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: Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for decoding a video signal. A decoder obtains a first reference picture and a second reference picture associated with a video block. The decoder obtains first and second horizontal and vertical gradient values. The decoder obtains first and second horizontal and vertical motion refinements based on control point motion vectors. The decoder obtains first and second prediction refinements based on the first and second horizontal and vertical gradient values and the first and second horizontal and vertical motion refinements. The decoder obtains first and second refined samples based on the first and second prediction samples, and the first and second prediction refinements. The decoder obtains final prediction samples of the video block based on the first and second refined samples by manipulating the first and second refined samples and prediction parameters to prevent multiplication overflow.

Abstract: A bit-width representation method of prediction refinement with optical flow (PROF), apparatus, and a non-transitory computer-readable storage medium are provided. The method includes obtaining a reference picture I associated with a video block within the video signal, obtaining prediction samples I(i,j) of the video block from a reference block in the reference picture I, controlling internal bit-widths of a PROF derivation process for various representation precisions of internal PROF parameters by applying right-shifting to the internal PROF parameters based on different bit-shift values, obtaining prediction refinement values for samples in the video block based on the PROF derivation process being applied to the video block based on the prediction samples I(i,j), and obtaining prediction samples of the video block based on the combination of the prediction samples and the prediction refinement values.

Abstract: An electronic apparatus performs a method of decoding video data. The method comprises, receiving, from bitstream, video data corresponding to a palette-mode coded block; determining a quantization parameter value from information included in a parameter set associated with the palette-mode coded block; identifying escape samples in the palette-mode coded block; in accordance with a determination that the quantization parameter value is greater than a threshold value: performing de-quantization on quantized escape samples according to a predefined formula to obtain reconstructed escape sample values; and in accordance with a determination that the quantization parameter value is less than or equal to the threshold value: setting the reconstructed escape samples to be the quantized escape sample values.

Abstract: A method for controlling bit-width for bi-directional optical flow (BDOF) for video coding includes decoding a first reference picture and a second reference picture, the second reference picture being different than the first reference picture, wherein the first reference picture is displayed before a current picture and the second reference picture is displayed after the current picture. A motion refinement of a coding unit (CU) is calculated by minimizing a difference between a first prediction L0 and a second prediction L1. First gradient values for the first prediction Lo and second gradient values for the second prediction L1 are calculated. A final bi-prediction of the CU is calculated. Also disclosed are an associated apparatus and an associated non-transitory computer readable storage medium.

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: A method of decoding video data, comprising: receiving, from bitstream, video data corresponding to a non-skip mode coded block; determining a parameter set associated with the non-skip mode coded block; if the parameter set satisfies a first condition, retrieving a first syntax element from the bitstream; if the parameter set satisfies a second condition, retrieving a second syntax element from the bitstream; if the parameter set satisfies a third condition, retrieving a third syntax element from the bitstream; decoding the video data corresponding to the non-skip mode coded block using palette mode when the first syntax element and the third syntax element have the first value; decoding the video data using intra prediction mode when the first syntax element has the first value and the third syntax element has a second value; and decoding the video data using inter prediction mode when the first syntax element has the second value.

Abstract: A method for coding video data comprises receiving a video picture comprising a plurality of coding units. The picture is divided into multiple non-overlapped blocks. An encoder calculates a hash value of each block of the multiple non-overlapped blocks. All the non-overlapped blocks are classified into at least two categories comprising a first category and a second category. The first category comprises one or more blocks representing one or more hash values covered by a first set of hash values, and the second category comprises all remaining blocks. The blocks in the second category are classified into at least two groups including a first group. The first group comprises one or more blocks representing the same hash value as another block in the second category. An associated computing device and a non-transitory computer readable storage medium are also provided.

Abstract: An electronic apparatus performs a method of decoding a video signal. The method comprises: receiving the video signal that includes a first component and a second component in a first picture frame; receiving, from the video signal, a plurality of sample offsets associated with the second component in the first picture frame; deriving a first class index for the second component from a first set of one or more samples of the first component relative to each sample of the second component; selecting a first sample offset from the plurality of sample offsets for the second component according to the first class index; and obtaining a cross-component offsetted sample value of the second component based on the first sample offset in the first picture frame. In some embodiments, the first picture frame is divided into a plurality of regions, and a different classifier is used for each of the plurality of regions.

Abstract: An electronic apparatus performs a method of decoding video data. The method comprises: receiving, from bitstream, video data corresponding to a transform-skip mode coded block; decoding, from the video data, a first codeword, a second codeword and a first group of codewords for a pixel within the transform-skip mode coded block; deriving an initial level value from the first group of codewords; converting the first codeword into a remainder of the pixel in accordance with a predefined mapping relationship that is generated using a constant Rice parameter; converting the second codeword into a sign value of the remainder; and deriving a quantified residual of the pixel from the remainder, the sign value and the initial level value.

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: Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for video decoding. The method includes dividing a video block to multiple non-overlapped video subblocks, dividing a video block to multiple non-overlapped video subblocks, obtaining a first reference picture I(0) and a second reference picture I(1), obtaining first prediction samples I(0)(i,j)'s, obtaining second prediction samples I(1)(i,j)'s, obtaining horizontal and vertical gradient values of the first prediction samples I(0)(i,j)'s and second prediction samples I(1)(i,j)'s, obtaining motion refinements for samples in the video subblock based on the BDOF when the video block is not coded in affine mode, obtaining motion refinements for samples in the video subblock based on the PROF when the video block is coded in affine mode, and obtaining prediction samples of the video block based on the motion refinements.

Abstract: An electronic apparatus performs a method of decoding video data. The method comprises: receiving, from a bitstream, a first control flag that indicates merge mode with motion vector difference (MMVD) is enabled for one or more coding units in a video sequence; receiving a first syntax from the video data that identifies a set of motion vector difference (MVD) offsets from a plurality sets of MVD offsets; receiving, a second control flag corresponding to a respective coding unit of the one or more coding units, which indicates the MMVD is applied to the coding unit; receiving a second syntax that selects an MVD offset from the identified set of MVD offsets, and a third syntax that selects an MVD direction; forming MVD based on the selected MVD offset and MVD direction; and reconstructing the coding unit by applying the formed MVD to generate motion vectors to the coding unit.

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: The present disclosure relates to a video coding method, a computing device, and a storage medium. The method includes: obtaining one or more reference blocks associated with a current block of a video picture and one or more previously coded pictures for predicting the current block; generating an inter prediction based on one or more motion vectors from the current block to the one or more reference blocks; generating a first intra prediction based on a plurality of neighboring reconstructed reference samples associated with a plurality of neighboring blocks of the current block in the video picture; determining a first weight based on the plurality of neighboring blocks; generating a third prediction by combining the inter prediction and the first intra prediction based on the first weight; and generating a final prediction based on the plurality of neighboring reconstructed samples and the third prediction.

Abstract: Methods and apparatuses are provided for video coding with lossless coding modes. The method includes: partitioning a video picture into a plurality of CUs comprising a lossless CU; determining a residual coding block size of the lossless CU; and in response to determining that the residual coding block size of the lossless CU is greater than a predefined maximum value, splitting the residual coding block into two or more residual blocks for residual coding.

Abstract: A method of decoding a syntax element for a current coding unit of video data is performed by an electronic apparatus. The electronic apparatus identifies, for the current coding unit, an above coding unit and a coding tree unit including the current coding unit. After determining that the above coding unit is within the coding tree unit, the electronic apparatus decodes, from a video bitstream, a corresponding syntax element for the current coding unit based, at least in part, on a syntax element associated with the above coding unit retrieved from a line buffer associated with the coding tree unit; otherwise, the electronic apparatus decodes, from the video bitstream, the corresponding syntax element for the current coding unit based, at least in part, on a default value assigned to the syntax element associated with the above coding unit.

Abstract: Methods, apparatuses, and non-transitory computer-readable storage mediums are provided for decoding a video signal. The method includes obtaining a first reference picture I associated with a video block, obtaining control point motion vectors (CPMVs) of an affine coding block based on the video block, obtaining prediction samples I(i, j) of the affine coding block, deriving PROF prediction sample refinements of the affine coding block based on the PROF, receiving an LIC flag that indicates whether the LIC is applied to the affine coding block, deriving, and when the LIC is applied, LIC weight and offset based on neighboring reconstructed samples of the affine coding block and their corresponding reference samples in the first reference picture, and obtaining final prediction samples of the affine coding block based on the PROF prediction sample refinements and the LIC weight and offset.

Abstract: Methods are provided for reducing the computation complexity and on-chip memory requirements as well as the decoding latency introduced by LMCS. In one method, a luma prediction sample is obtained for decoding a luma residual sample, a scaling factor is derived using the luma prediction sample, the scaling factor is used to scale the luma residual sample, and the reconstructed luma sample is calculated by adding the luma prediction sample and the scaled luma residual sample.