Abstract: Systems, methods, and instrumentalities for affine motion estimation for affine model-based video coding may be disclosed herein. A first motion vector (MV) set including one or more MVs may be derived for a first coding block. The MVs may be control point MVs (CPMVs) and the MVs may be derived by performing affine motion estimation (ME) associated with the first coding block. The first MV set may be added to a recently-estimated MV list. A head of the recently-estimated MV list may be set to the first MV set. The recently-estimated MV list may be empty or may contain one or more previously-added MV sets.

Abstract: Methods and apparatuses for video coding are provided. The method includes that a decoder determines whether one or more reference picture lists are signaled in a picture header (PH) associated with a picture and whether the one or more reference picture lists indicate that one or more slices associated with the picture are bi-predictive. The method further includes that the decoder adds one or more constraints to one or more syntax elements in the PH in response to determining that the one or more reference picture lists are signaled in the PH and the one or more reference picture lists indicate that the one or more slices are not bi-predictive.

Abstract: Methods, apparatuses, and non-transitory computer-readable storage medium are provided for decoding video signals. A decoder receives a bitstream that includes a sequence parameter set (SPS) for video data. The decoder obtains arranged partition constraint syntax elements in sequence parameter set (SPS) level, and the arranged partition constraint syntax elements include intra prediction related syntax elements and inter prediction related syntax elements, and the arranged partition constraint syntax elements are arranged so that the intra prediction related syntax elements are defined before the inter prediction related syntax elements. The decoder decodes the video data based on the arranged partition constraint syntax elements.

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 ail 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: Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for decoding a video signal. A decoder obtains a reference picture I associated with a video block within the video signal. The decoder may further obtain reference samples I(i,j) of the video block from a reference block in the reference picture I. The decoder may also obtain a first down-sampling filter and a second down-sampling filter to respectively generate luma and chroma inter prediction samples of the video block. The decoder may further obtain a third down-sampling filter and a fourth down-sampling filter to respectively generate the luma and chroma inter prediction samples of the video block when the video block is coded by affine mode. The decoder may also obtain inter prediction samples of the video block based on the third and fourth down-sampling filters being applied to the reference samples I(i,j).

Abstract: An electronic apparatus performs a method of decoding video data. The method comprises: receiving, from the bitstream, a plurality of syntax elements associated with a coding unit, wherein the plurality of syntax elements indicate the coding tree type of the coding unit, and whether the local dual tree mode is enabled for the coding unit; and in accordance with the determination that the coding tree type of the coding unit is a single tree, and the local dual tree mode is enabled for the coding unit: disabling the palette mode for the coding unit when the coding unit has the size equal to or less than a predefined threshold. In some embodiments, disabling palette mode for the coding unit includes: disabling the palette mode for both the luma component and chroma component of the coding unit, or disabling the palette mode for only the chroma component of the coding unit.

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: 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 may 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: An electronic apparatus performs a method of coding video data. The method includes receiving, from a bitstream of the video data, a first syntax that indicates an affine motion model enabled for a current coding block, estimating parameters of the affine motion model using gradients of motion vectors of multiple spatial neighboring blocks of the current coding block, and constructing motion vectors of the affine motion model for the current coding block by using the estimated parameters. In some embodiments, constructing motion vectors further includes converting the estimated parameters into control point motion vectors (CPMVs), and adding the CPMVs into a current affine merge candidate list. In some embodiments, constructing motion vectors further includes deriving a motion vector predictor for an affine mode.

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 GU 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: 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: 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: A method for video coding is provided. The method includes obtaining a first reference picture and a second reference picture associated with a current prediction block, obtaining a first prediction L0 based on a first motion vector MV0 from the current prediction block to a reference block in the first reference picture, obtaining a second prediction L1 based on a second motion vector MV1 from the current prediction block to a reference block in the second reference picture, determining whether a bidirectional optical flow (BDOF) operation is applied, and calculating a bi-prediction of the current prediction block based on the first prediction L0 and the second prediction L1, and first gradient values and second gradient values.

Abstract: Processing video data may include capturing the video data with multiple cameras and stitching the video data together to obtain a 360-degree video. A frame-packed picture may be provided based on the captured and stitched video data. A current sample location may be identified in the frame-packed picture. Whether a neighboring sample location is located outside of a content boundary of the frame-packed picture may be determined. When the neighboring sample location is located outside of the content boundary, a padding sample location may be derived based on at least one circular characteristic of the 360-degree video content and the projection geometry. The 360-degree video content may be processed based on the padding sample location.

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, methods, and instrumentalities are disclosed for motion vector clipping when affine motion mode is enabled for a video block. A video coding device may determine that an affine mode for a video block is enabled. The video coding device may determine a plurality of control point affine motion vectors associated with the video block. The video coding device may store the plurality of clipped control point affine motion vectors for motion vector prediction of a neighboring control point affine motion vector. The video coding device may derive a sub-block motion vector associated with a sub-block of the video block, clip the derived sub-block motion vector, and store it for spatial motion vector prediction or temporal motion vector prediction. For example, the video coding device may clip the derived sub-block motion vector based on a motion field range that may be based on a bit depth value.

Abstract: An electronic apparatus performs a method of decoding video data. The method comprises: receiving, from bitstream, a plurality of syntax elements associated with a coding unit, wherein the plurality of syntax elements indicate a size of the coding unit and a coding tree type of the coding unit; determining a minimum palette mode block size for the coding unit in accordance with the coding tree type of the coding unit; in accordance with a determination that the size of the coding unit is greater than the minimum palette mode block size: receiving, from the bitstream, a palette mode enable flag associated with the coding unit; and decoding, from the bitstream, the coding unit in accordance with the palette mode enable flag.

Abstract: An electronic apparatus performs a method of decoding video data. The method comprises: receiving, from bitstream, one or more syntax elements and video data corresponding to a coding unit; determining a Rice parameter according to the one or more syntax elements; decoding, from the video data, a first codeword and a second codeword for a pixel within the coding unit; converting the first codeword into a parameter of the pixel in accordance with a predefined mapping relationship that is generated using the determined Rice parameter; converting the second codeword into a sign value of the parameter; and determining a quantified pixel value of the pixel based on the parameter and the sign value.

Abstract: An electronic apparatus performs a method of coding video data. The method comprises: receiving, from the bitstream, the video data corresponding to a coding unit, wherein the coding unit is coded by intra-prediction mode or inter-prediction mode; receiving a first syntax element from the video data, wherein the first syntax element indicates whether the coding unit has been coded using adaptive color-space transform (ACT); processing the video data to generate residuals of the coding unit; in accordance with a determination based on the first syntax element that the coding unit has been coded using the ACT, performing a clipping operation that confines a dynamic range of the residuals of the coding unit within a predefined range; and applying an inverse ACT to the residuals of the coding unit after the clipping operation.

Abstract: An electronic apparatus performs a method of coding video data. The method comprises: receiving, from the video data in the bitstream, a first syntax element indicating whether adaptive color-space transform (ACT) is enabled for the coding unit; if the ACT is enabled for the coding unit, receiving a first set of syntax elements associated with block differential pulse coded modulation (BDPCM) for a luma component of the coding unit that includes a second syntax element indicating whether the BDPCM is enabled for the luma component of the coding unit; and if the BDPCM is enabled for the luma component of the coding unit, assigning respective values of the first set of syntax elements associated with the BDPCM for the luma component of the coding unit to a second set of syntax elements associated with the BDPCM to a chroma component of the coding unit.