Abstract: Methods, apparatus, and computer readable storage medium for processing video data. The method includes extracting a data block from the video data; scanning a first number of data items in the data block following a first scan order to generate a first data sequence; performing a non-separable transform to the first data sequence to obtain a second data sequence having a second number of data items; and replacing at least a portion of the first number of data items in the data block with a portion or all of the second data sequence following a second scan order.

Abstract: This disclosure relates to secondary transform of video blocks with adaptive kernel options. For example, a method for decoding a video block in an video stream is disclosed. The method may include comprising parsing and processing the video stream to generate: a set of secondary transform coefficients associated with the video block; an intra-prediction mode associated with the video block; and a kernel index indicating a secondary transform kernel among a group of secondary transform kernels. The method may further include identifying the group of secondary transform kernels based on the intra-prediction mode; and performing an inverse secondary transform of the set of secondary transform coefficients to generate primary transform coefficients of the video block based on the secondary transform kernel among the group of secondary transform kernels identified by the kernel index.

Abstract: A method of decoding image data is provided. The method may include generating a dequantized block of an image based on a coded bitstream; determining whether to use one from among an implicit method and an explicit method for selecting a hybrid transform kernel from among one or more hybrid transform kernel that are available for decoding the dequantized block, wherein the one or more hybrid transform kernel are available for decoding the dequantized block based on associations between prediction modes and sizes of blocks; selecting, by using the one from among the implicit method and the explicit method, the hybrid transform kernel from among the one or more hybrid transform kernel; and performing inverse transform coding of the dequantized block based on the selected hybrid transform kernel.

Abstract: A method of encoding image data performed by at least one processor, may include: receiving information regarding a data block of an image; performing control so that a residual block composed of residual signals after intra or inter prediction is generated; identifying one or more hybrid transform kernel that are available for encoding the residual block based on associations between prediction modes and sizes of residual blocks; selecting a hybrid transform kernel from among the one or more hybrid transform kernel that are available for encoding the residual block; and performing transform coding of the residual block using the selected hybrid transform kernel.

Abstract: This disclosure relates to cross component methods for refining decoded transform coefficients before or after dequantization in video decoding. For example, a method for video decoding is disclosed. The method may include, comprising extracting a first transform coefficient of a first color component from a bitstream of a coded video; extracting a second transform coefficient of a second color component from the bitstream of the coded video; deriving an offset value based on a magnitude or sign value of the first transform coefficient; adding the offset value to a magnitude of the second transform coefficient to generate a modified second transform coefficient for the second color component; and reconstructing the coded video based on at least the first transform coefficient of the first color component and the modified second transform coefficient of the second color component.

Abstract: Methods, apparatus, and computer readable storage medium for encoding/decoding video data in a decoder. The method includes receiving a first End of Block (EOB) flag associated with a first color component of a data block from the video data; deriving a context for entropy encoding the first EOB flag based on a second EOB flag associated with a second color component of the data block of the video data; and performing entropy decoding of the first EOB flag based on the derived context.

Abstract: Aspects of the disclosure provide a method and an apparatus including processing circuitry for video decoding. The processing circuitry can be configured to determine a transform skip for a transform block (TB) is in one direction. The processing circuitry can be configured to quantize transform coefficients in the TB based on a plurality of quantization steps. First transform coefficients in the TB can be quantized based on a smallest of the plurality of quantization steps. The first transform coefficients in the TB include one of a first row and a first column of the transform coefficients in the TB that has a DC spatial frequency, the one of the first row and the first column being along the one direction of the transform skip. Further, the processing circuitry can be configured to perform a transform on the quantized transform coefficients in the TB.

Abstract: Methods, apparatus, and computer readable storage medium for encoding/decoding video data in a decoder. The method includes receiving a coded bitstream comprising a luma transform skip flag associated with a luma coded block, the luma coded block comprising n transform blocks, n being a positive integer; receiving, via the coded bitstream, at least one chroma transform skip flag associated with at least one chroma coded block co-located with the luma coded block, the at least one chroma coded block comprising m transform blocks, m being a positive integer, wherein co-located refers to two coded blocks in different channels being located in a same spatial position; decoding the n transform blocks of the luma coded block based on the luma transform skip flag; and decoding the m transform blocks of the at least one chroma coded block based on the at least one chroma transform skip flag.

Abstract: Methods, apparatus, and computer readable storage medium for implementation of entropy encoding of sign value of transform coefficient. The method includes receiving a first data block comprising a first transform coefficient from a coded video bitstream for the video data; and performing entropy decoding of a sign value of the first transform coefficient based on a context information, wherein the context information is derived based on a sign value of a second transform coefficient in a second data block in the video data, the second data block being co-located with the first data block, wherein co-located refers to two data blocks in different channels being located in a same spatial position.

Abstract: Aspects of the disclosure provide a method and an apparatus including processing circuitry for video decoding. The processing circuitry can decode coding information of a transform block (TB) from a coded video bitstream. The coding information can indicate a transform skip in one direction for the TB. The processing circuitry can de-quantize transform coefficients in the TB based on a plurality of quantization steps. First transform coefficients in the TB can be de-quantized based on a smallest of the plurality of quantization steps. The first transform coefficients in the TB can include one of a first row and a first column of the transform coefficients in the TB that has a DC spatial frequency. The one of the first row and the first column can be along the one direction of the transform skip. The processing circuitry can perform an inverse transform on the de-quantized transform coefficients in the TB.

Abstract: This disclosure relates to a harmonized design among multiple reference line intra prediction, transform partitioning, and transform kernelsor processing video information. One example method is disclosed. The method includes retrieving a data block of a video frame, the data block having an adjacent reference line and one or more non-adjacent reference lines in the video frame; determining whether one of the one or more non-adjacent reference lines is to be used for intra prediction of the data block. When an adjacent reference line is used for the intra prediction of the data block, selecting a target transform kernel from a first set of transform kernels to transform the data block; and when a non-adjacent reference line is used for the intra prediction of the data block, selecting the target transform kernel from a second set of transform kernels to transform the data block.

Abstract: A method, computer program, and computer system is provided for coding video data. Video data is received. One or more transform cores corresponding to a transform associated with the video data are identified. The one or more transform cores include one or more of a line graph transform (LGT) and a discrete sine transform (DST) The video data is decoded based on the identified transform core. The transform cores correspond to one or more from among an 8-bit transform core and a 10-bit transform core. The transform corresponds to one or more from among a 2-point transform, a 4-point transform, an 8-point transform, and a 16-point transform.

Abstract: Methods, apparatus, and computer readable storage medium for encoding/decoding video data in a decoder. The method includes receiving a coded video bitstream for a data block; extracting, from the coded video bitstream, a transform partition type associated with the data block; and in response to the transform partition type belonging to a subset of a predefined set of transform partition types each specifying a split pattern for dividing the data block into transform blocks: extracting, as signaled in coded video bitstream, a transform type of a transform associated with a transform block split from the data block, wherein the transform type belongs to a first predefined set of transform types; and performing inverse transform on the transform block according to the transform type.

Abstract: This disclosure relates to a transform kernel sharing in video encoding and decoding. For example, a method is disclosed for such transform kernel sharing. The method may include identifying a plurality of transform kernels, wherein each of the plurality of transform kernels comprises a set of basis vectors from low to high frequencies; N high-frequency basis vectors of two or more of the plurality of transform kernels are shared, N being a positive integer; and low-frequency basis vectors of the two or more of the plurality of the transform kernels other than the N high-frequency basis vectors are individualized. The method may further include extracting a data block from a video bitstream; selecting a transform kernel from the plurality of transform kernels based on information associated with the data block; and applying the transform kernel to at least a portion of the data block to generate a transformed block.

Abstract: A method, computer program, and computer system is encoding or decoding video data. Video data may include a syntax element indicating a quantization index, wherein a range of the quantization index is extended by an offset value.

Abstract: A system includes code including first obtaining code to obtain a first syntax element that indicates a first quantization index value for an AC coefficient of an image; second obtaining code to obtain at least one second syntax element that indicates an offset value; third obtaining code to obtain a second quantization index value for another coefficient of the image; fourth obtaining code to obtain a quantization step size that corresponds to the second quantization index value that is obtained; and determining code to determine whether a mode in which the image is to be coded is a lossy mode or a lossless mode based on determining whether the first quantization index value is equal to a quantization index value associated with lossless coding, and based on determining whether the offset value is less than or equal to the quantization index value associated with the lossless coding.

Abstract: A method, computer program, and computer system is provided for coding video data. Video data is received. One or more transform cores corresponding to a transform associated with the video data are identified. The one or more transform cores include one or more of a line graph transform (LGT) and a discrete sine transform (DST) The video data is decoded based on the identified transform core. The transform cores correspond to one or more from among an 8-bit transform core and a 10-bit transform core. The transform corresponds to one or more from among a 2-point transform, a 4-point transform, an 8-point transform, and a 16-point transform.

Abstract: A method, computer program, and computer system is provided for coding video data. Video data is received. One or more transform cores corresponding to a transform associated with the video data are identified. The one or more transform cores include one or more of a line graph transform (LGT) and a discrete cosine transform (DCT) The video data is decoded based on the identified transform core. The transform cores correspond to one or more from among an 8-bit transform core and a 10-bit transform core. The transform corresponds to one or more from among a 2-point transform, a 4-point transform, an 8-point transform, a 16-point transform, a 32-point transform, and a 64-point transform.

Abstract: Video quality analysis may be used in many multimedia transmission and communication applications, such as encoder optimization, stream selection, and/or video reconstruction. An objective VQA metric that accurately reflects the quality of processed video relative to a source unprocessed video may take into account both spatial measures and temporal, motion-based measures when evaluating the processed video. Temporal measures may include differential motion metrics indicating a difference between a frame difference of a plurality of frames of the processed video relative to that of a corresponding plurality of frames of the source video. In addition, neural networks and deep learning techniques can be used to develop additional improved VQA metrics that take into account both spatial and temporal aspects of the processed and unprocessed videos.

Abstract: A system includes code including obtaining code to obtain a first syntax element that indicates a first quantization index value; at least one second syntax element that indicates an offset value, a second quantization index value for another coefficient by combining the first quantization index value and the offset value to obtain a combined value, and modifying the combined value to be a predetermined minimum value as the second quantization index value, fourth obtaining code to obtain a quantization step size that corresponds to the second quantization index value; and determining code to determine a mode in which the coded image is to be decoded based on determining whether the first quantization index value is equal to a quantization index value associated with lossless coding, and based on determining whether the offset value is less than or equal to the quantization index value associated with the lossless coding.