Tencent America LLC

Hfi Innovation Inc.

Mediatek Corporation

Roku, Inc.

Future Wei Technologies, Inc.

Sap Se

Mediatek Singapore Pte. Ltd.

Huawei Technologies Co., Limited

Jing Ye

Shan Liu

Xiaozhong Xu

Liang Zhao

Xiang Yang Li

Tzu-Der Chuang

Xin Zhao

Han Gao

Jungsun Kim

Wang-Lin Lai

Yu-Chen Sun

Ching-Yeh Chen

Guichun Li

Stephan Wenger

Shaw-Min Lei

Fei Xiao

Abhishek Bambha

Ronica Jethwa

Nam Vo

Yu-Wen Huang

Xiang Li

Cheung Auyeung

Byeongdoo Choi

Yu Wang

Wei W Wang

Weijia Zhu

Jicheng An

Zidong Wang

Jose Sanchez

Khaldun Aidarabsah

Jing Lu

Haoping Yu

Meng Xu

Yue Chen

Xiaoyun Zhu

Bin Zhu

Rohit Mahto

Zhan Ma

Yann Le Biannic

Prerna Makanawala

Prajesh K

Lian Liu

Pulkit Aggarwal

Xian Wang

Karthik S J

Daniel Chen

Sid Askary

Yushin Cho

Tianqi Liu

Anirban Das

Jinzhong Zhang

Huichao Zhao

Subhobrata Dey

Georg Glantschnig

Amy He

Xiaoqing He

Arjun Karat

Riya Thosar

Cj Hersh

Shu Zhang

Wei Wang

Kai Zhang

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.

Extension to block adaptive weighted prediction

Processing circuitry receives, from a coded video bitstream, coded information of a current coding block in a current picture. The coded information is indicative of a directional intra prediction of the current coding block. The processing circuitry determines an index to an entry in an angle-to-offset mapping lookup table according to the coded information of current coding block. The angle-to-offset mapping lookup table stores a set of derivative values that are associated with angles, the set of derivative values includes two or more integers that are powers of two. The processing circuitry accesses the entry to obtain a derivative value, determines, for a pixel in the current coding block, an offset indicative of a reference location in the current picture according to the derivative value and a location of the pixel, and reconstructs the pixel in the current coding block based on the reference location in the current picture.

Refined intra prediction angles

This disclosure relates to video processing that includes iteratively predicting a chroma block in a Chroma from Luma (CfL) prediction mode based on downsampled luma samples downsampled from a plurality of downsampling filters, and selecting a target downsampling filter from the plurality of downsampling filters that corresponds to an error score determined for the iteratively predicting.

Selecting downsampling filters for chroma from luma prediction

A set of content items can be accessed by a community of users having a set of interests. A set of interest based clusters for the set of content items correspond to the set of interests. For a user, a recommendation system can determine a group of user interest clusters selected from the set of interest based clusters. A popularity score for each content item of the set of content items with respect to the community of users can be generated, and an interest based popularity score for a content item within the interest based cluster can be generated based on a rank of the content item based on the popularity score of the content item. Recommendation candidates for the user can be generated based on the interest based popularity score of the content item for each content item in the group of user interest clusters.

Interest based recommendation system

This disclosure relates to video processing that includes: determining that a chroma block is to be predicted in a Chroma from Luma (CfL) mode, wherein the chroma block corresponds to a luma block; mapping a plurality of luma samples of the luma block to a plurality of neighbor chroma samples in at least one neighbor chroma block that neighbors the chroma block; and performing a CfL prediction of the chroma block using the plurality of neighbor chroma samples as a plurality of prediction samples of the chroma block. This disclosure also relates to video processing that includes: determining a type of chroma from luma (CfL) prediction process from among a plurality of different types of CfL prediction processes; and performing a CfL prediction process according to the type of CfL prediction process.

Chroma from luma prediction using mapping and different types

The various implementations described herein include methods and systems for decoding video. In one aspect, a method includes receiving a video stream having a sequence of frames. The sequence of frames includes one or more key frames. Each key frame has a respective downsampling filter type. The method includes, in accordance with a determination that a current frame corresponds to a first key frame, retrieving, from the video stream, a syntax element associated with a first downsampling filter type associated with the first key frame. The method includes a luma block of the current frame and a predefined set of frames immediately after the current frame using the first downsampling filter type to obtain downsampled frames. The method includes predicting a chroma block of the current frame based on the downsampled frames.

Systems and methods for signaling of downsampling filters for chroma from luma intra prediction mode

The various implementations described herein include methods and systems for coding video. In one aspect, a method of video decoding includes receiving video data including a first block and a syntax element, from a video bitstream, where the syntax element is signaled at a first processing unit level. The method further includes selecting a transform coding mode based on the syntax element and performing a transform process for the first block using the selected transform coding mode, where the transform process is performed on a transform block at a second processing unit level, and where the second processing unit level is not signaled (e.g., is inferred from coded information).

Flexible transform scheme for residual blocks

This disclosure describes a set of advanced video coding technologies and is particular related to an intra warp prediction of a sample in a video block where the sample is intra predicted using a weighted sum of basis functions of pixel coordinate position of the sample. A set of weighting coefficients for the weighted sum may be predefined or may be derived by an encoder and signaled in a bitstream containing the video block at various coding levels.

Warp mode for intra prediction

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

The various implementations described herein include methods and systems for coding video. In one aspect, a video bitstream includes a current coding block of an image frame and a syntax element for a cross-component intra prediction mode. A first chroma sample is generated by combining a first luma sample co-located with the first chroma sample and its associated neighboring luma samples using a plurality of weighing factors. The method includes extracting at least one of weighing factors from the video bitstream, and deriving the at least another weighing factor. The method further includes combining the first luma sample and the neighboring luma samples based on the at least one weighing factor that is signaled in the video bitstream and the at least another weighing factor that is not signaled in the video bitstream to generate the first chroma sample, which is applied to reconstruct the current coding block.

Cross component intra prediction with multiple parameters

This disclosure relates generally to video coding/decoding and particularly for providing extension to block adaptive weighted prediction (BAWP) with multiple motion vectors. One method includes receiving a coded video bitstream; identifying, from the coded video bitstream, a first motion vector corresponding to a first reference block and a second motion vector corresponding to a second reference block; obtaining a first scaling factor corresponding to the first motion vector and a second scaling factor corresponding to the second motion vector by parsing the coded video bitstream; generating a first predicted block based on the first scaling factor and the first reference block according to a first linear equation; generating a second predicted block based on the second reference block according to a second linear equation; and reconstructing the current block based on the first predicted block and the second predicted block.

A computing system receives a video bitstream that includes a current block and a syntax element indicating that the current block is to be predicted in a blending mode. The current block is encoded using information from first and second reference blocks. When a portion of the current block corresponds to a first area that (i) is within corresponding reference boundaries in both of the first and second reference blocks or (ii) is not within the corresponding reference boundaries in both of the first and second reference blocks, the system reconstructs the portion by averaging reference values from the first and second reference blocks. When the portion of the current block corresponds to a second area that is within the corresponding reference boundaries in only one of the first and second reference blocks, the system derives weighted reference values and reconstructs the portion by combining the weighted reference values.

Implicit masked blending mode

Coded information of a current block and a plurality of reference lines of the current block is received. A first offset value is determined in a first mapping table and associated with a first reference line of the plurality of reference lines that is adjacent to the current block. A second offset value is determined in a second mapping table and associated with a second reference line of the plurality of reference lines that is adjacent to the first reference line. A first reference sample for a sample of the current block is determined from the first reference line based on the first offset value. A second reference sample for the sample of the current block is determined from the second reference line based on the second offset value. The sample of the current block is reconstructed based on one of the first reference sample and the second reference sample.

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San Jose, CA, United States of America

Jing Ye