Abstract: A method of video processing includes performing a conversion between a video including a picture and a bitstream of the video, wherein the bitstream conforms to a format rule, wherein the format rule specifies that an indication of whether a first flag is signalled at a beginning of a picture header associated with the picture, wherein the first flag is indicative of whether the picture is an intra random access point (IRAP) picture or a gradual decoding refresh (GDR) picture.

Abstract: A method of video processing includes performing a conversion between a video including one or more pictures and a bitstream of the video, wherein the bitstream conforms to a format rule, wherein the format rule conditionally allows coding of a picture in one layer using reference pictures from other layers based on a first syntax element indicating whether the reference pictures from the other layers are present in the bitstream, and wherein the first syntax element is conditionally signaled in the bitstream based on a second syntax element that indicates whether an identifier of a parameter set associated with the picture is not equal to zero.

Abstract: A method for implementing an adaptive colour transform (ACT) mode during image/video encoding and decoding includes performing a conversion between a current video block of a video and a bitstream of the video, wherein the current video block is coded using the ACT mode, wherein the conversion comprises applying an inverse ACT transform on the current video block according to a rule, and wherein the rule specifies that a clipping operation, based on a bit depth of the current video block, is applied to an input of the inverse ACT transform.

Abstract: Methods, devices and systems for signaling the use of subpictures in coded video pictures are described. One example method ofvideo processing includesperforming a conversionbetween a picture of a video and a bitstream of the video, wherein the bitstream conforms to a format rule, wherein the format rule specifies a mapping between identifiers of one or more subpictures of the picture and the one or more subpictures is not included in a picture header of the picture, and wherein the format rule further specifies that the identifiers of the one or more subpictures are derived based on syntax elements in a sequence parameter set (SPS) and a picture parameter set (PPS) referred to by the picture.

Abstract: Methods, devices and systems for signaling the use of subpictures in coded video pictures are described. One example method of video processing includes performing a conversion between a video and a bitstream of a video, wherein the bitstream conforms to a format rule, wherein the format rule specifies that a first syntax element signaled in a sequence parameter set (SPS) of the bitstream is indicative of a length of identifiers of subpictures in the SPS, and wherein the signaling of the first syntax element is independent of a value of a second syntax element that is indicative of explicit signaling of the identifiers of the subpictures in the SPS or a picture parameter set (PPS).

Abstract: A method of video processing includes performing a conversion between a video and a bitstream of the video according to a rule, wherein the rule specifies that a sub-bitstream extraction process is implemented to generate a sub-bitstream for decoding, wherein the sub-bitstream extraction process is configured to extract, from the bitstream, a sub-bitstream with a target highest temporal identifier, and wherein, the rule specifies that, during the extracting, upon removing a video coding layer (VCL) network abstraction layer (NAL) unit, filler data units and filler supplemental enhancement information (SEI) messages in SEI NAL units that are associated with the VCL NAL unit are also removed.

Abstract: Methods, devices and systems for video coding and encoding, which include constraints, restrictions and signaling for subpictures, slices, and tiles, are described. One example method of video processing includes performing a conversion between a video and a bitstream of the video, wherein the bitstream comprises one or more access units according to a format rule, and wherein the format rule specifies an order in which a first message and a second message that apply to an operation point (OP) are present within an access unit (AU) such that the first message precedes the second message in a decoding order.

Abstract: A method of video processing includes performing a conversion between a video unit of a video and a bitstream of the video according to a rule, wherein the rule specifies whether the bitstream includes at least one of a control flag of a chroma block-based delta pulse code modulation (BDPCM) mode, a palette mode, or an adaptive color transform (ACT) mode is based on a value of a chroma array type of the video.

Abstract: A method of video processing, including performing a conversion between a video unit of a video and a bitstream representation of the video, wherein the conversion includes applying a deblocking filter to at least some samples on boundaries of the video unit, wherein deblocking quantization parameter (QP) values used in the deblocking filter are determined according to a rule, and wherein the rule specifies that whether the deblocking QP values are equal to dequantization QP values for the video unit is based on whether an adaptive color transform (ACT) mode is applied to the video unit.

Abstract: Described herein is method for purifying messenger RNA (mRNA) encoding a DNA endonuclease from a sample, the method comprising: (a) loading the sample comprising the mRNA onto a monolithic matrix comprising a poly(dT) or poly(U) nucleic acid molecule linked/coupled to the monolithic matrix under conditions allowing the mRNA to hybridize with the poly(dT) or poly(U) nucleic acid molecule; (b) eluting the mRNA from the monolith matrix after one or more contaminants have been separated from the bound mRNA; and (c) separating the mRNA from dsRNA by adsorption chromatography, thereby resulting in a purified mRNA solution.

Abstract: Devices, systems and methods for specifying the syntax and semantics of the decoding parameter set (DPS) are described. One example method of video processing includes determining, for a conversion between a video and a bitstream of the video, that each output layer set (OLS) in a coded video sequence (CVS) in the bitstream conforms to at least one profile-tier-level (PTL) syntax structure included in a data structure associated with decoding parameter semantics in the bitstream, and performing, based on the determining, the conversion, wherein the PTL syntax structure indicates a profile, a tier, and a level of the bitstream.

Abstract: Provided is a mask assembly, including: an annular mask frame; a supporting structure, located on a side of the mask frame, fixedly connected to the mask frame, and having an opening; and a mask structure, located on a side of the mask frame and fixedly connected to the mask frame, and including a strip-shaped mask body and a sheet-shaped mask piece corresponding to the opening, wherein the mask piece is fixedly connected to a side edge of the mask body and has a plurality of first through holes, wherein an orthographic projection of the mask body on a bearing surface of the mask frame does not overlap with an orthographic projection of the opening on the bearing surface, and an orthographic projection of the mask piece on the bearing surface overlaps with the orthographic projection of the opening on the bearing surface.

Abstract: A decoding method includes obtaining an identifier from a bitstream, where the identifier indicates a minimum decoding time interval k between library pictures that is allowed in the bitstream, obtaining, when parsing the bitstream, a decoding moment ti of a current decoded picture and a decoding moment tj of a first decoded picture that is closest to the current decoded picture and that references a new library picture when the current decoded picture is decoded by referencing a library picture, where the new library picture is a library picture that is not decoded or needs to be re-decoded when the first decoded picture is decoded, and determining a preset quantity of library pictures as candidate reference pictures of the current decoded picture based on a relationship between k and a difference between ti and tj.

Abstract: A mechanism for processing video data is disclosed. An essential property (EssentialProperty) of a Dynamic Adaptive Streaming over Hypertext transfer protocol (DASH) representation is determined. The EssentialProperty indicates that the representation is an external stream representation (ESR). A conversion is performed between a visual media data and a media presentation based on the based on the ESR.

Abstract: A video coding mechanism for viewpoint dependent video coding is disclosed. The mechanism includes mapping a spherical video sequence into a plurality of sub-picture video sequences. The mechanism further includes encoding the plurality of sub-picture video sequences as sub-picture bitstreams to support merging of the plurality of sub-picture bitstreams, the encoding ensuring that each sub-picture bitstream is self-referenced and two or more of the sub-picture bitstreams can be merged to generate a single video bitstream using a lightweight bitstream rewriting process that does not involve changing of any block-level coding results. A mergable indication is encoded to indicate that the sub-picture bitstream containing the indication is compatible with a multi-bitstream merge function for reconstruction of the spherical video sequence. A set of the sub-picture bitstreams and the mergable indication are transmitted toward the decoder to support decoding and displaying a virtual reality video viewport.

Abstract: Techniques are described related to output and removal of decoded pictures from a decoded picture buffer (DPB). The example techniques may remove a decoded picture from the DPB prior to coding a current picture. For instance, the example techniques may remove the decoded picture if that decoded picture is not identified in the reference picture set of the current picture.

Abstract: A mechanism for processing video data is disclosed. A level indicator for a set of subpictures in one or more subpicture tracks is determined. The level indicator is included in a sample group carrying information for the set of subpictures. A conversion is performed between a visual media data and a media data file based on the level indicator.

Abstract: A mechanism for processing video data is disclosed. A level indicator for a set of subpictures is determined. The set of subpictures is included in one or more subpicture tracks. The subpicture tracks are included in a subpicture entity group. When the level indicator is included in a sample group, an indication is signaled in an entity to group box to indicate the track that contains the sample group. A conversion is performed between a visual media data and a media data file based on the level indicator.

Abstract: A mechanism for processing video data is disclosed. One or more level indicators for a set of subpictures included in one or more subpicture tracks are determined. The subpicture tracks are included in a subpicture entity group. The level indicators are included in at least one of one or more sample groups carrying information for the set of subpictures, or in a data structure specifying the subpicture entity group. A conversion is performed between a visual media data and a media data file based on the level indicator.

Abstract: Methods, devices and systems for signaling the use of subpictures in coded video pictures are described. One example method of video processing includes performing a conversion between a video and a bitstream of a video, wherein the bitstream conforms to a format rule, and wherein the format rule specifies that a first syntax element, which indicates whether a picture of the video can be partitioned, is conditionally included in a picture parameter set (PPS) of the bitstream based on values of a second syntax element, which indicates whether identifiers of subpictures are signaled in the PPS, and a third syntax element, which indicates, in the PPS, a number of the subpictures.