Abstract: Systems, methods, and Instrumentalities are described herein for calculating local Illumination compensation (LIC) parameters for bi-predicted coding unit (CU). The LIC parameters may be used to generate adjusted samples for the current CU and to address local illumination changes that may exist among temporal neighboring pictures. LIC parameters may be calculated based on bi-predicted reference template samples and template samples for a current CU. Bi-predicted reference template samples may be generated based on reference template samples neighboring temporal reference CUs. For example, the bi-predicted reference template samples may be generated based on averaging the reference template samples. The reference template samples may correspond to template samples for the current CU. A CU may be or may include a coding block and/or a sub-block that may be derived by dividing the coding block.

Abstract: Methods and apparatus relate to picture and video coding in communication systems are provided. Included therein is a method comprising determining one or more layers associated with a parameter set, generating a syntax element including an indication indicating whether the one or more layers associated with the parameter set are independently coded, and generating a message including the syntax element.

Abstract: Methods, devices, apparatus, systems, architectures and interfaces to improve motion vector (MV) refinement based sub-block (SB) level motion compensated prediction are provided. A decoding method includes receiving a bitstream of encoded video data, the bitstream including at least one block of video data including a plurality of SBs; performing a MV derivation, including a decoder based MV (DMVR) process, for at least one SB in the block to generate a refined MV for each SB; performing SB based motion compensation on the at least one sub-block to generate a SB based prediction within each SB; obtaining a spatial gradient for the prediction within each SB; determining a MV offset for each pixel in each SB; obtaining an intensity change in each SB based on the spatial gradients and MV offsets via an optical flow equation; and refining the prediction within each SB based on the obtained intensity changes.

Abstract: Systems and methods are described for video coding using generalized bi-prediction. In an exemplary embodiment, to code a current block of a video in a bitstream, a first reference block is selected from a first reference picture and a second reference block is selected from a second reference picture. Each reference block is associated with a weight, where the weight may be an arbitrary weight ranging, e.g., between 0 and 1. The current block is predicted using a weighted sum of the reference blocks. The weights may be selected from among a plurality of candidate weights. Candidate weights may be signaled in the bitstream or may be derived implicitly based on a template. Candidate weights may be pruned to avoid out-of-range or substantially duplicate candidate weights. Generalized bi-prediction may additionally be used in frame rate up conversion.

Abstract: A device may determine whether to enable or disable bi-directional optical flow (BIO) for a current coding unit (CU) (e.g., block and/or sub-block). Prediction information for the CU may be identified and may include prediction signals associated with a first reference block and a second reference block (e.g., or a first reference sub-block and a second reference sub-block). A prediction difference may be calculated and may be used to determine the similarity between the two prediction signals. The CU may be reconstructed based on the similarity. For example, whether to reconstruct the CU with BIO enabled or BIO disabled may be based on whether the two prediction signals are similar, it may be determined to enable BIO for the CU when the two prediction signals are determined to be dissimilar. For example, the CU may be reconstructed with BIO disabled when the two prediction signals are determined to be similar.

Abstract: Systems, devices, and methods are described herein for symmetric merge mode motion vector coding. Symmetric bi-prediction (bi-pred) motion vectors (MVs) may be constructed from available candidates in a merge candidate list for regular inter prediction merge mode and/or affine prediction merge mode. Available MV merge candidates may be symmetrically extended or mapped in either direction (e.g., between reference pictures before and after a current picture), for example, when coding a picture that allows bi-directional motion compensation prediction (MCP). A symmetric bi-pred merge candidate may be selected among merge candidates for predicting the motion information of a current prediction unit (PU). The symmetric mapping construction may be repeated by a decoder (e.g., based on a coded index of the MV merge candidate list), for example, to obtain the same merge candidates and coded MV at an encoder.

Abstract: Systems and methods are described for video coding using adaptive Hadamard filtering of reconstructed blocks, such as coding units. In some embodiments, where Hadamard filtering might otherwise encompass samples outside the current coding unit, extrapolated samples are generated for use in the filtering. Reconstructed samples from neighboring blocks may be used in the filtering where available (e.g. in a line buffer). In some embodiments, different filter strengths are applied to different spectrum components in the transform domain. In some embodiments, filter strength is based on position of filtered samples within the block. In some embodiments, filter strength is based on the prediction mode used to code the current block.

Abstract: Cross-plane filtering may be used to restore blurred edges and/or textures in one or both chroma planes using information from a corresponding luma plane. Adaptive cross-plane filters may be implemented. Cross-plane filter coefficients may be quantized and/or signaled such that overhead in a bitstream minimizes performance degradation. Cross-plane filtering may be applied to select regions of a video image (e.g., to edge areas). Cross-plane filters may be implemented in single-layer video coding systems and/or multi-layer video coding systems.

Abstract: Coding techniques for 360-degree video are described. An encoder selects a projection format and maps the 360-degree video to a 2D planar video using the selected projection format. The encoder encodes the 2D planar video in a bitstream and further signals, in the bitstream, parameters identifying the projection format. The parameters identifying the projection format may be signaled in a video parameter set, sequence parameter set, and/or picture parameter set of the bitstream. Different projection formats that may be signaled include formats using geometries such as equirectangular, cubemap, equal-area, octahedron, icosahedron, cylinder, and user-specified polygon. Other parameters that may be signaled include different arrangements of geometric faces or different encoding quality for different faces. Corresponding decoders are also described. In some embodiments, projection parameters may further include relative geometry rotation parameters that define an orientation of the projection geometry.

Abstract: Inter-layer motion mapping information may be used to enable temporal motion vector prediction (TMVP) of an enhancement layer of a bitstream. For example, a reference picture and a motion vector (MV) of an inter-layer video block may be determined. The reference picture may be determined based on a collocated base layer video block. For example, the reference picture may be a collocated inter-layer reference picture of the reference picture of the collocated base layer video block. The MV may be determined based on a MV of the collocated base layer video block. For example, the MV may be determined by determining the MV of the collocated base layer video block and scaling the MV of the collocated base layer video block according to a spatial ratio between the base layer and the enhancement layer. TMVP may be performed on the enhancement layer picture using the MV of the inter-layer video block.

Abstract: Systems and methods are described for video coding using affine motion prediction. In an example method, motion vector gradients are determined from respective motion vectors of a plurality of neighboring sub-blocks neighboring a current block. An estimate of at least one affine parameter for the current block is determined based on the motion vector gradients. An affine motion model is determined based at least in part on the estimated affine parameter(s), and a prediction of the current block is generated using the affine motion model. The estimated parameter(s) may be used in the affine motion model itself. Alternatively, the estimated parameter(s) may be used in a prediction of the affine motion model. In some embodiments, only neighboring sub-blocks above and/or to the left of the current block are used in estimating the affine parameter(s).

Abstract: Intra sub-partitions (ISP) may be enabled for a current block, for example, based on an ISP indication. The block may be partitioned into multiple sub-partitions, and a sub-partition may belong to a prediction unit (PU). A sub-partition width for the current block and a minimum prediction block width may be obtained. A PU corresponding to a current sub-partition may be determined based on the sub-partition width and the minimum prediction block width. For example, when the sub-partition width is less than the minimum prediction block width, the PU may include multiple sub-partitions. In examples, the minimum prediction block width may be four samples. Reference samples may be determined, and the PU may be predicted using the reference samples.

Abstract: Bi-directional optical flow (BDOF) may be bypassed, for a current coding block, based on whether symmetric motion vector difference (8MVD) is used in motion vector coding for the current coding block, A coding device (e.g., an encoder or a decoder) may determine whether to bypass BDOF for the current coding block based at least in part on an SMVD indication for the current coding block, The coding device may obtain the SMVD indication that indicates whether SMVD is used in motion vector coding for the current coding block. If SMVD Indication indicates that SMVD is used in the motion vector coding for the current coding block, the coding device may bypass BDOF for the current coding block. The coding device may reconstruct, the current coding block without performing BDOF if it determines to bypass BDOF for the current coding block.

Abstract: Expressions of artistic intent are identified (e.g. by signaling or content analysis) and expressed as a set of artistic intent positions P.sub.ART and artistic intent characteristics C.sub.ART, Artistic intent characteristics C.sub.ART may be signaled and used to identify artistic intent positions P.sub.ART. Artistic intent preservation coding and processing may be applied to sample positions P.sub.ART to preserve characteristics C.sub.ART. A coding user interface may permit a user to specify an artistic set (e.g. P.sub.ART and/or C.sub.ART) and to select and/or configure treatment of pixels and/or blocks associated with an artistic set, such as a fidelity enhancement, QP adjustment value and/or postprocessing. Content priority or importance levels may be impliedly and/or expressly indicated at fine (e.g. pixel, sample) and/or coarse (e.g. block) levels of content for varying (e.g. enhanced, reduced) levels of treatment in content coding, delivery, processing and/or error resilience/robustness.

Abstract: Systems, methods, and instrumentalities are disclosed for obtaining coded video data comprising quantized transform coefficients for a plurality of blocks, obtaining a first precision factor associated with a first block for performing at least one decoding function on the first block, obtaining a second precision factor associated with a second block for performing the at least one decoding function on the second block, and performing the at least one decoding function on the quantized transform coefficients for the first block using the first precision factor and on the quantized transform coefficients for the second block using the second precision factor.

Abstract: Systems and methods are described for video coding. In some embodiments, inter prediction of a sample in a current block is performed by rounding an initial motion vector and determining a rounding error vector caused by the rounding. An unrefined prediction of the sample is generated using the rounded motion vector. Unrefined predictions are similarly generated for other samples in the current block. Based on the unrefined predictions, a spatial gradient is determined for each sample position in the block. A refined prediction is generated for each sample position by adding, to the unrefined prediction, a scalar product between the spatial gradient and the rounding error vector at the sample position. Example methods can reduce the number of reference pixels used to predict a current block and thus may reduce memory access bandwidth.

Abstract: Video coding methods are described for reducing latency in template-based inter coding. In some embodiments, a method is provided for coding a video that includes a current picture and at least one reference picture. For at least a current block in the current picture, a respective predicted value is generated (e.g. using motion compensated prediction) for each sample in a template region adjacent to the current block. Once the predicted values are generated for each sample in the template region, a process is invoked to determine a template-based inter prediction parameter by using predicted values in the template region and sample values the reference picture. This process can be invoked without waiting for reconstructed sample values in the template region. Template-based inter prediction of the current block is then performed using the determined template-based inter prediction parameter.

Abstract: Methods, procedures, architectures, apparatuses, systems, devices, interfaces, and computer program products for encoding/decoding data (e.g. a data stream) are provided. A video coding method for predicting a current block includes identifying a first block adjacent to the current block, the first block having motion information, performing motion compensation using the motion information to generate a set of reference samples adjacent to the current block, identifying a first line of reference samples from the set of generated reference samples to be used for intra prediction of the current block, and performing intra prediction of the current block using at least the first line of reference samples.

Abstract: Aspects include a method, apparatus and computer-readable medium of decoding video or blocks of an image, including receiving a bitstream of the image, deriving, for a block of the image in the bitstream, multiple intra-prediction modes (IPMs) to use in decoding the block, determining, based on the multiple IPMs, a final predictor to use in decoding the block, and decoding the block using the final predictor. Other aspects include method, apparatus and computer-readable medium for similarly encoding video or blocks of an image.

Abstract: Procedures, methods, architectures, apparatuses, systems, devices, and computer program products directed to improved linear model estimation for template-based video coding are provided. Included therein is a method comprising determining minimum and maximum (“min/max”) values of luma and chroma samples neighboring a coding block, wherein the min/max chroma values correspond to the min/max luma values; determining a first linear model parameter of a template-based video coding technique (i) based on a single look-up table and the min/max chroma values and (ii) at a precision no greater than 16 bits; determining a second linear model parameter of the template-based video coding technique (i) based on the first linear model parameter and the minimum chroma and luma values and (ii) at a precision no greater than 16 bits; and predicting chroma samples of the coding block based on reconstructed luma samples of the coding block and the first and second linear model parameters.