Abstract: A video encoder may transform residual data by using a transform selected from a group of transforms. The transform is applied to the residual data to create a two-dimensional array of transform coefficients. A scanning mode is selected to scan the transform coefficients in the two-dimensional array into a one-dimensional array of transform coefficients. The combination of transform and scanning mode may be selected from a subset of combinations that is based on an intra-prediction mode. The scanning mode may also be selected based on the transform used to create the two-dimensional array. The transforms and/or scanning modes used may be signaled to a video decoder.

Abstract: An example device for decoding video data includes a memory configured to store video data; and a processing system comprising one or more processors implemented in circuitry, the processing system being configured to: inverse transform a block of transform coefficients of a block of the video data using an inverse non-separable primary transform (NSPT), without using an inverse separable transform, to reconstruct a residual block of the block of the video data; and decode the block using the residual block.

Abstract: An example method includes determining a color component of a unit of video data; determining, based at least on the color component, a context for context-adaptive binary arithmetic coding (CABAC) a syntax element that specifies a value of a low-frequency non-separable transform (LFNST) index for the unit of video data; CABAC decoding, based on the determined context and via a syntax structure for the unit of video data, the syntax element that specifies the value of the LFNST index for the unit of video data; and inverse-transforming, based on a transform indicated by the value of the LFNST index, transform coefficients of the unit of video data.

Abstract: An example device for coding video data includes memory configured to store the video data and one or more processors implemented in circuitry and communicatively coupled to the memory. The one or more processors are configured to determine whether a sequence parameter set of the video data refers to a video parameter set. Based on the sequence parameter set not referring to the video parameter set, the one or more processors are configured to determine a value of a first syntax element to be indicative of a profile-tier-layer structure being signaled in the sequence parameter set and code the video data based on the profile-tier-layer structure.

Abstract: An example device for processing media data includes a memory configured to store media data; and a processing system comprising one or more processors implemented in circuitry, the processing system being configured to: determine one or more user interactions with a virtual scene, each of the one or more user interactions corresponding to a particular media type of one or more media types; construct a packet including data for a media communication session, the packet including header data indicating the one or more media types for the one or more user interactions and one or more attributes for each of the one or more media types; and send the packet to a device involved in the media communication session.

Abstract: An example device for requesting a reduced resolution for video data includes a memory configured to store video data; and one or more processors implemented in circuitry and configured to: decode a first sequence of pictures of a bitstream, the first sequence of pictures having a first resolution; in response to determining that the device is to enter a power saving mode, send a message requesting a reduced resolution relative to the first resolution for a second sequence of pictures, the second sequence of pictures being subsequent to the first sequence of pictures in coding order; and decode the second sequence of pictures of the video data of the bitstream, the second sequence of pictures having the reduced resolution. The reduced resolution may be reduced spatial resolution, reduced temporal resolution (frame rate), or both.

Abstract: Provided are systems and methods for processing 360-degree video data. In various implementations, a spherical representation of a 360-degree video frame can be segmented into a top region, a bottom region, and a middle region. The middle region can be mapped into one or more rectangular areas of an output video frame. The top region can be mapped into a first rectangular area of the output video frame using a mapping that converts a square to a circle, such that pixels in the circular top region are expanded to fill the first rectangular region. The bottom region can be mapped into a second rectangular area of the output video frame such that pixels in the circular bottom region are expanded to fill the second rectangular region.

Abstract: Systems, methods, and computer-readable storage media are provided for decoded picture buffer (DPB) operations and rewriting access unit delimiters (AUDs) after bitstream extractions. An example method can include storing one or more pictures associated with an access unit (AU) in a decoded picture buffer (DPB), the AU including a first plurality of pictures, the first plurality of pictures corresponding to a plurality of video coding layers; after each picture of a second plurality of pictures associated with the AU is removed from a coded picture buffer (CPB), removing at least one picture of the one or more pictures from the DPB; and storing, in the DPB, each picture of the second plurality of pictures removed from the CPB.

Abstract: A method of decoding video data includes determining an intra prediction mode from a plurality of intra prediction modes for a current block of the video data, determining a low frequency non-separable transform (LFNST) kernel from a plurality of LFNST kernels for the current block based on the determined intra prediction mode, wherein at least one LFNST kernel of the plurality of LFNST kernels is associated with at least two different intra prediction modes of the plurality of intra prediction modes, applying an inverse of the determined LFNST kernel to coefficient values generated from a transform unit (TU) of the current block to generate intermediate values, applying an inverse primary transform on the intermediate values to generate residual data, and reconstructing the current block based on the residual data.

Abstract: Video encoders and video decoders are configured to supplemental enhancement information (SEI) messages. The SEI messages may include picture orientation transform type syntax elements that indicate how a picture may be rotated and/or mirrored. The SEI messages may also include quality metrics.

Abstract: A video decoder may receive a supplemental enhancement information (SEI) processing order SEI message, decode a syntax element in the SEI processing order SEI message that indicates a preferred processing order of SEI messages in a bitstream, and process the SEI message present in the bitstream in accordance with the preferred processing order.

Abstract: A method of processing video data includes receiving a syntax element that defines a filtering mode for a neural network (NN) model for both a first color component and a second color component, applying an instance of the NN model, in the defined filtering mode, to a first block of the first color component to generate a first filtered block, and storing the first filtered block for a coding unit (CU).

Abstract: An example device for filtering video data includes a memory configured to store video data; and a processing system comprising one or more processors implemented in circuitry, the processing system being configured to: apply one or more neural network processing blocks to intermediate filtered video data, each of the neural network processing blocks including a first 1×1 convolutional filter, a parametric rectified linear unit (PReLU) filter, a second 1×1 convolutional filter, and a 3×3 convolutional filter; apply additional neural network processing blocks to output of the one or more neural network processing blocks to form filtered video data; and output the filtered video data.

Abstract: A device for decoding video data can be configured to receive a syntax element indicating a maximum block size for a transform skip mode; determine a maximum block size for a block-based delta pulse code modulation (BDPCM) mode based on the syntax element; and decode block of video data based on the determined maximum block size for the BDPCM mode.

Abstract: A video decoder determines, based on a block size of a current block and a low-frequency non-separable transform (LFNST) syntax element, a zero-out pattern of normatively defined zero-coefficients. The LFNST syntax element is signaled at a transform unit (TU) level. Additionally, the video decoder determines transform coefficients of the current block. The transform coefficients of the current block include transform coefficients in an LFNST region of the current block and transform coefficients outside the LFNST region of the current block. As part of determining the transform coefficients of the current block, the video decoder applies an inverse LFNST to determine values of one or more transform coefficients in the LFNST region of the current block. The video decoder also determines that transform coefficients of the current block in a region of the current block defined by the zero-out pattern are equal to 0.

Abstract: A video encoder may transform residual data by using a transform selected from a group of transforms. The transform is applied to the residual data to create a two-dimensional array of transform coefficients. A scanning mode is selected to scan the transform coefficients in the two-dimensional array into a one-dimensional array of transform coefficients. The combination of transform and scanning mode may be selected from a subset of combinations that is based on an intra-prediction mode. The scanning mode may also be selected based on the transform used to create the two-dimensional array. The transforms and/or scanning modes used may be signaled to a video decoder.

Abstract: Disclosed are systems, methods, apparatuses, and computer-readable media for processing video data. For instance, an apparatus for processing video data, may include: at least one memory; and at least one processor coupled to the at least one memory, the at least one processor being configured to: obtain a bitstream; retrieve a granularity type syntax element associated with the bitstream, the granularity type syntax element specifying a type of granularity of one or more pictures over which complexity metrics (CM) associated with the bitstream are applicable; retrieve a period type syntax element associated with the bitstream, the period type syntax element indicating an upcoming period of time or a set of pictures over which the CM are applicable; and decode a portion of the bitstream based on the granularity type syntax element and the period type syntax element.

Abstract: A video encoder maintains a first reference picture list; maintains a second reference picture list; determines that a picture is an instantaneous decoding refresh (IDR) picture; determines that reference picture list syntax elements are present in a slice header for the IDR picture; and in response to determining that the picture is the IDR picture and that the reference picture list syntax elements are present in the slice header for the IDR picture, updates the first reference picture list and the second reference picture list such that no picture in the first reference picture list and no picture in the second reference picture list precedes, in output order or decoding order, any preceding instant random access point (IRAP) picture in decoding order.

Abstract: Aspects of the present disclosure provide techniques for using a radio access network (RAN) level negative acknowledgement (NAK) feedback to indicate at least one missing frame from an encoding device. The RAN level NAK feedback replaces or preempts a decoding device sending an end-to-end feedback to the encoding device using real-time transport protocol (RTP) that has a long latency and may cause freezes at the decoding device. For example, an encoding device may send to a network entity a request for a configuration that configures the encoding device to transmit media frames to the decoding device. The network entity may provide a NAK feedback indicating at least one missing frame. Having received the configuration in response to the request, the encoding device transmits media frames to the decoding device via the network entity, and monitors for NAK feedback from the network entity in accordance with the configuration.

Abstract: A method for coding a block of video data using affine mode includes determining a refined affine model for the current block of video data from a linear regression process using a base motion vector field and a guidance motion vector field as inputs to the linear regression process. The method further includes determining affine merge candidates for the current block using the refined affine model, and coding the current block of video data using the affine merge candidates.