Beijing Dajia Internet Information Technology Co., Ltd.

Xianglin Wang

Yi-Wen Chen

Hong-Jheng Jhu

Xiaoyu Xiu

Tsung-Chuan Ma

Bing Yu

Wei Chen

Che-Wei Kuo

Shuiming Ye

Yun-fei Zheng

Ning Yan

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 includes: receiving, from the video signal, a picture frame that includes a first component and a second component; reconstructing samples of the first component through a first in-loop filter; reconstructing samples of the second component through a second in-loop filter; determining a classifier for the first component from one or more reconstructed samples of the second component relative to a respective reconstructed sample of the first component; selecting a first sample offset for the respective reconstructed sample of the first component according to the classifier; applying a plurality of filters in parallel with the selection of the first sample offset to obtain a plurality of parallel offsets; and clipping an output of a combination of the respective reconstructed sample of the first component, the first sample offset, and the plurality of parallel offsets from the plurality of filters.

Coding enhancement in cross-component sample adaptive offset

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 computing device performs a method of decoding video data by receiving bitstream encoding a chroma block, a corresponding luma block, neighboring luma samples, and neighboring chroma samples; decoding the luma block, the plurality of neighboring luma samples, and the plurality of neighboring chroma samples; selecting a group of reference luma samples and a group of reference chroma samples; computing a threshold luma value from the plurality of reconstructed neighboring luma samples, and a threshold chroma value from the plurality of reconstructed neighboring chroma samples; determining a maximum luma value and a minimum luma value from the group of the reference luma samples; generating multi-model linear model (MMLM) including a first linear model between the minimum luma value and the threshold luma value, and a second linear model between the threshold luma value and the maximum luma value; and reconstructing the chroma block from the luma block using MMLM.

Video coding using multi-model linear model

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 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 within a region of the picture frame according to the classifier; in response to the determination to modify the value of the respective sample of the second component within the region 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.

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 decoding video data. The method comprises: receiving, from the video signal, a picture frame that includes a first component, and a second component; determining a classifier for the first component based on a first set of one or more samples of the second component associated with a respective sample of the first component; determining a sample offset for the respective sample of the first component according to the classifier; and modifying a value of the respective sample of the first component based on the determined sample offset, wherein the first component and the second component are chroma components. The picture frame further includes a third component, and the classifier for the first component is additionally based on a second set of one or more samples of the third component associated with the respective sample of the first component.

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Beijing, China

Xianglin Wang