Abstract: Examples of video encoding methods and apparatus and video decoding methods and apparatus are described. An example method of processing video data includes determining, for a conversion between a video block of a video and a bitstream of the video, a gradient of a prediction vector at a sub-block level for the video block according to a rule, wherein the rule specifies to use a same gradient value is assigned for all samples within a sub-block of the video block; and performing the conversion based on the determining.

Abstract: Examples of video encoding methods and apparatus and video decoding methods and apparatus are described. An example method of processing video data includes determining, for a conversion between a video block of a video and a bitstream of the video, a gradient of a prediction vector at a sub-block level for the video block according to a rule, wherein the rule specifies to use a same gradient value is assigned for all samples within a sub-block of the video block; and performing the conversion based on the determining.

Abstract: A method implemented by a video coding apparatus includes applying a neural network (NN) filter to an unfiltered sample of a video unit to generate a filtered sample. The NN filter is applied based on a syntax element of the video unit. The method also includes converting between a video media file and a bitstream based on the filtered sample that was generated.

Abstract: A video image processing method includes determining a related block of a current image block according to a motion vector of a target neighboring block, the current image block, and a collocated frame of the current image block, decoding the current image block according to a motion vector of the related block of the current image block, constructing motion vectors of part of control points of the current image block according to neighboring blocks of the part of the control points of the current image block, and adding the motion vectors of the part of the control points of the current image block to a motion vector candidate list of the current image block.

Abstract: A video processing method includes obtaining motion information of a neighboring block of a current image block, dividing the current image block into a plurality of sub-blocks in response to the neighboring block satisfying a preset condition, determining, in a time-domain reference image of the current image block, related blocks of the plurality of sub-blocks according to a motion vector of the neighboring block, and performing prediction on the current image block according to motion vectors of the related blocks.

Abstract: A video processing method includes dividing a region of a current frame to obtain a plurality of image blocks, obtaining a historical motion information candidate list, and obtaining candidate historical motion information for the plurality of image blocks according to the historical motion information candidate list. The candidate historical motion information is a candidate in the historical motion information candidate list. The method further includes performing prediction for the plurality of image blocks according to the candidate historical motion information. A size of each of the plurality of image blocks is smaller than or equal to a preset size. The same historical motion information candidate list is used for the plurality of image blocks during the prediction. The historical motion information candidate list is not updated while the prediction is being performed for the plurality of image blocks.

Abstract: A method implemented by a video coding apparatus. The method includes applying a first filter to an unfiltered sample of a video unit to generate a filtered sample. The first filter is a neural network (NN) filter based on a non-deep learning-based filter (NDLF) being disabled, and the first filter is the NDLF based on the NN filter being disabled. The method also includes performing a conversion between a video media file and a bitstream based on the filtered sample that was generated.

Abstract: A video image processing method includes binarizing a chrominance prediction mode of the image block of a to-be-encoded/decoded image to obtain a bit string, the bit string including two adjacent bits, the to-be-encoded/decoded image being permitted to use a CCLM and/or a regular intra-frame chrominance prediction mode, and the CCLM including a first mode, a second mode, and a third mode, and using mutually independent probability models to encode/decode a first bit and a second bit. The first bit of the adjacent bits indicates whether the CCLM is used, the second bit indicates whether to use the first mode of the CCLM when the first bit indicates to use the CCLM, the third bit indicates whether the second mode or the third mode of the CCLM is used when the second bit indicates that the first mode of the CCLM is not used.

Abstract: A video image processing method including determining a current image block, constructing a motion information candidate list for the current image block, in response to a size of the current image block meeting a preset condition, turning off a temporal motion vector prediction (TMVP) operation so that a temporal candidate motion vector of the current image block is not determined according to the TMVP operation, and encoding the current image block. The TMVP operation includes determining a relevant block of the current image block in a temporal neighboring image, and determining the temporal candidate motion vector of the current image block according to a motion vector of the relevant block.

Abstract: Methods, system and apparatus for video processing are described. One example method of processing video data includes performing a conversion between a current block of a video and a bitstream of the video. Samples of the current block are represented in the bitstream using coefficients that are arranged according to a rule responsive to locations of the samples of the current block.

Abstract: A video image processing method includes determining a current image block; in response to a size of the current image block not meeting a first preset condition, skipping an advanced/alternative temporal motion vector prediction (ATMVP) operation so that a temporal candidate motion vector of the current image block is not determined according to the ATMVP operation; and encoding the current image block. The ATMVP operation includes determining a relevant block of the current image block in a temporal neighboring image; dividing the current image block into a plurality of sub-blocks; for each of the sub-blocks, determining a corresponding relevant sub-block in the relevant block; and determining temporal candidate motion vectors of the sub-blocks of the current image block according to motion vectors of the relevant sub-blocks corresponding to the sub-blocks.

Abstract: Methods, systems and devices for sample string processing in intra coding are described. An example method of video processing includes determining, for a conversion between a video comprising a current block and a bitstream of the video, whether a first sample string of the current block forms a rectangle, and performing, based on the determining, the conversion, wherein the determining is based on a position and a length of the first sample string.

Abstract: Methods, systems and devices for video coding using sample string vectors are described. An example method of video processing includes determining, for a conversion between a video including a current block and a bitstream of the video, an availability of a block vector of one or more non-adjacent neighboring blocks of the current block for a prediction of a block vector of the current block according to a rule, and performing, based on the determining, the conversion, wherein the rule specifies a pre-defined order for checking the one or more non-adjacent neighboring blocks.

Abstract: A video image processing method including determining a current image block, in response to a size of the current image block meeting a preset condition, skipping a temporal motion vector prediction (TMVP) operation so that a temporal candidate motion vector of the current image block is not determined according to the TMVP operation, and encoding the current image block. The TMVP operation includes determining a relevant block of the current image block in a temporal neighboring image, and determining the temporal candidate motion vector of the current image block according to a motion vector of the relevant block.

Abstract: Methods, system and apparatus for video processing are described. One example method of processing video data includes performing a conversion between a current block of a video and a bitstream of the video according to a rule. The rule specifies that whether a transform skip mode is enabled is determined based on coding information of the current block. The transform skip mode is a coding mode in which a transform is skipped on a prediction residual of a video block.

Abstract: Methods, system and apparatus for video processing are described. One example method of processing video data includes performing a conversion between a current block of a video and a bitstream of the video according to a rule. The rule specifies that coded information of the current block determines usage of coefficient reordering by which coefficients of the current block parsed from the bitstream are reordered prior to applying a dequantization process, an inverse transform process, or a reconstruction process.

Abstract: A video encoding method includes encoding images of an image sequence to generate a bitstream of the image sequence. Different identifiers are used for two chrominance components of one image in a syntax element of an image level in the bitstream to indicate whether the corresponding chrominance components are filtered by adaptive loop filtering (ALF).

Abstract: Examples of video encoding methods and apparatus and video decoding methods and apparatus are described. An example method of processing video data includes determining, for a conversion between a video block of a video and a bitstream of the video, a gradient of a prediction vector at a sub-block level for the video block according to a rule, wherein the rule specifies to use a same gradient value is assigned for all samples within a sub-block of the video block; and performing the conversion based on the determining.

Abstract: A video processing method includes performing a conversion between a video block of a video and a bitstream of the video according to a rule. The rule specifies whether or how usage of a secondary transform within a video unit is indicated in the bitstream. The secondary transform is applied before quantization or after de-quantization.

Abstract: Methods, system and apparatus for video processing are described. One example video processing method includes determining, for a conversion between a current video block of a video and a bitstream of the video, a usage of an identity transform mode for the conversion of the current video block according to a rule. The rule specifies that the usage is based on representative coefficients of one or more representative blocks of the video. The method also includes performing the conversion based on the determining.