Abstract: 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 format rule. The format rule specifies that a first video picture is an associated intra random access point picture of a second picture and that the second picture are constrained to belong to a same video layer.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a plurality of coded sequences of point cloud coding (PCC) frames. The plurality of coded sequences of PCC frames represent a plurality of PCC attributes including geometry, texture, and one or more of reflectance, transparency, and normal. Each coded PCC frame is represented by one or more PCC network abstraction layer (NAL) units. The mechanism also includes parsing the bitstream to obtain, for each PCC attribute, an indication of one of a plurality of video codecs used to code the corresponding PCC attribute. The mechanism also includes decoding the bitstream based on the indicated video codecs for the PCC attributes.

Abstract: A method of decoding a coded video bitstream is provided. The method includes parsing a parameter set represented in the coded video bitstream. The parameter set contains a set of syntax elements that include a set of reference picture list structures. The method also includes parsing a slice header of a current slice represented in the coded video bitstream. The slice header contains an index of a reference picture list structure among the set of reference picture list structures in the parameter set. The method further includes deriving, based on the set of syntax elements in the parameter set and the index of the reference picture list structure, a reference picture list of the current slice. The method also includes obtaining, based on the reference picture list, at least one reconstructed block of the current slice.

Abstract: Several techniques for video encoding and video decoding are described. One example method includes performing a conversion between a video picture of a video comprising one or more slices and a bitstream of the video picture according to a rule. The rule specifies that that whether a first syntax element indicating a usage of a coding tool is present at a first level is based on a syntax flag indicating whether a syntax structure of a second level is not present at the first level, wherein the second level is higher than the first level, and wherein the second level is the video picture level or higher than the video picture level.

Abstract: Methods, systems and apparatus for video processing are described. One example video processing method includes performing a conversion between a video including a video region and a bitstream of the video according to a rule, wherein the rule specifies that an adaptive loop filtering operation is allowed for the video region in response to an absence of one or more adaptation parameter set (APS) network abstraction layer (NAL) units that include adaptive loop filtering data.

Abstract: Techniques for video processing, including video coding, video decoding and video transcoding are described. One example method includes performing a conversion between a video picture that includes one or more tiles and one or more rectangular slices and a bitstream of the video according to a rule. The rule specifies that, for iteratively determining information about the one or more rectangular slices, a variable indicating a tile index is updated only for slices having indices that are smaller than a value equal to a number of slices in the video picture minus 1.

Abstract: Methods, systems and devices for signaling of coded buffer picture information in video bitstream processing are disclosed. An example method of video processing includes performing a conversion between a video comprising one or more pictures and a bitstream of the video, wherein the bitstream conforms to a format rule, wherein the format rule specifies that a first syntax element, when included in the bitstream, is access unit (AU) specific, wherein the value of the first syntax element is based on whether an associated AU is an intra random access points (IRAP) AU or a gradual decoding refresh (GDR) AU, and wherein the value of the first syntax element specifies (i) whether a second syntax element is present in a buffering period supplemental enhancement information (SEI) message, and (ii) whether alternative timing information is present in a picture timing SEI message in a current buffering period.

Abstract: A method of decoding a coded video bitstream implemented by a video decoder is disclosed. The method includes determining that a coded video sequence (CVS) of the coded video bitstream includes a video coding layer (VCL) network abstraction layer (NAL) unit having a gradual decoding refresh (GDR) network abstraction layer (NAL) unit type (GDR_NUT), the VCL NAL unit having the GDR_NUT containing a GDR picture; initiating decoding of the CVS at the GDR picture; and generating an image according to the CVS as decoded. A corresponding method of encoding is also disclosed.

Abstract: Examples of video encoding methods and apparatus and video decoding methods and apparatus are described. An example method of video processing includes performing a conversion between a video and a bitstream of the video. The bitstream includes one or more layers including one or more network abstraction layer (NAL) units according to a format rule that specifies that a first layer identifier in a header of an end of sequence network abstraction layer (EOS NAL) unit is required to be equal to a second layer identifier of one of the one or more layers in the bitstream.

Abstract: Methods, systems, apparatus for video processing are described. The processing may include encoding, decoding or transcoding. One example video processing method includes performing a conversion between a video including one or more pictures and a bitstream of the video according to a format rule. The format rule specifies to include, in a general constrain syntax structure, a syntax element indicating whether each picture includes only one slice, and whether a picture header syntax structure is present in a slice header.

Abstract: A method of decoding a coded video bitstream includes obtaining a reference picture list structure for a current slice represented in the coded video bitstream, wherein the reference picture list structure contains a number of entries; obtaining a default number of active entries in a reference picture list for the current slice; constructing a reference picture list for the current slice, the reference picture list containing a number of active and inactive entries; setting the number of active entries in the reference picture list equal to the number of entries in the reference picture list structure when the default number of active entries in the reference picture list is greater than the number of entries in the reference picture list structure; and obtaining, based on at least one active entry of the reference picture list, at least one reconstructed block of the current slice.

Abstract: Methods, systems, apparatuses for video processing are described. A method for processing video includes performing a conversion between a video and a bitstream of the video according to a format rule, and wherein the format rule specifies to include, in a general constraint syntax structure associated with the video, one or more general constraint flags indicating whether corresponding syntax elements are included in a sequence parameter set (SPS) and/or a picture parameter set (PPS) and/or a picture header (PH) and/or a slice header (SH) or to constrain values of the syntax elements in the SPS and/or the PPS and/or the PH and/or the SH.

Abstract: Methods and apparatus for processing of video are described. The processing may include video encoding, decoding, or transcoding. One example video processing method includes performing a conversion between a video including one or more pictures including one or more subpictures and a bitstream of the video. The bitstream conforms to a format rule that specifies that a subpicture cannot be a random access type of subpicture in response to the subpicture not being a leading subpicture of an intra random access point subpicture. The leading subpicture precedes the intra random access point subpicture in output order.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving an extracted bitstream that is a result of a sub-bitstream extraction process from an input bitstream containing a set of sub-pictures. The extracted bitstream contains only a subset of the sub-pictures of the input bitstream to the sub-bitstream extraction process. A flag from the extracted bitstream is set to indicate that sub-picture information related to the subset of the sub-pictures is present in the extracted bitstream. One or more sub-picture identifiers (IDs) for the subset of the sub-pictures are obtained based on the flag. The subset of the sub-pictures is decoded based on the sub-picture IDs.

Abstract: Methods, systems and apparatus for video processing are described. One example video processing method includes performing a conversion between a video comprising a video block and a bitstream of the video according to a rule, wherein the video block is a coding tree node that includes one or more coding units, and wherein the rule specifies that a coded information of the video block is indicative of whether a coding mode is enabled for the one or more coding units of the video block.

Abstract: A mechanism for processing video data is disclosed. A value of an annotated region (AR) object label index of an i-th AR object index (ar_object_label_idx[ar_object_idx[i]]) syntax element is determined. The ar_object_label_idx[ar_object_idx[i]] syntax element is specified to be in a range of N to M, where N and M are integers and N is less than M. A conversion is performed between a visual media data and a bitstream based on the ar_object_label_idx[ar_object_idx[i]] syntax element.

Abstract: Methods, systems and apparatus for video processing are described. One example video processing method includes performing a conversion between a video including a video block and a bitstream of the video according to a rule, wherein the rule specifies whether to include, in a slice header (SH), a first syntax element that indicates whether a transform skip based residual coding is disabled for a slice, and wherein the rule specifies that whether to include the first syntax element in the SH is selectively based on a second syntax element in a sequence parameter set (SPS) that indicates whether a TS mode is enabled for the video block.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving an extracted bitstream that is a result of a sub-bitstream extraction process from an input bitstream containing a set of sub-pictures. The extracted bitstream contains only a subset of the sub-pictures of the input bitstream to the sub-bitstream extraction process. A flag from the extracted bitstream is set to indicate that sub-picture information related to the subset of the sub-pictures is present in the extracted bitstream. One or more sub-picture identifiers (IDs) for the subset of the sub-pictures are obtained based on the flag. The subset of the sub-pictures is decoded based on the sub-picture IDs.

Abstract: Devices, systems and methods related to digital video coding, and specifically, to signaling of slice types in video picture headers are described. One example method of video processing includes performing a conversion between a video including one or more video pictures including one or more slices and a bitstream of the video, wherein the bitstream conforms to a format rule, and wherein the format rule specifies that for a video picture of the one or more video pictures having all slices coded as I slices, P slice and B slice related syntax elements are omitted from a picture header for the video picture.

Abstract: Embodiments for video processing, including video coding, video decoding and video transcoding are described. One example method includes performing a conversion between a video comprising one or more video pictures comprising one or more subpictures and a bitstream of the video, wherein the conversion conforms to a rule that specifies that one or more parameters for a scaling window applicable to a subpicture are determined from one or more syntax elements during a subpicture sub-bitstream extraction process.