Abstract: Systems, methods, and instrumentalities for sub-block motion derivation and motion vector refinement for merge mode may be disclosed herein. Video data may be coded (e.g., encoded and/or decoded). A collocated picture for a current slice of the video data may be identified. The current slice may include one or more coding units (CUs). One or more neighboring CUs may be identified for a current CU. A neighboring CU (e.g., each neighboring CU) may correspond to a reference picture. A (e.g., one) neighboring CU may be selected to be a candidate neighboring CU based on the reference pictures and the collocated picture. A motion vector (MV) (e.g., collocated MV) may be identified from the collocated picture based on an MV (e.g., a reference MV) of the candidate neighboring CU. The current CU may be coded (e.g., encoded and/or decoded) using the collocated MV.

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: A method of encoding a video sequence into a bitstream is provided. The method includes: receiving a video sequence; and encoding one or more pictures of the video sequence; wherein the encoding includes: signaling a first flag in a slice header to indicate whether an active reference index number is present in a slice header; in response to the first flag indicating that the active reference index number is present, determining a number of entries of reference picture list 0, and signaling an active reference index number of reference picture list 0 in the slice header for P and B slices; and determining a number of entries of reference picture list 1, and signaling an active reference index number of reference picture list 1 in the slice header for B slice.

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: Systems, methods and instrumentalities are disclosed for adaptively selecting an adaptive loop filter (ALF) procedure for a frame based on which temporal layer the frame is in. ALF procedures may vary in computational complexity. One or more frames including the current frame may be in a temporal layer of a coding scheme. The decoder may determine the current frame's temporal layer level within the coding scheme. The decoder may select an ALF procedure based on the current frame's temporal layer level. If the current frame's temporal layer level is higher within the coding scheme than some other temporal layer levels, an ALF procedure that is less computationally complex may be selected for the current frame. Then the decoder may perform the selected ALF procedure on the current frame.

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: Sketch copy mode may be used to code blocks comprising irregular lines, syntax redundancy may be removed from blocks with special characteristics, and/or run value coding may be simplified. The parsing dependencies in palette coding design may be removed. For example, the context modeling dependency of the syntax element palette_transpose_flag be removed, for example, by simplifying the corresponding context model. The context modeling of the syntax element palette mode may be removed, for example, by using run-length coding without using context. The syntax parsing dependencies and/or the syntax signaling dependencies that are related with escape color signaling may be removed. A palette table generation process may handle input screen content video with high bit depths, for example, at the encoder side.

Abstract: The present disclosure provides methods, apparatus and non-transitory computer readable medium for processing video data. According to certain disclosed embodiments, a method includes: determining a set of parameters from a plurality of sets of parameters wherein the set of parameters includes a scaling factor; determining a predicted sample value of a first chroma component based on the set of the parameters, a reconstructed sample value of a luma component and a reconstructed sample value of a second chroma component; and signaling an index associated with the set of parameters in a bitstream.

Abstract: Embodiments of video coding systems and methods are described for reducing coding latency introduced by decoder-side motion vector refinement (DMVR). In one example, two non-refined motion vectors are identified for coding of a first block of samples (e.g. a first coding unit) using bi-prediction. One or both of the non-refined motion vectors are used to predict motion information for a second block of samples (e.g. a second coding unit). The two non-refined motion vectors are refined using DMVR, and the refined motion vectors are used to generate a prediction signal of the first block of samples. Such embodiments allow the second block of samples to be coded substantially in parallel with the first block without waiting for completion of DMVR on the first block. In additional embodiments, optical-flow-based techniques are described for motion vector refinement.

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: A VVC-standard encoder and a VVC-standard decoder implement improvements over VVC and ECM in a number of regards: a temporal motion vector prediction candidate selection method utilizing relocation of a collocated CTU; a temporal motion vector prediction candidate selection method utilizing expanded selection range; a temporal motion vector prediction candidate selection method utilizing unconditional derivation of a scaled motion vector; a temporal motion vector prediction candidate selection method utilizing omission of scaling uni-predicted motion vectors to bi-predicted motion vectors; a temporal motion vector prediction candidate selection method utilizing multiple options in setting a reference picture index; a temporal motion vector prediction candidate selection method utilizing scaling factor offsetting; a merge candidate list building method omitting a temporal motion vector prediction candidate; and a picture reconstruction method utilizing motion information refinement.

Abstract: Systems, methods, and instrumentalities are provided to implement video coding system (VCS). The VCS may be configured to receive a video signal, which may include one or more layers (e.g., a base layer (BL) and/or one or more enhancement layers (ELs)). The VCS may be configured to process a BL picture into an inter-layer reference (ILR) picture, e.g., using picture level inter-layer prediction process. The VCS may be configured to select one or both of the processed ILR picture or an enhancement layer (EL) reference picture. The selected reference picture(s) may comprise one of the EL reference picture, or the ILR picture. The VCS may be configured to predict a current EL picture using one or more of the selected ILR picture or the EL reference picture. The VCS may be configured to store the processed ILR picture in an EL decoded picture buffer (DPB).

Abstract: Embodiments of the present disclosure provides systems and methods for processing video content. The methods include: reconstructing a plurality of luma samples associated with a picture; and reconstructing a chroma block associated with the picture. The reconstructing of the chroma block includes: determining whether the chroma block has non-zero residues; and in response to a determination that the chroma block has one or more non-zero chroma residues, determining an averaged value of the plurality of reconstructed luma samples, and scaling residues of the chroma block based on the averaged value, prior to reconstructing the chroma block.

Abstract: Overlapped block motion compensation (OBMC) may be performed for a current video block based on motion information associated with the current video block and motion information associated with one or more neighboring blocks of the current video block. Under certain conditions, some or all of these neighboring blocks may be omitted from the OBMC operation of the current block. For instance, a neighboring block may be skipped during the OBMC operation if the current video block and the neighboring block are both uni-directionally or bi-directionally predicted, if the motion vectors associated with the current block and the neighboring block refer to a same reference picture, and if a sum of absolute differences between those motion vectors is smaller than a threshold value. Further, OBMC may be conducted in conjunction with regular motion compensation and may use simplified filters than traditionally allowed.

Abstract: A device may be configured to render at least one spatial region of 360-degree media content, which may include two or more spatial regions. The device may include a receiver configured to receive the 360-degree media content and metadata associated with the 360-degree content. The metadata may include a classification of a respective spatial region of the 360-degree media content. The device may further include a memory configured to store a user preference and a sensor configured to detect a user movement. The device may include a processor configured to determine that the user movement is associated with a rendering of the respective spatial region. The processor may further determine whether the classification complies with the user preference and alter the rendering of the respective spatial region if the classification violates the user preference.

Abstract: Systems and methods described herein provide for rendering and quality monitoring of rendering of a 360-degree video, where the video has a plurality of representations with different levels of quality in different regions. In an exemplary method, a client device tracks a position of a viewport with respect to the 360-degree video and renders to the viewport a selected set of the representations. The client adaptively adds and removes representations from the selected set based on the viewport position. The client also measures and reports a viewport switching latency. In some embodiments, the latency for a viewport switch is a comparable-quality viewport switch latency that represents the time it takes after a viewport switch to return to a quality comparable to the pre-switch viewport quality.

Abstract: A system, method, and/or instrumentality may be provided for coding a 360-degree video. A picture of the 360-degree video may be received. The picture may include one or more faces associated with one or more projection formats. A first projection format indication may be received that indicates a first projection format may be associated with a first face. A second projection format indication may be received that indicates a second projection format may be associated with a second face. Based on the first projection format, a first transform function associated with the first face may be determined. Based on the second projection format, a second transform function associated with the second face may be determined. At least one decoding process may be performed on the first face using the first transform function and/or at least one decoding process may be performed on the second face using the second transform function.

Abstract: A method for video processing, wherein a combined inter and intra prediction (CIIP) and luma mapping with chroma scaling (LMCS) are applied. The method includes obtaining an inter prediction signal, an intra prediction signal, and an overlapped block motion compensation (OBMC) prediction signal; obtaining an intermediate weighted prediction signal by weighting the inter prediction signal and a first prediction signal of the intra prediction signal and the OBMC prediction signal; and obtaining a final prediction signal by weighting the intermediate weighted prediction signal and a second prediction signal of intra prediction signal and the OBMC prediction signal; wherein the intermediate weighted prediction signal and the second prediction signal are both in one of a mapped domain or an original domain.

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.