Systems, methods, and computer-readable media are provided for updating history-based motion vector tables. In some examples, a method can include obtaining one or more blocks of video data; determining a first motion vector derived from a first control point of a block of the one or more blocks, the block being coded using an affine motion mode; determining a second motion vector derived from a second control point of the block; based on the first motion vector and the second motion vector, estimating a third motion vector for a predetermined location within the block; and populating a history-based motion vector predictor (HMVP) table with the third motion vector.

Systems, methods, and computer-readable media are provided for updating history-based motion vector tables. In some examples, a method can include obtaining one or more blocks of video data; determining a first motion vector derived from a first control point of a block of the one or more blocks, the block being coded using an affine motion mode; determining a second motion vector derived from a second control point of the block; based on the first motion vector and the second motion vector, estimating a third motion vector for a predetermined location within the block; and populating a history-based motion vector predictor (HMVP) table with the third motion vector.

A set of rough prediction modes including a MPM subset is determined for a code block during image encoding. A first prediction mode having a mode cost less than a first threshold is selected from the set of rough prediction modes, and a second prediction mode having a mode cost less than a second threshold is selected from the MPM subset. A candidate mode subset is determined based on mode types of prediction modes contained in the set of rough prediction modes and a ranking result of mode costs of the prediction modes, when the mode cost of the first prediction mode is different from the mode cost of the second prediction mode. A target prediction mode is determined for the code block from the candidate mode subset. The code block is encoded with the target prediction mode.

A set of rough prediction modes including a MPM subset is determined for a code block during image encoding. A first prediction mode having a mode cost less than a first threshold is selected from the set of rough prediction modes, and a second prediction mode having a mode cost less than a second threshold is selected from the MPM subset. A candidate mode subset is determined based on mode types of prediction modes contained in the set of rough prediction modes and a ranking result of mode costs of the prediction modes, when the mode cost of the first prediction mode is different from the mode cost of the second prediction mode. A target prediction mode is determined for the code block from the candidate mode subset. The code block is encoded with the target prediction mode.

A method, computer program, and computer system is provided for video encoding and decoding. Video data including one or more frames is received. One or more quantization parameters associated with the received video data are determined for frame generation or enhancement of a target frame from among the one or more frames. The video data is decoded based on the determined quantization parameters.

A method, computer program, and computer system is provided for video encoding and decoding. Video data including one or more frames is received. One or more quantization parameters associated with the received video data are determined for frame generation or enhancement of a target frame from among the one or more frames. The video data is decoded based on the determined quantization parameters.

The present disclosure provides video decoding method. An exemplary method includes: decoding a first parameter for a coding unit from a bitstream, and determining a candidate for the coding unit based on the first parameter; determining a value of a second parameter associated with the coding unit based on a value of a second parameter associated with the candidate, wherein the second parameter indicates whether a bi-directional prediction correction is enabled; and in response to the value of the second parameter associated with the coding unit indicating the bi-directional prediction correction being enabled, performing the bi-directional prediction correction on the coding unit.

The present disclosure provides video decoding method. An exemplary method includes: decoding a first parameter for a coding unit from a bitstream, and determining a candidate for the coding unit based on the first parameter; determining a value of a second parameter associated with the coding unit based on a value of a second parameter associated with the candidate, wherein the second parameter indicates whether a bi-directional prediction correction is enabled; and in response to the value of the second parameter associated with the coding unit indicating the bi-directional prediction correction being enabled, performing the bi-directional prediction correction on the coding unit.

In a method and a device for encoding or decoding an image according to the present invention, motion information for bidirectional prediction of a current block may be derived on the basis of an inter mode previously defined in the device for encoding or decoding an image, and inter prediction may be performed on the current block on the basis of the motion information, wherein the motion information for bidirectional prediction is adjusted to be motion information for unidirectional prediction according to the predefined inter mode.

In a method and a device for encoding or decoding an image according to the present invention, motion information for bidirectional prediction of a current block may be derived on the basis of an inter mode previously defined in the device for encoding or decoding an image, and inter prediction may be performed on the current block on the basis of the motion information, wherein the motion information for bidirectional prediction is adjusted to be motion information for unidirectional prediction according to the predefined inter mode.