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 a coded video bitstream implemented by a video decoder is provided. The method includes receiving, by a receiver of the video decoder, a mixed intra random access point (IRAP) picture including a first sub-picture and a second sub-picture, wherein the first sub-picture is an IRAP picture and the second sub-picture is a non-IRAP sub-picture; receiving, by the receiver; a reference picture list (RPL) for the mixed IRAP picture; decoding, by a processor of the video decoder, the second sub-picture using the RPL; and generating, by the processor, an image based on the second sub-picture as decoded. A corresponding encoding method is also provided.

Abstract: A video coding mechanism is disclosed. The mechanism includes encoding a bitstream comprising one or more layers of coded pictures. A video parameter set (VPS) is also encoded into the bitstream. The VPS includes an each layer is an output layer set (OLS) flag (each_layer_is_an_ols_flag) when all layers specified by the VPS are independently coded without inter-layer prediction. The each_layer_is_an_ols_flag specifies whether each OLS contains only one layer. The bitstream is stored for communication toward a decoder.

Abstract: A mechanism for processing video data is disclosed. One or more random access picture (RAP) picture identifiers are signaled for one or more Cross RAP Referencing (CRR) pictures. A conversion is performed between a visual media data and a bitstream based on the one or more RAP picture identifiers.

Abstract: A video coding mechanism is disclosed. The mechanism includes encoding a coded layer video sequence (CLVS) for a layer in a bitstream. A sequence parameter set (SPS) referred to by the CLVS is also encoded into the bitstream. The SPS is constrained to have a network abstraction layer (NAL) unit header layer identifier (nuh_layer_id) value equal to a nuh_layer_id value of the CLVS when the layer does not use inter-layer prediction. The bitstream is stored for communication toward a decoder.

Abstract: A method comprises obtaining media content associated with a first viewpoint and a second viewpoint, wherein a first position of the first viewpoint is static and a second position of the second viewpoint is dynamic; generating a first VWPT descriptor based on the media content and describing the first viewpoint; generating a second VWPT descriptor based on the media content and describing the second viewpoint; generating an MPD comprising the first VWPT descriptor and the second VWPT descriptor; and transmitting the MPD.

Abstract: A video coding mechanism is disclosed. The mechanism includes encoding into a bitstream a gradual decoding refresh (GDR) access unit (AU) and a buffering period (BP) supplemental enhancement information (SEI) message associated with the GDR AU. A hypothetical reference decoder (HRD) is initialized based on the BP SEI message. A HRD conformance test is performed on the bitstream using the HRD. The bitstream is stored for communication toward a decoder.

Abstract: Several techniques for video encoding and video decoding are described. One example method includes performing a conversion between a subpicture in a video picture of a video and a bitstream of the video according to a rule. The rule specifies that, in in case a subpicture is treated as a video picture for the conversion, a cross-layer alignment restriction is applied to less than all of the multiple layers including a current layer that includes the subpicture and a subset of layers associated with the current layer.

Abstract: Methods, apparatus and systems for processing video are described. One example method includes performing a conversion between a video comprising a video unit and a bitstream of the video, wherein the bitstream conforms to a format rule, and wherein the format rule specifies that a first syntax element indicating whether an in-loop filtering operation is performed across tile boundaries is selectively included in the bitstream responsive to whether or how the video unit is partitioned into tiles.

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 a coded video bitstream is provided. The method includes parsing a slice header of a current slice represented in the coded video bitstream. The slice header includes a reference picture list structure. The method also includes deriving, based on the reference picture list structure, a reference picture list of the current slice; and obtaining, based on the reference picture list, at least one reconstructed block of the current slice.

Abstract: A method of decoding a coded video bitstream implemented by a video decoder is provided. The method includes parsing a flag; parsing candidates for a first reference picture list structure; determining that candidates for a second reference picture list structure are not present in the coded video bitstream and inferring that the candidates for the second reference picture list structure are the same as the candidates for the first reference picture list structure when the flag has a first value; determining that the candidates for the second reference picture list structure are present in the coded video bitstream when the flag has a second value; generating a reference picture list using the candidates for the first reference picture list structure or the candidates for the second reference picture list structure; and performing inter-prediction based on the reference picture list to generate a reconstructed block.

Abstract: A method of decoding implemented by a video decoder is provided. The method includes receiving a bitstream including a coded video sequence start (CVSS) access unit (AU), wherein the CVSS AU contains a picture unit (PU) for each layer, and wherein a coded picture in each PU is a coded layer video sequence start (CLVSS) picture; identifying the coded picture from one of the layers based on a picture order count (POC) value; and decoding the coded picture to obtain a decoded picture.

Abstract: Methods and apparatus for video processing are described. The processing may include video encoding, video decoding, or video transcoding. An 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 one or more pictures and/or the one or more subpictures are included into the bitstream according to an order rule. The order rule specifies a relationship between a position of a current instantaneous decoder refresh (IDR) picture or a current IDR subpicture in the bitstream with respect to another picture referred to by an entry in a reference picture list for a current slice of the current IDR picture or the current IDR subpicture.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a gradual decoding refresh (GDR) picture, a recovery point picture following the GDR picture in decoding order, and a header associated with the GDR picture. The header includes a picture order count (POC) least significant bit (LSB) value coded prior to a recovery POC value. A POC for the GDR picture is determined based on the POC LSB value. The recovery POC value is determined based on the POC for the GDR picture. The recovery POC value indicates a POC for the recovery point picture. The bitstream is decoded according to GDR based on the GDR picture and the recovery point picture.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a sub-picture partitioned from a picture and a sequence parameter set (SPS) comprising a sub-picture size and a sub-picture location. The SPS is parsed to obtain the sub-picture size of the sub-picture and the sub-picture location of the sub-picture. The sub-picture is decoded based on the sub-picture size and the sub-picture location to create a video sequence. The video sequence is forwarded for display.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising a current picture and a reference picture list syntax structure (ref_pic_list_struct( )) comprising a number of reference entries (num_ref_entries) constrained to a range of zero to a maximum decoded picture buffer size plus an offset. The current picture is decoded based on the ref_pic_list_struct( ) to produce a decoded picture.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream comprising an output layer set (OLS) and a video parameter set (VPS). The OLS includes one or more layers of coded pictures and the VPS includes an OLS mode identification code (ols_mode_idc) specifying that for each OLS, all layers in the each OLS are output layers. The output layers are determined based on the ols_mode_idc in the VPS. A coded picture from the output layers is decoded to produce a decoded picture. The decoded picture is forwarded for display as part of a decoded video sequence.

Abstract: A method for storing a coded video bitstream. The method includes obtaining the coded video bitstream and storing the coded video bitstream in at least one storage medium. The coded video bitstream includes a first reference picture list syntax structure and a second reference picture list syntax structure. Each reference picture list syntax structure contains a number of entries. A first reference picture list of a current slice and a second reference picture list of the current slice are derived based on the first reference picture list syntax structure and the second reference picture list syntax structure. The first reference picture list and the second reference picture list are derived for bitstream conformance checking instead of for decoding a current picture or pictures following the current picture in decoding order when the current slice comprises an intra (I) slice of a non-intra random access point (IRAP) picture.

Abstract: A method implemented in an encoder for encoding a video bitstream that includes coded data for a plurality of pictures, each of the plurality of pictures comprises at least one slice. The method includes encoding a flag that indicates whether tile information for a picture is present in a picture parameter set or present in a slice header, where the tile information indicates a location of a slice within the picture; encoding the tile information in only the picture parameter set when the flag indicates that the tile information for the picture is encoded in the picture parameter set; encoding the tile information in only the slice header when the flag indicates that the tile information for the picture is encoded in the slice header; and encoding data of the picture in the video bitstream based on the tile information.