A method includes performing a conversion between a video including a video picture and a bitstream of the video according to a rule, wherein the video picture including a subpicture, a tile, and a slice, and wherein the rule specifies that, due to the subpicture including the slice that is partitioned from the tile, the conversion is performed by refraining from counting a height of the subpicture using a number of tiles of the video picture.

A method includes performing a conversion between a video including a video picture and a bitstream of the video according to a rule, wherein the video picture including a subpicture, a tile, and a slice, and wherein the rule specifies that, due to the subpicture including the slice that is partitioned from the tile, the conversion is performed by refraining from counting a height of the subpicture using a number of tiles of the video picture.

A video processing method includes performing a conversion between a video having one or more video layers including one or more video pictures and a bitstream of the video according to a rule. The rule specifies a condition under which no picture that has been generated by a decoding process for generating an unavailable reference picture is referred to by an active entry in a reference picture list of a current slice of a current picture.

A video processing method includes performing a conversion between a video having one or more video layers including one or more video pictures and a bitstream of the video according to a rule. The rule specifies a condition under which no picture that has been generated by a decoding process for generating an unavailable reference picture is referred to by an active entry in a reference picture list of a current slice of a current picture.

A method, computer program, and computer system is provided for coding video data. Video data including one or more subpictures is received. A network abstraction layer (NAL) unit type associated with each of the one or more subpictures is identified based on checking a flag corresponding to mixed NAL units in the one or more subpictures. The video data is decoded based on the identified NAL unit types.

A method, computer program, and computer system is provided for coding video data. Video data including one or more subpictures is received. A network abstraction layer (NAL) unit type associated with each of the one or more subpictures is identified based on checking a flag corresponding to mixed NAL units in the one or more subpictures. The video data is decoded based on the identified NAL unit types.

A video signal processing method comprises: obtaining, from a bitstream, a skip parameter (cu_skip_flag) indicating whether a skip mode is applied to a current block; when the skip parameter indicates that a mode is not the skip mode, obtaining, from the bitstream, a merge parameter (merge_flag) indicating whether the current block is coded with a merge mode; and determining whether a coded block flag (CBF) parameter (cu_cbf), which indicates whether a syntax element related to transform is obtained from the bitstream, is obtained, according to a value of the merge parameter, wherein, when the value of the merge parameter indicates the merge mode, the CBF parameter is not obtained from the bitstream and is determined to be a preconfigured value.

A video decoding method performed by a video decoding apparatus according to the present document may comprise the steps of: parsing a prediction weighted table syntax from a bitstream; parsing number information about weighted reference pictures in a reference picture list from the prediction weighted table syntax; deriving a weighting factor-related flag about the reference picture list on the basis of the number information; performing weighted prediction on a current block on the basis of the weighting factor-related flag so as to derive prediction samples of the current block; generating residual samples on the basis of residual information obtained from the bitstream; and reconstructing a current picture on the basis of the prediction samples and the residual samples, wherein the prediction weighted table syntax is parsed from a picture header of the bitstream.

A video decoding method performed by a video decoding apparatus according to the present document may comprise the steps of: parsing a prediction weighted table syntax from a bitstream; parsing number information about weighted reference pictures in a reference picture list from the prediction weighted table syntax; deriving a weighting factor-related flag about the reference picture list on the basis of the number information; performing weighted prediction on a current block on the basis of the weighting factor-related flag so as to derive prediction samples of the current block; generating residual samples on the basis of residual information obtained from the bitstream; and reconstructing a current picture on the basis of the prediction samples and the residual samples, wherein the prediction weighted table syntax is parsed from a picture header of the bitstream.

An image decoding method according to the present invention may include splitting a picture into a plurality of tiles; and determining at least one slice on the basis of the plurality of tiles. Here, splitting a picture into a plurality of tiles may include: determining the width of a first tile column in the picture; and determining the width of a second tile column neighboring the first tile column.