Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes processing circuitry. The processing circuitry decodes prediction information for a current block in a current coded picture that is a part of a coded video sequence. The prediction information indicates a first prediction mode used for the current block. The processing circuitry determines whether a neighboring block that neighbors the current block and is reconstructed prior to the current block uses the first prediction mode. Then the processing circuitry inserts prediction information from the neighboring block into a predictor list for the first prediction mode in response to the determination that the neighboring block uses the first prediction mode. Finally the processing circuitry reconstructs the current block in accordance with the predictor list for the first prediction mode.

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes processing circuitry. The processing circuitry decodes prediction information for a current block in a current coded picture that is a part of a coded video sequence. The prediction information indicates a first prediction mode used for the current block. The processing circuitry determines whether a neighboring block that neighbors the current block and is reconstructed prior to the current block uses the first prediction mode. Then the processing circuitry inserts prediction information from the neighboring block into a predictor list for the first prediction mode in response to the determination that the neighboring block uses the first prediction mode. Finally the processing circuitry reconstructs the current block in accordance with the predictor list for the first prediction mode.

According to the present invention, an image encoding apparatus comprises: a motion prediction unit which derives motion information on a current block in the form of the motion information including L0 motion information and L1 motion information; a motion compensation unit which performs a motion compensation for the current block on the basis of at least one of the L0 motion information and L1 motion information so as to generate a prediction block corresponding to the current block; and a restoration block generating unit which generates a restoration block corresponding to the current block based on the prediction block. According to the present invention, image encoding efficiency can be improved.

An example method of video processing includes performing a conversion between a video picture of a video and a bitstream representation of the video. The bitstream representation conforms to a format rule. The format rule specifies that applicability of a Decoder-side Motion Vector Refinement coding tool and a Bi-Directional Optical Flow coding tool for the video picture are indicated separately in the bitstream representation.

An image decoding method includes: dividing a current block into sub-blocks; deriving, for each sub-block, one or more prediction information candidates; obtaining an index; and decoding the current block using the prediction information candidate selected by the index. The deriving includes: determining whether a neighboring block neighboring each sub-block is included in the current block, and when not included in the current block, determining the neighboring block to be a reference block available to the sub-block, and when included in the current block, determining the neighboring block not to be the reference block; and deriving a prediction information candidate of the sub-block from prediction information of the reference block; and when the number of prediction information candidates is smaller than a predetermined number, generating one or more new candidates without using the prediction information of the reference block till the number of prediction information candidates reaches the predetermined number.

An image coding device is provided with a determination unit which determines whether to apply an orthogonal transform to a transform block obtained by dividing a prediction difference signal indicating a difference between an input image and a predicted image or perform a transform skip by which the orthogonal transform is not applied, and an orthogonal transform unit which performs processing selected on the basis of the determination, the image coding device comprising a quantization unit which, when the transform skip is selected on the basis of the determination, quantizes the transform block using a first quantization matrix in which the quantization roughnesses of all elements previously shared with a decoding side are equal, and when the orthogonal transform is applied to the transform block on the basis of the determination, quantizes the transform block using the first quantization matrix or a second quantization matrix that is transmitted to the decoding side.

An image coding device is provided with a determination unit which determines whether to apply an orthogonal transform to a transform block obtained by dividing a prediction difference signal indicating a difference between an input image and a predicted image or perform a transform skip by which the orthogonal transform is not applied, and an orthogonal transform unit which performs processing selected on the basis of the determination, the image coding device comprising a quantization unit which, when the transform skip is selected on the basis of the determination, quantizes the transform block using a first quantization matrix in which the quantization roughnesses of all elements previously shared with a decoding side are equal, and when the orthogonal transform is applied to the transform block on the basis of the determination, quantizes the transform block using the first quantization matrix or a second quantization matrix that is transmitted to the decoding side.

Disclosed herein are an image encoding method and an image decoding method. The image decoding method includes determining an initial motion vector of a current block using a motion vector of a reconstructed region, searching for the motion vector of the current block based on the initial motion vector, and generating a prediction sample of the current block using the motion vector. The initial motion vector includes a motion vector in a past direction and a motion vector in a future direction.

Disclosed herein are an image encoding method and an image decoding method. The image decoding method includes determining an initial motion vector of a current block using a motion vector of a reconstructed region, searching for the motion vector of the current block based on the initial motion vector, and generating a prediction sample of the current block using the motion vector. The initial motion vector includes a motion vector in a past direction and a motion vector in a future direction.

A method is provided for processing a video bitstream which includes a first picture and a sequence parameter set containing information indicating a mode is enabled in which a first area of a picture can be extracted and replaced by a second area of another picture. Using the mode, the first picture is modified by extracting the first area and replacing the extracted area with the second area from the other picture. The modified first picture is stored and a predictor is formed using the modified first picture as a reference picture. A block of a subsequent picture is decoded using the predictor.