Abstract: The present disclosure provides systems and methods for performing residual coding of video data. According to certain disclosed embodiments, the methods include: receiving control information for coding a video sequence; and determining, based on the control information, a coding method for coding a prediction residual signal of a coding block in the video sequence. The coding method is one of a transform residual coding and a transform-skip residual coding.

Abstract: The present disclosure provides methods and apparatuses for processing video content. The method can include: determining whether a picture-header (PH) network-abstraction-layer (NAL) unit is present in a picture unit (PU); in response to the PH NAL unit being present in the PU, determining a first video-coding-layer (VCL) NAL unit of the PU to be a first VCL NAL unit following the PH NAL unit, or in response to the PH NAL unit being not present in the PU, determining that the PU has only one VCL NAL unit and the first VCL NAL unit of the PU is the VCL NAL unit in the PU; and determining whether the first VCL NAL unit of the PU is the first VCL NAL unit of an access unit (AU) containing the PU.

Abstract: Systems, methods, and instrumentalities are disclosed for a combined inter and intra prediction. A video coding device may receive a motion vector difference (MMVD) mode indication that indicates whether MMVD mode is used to generate inter prediction of a coding unit (CU). The video coding device may receive a combined inter merge/intra prediction (CIIP) indication, for example, when the MMVD mode indication indicates that MMVD mode is not used to generate the inter prediction of the CU. The video coding device may determine whether to use triangle merge mode for the CU, for example, based on the MMVD mode indication and/or the CIIP indication. On a condition that the CIIP indication indicates that CIIP is applied for the CU or the MMVD mode indication indicates that MMVD mode is used to generate the inter prediction, the video coding device may disable the triangle merge mode for the CU.

Abstract: The present disclosure provides a computer-implemented method for encoding video. The method includes: determining whether a coded video sequence (CVS) contains equal number of profile, tier and level (PTL) syntax structures and output layer sets (OLSs); and in response to the CVS containing equal number of PTL syntax structures and OLSs, coding the bitstream without signaling a first PTL syntax element specifying an index, to a list of PTL syntax structures in the VPS, of a PTL syntax structure that applies to a corresponding OLS in the VPS.

Abstract: There are provided methods and apparatus for video usability information (VUI) for scalable video coding (SVC). An apparatus includes an encoder (100) for encoding video signal data into a bitstream. The encoder specifies video user information, excluding hypothetical reference decoder parameters, in the bitstream using a high level syntax element. The video user information corresponds to a set of interoperability points in the bitstream relating to scalable video coding (340, 355).

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: The present disclosure provides methods for picture processing. The method can include: receiving a bitstream comprising a set of pictures; determining, according to the received bitstream, whether a virtual boundary is signaled at a sequence level for the set of pictures; in response to the virtual boundary being signaled at the sequence level, determining a position of the virtual boundary for the set of pictures, the position being bounded by a range signaled in the received bitstream; and disabling in-loop filtering operations across the virtual boundary.

Abstract: Systems, methods, and instrumentalities are disclosed for sub-block/block refinement, including sub-block/block boundary refinement, such as block boundary prediction refinement with optical flow (BBPROF). A block comprising a current sub-block may be decoded based on a sample value for a first pixel that is obtained based on, for example, an MV for a current sub-block, an MV for a sub-block adjacent the current sub-block, and a sample value for a second pixel adjacent the first pixel. BBPROF may include determining spatial gradients at pixel(s)/sample location(s). An MV difference may be calculated between a current sub-block and one or more neighboring sub-blocks. An MV offset may be determined at pixel(s)/sample location(s) based on the MV difference. A sample value offset for the pixel in a current sub-block may be determined. The prediction for a reference picture list may be refined by adding the calculated sample value offset to the sub-block prediction.

Abstract: Techniques are disclosed for coding video in applications where regions of video are inactive on a frame to frame basis. According to the techniques, coding processes update and reconstruct only a subset of pixel blocks of pixels within a frame, while other pixel blocks are retained from a previously coded frame stored in a coder's or decoder's reference frame buffer. The technique is called Backward Reference Updating (or “BRU”) for convenience. At a desired pixel block granularity, based on the activity between a current frame to be coded and its reference frame(s), BRU will only perform prediction, transform, quantization, and reconstruction on selected regions that are determined to be active. The reconstructed pixels in these active regions are directly placed onto a specified reference frame in memory instead of creating a new frame. Therefore, fewer memory transfers need to be performed.

Abstract: Methods and apparatuses video processing include: in response to receiving a video sequence, encoding first flag data in a parameter set associated with the video sequence, wherein the first flag data represents whether gradual decoding refresh (GDR) is enabled or disabled for the video sequence; when the first flag data represents that the GDR is disabled for the video sequence, encoding a picture header associated with a picture in the video sequence to indicate that the picture is a non-GDR picture; and encoding the non-GDR picture.

Abstract: Systems, methods, and instrumentalities are disclosed for processing history-based motion vector prediction (HMVP). A video coding device may generate a history-based motion vector prediction (HMVP) list for a current block. The video coding device derive an HMVP candidate from a previously coded block. The HMVP candidate may include motion information associated with a neighboring block of the current block, one or more reference indices, and a bi-prediction weight index. The video coding device may add the HMVP candidate to the HMVP list for motion compensated prediction of a motion vector associated with the current block. The video coding device use one HMVP selected from the HMVP list to perform motion compensated prediction of the current block. The motion compensated prediction may be performed using the motion information associated with the neighboring block of the current block, the one or more reference indices, and the bi-prediction weight index.

Abstract: The present disclosure provides systems and methods for wrap-around motion compensation. One exemplary method comprises: receiving a wrap-around motion compensation flag; determining whether a wrap-around motion compensation is enabled based on the wrap-around motion compensation flag; in response to a determination that the wrap-around motion compensation is enabled, receiving data indicating a difference between a width of the picture and an offset used for determining a horizontal wrap-around position; and performing a motion compensation according to the wrap-around motion compensation flag and the difference.

Abstract: The present disclosure provides video processing method and apparatus. An exemplary method includes: determining whether a coding block comprises samples outside a picture boundary; and in response to the coding block being determined to comprise samples outside a picture boundary, performing quad tree splitting of the coding block regardless of a value of a first parameter, wherein the first parameter indicates whether the quad tree is allowed to be used to split the coding block.

Abstract: Systems, methods, and instrumentalities are disclosed for a combined inter and intra prediction, A video coding device may receive a motion vector difference (MMVD) mode indication that indicates whether MMVD mode is used to generate inter prediction of a coding unit (CU). The video coding device may receive a combined inter merge/intra prediction (CUP) indication, for example, when the MMVD mode indication indicates that MMVD mode is not used to generate the inter prediction of the CU, The video coding device may determine whether to use triangle merge mode for the CU, for example, based on the MMVD mode indication and/or the CUP indication. On a condition that the CUP indication indicates that CUP is applied for the CU or the MMVD mode indication indicates that MMVD mode is used to generate the inter prediction, the video coding device may disable the triangle merge mode for the CU.

Abstract: Method, apparatus and systems are disclosed. In one embodiment, a method of decoding includes obtaining a sub-block based motion prediction signal for a current block of the video; obtaining one or more spatial gradients of the sub-block based motion prediction signal or one or more motion vector difference values; obtaining a refinement signal for the current block based on the one or more obtained spatial gradients or the one or more obtained motion vector difference values; obtaining a refined motion prediction signal for the current block based on the sub-block based motion prediction signal and the refinement signal; and decoding the current block based on the refined motion prediction signal.

Abstract: There are provided methods and apparatus for video usability information (VUI) for scalable video coding (SVC). An apparatus includes an encoder (100) for encoding video signal data into a bitstream. The encoder specifies video user information, excluding hypothetical reference decoder parameters, in the bitstream using a high level syntax element. The video user information corresponds to a set of interoperability points in the bitstream relating to scalable video coding (340, 355).

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: The present disclosure provides methods for picture processing. The method can include: receiving a bitstream comprising a set of pictures; determining, according to the received bitstream, whether a virtual boundary is signaled at a sequence level for the set of pictures; in response to the virtual boundary being signaled at the sequence level, determining a position of the virtual boundary for the set of pictures, the position being bounded by a range signaled in the received bitstream; and disabling in-loop filtering operations across the virtual boundary.

Abstract: The present disclosure provides methods and apparatuses for processing chroma sampled pictures. An exemplary video processing method includes: determining whether a chroma component is included in a sequence of frames; and in response to a determination that the chroma component is included in the sequence, activating a sub-process for processing the sequence, wherein the sub-process comprises one or more of joint coding for chroma residues (JCCR), block differential pulse coded modulation (BDPCM), palette mode, or adaptive color transform (ACT).

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.