Abstract: A picture prediction method includes: determining two pixel samples in a current picture block, and determining a candidate motion information unit set corresponding to each of the two pixel samples; determining a merged motion information unit set i including two motion information units; and predicting a pixel value of the current picture block by using an atone motion model and the merged motion information unit set i.

Abstract: A picture prediction method and a related apparatus are disclosed. A picture prediction method includes: determining K1 pixel samples in a picture block x, and determining a candidate motion information unit set corresponding to each pixel sample in the K1 pixel samples, where the candidate motion information unit set corresponding to each pixel sample includes at least one candidate motion information unit; determining a merged motion information unit set i including K1 motion information units, where each motion information unit in the merged motion information unit set i is selected from at least a part of motion information units in candidate motion information unit sets corresponding to different pixel samples in the K1 pixel samples; and predicting a pixel value of the picture block x by using a non-translational motion model and the merged motion information unit set i.

Abstract: This application discloses a processing method applied to video encoding or video decoding. The method includes: obtaining size information of a current block; determining a context model index ctxInc of a flag of the current block based on the obtained size information of the current block and a size-based constraint; and performing subsequent processing based on the context model index ctxInc of the flag of the current block. The method can be used to improve coding efficiency.

Abstract: An inter prediction method is provided, including: when a prediction mode of a to-be-processed picture block is an affine motion model-based advanced motion vector prediction mode (S901), obtaining control point motion vectors of the to-be-processed picture block (S902), where the control point motion vectors meet preset first motion vector resolution and/or first motion vector bit depth; then, deriving a motion vector of each motion compensation unit in the to-be-processed picture block based on the control point motion vectors (S903); and obtaining a reconstructed block of the to-be-processed picture block based on the motion vector of each motion compensation unit (S904).

Abstract: Disclosed is a mechanism for selecting an interpolation filter for use in conjunction with an affine block in video coding. A motion vector is determined for a sub-block of the affine block based on control points. A sub-block size of the sub-block is also determined. The interpolation filter is selected for application to a reference block corresponding to the sub-block. The interpolation filter is selected based on the sub-block size. The motion vector of the sub-block and an offset of a current sample of the sub-block are employed to determine a reference sample at the reference block. This includes applying the interpolation filter to the reference block to determine the reference sample when the motion vector at the offset points to a fractional position at the reference block. The reference samples are employed to determine residual information in order to encode the affine block.

Abstract: This application discloses an inter prediction method and apparatus. The method includes: determining a plurality of first picture blocks in a to-be-processed picture block based on a preset picture split width, a preset picture split height, and a width and a height of the to-be-processed picture block; separately performing bi-directional optical flow prediction on the plurality of first picture blocks to obtain a predictor of each first picture block; and obtaining a predictor of the to-be-processed picture block with a combination of the predictors of the plurality of first picture blocks. The apparatus includes a determining module, a prediction module, and a combination module. In this application, complexity of implementing inter prediction can be reduced, and processing efficiency can be improved.

Abstract: An image prediction method and apparatus includes obtaining predicted motion information of an image block; determining an initial predicted block of the image block according to the predicted motion information and a reference image of the image block; performing, according to the predicted motion information, L iterative searches in the reference image using an integer pixel step size to obtain an intermediate predicted block of the image block; performing a single search in the reference image using a fractional pixel step size to obtain M predicted blocks of the image block; determining a target predicted block of the image block according to the M predicted blocks and the intermediate predicted block; and obtaining a predicted value of a pixel value of the image block according to a pixel value of the target predicted block.

Abstract: A video coding mechanism is disclosed. The mechanism includes selecting a split mechanism to split a coding unit (CU) into sub-CUs for application of one or more transform units (TUs), the selection of the split mechanism based on comparing a CU width to a max TU width and comparing a CU height to a max TU height. The selected split mechanism is applied to the CU to obtain sub-CUs. A residual of one of the sub-CUs is determined. The residual includes a difference between sample values for the sub-CU and prediction samples for the sub-CU. The TUs are applied to transform the residual of the CU based on results of the selected split mechanism. A transformed residual for the CU is encoded into a bitstream.

Abstract: A video picture prediction method and apparatus are provided, to provide a manner of determining a maximum length of a candidate motion vector list corresponding to a subblock merge mode. The method comprises: parsing a first indicator from a bitstream; if the first indicator indicates that a candidate mode used to inter predict the to-be-processed block comprises an affine mode, parsing a second indicator from the bitstream, where the second indicator is used to indicate a maximum length of a first candidate motion vector list, and the first candidate motion vector list is constructed for the to-be-processed block, a subblock merge prediction mode is used for the to-be-processed block; and determining the maximum length of the first candidate motion vector list based on the second indicator.

Abstract: The present disclosure provides a video image decoding method in which a size of an affine motion compensation image sub-block in an affine image block is determined based on a motion vector difference, motion vector precision, a distance between control points in the affine image block, and a size of the affine image block, where the size includes a length in a horizontal direction and a length in a vertical direction, so that a length of the affine image block in a horizontal/vertical direction is an integer multiple of the length of the affine motion compensation image sub-block in the horizontal/vertical direction.

Abstract: This application discloses a motion vector prediction method based on an affine motion model and a device. The method includes: obtaining one spatial reference block of a to-be-processed picture block; determining a plurality of preset subblock locations of the spatial reference block; obtaining motion vectors corresponding to preset pixel locations of the to-be-processed picture block that are extrapolated from motion vectors corresponding to the preset subblock locations; and obtaining motion vectors corresponding to a plurality of subblock locations of the to-be-processed picture block that are interpolated from the motion vectors corresponding to the preset pixel locations. According to this application, prediction accuracy in coding can be improved, and coding efficiency can be improved.

Abstract: Embodiments of this application disclose a picture prediction method and apparatus, and a corresponding encoder and decoder. A prediction direction of a current picture block is considered when a size of a subblock in the current picture block is determined. For example, if a prediction mode of the current picture block is unidirectional prediction, the size of the subblock is 4×4; or if a prediction mode of the current picture block is bidirectional prediction, the size of the subblock is 8×8.

Abstract: This application provides a video picture prediction method and apparatus, to resolve a problem in a conventional technology that a length of a coded video sequence is increased. The first type of identifier may be added to a bitstream. The first type of identifier is used to indicate whether an affine motion model-based inter prediction mode is enabled for a video picture. For a video picture or a picture block included in the slice for which the affine motion model does not need to be used, a parameter, related to the affine motion model, of the picture block may not need to be transmitted. On a decoder side, during decoding of the picture block, the parameter related to the affine motion model does not need to be parsed. This can reduce load of a decoder, increase a processing speed, and decrease a processing time.

Abstract: A video decoding method includes obtaining a to-be-entropy-decoded syntax element in a current block by parsing a received bitstream, where the to-be-entropy-decoded syntax element includes a syntax element 1 or a syntax element 2 in the current block, obtaining a context model corresponding to the to-be-entropy-decoded syntax element, where both of a context model corresponding to the syntax element 1 and a context model corresponding to the syntax element 2 are determined from the same preset context model set, entropy decoding the to-be-entropy-decoded syntax element based on the context model corresponding to the to-be-entropy-decoded syntax element, and obtaining a reconstructed image of the current block based on the syntax element obtained by entropy decoding.

Abstract: Embodiments of this application relate to the field of video picture coding technologies, and disclose a reference frame obtaining method and apparatus applied to bidirectional inter prediction, to improve coding efficiency. The method includes: determining a first reference frame list and a second reference frame list of a current picture block; determining, from the first reference frame list, whether an X-directional reference frame x1 satisfying a condition A1 exists; determining, from the second reference frame list, whether a Y-directional reference frame y1 satisfying a condition B1 exists; and in response to determining that the X-directional reference frame x1 exists and determining that the Y-directional reference frame y1 exists, obtaining index values (R1, R2) of bidirectional reference frames of the current picture block.

Abstract: Embodiments of this application disclose bi-directional inter prediction methods and apparatuses. In an embodiment, a method comprises: determining that a first reference picture index of a first reference picture list is associated with a current block to be predicted; determining that a second reference picture index of a second reference picture list is associated with the current block; and predicting the current block based on the first reference picture index and the second reference picture index.

Abstract: A motion information candidate list construction method includes: performing a first processing process on all neighboring image blocks of a current image block until a quantity of candidate motion information sets in a candidate motion information list is equal to a first preset value or all the neighboring image blocks are traversed; then traversing at least two extra to be selected motion information sets, and storing, in the candidate motion information list, an extra to be selected motion information set that satisfies a preset condition, until the quantity of candidate motion information sets in the candidate motion information list is equal to a preset quantity value or the extra to be selected motion information sets are traversedextra to be selected motion.

Abstract: This application provides an inter prediction method and apparatus, a video encoder, and a video decoder. The method includes: determining N target picture blocks from M picture blocks in which M neighboring locations of a current picture block are respectively located, where any two of the N target picture blocks are different, M and N are both positive integers, and M is greater than or equal to N; determining candidate motion information of the current picture block based on motion information of the N target picture blocks, and adding the candidate motion information of the current picture block to a motion information candidate list of the current picture block; and performing inter prediction on the current picture block based on the motion information candidate list. In this application, comparison operations during obtaining of the motion information candidate list can be reduced, to improve inter prediction efficiency.

Abstract: The present disclosure provides a video image decoding method in which a size of an affine motion compensation image sub-block in an affine image block is determined based on a motion vector difference, motion vector precision, a distance between control points in the affine image block, and a size of the affine image block, where the size includes a length in a horizontal direction and a length in a vertical direction, so that a length of the affine image block in a horizontal/vertical direction is an integer multiple of the length of the affine motion compensation image sub-block in the horizontal/vertical direction.

Abstract: This disclosure discloses a method for obtaining a candidate motion vector list, an apparatus, an encoder, and a decoder. The method for obtaining a candidate motion vector list comprises: when a first candidate picture block is encoded/decoded and an inter prediction mode is used, determining whether a reference picture of the first candidate picture block is the same as a reference picture of a current block; and constructing a candidate motion vector list of the current block based on a determining result; when the reference picture of the first candidate picture block is different from the reference picture of the current block, the MV of the first candidate picture block is not used to construct the list. Implementing this disclosure can reduce complexity of a motion information derivation process, and improve coding efficiency.