This application provides a method for constructing a motion information list in video encoding and decoding performed by a computer device. The method includes: obtaining a motion information list, which is a candidate motion information list is used for providing a candidate prediction displacement vector; determining at least one piece of motion information when a length of the motion information list meets a condition; and adding the at least one piece of motion information to the candidate motion information list to obtain an updated motion information list when a length of the candidate motion information list is less than a threshold. According to the embodiments of this application, by filling a motion information list using extra motion information when motion information included in the motion information list is insufficient, more effective displacement vectors are provided in the motion information list to achieve a better displacement vector prediction effect.

This application provides a method for constructing a motion information list in video encoding and decoding performed by a computer device. The method includes: obtaining a motion information list, which is a candidate motion information list is used for providing a candidate prediction displacement vector; determining at least one piece of motion information when a length of the motion information list meets a condition; and adding the at least one piece of motion information to the candidate motion information list to obtain an updated motion information list when a length of the candidate motion information list is less than a threshold. According to the embodiments of this application, by filling a motion information list using extra motion information when motion information included in the motion information list is insufficient, more effective displacement vectors are provided in the motion information list to achieve a better displacement vector prediction effect.

A video decoder can be configured to determine that a current block of the video data is coded in a bi-prediction inter mode; receive a first syntax element identifying a motion vector predictor from a first candidate list of motion vector predictors; receive a second syntax element identifying a motion vector difference; determine a first motion vector for the current block based on the motion vector predictor and the motion vector difference; determine a second motion vector for the current block from a second list of candidate motion vector predictors based on bilateral matching; and determine a prediction block for the current block using the first motion vector and the second motion vector.

Overlapped block disparity estimation and compensation is described. Compensating for images with overlapped block disparity compensation (OBDC) involves determining if OBDC is enabled in a video bit stream, and determining if OBDC is enabled for one or more macroblocks that neighbor a first macroblock within the video bit stream. The neighboring macroblocks may be transform coded. If OBDC is enabled in the video bit stream and for the one or more neighboring macroblocks, predictions may be made for a region of the first macroblock that has an edge adjacent with the neighboring macroblocks. OBDC can be causally applied. Disparity compensation parameters or modes may be shared amongst views or layers. A variety of predictions may be used with causally-applied OBDC.

Overlapped block disparity estimation and compensation is described. Compensating for images with overlapped block disparity compensation (OBDC) involves determining if OBDC is enabled in a video bit stream, and determining if OBDC is enabled for one or more macroblocks that neighbor a first macroblock within the video bit stream. The neighboring macroblocks may be transform coded. If OBDC is enabled in the video bit stream and for the one or more neighboring macroblocks, predictions may be made for a region of the first macroblock that has an edge adjacent with the neighboring macroblocks. OBDC can be causally applied. Disparity compensation parameters or modes may be shared amongst views or layers. A variety of predictions may be used with causally-applied OBDC.

A method is provided for inter-coding video in which transmission bandwidth requirements associated with second motion vectors for bi-directional temporal prediction is reduced. In the method, vector information for one of motion vectors for multi-directional temporal prediction can be transmitted together with information on how to derive or construct the second motion vectors. Thus, rather than sending express information regarding each of the plurality of motion vectors, express information related to only one motion vector along with information related to reconstruction/derivation of the second motion vectors is transmitted, thus reducing bandwidth requirements and increasing coding efficiency.

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes receiving circuitry and processing circuitry. The processing circuitry decodes prediction information of a current block in a current picture from a coded video bitstream. The prediction information is indicative of an affine model in a merge mode. The processing circuitry obtains, from a buffer, motion information of bottom locations in a neighboring block that is adjacent of the current block in the current picture, and determines parameters of the affine model that is used to transform between the block and a reference block in a reference picture based on the motion information of the bottom locations in the neighboring block. Further, the processing circuitry reconstructs samples of the current block based on the affine model.

Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes receiving circuitry and processing circuitry. The processing circuitry decodes prediction information of a current block in a current picture from a coded video bitstream. The prediction information is indicative of an affine model in a merge mode. The processing circuitry obtains, from a buffer, motion information of bottom locations in a neighboring block that is adjacent of the current block in the current picture, and determines parameters of the affine model that is used to transform between the block and a reference block in a reference picture based on the motion information of the bottom locations in the neighboring block. Further, the processing circuitry reconstructs samples of the current block based on the affine model.

The present disclosure provides a computer-implemented method for video processing. The method includes deriving a total number by summing a number of reference picture list structures in sequence parameter set (SPS) and one; allocating memory for the total number of reference picture list structures in response to a reference picture list structure being signaled in a picture header of a current picture or a slice header of a current slice; and processing a current picture or a current slice using the allocated memory.

The present disclosure provides a computer-implemented method for video processing. The method includes deriving a total number by summing a number of reference picture list structures in sequence parameter set (SPS) and one; allocating memory for the total number of reference picture list structures in response to a reference picture list structure being signaled in a picture header of a current picture or a slice header of a current slice; and processing a current picture or a current slice using the allocated memory.