Beijing Dajia Internet Information Technology Co., Ltd.

Tsung-Chuan Ma

Xianglin Wang

Yi-Wen Chen

Xiaoyu Xiu

Hong-Jheng Jhu

Bing Yu

Wei Chen

Che-Wei Kuo

Shuiming Ye

Yun-fei Zheng

An electronic apparatus performs a method of decoding video data that includes: if the adaptive color transform (ACT) is enabled for the residuals of a coding unit, receiving, from information in a bitstream, the adjustment values applied to the quantization parameters for de-quantization, and the coefficients for the residuals of the coding unit; reconstructing the residuals of the coding unit by applying the de-quantization and inverse transform to the received coefficients for the residuals of the coding unit; and if the residuals of the coding unit have been coded using the ACT, modifying the reconstructed residuals of the coding unit by applying an inverse ACT to convert the reconstructed residuals of the coding unit from the YCgCo color space to the original color space based on one same inverse ACT matrix that is applied to the one coding unit being coded either in a lossy or lossless coding mode.

Methods and apparatus of video coding

An electronic apparatus performs a method of decoding video data, including receiving, from bitstream, a first syntax element in a slice header of a slice that indicates whether luma mapping with chroma scaling (LMCS) is applied to a coding unit in the slice; receiving a second syntax element for the coding unit that indicates whether the coding unit has been coded using adaptive color-space transform (ACT); if the second syntax element has a non-zero value, decoding the coding unit by applying inverse ACT to convert luma and chroma residuals of the coding unit from a transformed color space to an original color space of the video data; and if the first syntax element has a non-zero value, decoding the coding unit by performing inverse luma mapping to the luma samples and inverse scaling to the chroma residuals of the coding unit after performing the inverse ACT.

Methods and apparatus of video coding in 4:4:4 chroma format

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.

Methods and apparatus of residual and coefficient coding

A method for video encoding includes determining whether any coding group of a transform block located within a zero-out region has a non-zero coefficient. The transform block comprises a non-zero region and the zero-out region. Further, in accordance with a determination that no coding group of the transform block located within the zero-out region has a non-zero coefficient, the method includes applying respective inverse transforms to transform coefficients of the transform block in both horizontal and vertical directions.

Methods and apparatus on transform and coefficient signaling

An electronic apparatus performs a method of decoding video data. The method comprises: receiving, from a bitstream, multiple syntax elements at one or more of sequence parameter set (SPS) level, picture parameter set (PPS) level, and slice level, wherein the multiple syntax elements are associated with a predefined function and sequentially arranged in the bitstream; in accordance with a determination that at least one of the multiple syntax elements satisfies a predefined condition: receiving, from the bitstream, a second syntax element after the multiple syntax elements; in accordance with a determination that the at least one of the multiple syntax elements does not satisfy the predefined condition: setting a value of the second syntax element to a default value; and performing the predefined function for video data from the bitstream in accordance with at least one of the multiple syntax elements and the second syntax element, wherein the predefined function is one selected from the group consisting of intra prediction function, inter prediction function, and merge mode.

Methods and apparatus for high-level syntax in video coding

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.

Merge mode with motion vector differences

A method for video coding includes determining whether any coding group of a transform block located within a second region has a non-zero coefficient. The transform block comprises a first region and the second region. Further, in accordance with a determination that no coding group of the transform block located within the second region has a non-zero coefficient, the method includes applying respective inverse transforms to transform coefficients of the transform block in horizontal and vertical directions.

An electronic apparatus performs a method of decoding video data. The method includes: receiving, from the video signal, a picture frame that includes a first component and a second component; determining a classifier for the second component from a set of one or more samples of the first component associated with a respective sample of the second component; determining whether to modify a value of the respective sample of the second component of a current block of the picture frame within a virtual boundary according to the classifier; in response to the determination to modify the value of the respective sample of the second component of the current block according to the classifier, determining a sample offset for the respective sample of the second component according to the classifier; and modifying the value of the respective sample of the second component based on the determined sample offset.

Chroma coding enhancement in cross-component sample adaptive offset with virtual boundary

A method of encoding video data includes obtaining a parameter set associated with a non-skip mode coded block; signaling a first syntax element in a bitstream; signaling a second syntax element in the bitstream; and signaling a third syntax element in the bitstream. The method further includes encoding video data corresponding to the non-skip mode coded block using palette mode when the first syntax element has a first value and the third syntax element has the first value; encoding the video data corresponding to the non-skip mode coded block using intra prediction mode when the first syntax element has the first value and the third syntax element has a second value; encoding the video data corresponding to the non-skip mode coded block using inter prediction mode when the first syntax element has the second value; and transmitting the video data corresponding to the non-skip mode coded block via the bitstream.

Prediction mode signaling in video coding

An electronic apparatus performs a method for video decoding. The method comprises: receiving, from a bitstream, a coding unit and determining a mode type condition of the coding unit; if the coding unit is encoded in a first chroma format, setting the mode type condition of the coding unit to a first mode type condition; if the coding unit is encoded in a second chroma format and the coding unit is a smallest chroma intra prediction unit, setting the mode type condition of the coding unit to a second mode type condition if a luma block of the coding unit and the splitting method satisfy a first criterion; setting the mode type condition of the coding unit to a third mode type condition if the luma block of the coding unit and the splitting method satisfy a second criterion, and decoding the coding unit based on the mode type condition.

Small chroma block size restriction in video coding

This application is directed to coding video data that includes a plurality of image samples of a video frame. Each image sample corresponds to one of a luma sample and a chroma sample. Each image sample is filtered using an adaptive in-loop filter having a filter length and a set of filter coefficients. A set of related image samples are identified in the filter length of each image sample. For each related image sample, a respective clip value index and a corresponding filter coefficient are identified. A difference of each related image sample and the respective image sample is clipped based on the respective clip value index that corresponds to a respective clipping boundary value equal to 2 to a power of a respective clipping number. The respective image sample is modified with the clipped difference of each of the related image samples based on the respective filter coefficient.

In-loop filters for video coding

An electronic apparatus performs a method of encoding and decoding video data. The method comprises: receiving, from a bitstream, the video data corresponding to a coding unit; receiving, from the video data, a first syntax element that defines a Motion Estimation Region (MER); receiving a plurality of second syntax elements from the video data, wherein the plurality of second syntax elements indicate whether the coding unit is in a subblock-based temporal motion vector prediction (SbTMVP) mode; in accordance with a determination that the coding unit is in the SbTMVP mode, determining whether both a spatial neighboring block used to determine a temporal vector of the coding unit and the coding unit are within the same MER; and in accordance with a determination that both the spatial neighboring block and the coding unit are within the same MER, setting the temporal vector of the coding unit to zero.

Motion estimation region for the merge candidates

An electronic apparatus performs a method of decoding video data, comprising: receiving, from bitstream, video data corresponding to a coding unit, wherein the coding unit is encoded in inter prediction mode or intra block copy mode; receiving a first syntax element from the video data, wherein the first syntax element indicates whether the coding unit has any non-zero residuals; in accordance with a determination that the first syntax element has a non-zero value: receiving a second syntax element from the video data, wherein the second syntax element indicates whether the coding unit has been encoded using adaptive color-space transform (ACT); in accordance with a determination that the first syntax element has a zero value: assigning the zero value to the second syntax element; and determining whether or not to perform inverse ACT on the video data of the coding unit in accordance with a value of the second syntax element.

An electronic apparatus performs a method of decoding video data. The method comprises: receiving, from the video signal, a picture frame that includes a first component and a second component; receiving, from the video signal, a first syntax element that indicates whether Cross-component Sample Adaptive Offset (CCSAO) is enabled for the second component at a picture level; when the first syntax element indicates the CCSAO is enabled for the second component at the picture level, receiving, from the video signal, a second syntax element that indicates whether the CCSAO is controlled for the second component at a coding tree block (CTB) level; and when the second syntax element indicates the CCSAO is controlled for the second component at the CTB level, receiving, from the video signal, a third syntax element that indicates whether the CCSAO is enabled for the second component at the CTB level.

Chroma coding enhancement in cross-component sample adaptive offset

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.

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Beijing, China

Tsung-Chuan Ma