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: A video coding mechanism is disclosed. The mechanism includes partitioning a picture into a plurality of tiles. A number of the tiles are included in a tile group. The mechanism determines whether the tile group is a raster scan tile group or a rectangular tile group. The number of tiles in the tile group is determined based on whether the tile group is the raster scan tile group or the rectangular tile group. The tiles are encoded into a bitstream based on the tile group. The bitstream is stored for communication toward a decoder.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream including a first slice of a coded image. The coded image is associated with a picture parameter set (PPS) in the bitstream. The first slice is associated with a slice header in the bitstream. A list of identifiers (IDs) is parsed from the PPS. A first ID is parsed from the slice header of the first slice. The first ID matches one of the IDs in the list of IDs in the PPS. A list of tiles coded in the first slice is determined based on the first ID. The first slice is determined to generate a reconstructed sub-image of the coded image.

Abstract: A video coding mechanism is disclosed. The mechanism includes partitioning a picture into a plurality of first level tiles. A subset of the first level tiles is partitioned into a plurality of second level tiles. The first level tiles and the second level tiles are encoded into a bitstream. A split indication is encoded into the bitstream. The split indication indicates that at least one of the first level tiles is split into the second level tiles. The bitstream is stored for communication toward a decoder.

Abstract: The present disclosure provides an encoding and decoding device, as well as an encoding and decoding method. In particular, the present disclosure relates to method for decoding of a video bitstream implemented by a decoding device, wherein the video bitstream includes data representing a coded picture comprising tile columns, the decoding method comprising: obtaining a syntax element by parsing the video bitstream, wherein the syntax element is used to derive the width of the tile columns, wherein the width of the tile columns is uniform; predicting the picture according the width of the tile columns.

Abstract: A video coding mechanism is disclosed. The mechanism includes partitioning a picture into a plurality of tiles. A number of the tiles are included in a tile group. The mechanism determines whether the tile group is a raster scan tile group or a rectangular tile group. The number of tiles in the tile group is determined based on whether the tile group is the raster scan tile group or the rectangular tile group. The tiles are encoded into a bitstream based on the tile group. The bitstream is stored for communication toward a decoder.

Abstract: A method of decoding a coded video bitstream is provided. The method includes obtaining a first reference picture list structure and a second reference picture list structure represented in the coded video bitstream; deriving, based on the first reference picture list structure and the second reference picture list structure, a first reference picture list of a current slice and a second reference picture list of the current slice, wherein the current slice comprises an intra (I) slice or a uni-predictive (P) slice; and obtaining at least one reconstructed block of the current slice following derivation of the first reference picture list and the second reference picture list.

Abstract: A method of decoding a coded video bitstream. The method includes obtaining a first reference picture list of a current slice represented in the coded video bitstream and a second reference picture list of the current slice, and marking a status of a reference picture in a decoded picture buffer (DPB) based on the first reference picture list and the second reference picture list when the current slice is a first slice in a current picture to which the current slice belongs. The status of the reference picture in the decoded picture buffer is one of used for short-term reference, used for long-term reference, or unused for reference. The method also includes using the reference picture in a reconstructing process of the current picture or a picture following the current picture when the status of the reference picture is used for short-term reference or used for long-term reference.

Abstract: File formats and parsing and coding of video data are defined to promote more efficient random accessibility of coded video data. Constraints may be imposed on placement of parameter sets and the definition of sync samples in video files. Parameter set data for video data may be coded, for a non-sync sample, only in the sample entry for the sample, the sample, a previous sample in decoding order that is a sync sample, or in a sample occurring in decoding order between the sample and the previous sample in decoding order that is a sync sample.

Abstract: A method implemented by a video decoder and comprising: receiving, by the video decoder, a video bitstream comprising a picture and loop_filter_across_subpic_enabled_flag, wherein the picture comprises a subpicture; and applying a deblocking filter process to all subblock edges and transform block edges of the picture except edges that coincide with boundaries of the subpicture when loop_filter_across_subpic_enabled_flag is equal to 0. A method implemented by a video decoder and comprising: receiving, by the video decoder, a video bitstream comprising a picture, EDGE_VER, and loop_filter_across_subpic_enabled_flag, wherein the picture comprises a subpicture; and setting filterEdgeFlag to 0 if edgeType is equal to the EDGE_VER, a left boundary of a current coding block is a left boundary of the subpicture, and the loop_filter_across_subpic_enabled_flag is equal to 0.

Abstract: A method of decoding is provided. The method includes receiving a video bitstream including a picture unit (PU), where the PU includes a picture header (PH) network abstraction layer (NAL) unit preceding a first video coding layer (VCL) NAL unit, and decoding a coded picture from the PU to obtain a decoded picture.

Abstract: According to certain aspects, an apparatus for coding video information includes a memory and a processor configured to determine whether a first syntax element is present in a bitstream, the first syntax element associated with a sequence parameter set (SPS) and a first flag indicative of whether a temporal identifier (ID) of a reference picture for pictures that refer to the SPS can be nested; and in response to determining that the first syntax element is not present in the bitstream: obtain a second syntax element indicative of a maximum number of temporal sub-layers in a particular layer of the plurality of layers; and determine whether to set the first flag equal to a second flag indicative of whether a temporal ID of a reference picture for any pictures can be nested based at least in part on a value of the second syntax element.

Abstract: A method of decoding is provided. The method includes receiving a video bitstream including a picture unit (PU), the PU including a picture header (PH) network abstraction layer (NAL) unit having a picture header NAL unit type (PH_NUT) and an associated video coding layer (VCL) NAL unit, the PH_NUT signifying that a layer identifier (ID) of the PH NAL unit is equal to a layer ID of the associated video coding layer (VCL) NAL unit and a temporal ID of the PH NAL unit is equal to a temporal ID of the PU; and decoding a coded picture from the PU to obtain a decoded picture.

Abstract: A method of video decoding comprises receiving a bitstream including a picture parameter set (PPS) containing a single slice per subpicture flag; determining whether the single slice per subpicture flag has a first value or a second value, where the first value specifies that each subpicture referring to the PPS includes one and only one rectangular slice, and where the second value specifies that each subpicture referring to the PPS may include one or more rectangular slices; decoding the one and only one rectangular slice when the single slice per subpicture flag has the first value and the one or more rectangular slices when the single slice per subpicture flag has the second value.

Abstract: A method comprises: receiving, by a video decoder, a video bitstream comprising an RPL flag, wherein the RPL flag equal to a first value specifies that RPL signaling is present in a PH, and wherein the RPL flag equal to a second value specifies that RPL signaling is not present in the PH and may be present in slice headers; and decoding, by the video decoder using the RPL flag, a coded picture to obtain a decoded picture. A comprises: receiving, by a video decoder, a video bitstream comprising an SAO flag, wherein the SAO flag specifies that SAO information may be present or is not present in a PH or specifies that the SAO information may be present or is not present in slice headers; and decoding, by the video decoder using the SAO flag, a coded picture to obtain a decoded picture.

Abstract: A method of decoding is provided. The method includes receiving a video bitstream including a picture unit (PU) having a picture header (PH) with a PH syntax structure, where the PH syntax structure includes the following syntax elements common for all slices of a coded picture associated with the PH syntax structure: a non-reference picture flag, a picture parameter set (PPS) identifier (ID), a picture order count (POC) least significant bit (LSB), a no output of prior pictures flag, a recovery point POC, and a picture output flag; and decoding the coded picture from the PU to obtain a decoded picture.

Abstract: A method of decoding is provided. The method includes receiving a video bitstream including a picture unit (PU), where any decoding capability information (DCI) network abstraction layer (NAL) unit, video parameter set (VPS) NAL unit, sequence parameter set (SPS) NAL unit, or picture parameter set (PPS) NAL unit referred to by the PU precedes a picture header (PH) NAL unit of the PU and a first video coding layer (VCL) NAL unit of the PU; and decoding a coded picture from the PU to obtain a decoded picture.

Abstract: A method of decoding is provided. The method includes receiving a picture unit (PU) including zero or one picture header (PH) network abstraction layer (NAL) unit and only one coded picture; and decoding the only one coded picture from the PU to obtain a decoded picture. A corresponding method of encoding is also provided. The method includes generating a PU including zero or one PH NAL units and only one coded picture; encoding the PU into a video bitstream; and storing the video bitstream for communication toward a video decoder.

Abstract: A method of decoding is provided. The method includes receiving a video bitstream including a picture unit (PU), where a gradual decoding refresh (GDR) flag in a picture header (PH) of the PU has a first value to specify that a picture associated with the PH is a GDR picture; and decoding the GDR picture from the PU to obtain a decoded picture.

Abstract: A method of decoding a coded video bitstream. The method includes obtaining a first reference picture list of a current slice represented in the coded video bitstream and a second reference picture list of the current slice, and marking a status of a reference picture in a decoded picture buffer (DPB) based on the first reference picture list and the second reference picture list when the current slice is a first slice in a current picture to which the current slice belongs. The status of the reference picture in the decoded picture buffer is used for short-term reference, used for long-term reference, or unused for reference. The method also includes using the reference picture in a reconstructing process of the current picture or a picture following the current picture when the status of the reference picture is used for short-term reference or used for long-term reference.