtering network is a neural network that has a filtering function and is obtained through training, the output pixel matrix includes a third pixel matrix. Thus, filtering effect can be improved for reconstructed pictures of various quality levels.

A loop filtering method and apparatus are provided. The method includes: obtaining a first pixel matrix, where a value of a pixel at a corresponding location in the first pixel matrix corresponds to a luminance value of a pixel at a corresponding location in a first picture block; obtaining a second pixel matrix, where a pixel at a corresponding location in the second pixel matrix corresponds to a quantization step value corresponding to the luminance value of the pixel at the corresponding location in the first picture block; performing filtering processing on an input pixel matrix by using a filtering network to obtain an output pixel matrix, where the filtering network is a neural network that has a filtering function and is obtained through training, the output pixel matrix includes a third pixel matrix. Thus, filtering effect can be improved for reconstructed pictures of various quality levels.