Efficient prediction of samples within a block in a video encoder and decoder by means of computing both an inter-predicted prediction hypothesis as well as an intra-predicted prediction-hypothesis. The two prediction hypotheses are then combined together by means of parametric transformation to form a new prediction hypothesis which may be more accurate in predicting the content of the original block.

Disclosed herein is an intra prediction method including: deriving neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode; deriving an intra prediction mode for a decoding target unit by using the derived neighbor prediction mode information; and performing intra prediction on the decoding target unit based on the intra prediction mode. According to exemplary embodiments of the present invention, image encoding/decoding efficiency can be improved.

Disclosed herein is an intra prediction method including: deriving neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode; deriving an intra prediction mode for a decoding target unit by using the derived neighbor prediction mode information; and performing intra prediction on the decoding target unit based on the intra prediction mode. According to exemplary embodiments of the present invention, image encoding/decoding efficiency can be improved.

A method for video coding is provided. The method includes obtaining a first reference picture and a second reference picture associated with a current prediction block, obtaining a first prediction L0 based on a first motion vector MV0 from the current prediction block to a reference block in the first reference picture, obtaining a second prediction L1 based on a second motion vector MV1 from the current prediction block to a reference block in the second reference picture, determining whether a bidirectional optical flow (BDOF) operation is applied, and calculating a bi-prediction of the current prediction block based on the first prediction L0 and the second prediction L1, and first gradient values and second gradient values.

A video encoder for encoding a video into a data stream using motion compensated prediction for inter predicted blocks, comprising a hypothesis number control, configured to control a number of prediction hypotheses of the inter predicted blocks within a predetermined portion of the video to meet a predetermined criterion.

A video encoder for encoding a video into a data stream using motion compensated prediction for inter predicted blocks, comprising a hypothesis number control, configured to control a number of prediction hypotheses of the inter predicted blocks within a predetermined portion of the video to meet a predetermined criterion.

Disclosed herein is an intra prediction method including: deriving neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode; deriving an intra prediction mode for a decoding target unit by using the derived neighbor prediction mode information; and performing intra prediction on the decoding target unit based on the intra prediction mode. According to exemplary embodiments of the present invention, image encoding/decoding efficiency can be improved.

Disclosed herein is an intra prediction method including: deriving neighbor prediction mode information from a left neighbor prediction mode and an upper neighbor prediction mode; deriving an intra prediction mode for a decoding target unit by using the derived neighbor prediction mode information; and performing intra prediction on the decoding target unit based on the intra prediction mode. According to exemplary embodiments of the present invention, image encoding/decoding efficiency can be improved.

A method of video processing comprises determining, for a conversion between a first block of video and a bitstream representation of the first block, a range of motion vector difference (MVD) component associated with the first block, wherein the range of MVD component is [−2.sup.M, 2.sup.M−1], where M=17; constraining value of the MVD component to be in the range of MVD component; and performing the conversion based on the constrained MVD component.

A method of video processing comprises determining, for a conversion between a first block of video and a bitstream representation of the first block, a range of motion vector difference (MVD) component associated with the first block, wherein the range of MVD component is [−2.sup.M, 2.sup.M−1], where M=17; constraining value of the MVD component to be in the range of MVD component; and performing the conversion based on the constrained MVD component.