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: A video processing method is provided. The method includes inserting a set of spatial merge candidates to a first merge candidate list of a coding block, wherein the first merge candidate list is constructed by: adding a top neighboring block B1 to the first merge candidate list when the top neighboring block B1 is available; adding a left neighboring block A1 to the first merge candidate list when the left neighboring block A1 is available; adding a top neighboring block B0 to the first merge candidate list when the top neighboring block B0 is available; adding a left neighboring block A0 to the first merge candidate list when the left neighboring block A0 is available; and adding an above-left neighboring block B2 to the first merge candidate list when the above-left neighboring block B2 is available.

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: Methods for performing palette coding of video data may include: determining whether a luma component of a coding unit (CU) and chroma components of the CU are coded jointly or separately in a palette mode; and in response to the luma component and the chroma components being coded separately in the palette mode, determining a maximum separate palette-table size for the CU; determining a maximum separate palette-predictor size for the CU; and predicting the CU based on the maximum separate palette-table size and the maximum separate palette-predictor size.

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: 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: The present disclosure provides methods and systems for motion compensation. The method can include: determining a plurality of intermediate interpolation coefficients of an interpolation filter, the determining of the plurality of intermediate interpolation coefficients being: based on positions of a plurality of integer samples respectively, and based on fractional reference positions of a plurality of fractional samples respectively; determining a plurality of integer interpolation coefficients of the interpolation filter by rounding the plurality of intermediate interpolation coefficients to a plurality of integers respectively; and applying the plurality of integer interpolation coefficients on a picture to perform motion compensation prediction.

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: The present disclosure provides methods for processing video content. One exemplary method comprises: receiving a bitstream comprising coded video data; determining a first parameter of a coding block; determining, according to the first parameter, one or more second parameters associated with a delta quantization parameter (QP) value or a chroma QP offset value; and determining, according to the one or more second parameters, at least one of the delta QP value or the chroma QP offset value.

Abstract: The present disclosure provides methods for performing wrap-around motion compensation. The method can include receiving a first wrap-around motion compensation flag, wherein the second wrap-around motion compensation flag is associated with a picture; determining whether the first wrap-around motion compensation flag is enabled; in response to a determination that the first wrap-around motion compensation flag is enabled, receiving a wrap-around motion compensation offset, wherein the wrap-around motion compensation offset is associated with the picture; and performing wrap-around motion compensation on the picture according to the first wrap-around motion compensation flag and the wrap-around motion compensation offset.

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: Systems, methods, and instrumentalities may be provided for determining whether to bypass bi-directional optical flow (BDOF) if BDOF is used in combination with bi-prediction with coding unit (CU) weights (e.g., generalized bi-prediction (GBi)). A coding system may combine coding modes, coding techniques, and/or coding tools. The coding system may include a wireless transmit/receive unit (WTRU). For example, the coding system may combine BDOF and bi-prediction with CU weights (BCW). BDOF may include refining a motion vector associated with a current CU based at least in part on gradients associated with a location in the current CU. The coding system may determine that BDOF is enabled, and/or that bi-prediction with CU weights is enabled for the current CU. The coding system’s determination that bi-prediction with CU weights is enabled and/or that BDOF is enabled may be based on one or more indications.

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 apparatus and methods for signaling sub-block transform (SBT) information. The SBT information is used for coding video data. According to certain disclosed embodiments, an exemplary method includes: signaling a first flag in a Sequence Parameter Set (SPS) of a video sequence indicating whether a sub-block transform (SBT) is enabled; and signaling a second flag indicating a maximum transform block (TB) size that allows the SBT. A maximum coding unit (CU) size that allows the SBT is determined directly based on the maximum TB size in response to the first flag indicating that the SBT is enabled.

Abstract: The present disclosure provides methods and apparatuses for controlling a coding mode for video data. The methods and apparatuses include receiving a bitstream of video data; enabling or disabling a coding mode for a video sequence, based on a first flag in the bitstream; and determining whether controlling of the coding mode is enabled or disabled at a level lower than a sequence level, based on a second flag in the bitstream.

Abstract: Systems and methods are described for video coding using affine motion models with adaptive precision. In an example, a block of video is encoded in a bitstream using an affine motion model, where the affine motion model is characterized by at least two motion vectors. A precision is selected for each of the motion vectors, and the selected precisions are signaled in the bitstream. In some embodiments, the precisions are signaled by including in the bitstream information that identifies one of a plurality of elements in a selected predetermined precision set. The identified element indicates the precision of each of the motion vectors that characterize the affine motion model. In some embodiments, the precision set to be used is signaled expressly in the bitstream; in other embodiments, the precision set may be inferred, e.g., from the block size, block shape or temporal layer.

Abstract: The present disclosure provides a computer-implemented method for encoding video. The method includes coding one or more first flags in a sequence parameter set (SPS) of a bitstream, and coding at least one second flag in the SPS if one or more coding modes are enabled for a video sequence associated with the SPS. The one or more first flags indicate whether the one or more coding modes are enabled for the video sequence. The at least one second flag indicates whether a multi-level control is activated for the one or more coding modes.

Abstract: Bi-directional optical flow (BDOF) may be bypassed, for a current coding block, based on whether symmetric motion vector difference (SMVD) 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: A method for performing motion compensation includes: receiving a first wrap-around motion compensation flag associated with one or more pictures and indicating whether horizontal wrap-around motion compensation is enabled for the one or more pictures; and in response to the horizontal wrap-around motion compensation being enabled for the one or more pictures, receiving a parameter associated with a wrap-around motion compensation offset, the wrap-around motion compensation offset being associated with the one or more pictures, wherein a value of the wrap-around motion compensation offset is less than or equal to a difference minus 2, and the difference is obtained by a quotient of a picture width in luma samples divided by a minimum luma coding block size minus a quotient of a luma coding tree block size divided by the minimum luma coding block size.

Abstract: The present disclosure provides methods and apparatuses for signaling subpicture partitioning information. An exemplary method includes: determining, according to a subpicture information present flag signaled in a bitstream, whether the bitstream comprises subpicture information; and in response to the bitstream comprising the subpicture information, signaling in the bitstream at least one of: a number of subpictures in a picture, a width, a height, a position, and an identifier (ID) mapping of a target subpicture, a subpic_treated_as_pic_flag, and a loop_filter_across_subpic_enabled_flag.