Abstract: A device determines, based at least in part on a syntax element in a scalable nesting supplemental enhancement information (SEI) message encapsulated by an SEI Network Abstraction Layer (NAL) unit, whether a nested SEI message encapsulated by the scalable nesting SEI message is applicable to a default sub-bitstream. The default sub-bitstream is an operation point representation of an operation point defined by a layer identifier specified in a NAL unit header of the SEI NAL unit and a temporal identifier specified in the NAL unit header. When the nested SEI message is applicable to the default sub-bitstream, the device uses the nested SEI message in an operation on the default sub-bitstream.

Abstract: A device generates a file that stores coded samples that contain coded pictures of the video data. The file also includes a sample entry that includes an element that indicates whether all sequence parameter sets (SPSs) that are activated when a stream to which the sample entry applies is decoded have syntax elements that indicate that temporal sub-layer up-switching to any higher temporal sub-layer can be performed at any sample associated with the SPSs. The same or different device determines, based on the element in the sample entry, that all SPSs that are activated when the stream to which the sample entry applies is decoded have syntax elements that indicate that temporal sub-layer up-switching to any higher temporal sub-layer can be performed at any sample associated with the SPSs.

Abstract: Techniques are described for signaling decoding unit identifiers for decoding units of an access unit. The video decoder determines which network abstraction layer (NAL) units are associated with which decoding units based on the decoding unit identifiers. Techniques are also described for including one or more copies of supplemental enhancement information (SEI) messages in an access unit.

Abstract: A device for processing video data receives an indication of a maximum layer identification (ID) value for a bitstream; receives a flag for a first layer with a layer ID value less than the maximum layer ID value; and, based on a value of the flag, determines if the first layer is included in an operation point.

Abstract: Techniques described herein are related to coding layer identifiers for operation points in video coding. In one example, a method of decoding video data is provided. The method comprises decoding syntax elements in a video parameter set (VPS) within a conforming bitstream indicating a first operation point having a first set of content. The method further comprises decoding, if present, syntax elements in the VPS within the conforming bitstream indicating hypothetical reference decoder (HRD) parameter information having a second set of content for the first operation point, wherein the conforming bitstream does not include syntax elements in the VPS that duplicate at least one of the first or second set of content for a second operation point, and wherein decoding syntax elements comprises decoding the syntax elements indicating the first operation point and the HRD parameter information only within conforming bitstreams.

Abstract: Techniques are described for signaling decoding unit identifiers for decoding units of an access unit. The video decoder determines which network abstraction layer (NAL) units are associated with which decoding units based on the decoding unit identifiers. Techniques are also described for including one or more copies of supplemental enhancement information (SEI) messages in an access unit.

Abstract: Techniques are described for modal sub-bitstream extraction. For example, a network entity may select a sub-bitstream extraction mode from a plurality of sub-bitstream extraction modes. Each sub-bitstream extraction mode may define a particular manner in which to extract coded pictures from views or layers to allow a video decoder to decode target output views or layers for display. In this manner, the network entity may adaptively select the appropriate sub-bitstream extraction technique, rather than a rigid, fixed sub-bitstream extraction technique.

Abstract: During a coding process, systems, methods, and apparatus may code information indicating whether gradual decoder refresh (GDR) of a picture is enabled. When GDR is enabled, the coding process, systems, methods, and apparatus may code information that indicates whether one or more slices of the picture belong to a foreground region of the picture. In another example, during a coding process, systems, methods, and apparatus may decode video data corresponding to an ISP identification (ISP ID) for one of the ISPs for slices of a picture. The systems, methods, and apparatus may decode video data corresponding to an ROI using the ISP.

Abstract: In some examples, a video encoder includes multiple sequence parameter set (SPS) IDs in an SEI message, such that multiple active SPSs can be indicated to a video decoder. In some examples, a video decoder activates a video parameter set (VPS) and/or one or more SPSs through referencing an SEI message, e.g., based on the inclusion of the VPS ID and one or more SPS IDs in the SEI message. The SEI message may be, as examples, an active parameter sets SEI message or a buffering period SEI message.

Abstract: In some examples, a video encoder includes multiple sequence parameter set (SPS) IDs in an SEI message, such that multiple active SPSs can be indicated to a video decoder. In some examples, a video decoder activates a video parameter set (VPS) and/or one or more SPSs through referencing an SEI message, e.g., based on the inclusion of the VPS ID and one or more SPS IDs in the SEI message. The SEI message may be, as examples, an active parameter sets SEI message or a buffering period SEI message.

Abstract: A video coding device, such as a video encoder or a video decoder, may be configured to code a duration between coded picture buffer (CPB) removal time of a first decoding unit (DU) in an access unit (AU) and a second DU, wherein the second DU is subsequent to the first DU in decoding order and in the same AU as the first DU. The video coding device may further determine a removal time of the DU based at least on the coded duration. The coding device may also code a sub-picture timing supplemental enhancement information (SEI) message associated with the first DU. The video coding device may further determine a removal time of the DU based at least in part on the sub-picture timing SEI message.

Abstract: A device signals a property of a bitstream. The bitstream comprises a plurality of coded video sequences (CVSs). When the property has a particular value, all the CVSs of the bitstream conform to the same profile. A video processing device is able to determine, based on the property, whether to process the bitstream.

Abstract: A device performs a decoding process as part of a bitstream conformance test. As part of the decoding process, the device performs a bitstream extraction process to extract, from a bitstream, an operation point representation of an operation point defined by a target set of layer identifiers and a target highest temporal identifier. The target set of layer identifiers contains values of layer identifier syntax elements present in the operation point representation, the target set of layer identifiers being a subset of values of layer identifier syntax elements of the bitstream. The target highest temporal identifier is equal to a greatest temporal identifier present in the operation point representation, the target highest temporal identifier being less than or equal to a greatest temporal identifier present in the bitstream. The device decodes network abstraction layer (NAL) units of the operation point representation.

Abstract: A video coding device, such as a video decoder, may be configured to derive at least one of a coded picture buffer (CPB) arrival time and a CPB nominal removal time for an access unit (AU) at both an access unit level and a sub-picture level regardless of a value of a syntax element that defines whether a decoding unit (DU) is the entire AU. The video coding device may further be configured to determine a removal time of the AU based at least in part on one of the CPB arrival time and a CPB nominal removal time and decode video data of the AU based at least in part on the removal time.

Abstract: A video coding device, such as a video encoder or a video decoder, may be configured to code a sub-picture timing supplemental enhancement information (SEI) message associated with a first decoding unit (DU) of an access unit (AU). The video coding device may further code a duration between coded picture buffer (CPB) removal time of a second DU of the AU in decoding order and CPB removal time of the first DU in the sub-picture SEI message. The coding device may also derive a CPB removal time of the first DU based at least in part on the sub-picture timing SEI message.

Abstract: A computing device selects, from among a set of hypothetical reference decoder (HRD) parameters in a video parameter set and a set of HRD parameters in a sequence parameter set, a set of HRD parameters applicable to a particular operation point of a bitstream. The computing device performs, based at least in part on the set of HRD parameters applicable to the particular operation point, an HRD operation on a bitstream subset associated with the particular operation point.

Abstract: A video coding device, such as a video encoder or a video decoder, may be configured to decode a sequence level flag to determine the presence of one or more sub-picture level coded picture buffer (CPB) parameters for a decoding unit (DU) of an access unit (AU) in either in a picture timing supplemental enhancement information (SEI) message or a sub-picture timing SEI message associated with the DU. The coding device may also decode the one or more sub-picture level CPB parameters from the picture timing SEI message or the sub-picture timing SEI message based on the sequence level flag.

Abstract: A video coding device, such as a video encoder or a video decoder, may be configured to decode a duration between coded picture buffer (CPB) removal time of a first decoding unit (DU) in an access unit (AU) and CPB removal time of a second DU, wherein the first DU comprises a non-video coding layer (VCL) network abstraction layer (NAL) unit with nal_unit_type equal to UNSPEC0, EOS_NUT, EOB_NUT, in the range of RSV_NVCL44 to RSV_NVCL47 or in the range of UNSPEC48 to UNSPEC63. The video decoder determines a removal time of the first DU based at least in part on the decoded duration and decodes video data of the first DU based at least in part on the removal time.

Abstract: A video encoder signals, in a slice header for a current slice of a current picture, a first long-term reference picture (LTRP) entry, the first LTRP entry indicating that a particular reference picture is in a long-term reference picture set of the current picture. Furthermore, the video encoder signals, in the slice header, a second LTRP entry only if second LTRP entry does not indicate that the particular reference picture is in the long-term reference picture set of the current picture.

Abstract: A video coding device, such as a video decoder, may be configured to decode a buffering period supplemental enhancement information (SEI) message associated with an access unit (AU). The video decoder is further configured to decode a duration between coded picture buffer (CPB) removal time of a first decoding unit (DU) in the AU and CPB removal time of a second DU from the buffering period SEI message, wherein the AU has a TemporalId equal to 0. The video decoder is configured to determine a removal time of the first DU based at least in part on the decoded duration and decode video data of the first DU based at least in part on the removal time.