Abstract: An image decoding method includes: deriving an L0 motion vector and a L1 motion vector of the current block; deriving prediction samples of the current block based on the L0 motion vector and the L1 motion vector; and generating reconstructed samples of the current block based on the prediction samples. Deriving the prediction samples includes applying bi-directional optical flow (BDOF) to the current block based on whether the condition for applying BDOF to the current block is satisfied, and the application condition of the BDOF includes a condition whereby the values of L0 luma weighted prediction flag information and L1 luma weighted prediction flag information are both zero, where the a value of each of the L0 luma weighted prediction flag information and L1 luma weighted prediction flag information being 0 represents that a weight factor for each of a L0 and L1 prediction luma components does not exist, respectively.

Abstract: Devices, systems and methods related to management of syntax flags with respect chroma formats in video processing are described. In one representative aspect, a video decoding method includes determining, for a conversion between a video and a coded representation of the video, whether a syntax element associated with an adaptive loop filtering (ALF) operation for a chroma component of the video is included in the coded representation based on a condition. The method also includes performing the conversion according to the determining.

Abstract: A video processing method includes receiving a reconstructed frame, and applying in-loop filtering, by at least one in-loop filter, to the reconstructed frame. The step of in-loop filtering includes performing a sample adaptive offset (SAO) filtering operation. The step of performing the SAO filtering operation includes keeping a value of a current pixel unchanged by blocking the SAO filtering operation of the current pixel included in the reconstructed frame from being applied across a virtual boundary defined in the reconstructed frame.

Abstract: An image processing device includes an image processing unit configured to execute image processing on an image based on an input image and output a result of the image processing, the input image is a post-conversion image obtained by performing image conversion on an original image, and the conversion includes image conversion for further decreasing a data size of the original image while maintaining a feature quantity used in the image processing and processing accuracy of the image processing.

Abstract: Systems and methods are described for selecting a motion vector (MV) to use in frame-rate up conversion (FRUC) coding of a block of video. In one embodiment, a first set of motion vector candidates is identified for FRUC prediction of the block. A search center is defined based on the first set of motion vector candidates, and a search window is determined, the search window having a selected width and being centered on the search center. A search for a selected MV is performed within the search window. In some embodiments, an initial set of MVs is processed with a clustering algorithm to generate a smaller number of MVs that are used as the first set. The selected MV may be subject to a motion refinement search, which may also be performed over a constrained search range. In additional embodiments, search iterations are constrained to limit complexity.

Abstract: Systems and methods are described for reducing the complexity of using bi-directional optical flow (BIO) in video coding. In some embodiments, bit-width reduction steps are introduced in the BIO motion refinement process to reduce the maximum bit-width used for BIO calculations. In some embodiments, simplified interpolation filters are used to generate predicted samples in an extended region around a current coding unit. In some embodiments, different interpolation filters are used for vertical versus horizontal interpolation. In some embodiments, BIO is disabled for coding units with small heights and/or for coding units that are predicted using a sub-block level inter prediction technique, such as advanced temporal motion vector prediction (ATMVP) or affine prediction.

Abstract: A video processing method is provided to include determining, for a conversion between a current block of a current video picture of a video and a coded representation of the video, that both a local illumination compensation (LIC) tool and an intra block copy (IBC) tool are enabled for the conversion of the current block, and performing the conversion based on the determining. The LIC tool uses a linear model of illumination changes in the current block during the conversion, and the IBC tool uses a portion of the current video picture for the conversion of the current block.

Abstract: A video decoding method comprises: deriving L0 and L1 motion vectors of a current block; deriving decoder-side motion vector refinement (DMVR) flag information indicating whether to apply a DMVR to the current block; when the DMVR flag information indicates that the DMVR is to be applied to the current block, deriving refined L0 and L1 motion vectors based on the L0 and L1 motion vectors by applying the DMVR to the current block; deriving prediction samples of the current block based on the refined L0 and L1 motion vectors; and generating reconstructed samples of the current block based on the predicted samples, wherein deriving DMVR flag information comprises deriving the DMVR flag information by applying the DMVR to the current block when the height of the current block is 8 or more, and when the values of L0 and L1 luma weighted prediction flag information are both 0.

Abstract: A device for decoding video data includes a memory configured to store the video data; and one or more processors configured to decode syntax information that indicates a selected intra prediction mode for the block of video data from among a plurality of intra prediction modes. The one or more processors apply an N-tap intra interpolation filter to neighboring reconstructed samples of the block of video data according to the selected intra prediction mode, wherein N is greater than 2. The one or more processors reconstruct the block of video data based on the filtered neighboring reconstructed samples according to the selected intra prediction mode.

Abstract: An example apparatus includes a first line buffer and a second line buffer, where each memory location in the first line buffer and the second line buffer corresponds to a row or column of a palette token block. The first line buffer may store two of the neighboring palette token values (e.g., above and left palette token values), and the second line buffer may store one of the neighboring palette token value (e.g., above-left). As a video coder is coding palette token values, the video coder may shift values stored in the first line buffer to the overwrite a memory location in the second line buffer, and overwrite values stored in the first line buffer based in part on the row or column of the palette token block to which the memory locations in the first and second line buffer correspond.

Abstract: A method, computer program, and computer system is provided for video encoding and decoding. A bitstream of data corresponding to an image having pre-determined multiple regions is received, and a number is determined from the bitstream corresponding to a number of filters in an adaptive loop filter associated with the image. A region index to filter an index lookup table is decoded. The filter coefficients of the filters in the adaptive loop filter are decoded. The image is decoded based on the decoded filter coefficients and the decoded region index to filter the index lookup table.

Abstract: A method of performing motion vector prediction for a current block in a picture is provided which includes: deriving a candidate for a motion vector predictor to code a current motion vector of the current block, from a first motion vector of a first block that is spatially adjacent or temporally adjacent to the current block; adding the derived candidate to a list of candidates; and deriving at least one motion vector predictor based on a selected candidate from the list of candidates, wherein the deriving of the candidate includes determining whether to derive the candidate from the first motion vector, based on a type of a current reference picture and a type of a first reference picture, the current reference picture being referred to from the current block using the current motion vector, the first reference picture being referred to from the first block using the first motion vector.

Abstract: A method includes obtaining a first control parameter in a sequence parameter set (SPS) level, wherein a first value of the first control parameter in the SPS level indicates that a smoothing is not applied for any block of a sequence, a second value of the first control parameter in the SPS level indicates that the smoothing is applied for each block of the sequence, and obtaining a second control parameter in a slice header when a third value of the first control parameter in the SPS level is equal to a predefined value, wherein a first value of the second control parameter indicates that the smoothing is applied for each block of a slice.

Abstract: A method of video processing is described. The method includes determining, for subblocks of a current video block of a video, subblock boundaries to which a deblocking filter is to be applied according to a rule; and performing a conversion between the video and a coded representation of the video using the deblocking filter, wherein the rule specifies that a deblocking filter length is determined without checking a relationship between i) a sum of a position of a subblock of the current video block and a predefined value and ii) a width or a height of the current video block.

Abstract: An image coding method and apparatus, and an image decoding method and apparatus are provided. In the coding method, a scanning manner parameter of a coding block is determined, and the scanning manner parameter may include at least one of: a region indication parameter used for determining a scanning region of the coding block and a scanning indication parameter used for determining a scanning order of pixels in a scanning region of the coding block; predicted values of part or all of pixels in the coding block are determined according to the scanning manner parameter; and the coding block is coded according to the predicted values, and a coding result is written into a bitstream.

Abstract: An image decoding method performed by a decoding device according to the present disclosure comprises the steps of: receiving a bitstream including prediction information for a current block; deriving a chroma array type for the current block on the basis of a separate color plane flag indicating whether three color components are separately coded and a chroma format index indicating a chroma format sampling structure for the current block, which are included in the prediction information for the current block; deriving prediction samples for the current block on the basis of the derived chroma array type; and deriving reconstructed samples for the current block on the basis of the prediction samples.

Abstract: A system and method for improving the coding efficiency of motion vector information in video coding. According to various embodiments, a list of motion vector predictor candidates is arranged according to predefined rules. Each motion vector also has a reference index associated with it. One of the motion vector candidates is then selected as a predictor based on predefined rules, or the selection is explicitly signaled in the bitstream. The reference index associated with the selected motion vector is used as a reference index for the current block. The reference index is predicted along with the motion vector. Such embodiments can improve the compression efficiency of modern video codecs.

Abstract: An image decoding method according to the present specification comprises the steps of: deriving transform coefficients through inverse quantization on the basis of quantized transform coefficient for a target block; deriving modified transform coefficients on the basis of inverse reduced secondary transform (RST) of the transform coefficients; and generating a reconstructed picture on the basis of residual samples for the target block on the basis of an inverse primary transform of the modified transform coefficients, wherein the step of deriving the modified transform coefficients is characterized in deriving 16 modified transform coefficients by applying a transform kernel matrix to 8 transform coefficients in a 4×4 region of the target block.

Abstract: The present invention relates to a method and apparatus for video encoding/decoding by using a geometric modified picture. The encoding method according to the present invention includes: generating a geometric modified picture by geometrically modifying a reference picture; and generating a first prediction block of a current block by performing inter prediction referencing the geometric modified picture.

Abstract: Aspects of the disclosure provide methods and an apparatus for video coding. The apparatus includes processing circuitry that decodes coding information of a current block from a coded video bitstream. The coding information can indicate an inter merge mode for the current block. The processing circuitry can prune, for the current block, a merge candidate list including at least one merge candidate based on motion information and a flag associated with each of the at least one merge candidate. Each of the at least one merge candidate can be of a respective neighboring block of the current block. The flag can indicate whether an alternative half pixel (half-Pel) interpolation filter (IF) is used for the respective neighboring block. The processing circuitry can reconstruct a sample in the current block based on one of the at least one merge candidate.

Abstract: According to the disclosure of the present document, the resources necessary for an LMCS process may be reduced by limiting the range that an LMCS APS occupies in all APSs. Thus, the degree of complexity in LMCS may be reduced, and video/image coding efficiency may be increased.

Abstract: A method of generating an encoded video bitstream using at least one processor, including making a first determination regarding whether a current layer of a current picture is an independent layer; making a second determination regarding whether reference picture resampling is enabled for the current layer; based on the first determination and the second determination, disabling wrap-around compensation for the current layer; and encoding the current layer without the wrap-around compensation.

Abstract: The present invention relates to a method for encoding and decoding image information and to an apparatus using same, and the method for encoding the image information, according to the present invention, comprises the steps of: generating a recovery block; applying a deblocking filter to the recovery block; applying a sample adaptive offset (SAO) to the recovery block to which the deblocking filter is applied; and transmitting the image information including information on the SAO which is applied, wherein in the step of transmitting, information for specifying bands that cover a scope of a pixel value, to which a band off set is applied, is transmitted when the band offset is applied during the step of applying the SAO.

Abstract: Techniques are described of hybrid coders that are configured to selectively use adaptive or non-adaptive coding techniques. A video coder (e.g., video encoder or video decoder) may code (e.g., encode or decode) first video data (e.g., a syntax element or value), for coding a first block, based on an adaptive context model (e.g., one or more adaptive context models) and code second video data, for coding a second block, based on a non-adaptive context model (e.g., one or more non-adaptive context models).

Abstract: Devices, systems and methods related to management of syntax flags with respect chroma formats in video processing are described. In one representative aspect, a video decoding method includes determining, for a conversion between a video and a coded representation of the video, whether a syntax element associated with an adaptive loop filtering (ALF) operation for a chroma component of the video is included in the coded representation based on a condition. The method also includes performing the conversion according to the determining.

Abstract: An inter prediction method is provided, including: obtaining a first reference frame index and a first motion vector of a to-be-processed block (101); deriving a second reference frame index from the first reference frame index, where the second reference frame index is different from the first reference frame index (102); scaling the first motion vector to obtain a second motion vector (103); obtaining a first reference block of the to-be-processed block according to the first reference frame index and the first motion vector (104); obtaining a second reference block of the to-be-processed block according to the second reference frame index and the second motion vector (105); and weighting the first reference block and the second reference block to obtain a combined prediction block (106). Each reference list for inter prediction is allowed to include two groups of motion information, which helps improve an inter prediction effect.

Abstract: A video coder may be configured to code video data by performing adaptive loop filtering processes. A video coder may decode a syntax element that indicates a manner in which to perform an adaptive loop filtering process, the syntax element indicating that a nonlinear operation is to be applied to the video data, where the nonlinear operation is configured to be applied in combination with a filtering operation of the adaptive loop filtering process. In addition, the video coder may perform the adaptive loop filtering process based on the syntax element.

Abstract: The present invention relates to systems and methods suitable for real-time streaming over a decentralized or centralized network. In the decentralized network, the present invention relates to a system and method that utilizes a block-chain distributed network to securely and reliably stream multimedia in real-time. In the centralized network, the present invention utilizes a centralized stream manager to manage nodes within the distributed network to securely and reliably stream multimedia in real-time.

Abstract: A method for visual media processing, including: computing, during a conversion between a current video block of visual media data and a bitstream representation of the current video block, a cross-component linear model (CCLM) and/or a chroma residual scaling (CRS) factor for the current video block based, at least in part, on neighboring samples of a corresponding luma block which covers a top-left sample of a collocated luma block associated with the current video block, wherein one or more characteristics of the current video block are used for identifying the corresponding luma block.

Abstract: An image decoding method according to the present invention can comprise the steps of: deriving merge candidates from neighboring blocks adjacent to a current block; generating a merge candidate list including the merge candidates, wherein the arrangement order of the merge candidates in the merge candidate list is determined on the basis of initial priorities; re-arranging the merge candidates included in the merge candidate list; decoding information for specifying at least one of the merge candidates included in the merge candidate list; and deriving motion information of the current block from a merge candidate corresponding to the information.

Abstract: The present invention provides an image encoding method and an image decoding method. The image decoding method, according to the present invention, comprises the steps of: decoding information associated with a clipping range of a current block; and performing sample adaptive offset (SAO) filtering on the basis of the information associated with the clipping range, wherein the information associated with the clipping range may include information on the maximum and minimum values of a pixel value included in the current block.

Abstract: Methods and systems for generating an interpolated reshaping function for the efficient coding of high-dynamic range images are provided. The interpolated reshaping function is constructed based on a set of pre-computed basis reshaping functions. Interpolation schemes are derived for pre-computed basis reshaping functions represented as look-up tables, multi-segment polynomials, or matrices of coefficients in a multivariate, multi-regression representation. Encoders and decoders using asymmetric reshaping and interpolated reshaping functions for mobile applications are also presented.

Abstract: A method of visual media processing includes performing, based at least in part on a rule for using an extended quadtree (EQT) partitioning process, a conversion between a current block of visual media data and a corresponding coded representation of the visual media data, wherein the EQT partitioning process includes partitioning a given block into exactly four sub-blocks, at least one of which has a size different from half of a width of the given block times half of a height of the given block; and wherein the rule specifies that if the rule is used for partitioning the current block, then each subblock is further split in accordance with a binary tree (BT) partitioning process or a second EQT partitioning process, and further wherein, both the BT process and the second EQT partitioning process have tree depths that meet a pre-defined relationship.

Abstract: A method is provided for decoding an encoded video stream on a processor having a plurality of processing cores includes receiving and examining a video stream to identify any macroscopic constructs present therein that support parallel processing. Decoding of the video stream is divided into a plurality of decoding functions. The plurality of decoding functions is scheduled for decoding the video stream in a dynamic manner based on availability of any macroscopic constructs that have been identified and then based on a number of bytes used to encode each block into which each picture of the video stream is partitioned. Each of the decoding functions is dispatched to the plurality of processing cores in accordance with the scheduling.

Abstract: A loop filtering method based on an adaptive self-guided filtering is mainly an adaptive self-guided filtering technology considering local structure information of an image, wherein a regularization coefficient is adjusted by calculating a weight coefficient of the regularization coefficient to realize the adaptive self-guide filtering, and then a region-level subspace mapping iterative optimization implemented on each region enables a mapping result of the each region to be optimal, wherein the mapping result of a whole image is closer to an original image. Beneficial effects of the loop filtering method are as follows: a filtering effect of a loop filtering is improved, a distortion effect of a reconstruction image is reduced and a reconstruction quality of a video frame is improved, wherein the reconstruction image is more favorable for a subsequent reference and a subjective and objective quality of the video is further improved.

Abstract: The present invention relates to efficient signaling of an intra prediction mode for predicting a current block in intra prediction coding. According to an aspect of the present invention, a video encoding apparatus divides dozens of intra modes into groups, selects a group to which an actual intra mode of the current block to be encoded belongs, and signals a value corresponding to the group. The video decoding apparatus acquires information on the group to which the actual intra mode of the current block belongs from a bit-stream and then evaluates intra modes belonging to the group to select a final intra mode.

Abstract: Embodiments of this application provide a data transmission method and apparatus and a storage medium. The method includes: After obtaining a first identifier and a second identifier that uniquely identify a first device, the first device scrambles, by using the first identifier, checked data obtained through CRC check. After performing channel coding on to-be-transmitted data and scrambled checked data, the first device scrambles, by using the second identifier, coded data obtained through channel coding, and finally sends scrambled data. In this way, after receiving the scrambled data, a second device may perform descrambling by using the second identifier, and then perform CRC check, to determine whether the received data is correct and determine the first identifier of the first device.

Abstract: A method, computer program, and computer system is provided for signaling output layer sets in a coded video stream. Video data having multiple layers is received. One or more syntax elements are identified. The syntax elements specify one or more output layer sets corresponding to output layers from among the multiple layers of the received video data. The one or more output layers corresponding to the specified output layer sets are decoded and displayed.

Abstract: A video image processing method includes dividing a coding unit into one or more sub-block, constructing first and second motion vector candidate lists, and performing prediction for the coding unit according to the first and second motion vector candidate lists. The first motion vector candidate list includes a motion vector of a sub-block of the coding unit, and the second motion vector candidate list includes a motion vector of the coding unit. Constructing the first motion vector candidate list includes determining a reference motion vector of the coding unit, determining a related reference block of the sub-block of the coding unit in a co-located reference image of the coding unit according to the reference motion vector, determining a scaling factor of the motion vector of the related reference block, adding the scaled motion vector into the first motion vector candidate list.

Abstract: Disclosed are a colour component prediction method, an encoder, a decoder, and a storage medium. The method includes: determining adjacent reference pixels of a current block in a picture; constructing a subset of adjacent reference pixels according to the adjacent reference pixels, wherein the subset of adjacent reference pixels contains a part of the adjacent reference pixels; and calculating model parameters of a prediction model according to the subset of adjacent reference pixels, wherein the prediction model includes N prediction sub-models, the N prediction sub-models correspond to N groups of model parameters, and the prediction sub-models are used to perform, through corresponding model parameters, cross-component prediction of colour components to be predicted, and N is a positive integer greater than or equal to 2.

Abstract: Disclosed herein is a method for decoding a video including determining a coding unit to be decoded by block partitioning, decoding prediction syntaxes for the coding unit, the prediction syntaxes including a skip flag indicating whether the coding unit is encoded in a skip mode, after the decoding of the prediction syntaxes, decoding transform syntaxes including a transformation/quantization skip flag and a coding unit cbf, wherein the transformation/quantization skip flag indicates whether inverse transformation, inverse quantization, and at least part of in-loop filterings are skipped, and the coding unit cbf indicates whether all coefficients in a luma block and two chroma blocks constituting the coding unit are zero, and reconstructing the coding unit based on the prediction syntaxes and the transform syntaxes.

Abstract: A video processing apparatus and a processing method of video stream are provided. In the method, at least one encoding unit is formed in an image frame, sub-encoding units in multiple encoding units of an image sequence are encoded according to a correlation between a first sub-encoding unit and a second sub-encoding unit in the sub-encoding units, and a video stream is generated according to an encoded result of the image sequence. The image frame is an image of the image sequence, and each of the encoding units records encoding information of a belonging block.

Abstract: A method for decoding a video according to the present invention may comprise: determining whether to divide a current block with quad tree partitioning, determining whether to divide the current block with binary tree partitioning when the current block is not divided with the quad tree partitioning, determining a binary tree partition type for the current block when it is determined to divide the current block with the binary tree partitioning, and dividing the current block into two partitions according to the determined binary tree partition type.

Abstract: A method of extracting a sub-bitstream from an encoded video bitstream using at least one processor includes: obtaining an encoded video bitstream, the encoded video bitstream including a plurality of Network Abstraction Layer (NAL) units; obtaining an output layer set list; comparing the NAL units with the output layer set list; and removing NAL units that are not included in the output layer set list.

Abstract: Method and apparatus for constrained de-blocking filter are disclosed. According to one method, a current block is partitioned into a plurality of sub-blocks using SDIP (Short Distance Intra Prediction mod). A first Bs (boundary strength) for an internal block boundary of the plurality of sub-blocks is determined by setting the first Bs to a second Bs of an Intra-coded boundary block of the current block. De-blocking process is applied, using the first Bs, to reconstructed samples across the internal block boundary of the plurality of sub-blocks to generate filtered-reconstructed samples. In another method, the current block is partitioned into two sub-blocks using SBT (sub-block transform) horizontally or vertically and the first Bs (boundary strength) is determined for an internal block boundary between the two sub-blocks by setting the first Bs to a second Bs of a non-zero cbf (coded block flag) block of the two sub-blocks in step.

Abstract: A method for decoding a video according to the present invention may comprise: determining whether to divide a current block with quad tree partitioning, determining whether to divide the current block with binary tree partitioning when the current block is not divided with the quad tree partitioning, determining a binary tree partition type for the current block when it is determined to divide the current block with the binary tree partitioning, and dividing the current block into two partitions according to the determined binary tree partition type.

Abstract: A method for decoding a video according to the present invention may comprise: determining whether to divide a current block with quad tree partitioning, determining whether to divide the current block with binary tree partitioning when the current block is not divided with the quad tree partitioning, determining a binary tree partition type for the current block when it is determined to divide the current block with the binary tree partitioning, and dividing the current block into two partitions according to the determined binary tree partition type.

Abstract: The present disclosure aims to provide a method for detecting a GOP boundary of an encoded bit stream of each layer and associating GOPs of the layers for hierarchical transmission in a video transmission device that transmits a hierarchically encoded bit stream. The present disclosure provides a video transmission device and a video transmission method that detect a GOP head access unit in a base layer of a hierarchically encoded bit stream by analyzing the base layer and detect a head access unit of an enhancement layer of an identical GOP to that of the aforementioned access unit from a decoding time stamp of the access unit by using the relationship between a decoding time stamp of the base layer and a decoding time stamp of the enhancement layer.

Abstract: The image decoding method includes determining a context for use in a current block to be processed, from among a plurality of contexts, wherein in the determining: the context is determined under a condition that control parameters of a left block and an upper block are used, when the signal type is a first type; and the context is determined under a third condition that the control parameter of the upper block is not used and a hierarchical depth of a data unit to which the control parameter of the current block belongs is used, when the signal type is a third type, and the third type is one or more of (i) “merge_flag”, (ii) “ref_idx_l0” or “ref_idx_l1”, (iii) “inter_pred_flag”, (iv) “mvd_l0” or “mvd_l1”, (v) “intra_chroma_pred_mode”, (vi) “cbf_luma”, and (vii) “cbf_cb” or “cbf_cr”.

Abstract: A method for video processing is provided to include: performing a conversion between a current video block of a video that is a chroma block and a coded representation of the video, wherein, during the conversion, the current video block is constructed based on a first domain and a second domain, and wherein the conversion further includes applying a forward reshaping process and/or an inverse reshaping process to one or more chroma components of the current video block.