BEIJING DAJIA INTERNET INFORMATION TECHNOLOGY CO., LTD.

A method for video decoding, a method for video encoding, computing devices, and non-transitory computer readable storage mediums are provided. In the video decoding method, a decoder receives a control flag in a sequence parameter set (SPS), where the control flag indicates whether decoder side motion vector refinement (DMVR) is enabled for decoding video blocks in a current video sequence. The decoder receives a presence flag in the SPS when the control flag is true. The decoder receives a picture control flag in a picture header of each picture that refers to the SPS when the presence flag in the SPS is true, where the picture control flag indicates whether the DMVR is disabled for video blocks in the picture.

Methods for video decoding and encoding, apparatuses and non-transitory storage media are provided. The method for video decoding includes: obtaining, by a decoder, a plurality of first motion vectors of a plurality of sub-blocks of a current block, based on a subblock-based temporal motion vector prediction (SbTMVP) mode; deriving, by the decoder, a set of linear model parameters by inputting the plurality of first motion vectors and a plurality of center positions of the plurality of sub-blocks into a linear regression process; and obtaining, by the decoder, a plurality of predictions of the plurality of sub-blocks based on the set of linear model parameters.

A method for decoding video data. The method including obtaining, from a bitstream, a video block and region information, wherein the region information comprises an index indicating a region selected from a set of regions located external to the video block for deriving a multiple linear regression (MLR) model, obtaining luma and chroma sample values in the region based on the region information; deriving the MLR model using the luma and chroma sample values in the region, predicting each of the chroma sample values in the video block by applying the MLR model to corresponding luma sample values for that chroma sample, and obtaining decoded video block using the predicted chroma sample values.

Implementations of the disclosure provide a video processing method for motion information derivation. The video processing method may include determining, by a video decoder, that one or more motion related parameters for a video block in a video frame of a video are not signaled in a bitstream. The video processing method may further include determining, by the video decoder, the one or more motion related parameters for the video block by applying a coding matching technique.

An electronic apparatus performs a method of coding video data. The method comprises: receiving, from the bitstream, syntax elements associated with a coding unit, wherein the syntax elements include a first coded block flag (CBF) for residual samples of a first chroma component, a second CBF for residual samples of a second chroma component, and a third syntax element indicating whether adaptive color transform (ACT) is applied to the coding unit; determining whether to perform the chroma residual scaling to the residual samples of the chroma components according to the first CBF, the second CBF, and the third syntax element; in accordance with a determination to perform the chroma residual scaling to the residual samples of the first and second chroma components, scaling the residual samples of the at least one of the first and second chroma components based on a corresponding scaling parameter.

An electronic apparatus performs a method of coding video data. The method comprises: receiving, from the bitstream, syntax elements associated with a coding unit, wherein the syntax elements include a first coded block flag (CBF) for residual samples of a first chroma component, a second CBF for residual samples of a second chroma component, and a third syntax element indicating whether adaptive color transform (ACT) is applied to the coding unit; determining whether to perform the chroma residual scaling to the residual samples of the chroma components according to the first CBF, the second CBF, and the third syntax element; in accordance with a determination to perform the chroma residual scaling to the residual samples of the first and second chroma components, scaling the residual samples of the at least one of the first and second chroma components based on a corresponding scaling parameter.

Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for video decoding. In one method, a decoder determines a fusion scheme applied in decoder-side intra mode derivation (DIMD) mode and in template-based intra mode derivation (TIMD) mode, and the fusion scheme is applied as a weighted average of predictors in the DIMD mode and in the TIMD mode.

A method for video decoding including determining a decoded video block predicted with Extrapolation Filter-based intra Prediction (EIP) mode; obtaining a stored filter shape and stored filter coefficients corresponding to an extrapolation filter of the decoded video block, and predicting the sample values of the current block with EIP mode based on the stored filter shape and the stored filter coefficients.

A method, apparatus, and a non-transitory computer-readable storage medium for encoding a video signal are provided. In one method, an encoder may generate constraint flags, where at least one of the constraint flags indicates whether a slice is an intra slice. The encoder may transmit the constraint flags in a bitstream. The constraint flags comprise a single constraint flag that is different from the at least one of the constraint flags indicating whether a slice is an intra slice, and the single constraint flag being equal to 1 indicates that sps_weighted_pred_flag and sps_weighted_bipred_flag shall both be equal to 0.

Methods and apparatuses are provided for video coding, including: partitioning a video picture into a plurality of blocks; constructing a first merge list including a plurality of candidates each including one or more motion vectors for a current block; obtaining, directly from the first merge list, a plurality of uni-prediction merge candidates each including one motion vector of a corresponding candidate in the first merge list; obtaining a predictor for the current block based on the motion vectors of the plurality of uni-directional motion vector candidates; and forming a video bitstream based on the predictor, wherein each candidate includes a List 0 and/or List 1 motion vector, and each uni-prediction merge candidate includes a single one of the List 0 and List 1 motion vectors, wherein the List 0 and/or List 1 motion vectors are indexed based on a certain order and accessed directly from the first merge list.