Tencent America LLC

Beijing Dajia Internet Information Technology Co., Ltd.

Han Gao

Shan Liu

Xin Zhao

Liang Zhao

Jing Ye

Guichun Li

Lien-Fei Chen

Yushin Cho

Xiaozhong Xu

Madhu Peringassery Krishnan

Tianqi Liu

Xianglin Wang

Xiaoyu Xiu

Yi-Wen Chen

Bing Yu

Wei Chen

Hong-Jheng Jhu

Che-Wei Kuo

Ning Yan

Biao Wang

Lien-fei Chen

A decoding device is provided for decoding of a bitstream, and more specifically for predicting a picture area of an input image for decoding. The picture area has been divided into at least first and second parts by a partitioning boundary, and the pixels of each part are predicted according to suitable measures. Blending masks are then applied to generate blended regions for the predicted pixels, modifying the pixels to generate a complete prediction of the picture area based on both parts. The blending mask is based on first and second thresholds, which are defined relative to the partitioning boundary, and which may have different values to produce an asymmetrical blending relative to the boundary. Based on suitable threshold values, the prediction, combination, and decoding of the picture area is more adaptive to differing contents of the parts therein.

Method and apparatus for asymmetric blending of predictions of partitioned pictures

The various implementations described herein include methods and systems for coding video. In one aspect, a method includes receiving video data including a picture, wherein the picture is coded using at least a first color component and a second color component, and the picture includes a first block that is coded in a geometric partition mode, the first block including a first geometric partition and a second geometric partition; reconstructing samples in a first geometric partition of the first color component of the first block; deriving samples in the first geometric partition of the second color component of the first block based on the reconstructed samples of the first color component of the first block; and decoding the first block in the picture based at least on the reconstructed samples in the first geometric partition of the first color component and the second color component of the first block.

Systems and methods for cross-component geometric/wedgelet partition derivation

An example method of video coding includes receiving a video bitstream including a plurality of coding blocks; identifying, based on a first indicator in the video bitstream, a coding region that comprises two or more blocks of the plurality of coding blocks, where at least one block in the coding region is encoded in an intra prediction mode and at least one block in the coding region is encoded in a non-intra prediction mode. For a last block in the coding region, when all preceding blocks in the coding region are encoded in the intra prediction mode, the method includes inferring a prediction mode of the last block as being an inter prediction mode without receiving an inter prediction mode indicator for the last block; and reconstructing the last block using the inferred prediction mode.

Systems and methods for implicit derivation in a recursive intra region

Implementations of the disclosure provide video processing apparatuses and methods for inter-prediction. A video processing method for the inter-prediction performed by a video decoder includes determining a reference index for a video block in a video frame of a video from a bitstream. The video processing method also includes generating a joint list including a plurality pairs of reference pictures based on a first reference list and a second reference list for the video block. The video processing method further includes reordering the plurality pairs of reference pictures in the joint list based on bilateral matching using one or more motion vectors of the video block to generate a reordered joint list. The video processing method further includes performing the inter-prediction on the video block based on the reordered joint list and the reference index.

Bilateral matching based reference picture reordering

Various implementations described herein include methods and systems for coding video. In one aspect, a video bitstream includes a high level syntax element for a frame level cross-component sample offset (CCSO) flag indicating whether to apply CCSO filtering on a current image frame. When the frame level CCSO flag indicates that CCSO filtering is applied the current image frame, an electronic device identifies, in the video bitstream, a first syntax element for a first component CCSO flag indicating whether to apply CCSO filtering on a first color component of the current image frame, and determines whether to apply CCSO filtering on a first color sample of the first color component based on the first syntax element. The current image frame including the first color sample of the first color component is reconstructed.

CCSO with high level flags

The various implementations described herein include methods and systems for coding video. In one aspect, a method of video decoding includes receiving video data that includes a first block and a plurality of residual coefficients, from a video bitstream. The first block is encoded in an intra prediction mode, and the plurality of residual coefficients are generated by applying a short distance intra prediction to a residue block for the first block. The residue block generated from applying the intra prediction mode to the first block. The method includes generating, from the plurality of residual coefficients, a refined residue block for the first block, and generating a reconstructed residue block for the first block, where the reconstructed residue block is generated using an intra prediction block and the refined residue block. The method also includes reconstructing the first block using the refined residue block.

Short distance predictions for residual blocks

Coded information of a current block and neighboring blocks of the current block is received, where the current block is predicted in an intra directional mode. The intra directional mode of the current block is determined to be associated with an angle that is one of smaller than 90 degrees and larger than 180 degrees. In response to the intra directional mode of the current block being associated with the angle, whether a delta angle associated with the current block is a pre-defined delta angle is determined. In response to the delta angle associated with the current block not being the pre-defined delta angle, a single direction intra prediction and not a bi-direction intra prediction is applied to the current block. A sample of the current block is reconstructed based on an adjacent reference sample on a reference line that is determined according to the single direction intra prediction.

Angular intra prediction

Various implementations described herein include methods and systems for coding video. In one aspect, a video bitstream includes a current image frame and a first syntax element. An electronic device determines that the first syntax element has a first predefined value indicating that the cross-component sample offset (CCSO) mode is enabled, and generates a set of adapted luma samples including an adapted first luma sample and its adapted neighboring luma samples based on a set of reconstructed luma samples. The reconstructed luma samples include a first luma sample that is collocated with a first color sample. The electronic device determines the first sample offset of the first color sample based on the adapted first luma sample and the one or more adapted neighboring luma samples. The current image frame is reconstructed at least by adjusting the first color sample based on the first sample offset.

CCSO with downsampling filters and sample position selection

Methods and systems for determining contexts for coding and decoding various syntax elements of a video stream in inter prediction modes are described. The methods and systems enable a limitation on numbers of possible coding contexts for syntax elements related to the inter prediction mode, and a selection of coding contexts for a current block based on coding information of spatially neighboring blocks and temporal motion prediction information.

Context design for coding and decoding syntax elements in inter prediction modes

This disclosure describes aspects of advanced video coding technologies and is particular related to cross-component sample offset (CCSO) filtering of reconstructed samples. For example, a quantizer for quantizing sample deltas in order to apply a CCSO filter may be constructed as an asymmetric quantizer with respect to zero sample delta. Either a symmetric or an asymmetric quantizer may be selected for processing sample deltas prior to applying a CCSO filter. An asymmetric quantizer may relate to a corresponding symmetric quantizer by a non-zero offset. Signaling of a selection of an asymmetric quantizer may be provided separately from or dependent on a signaling of a symmetric quantizer.

Cross component sample offset filtering with asymmetric quantizer

The implementations described herein include methods and systems for coding video. In one aspect, a method includes receiving a current frame including a current coding block. The current coding block has multiple subblocks. The subblocks are associated with different motion vectors, and include a first subblock located at a boundary of the current coding block. The method includes determining a motion vector of the current coding block, determining a first motion vector of the first subblock, and generating motion compensation data of the first subblock based on the motion vector and the first motion vector of the first subblock, e.g., by identifying a prediction block based on the motion vector of the current coding block, identifying a first prediction block based on the first motion vector of the first subblock, and combining the prediction block and the first prediction block to generate the motion compensation data of the first subblock.

Systems and methods for combining subblock motion compensation and overlapped block motion compensation

This disclosure relates generally to video coding and particularly to methods and systems for deriving context adaptive interpolation filter used for generating prediction samples in inter prediction involving a fractional motion vector or block vector. For example, an encoder and a decoder may derive interpolation filters adaptively using reconstructed samples. The reconstructed samples may belong to templates near a current block and a reference block related by the motion vector or block vector. The derivation of the adaptive interpolation filters may be based on minimizing distortions between interpolated templates associated with the reference block and the templates associated with the current block.

Context adaptive interpolation filter

This disclosure generally describes a set of advanced video coding technologies, and is specifically related to cross-component sample offset (CCSO) filtering. For example, a CCSO filter having fractional CCSO filtering tap positions may be used to generate sample offsets from one color component of a reconstructed video. The sample offsets may then be applied to a second color component of the reconstructed video. The reconstructed samples of the first color component may first be interpolated by an interpolation filter in order to generate interpolated samples of the first color component at the fractional CCSO tap positions. The interpolated samples may be used as input to the CCSO filter for the generation of the sample offsets.

Cross component sample offset filtering with interpolated filter taps

This disclosure relates generally to video coding/decoding and particularly for a transform dictionary. A method includes receiving the coded video bitstream; determining, based on the coded video bitstream, a transform pile for the current block, the transform pile being one transform pile in a transform dictionary, the transform dictionary comprising a plurality of transform piles, and the transform pile comprising a plurality of transform sets; determining a transform set in the transform pile; determining a transform kernel in the transform set; performing an inverse transform for the current block based on the transform kernel for obtaining a residual block for the current block; and reconstructing the current block based on the residual block.

Dictionary of transforms

This disclosure relates generally to video coding/decoding and particularly for providing extension to block adaptive weighted prediction (BAWP). One method includes receiving a coded video bitstream; determining, based on a syntax element signaled in the coded video bitstream, a prediction mode for predicting the current block based on a reference block, wherein the prediction mode comprises a linear equation; deriving a scaling factor for the current block, from at least one of the following: multiple scaling factors of neighboring blocks with respect to the current block, or a stored scaling factor bank; and reconstructing the current block based on the reference block and the identified scaling factor according to the linear equation.

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San Diego, CA, United States of America

Han Gao