A video decoding method performed by a video decoding device according to the present document may comprise the steps of: acquiring image information from a bitstream, the image information including a picture header associated with the current picture including a plurality of slices; parsing, from the picture header, at least one of a first flag indicating whether information necessary for an inter-prediction operation for a decoding process is present in the picture header, or a second flag indicating whether information necessary for an intra-prediction operation for the decoding process is present in the picture header; generating prediction samples by performing at least one of intra-prediction or inter-prediction for the slices in the current picture on the basis of at least one of the first flag or the second flag; and generating reconstructed samples on the basis of the prediction samples.

A video decoding method performed by a video decoding device according to the present document may comprise the steps of: acquiring image information from a bitstream, the image information including a picture header associated with the current picture including a plurality of slices; parsing, from the picture header, at least one of a first flag indicating whether information necessary for an inter-prediction operation for a decoding process is present in the picture header, or a second flag indicating whether information necessary for an intra-prediction operation for the decoding process is present in the picture header; generating prediction samples by performing at least one of intra-prediction or inter-prediction for the slices in the current picture on the basis of at least one of the first flag or the second flag; and generating reconstructed samples on the basis of the prediction samples.

According to an image coding method according to embodiments of the present document, information related to in-loop filtering may be efficiently signaled, and repetitive procedures for signaling subpicture-related information may be reduced.

A method for video processing is described. The method includes performing a conversion between a video including one or more pictures including one or more subpictures including one or more slices and a bitstream representation of the video according to a rule, and wherein the bitstream representation includes a number of coded units, wherein the rule specifies that a decoding order of coded units within a subpicture is in an increasing order of subpicture level slice index values of the coded units.

A method for video processing is described. The method includes performing a conversion between a video including one or more pictures including one or more subpictures including one or more slices and a bitstream representation of the video according to a rule, and wherein the bitstream representation includes a number of coded units, wherein the rule specifies that a decoding order of coded units within a subpicture is in an increasing order of subpicture level slice index values of the coded units.

Image data encoding apparatus, comprises an entropy encoder configured to selectively encode data items representing image data so as to generate encoded binarized symbols of successive output data units; the entropy encoder being configured to generate an output data stream subject to a constraint defining an upper limit to the number of binarized symbols that may be expressed by any individual output data unit relative to the size in bytes of that output data unit, in which the entropy encoder is configured to provide padding data, for each output data unit which does not meet the constraint, so as to increase the size in bytes of that output data unit in order to meet the constraint; the apparatus comprising: an attribute detector configured to detect an encoding attribute applicable to a given output data unit; and a selector configured to select, in response to the detected encoding attribute, a constraint, for use with the given output data unit, from two or more candidate constraints.

Image data encoding apparatus, comprises an entropy encoder configured to selectively encode data items representing image data so as to generate encoded binarized symbols of successive output data units; the entropy encoder being configured to generate an output data stream subject to a constraint defining an upper limit to the number of binarized symbols that may be expressed by any individual output data unit relative to the size in bytes of that output data unit, in which the entropy encoder is configured to provide padding data, for each output data unit which does not meet the constraint, so as to increase the size in bytes of that output data unit in order to meet the constraint; the apparatus comprising: an attribute detector configured to detect an encoding attribute applicable to a given output data unit; and a selector configured to select, in response to the detected encoding attribute, a constraint, for use with the given output data unit, from two or more candidate constraints.

A method of visual media processing video, includes determining that palette mode is to be used for processing a first portion of a video block and intra block copy (IBC) mode is to be used for processing a second portion of the video block, and performing further processing of the first portion of the video block using the palette mode and the second portion of the video using the IBC mode, wherein indications of the first portion of the video block processed using the palette mode and indications of the second portion of the video block processed using the IBC mode are included in a palette index identifying the first portion of the video block and the second portion of the video block.

Methods, apparatuses, and non-transitory computer-readable mediums are provided. A block vector of a current block that is to be coded in intra block copy (IBC) mode is determined. The block vector points to a first reference block of the current block in a current picture. An operation is performed on at least one component of the block vector based on the first reference block being outside a search range of the current block. The block vector is modified by the operation to point to a second reference block that is within the search range for the current block. The current block is encoded based on the modified block vector. The performing the operation includes performing a modulo operation on a y component of the block vector based on a size of a current coding tree unit (CTU) that includes the current block.

Methods, apparatuses, and non-transitory computer-readable mediums are provided. A block vector of a current block that is to be coded in intra block copy (IBC) mode is determined. The block vector points to a first reference block of the current block in a current picture. An operation is performed on at least one component of the block vector based on the first reference block being outside a search range of the current block. The block vector is modified by the operation to point to a second reference block that is within the search range for the current block. The current block is encoded based on the modified block vector. The performing the operation includes performing a modulo operation on a y component of the block vector based on a size of a current coding tree unit (CTU) that includes the current block.