Alibaba Group Holding Limited

Interdigital Vc Holdings, Inc.

Thomson Licensing

Vid Scale, Inc.

Thomson Licensing Dtv

Dolby Laboratories Licensing Corporation

Interdigital Madison Patent Holdings

Alibaba Group Holding Limtted

Dolby Laboratories Licensing Corporaton

Atibaba Group Holding Limited

Dolby International Ab

Jiancong Luo

Yan Ye

Jie Chen

Ru-Ling Liao

Mohammed Golam Sarwer

Peng Yin

Yuwen He

Xiaoyu Xiu

Lihua Zhu

Zhao Wang

Wei Chen

Yu Wen Wu

Yong Ying Gao

Dong Tian

Hua Yang

Jiheng Yang

Zhan Ma

Polin Lai

Wei Yu Chen

Cristina Gomila

Purvin Bibhas Pandit

Joan Llach

Xinwei Li

Po-Lin Lai

Richard Edwin Goedeken

Yin Peng

Yamei Chen

Yuwen Wu

Li Hua Zhu

Linhua Zhu

Systems and methods are described for reducing the complexity of using bi-directional optical flow (BIO) in video coding. In some embodiments, bit-width reduction steps are introduced in the BIO motion refinement process to reduce the maximum bit-width used for BIO calculations. In some embodiments, simplified interpolation filters are used to generate predicted samples in an extended region around a current coding unit. In some embodiments, different interpolation filters are used for vertical versus horizontal interpolation. In some embodiments, BIO is disabled for coding units with small heights and/or for coding units that are predicted using a sub-block level inter prediction technique, such as advanced temporal motion vector prediction (ATMVP) or affine prediction.

Complexity reduction and bit-width control for bi-directional optical flow

A video processing method is provided. The method includes inserting a set of spatial merge candidates to a first merge candidate list of a coding block, wherein the first merge candidate list is constructed by: adding a top neighboring block Bto the first merge candidate list when the top neighboring block Bis available; adding a left neighboring block Ato the first merge candidate list when the left neighboring block Ais available; adding a top neighboring block Bto the first merge candidate list when the top neighboring block Bis available; adding a left neighboring block Ato the first merge candidate list when the left neighboring block Ais available; and adding an above-left neighboring block Bto the first merge candidate list when the above-left neighboring block Bis available.

Methods for constructing a merge candidate list

The present disclosure provides methods and apparatuses for signaling subpicture partitioning information. An exemplary method includes: determining, according to a subpicture information present flag signaled in a bitstream, whether the bitstream comprises subpicture information; and in response to the bitstream comprising the subpicture information, signaling in the bitstream at least one of: a number of subpictures in a picture, a width, a height, a position, and an identifier (ID) mapping of a target subpicture, a subpic_treated_as_pic_flag, and a loop_filter_across_subpic_enabled_flag.

Method and apparatus for signaling subpicture partitioning information

A method for performing motion compensation includes: receiving a first wrap-around motion compensation flag associated with one or more pictures, and a second wrap-around motion compensation flag associated with a sequence of pictures; and determining whether the first wrap-around motion compensation flag is equal to a first value or a second value based on the second wrap-around motion compensation flag or a luma coding tree block size: when the second wrap-around motion compensation flag is equal to the second value, determining the first wrap-around motion compensation flag equal to the second value, or when the luma coding tree block size in unit of minimum coding block plus 1 is greater than a picture width in unit of minimum coding block minus 1, determining the first wrap-around motion compensation flag is equal to the second value.

Methods for performing wrap-around motion compensation

The present disclosure provides methods and systems for motion compensation. The method can include: determining a plurality of intermediate interpolation coefficients of an interpolation filter, the determining of the plurality of intermediate interpolation coefficients being: based on positions of a plurality of integer samples respectively, and based on fractional reference positions of a plurality of fractional samples respectively; determining a plurality of integer interpolation coefficients of the interpolation filter by rounding the plurality of intermediate interpolation coefficients to a plurality of integers respectively; and applying the plurality of integer interpolation coefficients on a picture to perform motion compensation prediction.

Motion compensation methods for video coding

The present disclosure provides systems and methods for signaling a maximum transform size and a residual coding method. According to certain disclosed embodiments, the methods include: receiving a bitstream comprising a set of pictures, determining, according to the received bitstream, a value of a coded tree block size; and determining, based on the value of the coded tree block size, whether to signal a flag indicating a maximum transform size for luma samples.

Signaling of maximum transform size and residual coding method

Methods and apparatuses for video encoding, comprising: receiving a video sequence; encoding the video sequence by using control flags for luma mapping with chroma scaling (LMCS) at a sequence level, a picture level, or a slice level, wherein the sequence level, the picture level, and the slice level are levels ranking from high to low; signaling a first control flag indicating whether the LMCS is enabled at a first level; and in response to the first control flag indicating the LMCS is enabled at the first level, signaling a second control flag indicating whether LMCS is enabled at a second level, wherein: the LMCS is enabled at the second level when a value of the second control flag equals to 1; the LMCS is disabled at the second level when the value of the second control flag equals to 0; and the second level is a lower level than the first level.

High level syntax control of loop filter

The present disclosure provides systems and methods for processing video content. The method can include: partitioning, along a partitioning edge, a plurality of blocks associated with a picture into a first partition and a second partition; performing inter prediction on the plurality of blocks, to generate a first prediction signal for the first partition and a second prediction signal for the second partition; and blending the first and second prediction signals for edge blocks associated with the partitioning edge.

Block partitioning methods for video coding

The present disclosure provides systems and methods for processing video content using motion compensation interpolation. The methods include: encoding or decoding a picture block by applying one or more filters to a reference picture, wherein the applying of the one or more filters generates a sample at a fractional sample position, and wherein the one or more filters comprise an 8-tap filter that has a plurality of coefficients [p0, p1, . . . , p7] for each 1/16 fractional sample position p.

Filters for motion compensation interpolation with reference down-sampling

Methods, devices, apparatus, systems, architectures and interfaces to improve motion vector (MV) refinement based sub-block (SB) level motion compensated prediction are provided. A decoding method includes receiving a bitstream of encoded video data, the bitstream including at least one block of video data including a plurality of SBs; performing a MV derivation, including a decoder based MV (DMVR) process, for at least one SB in the block to generate a refined MV for each SB; performing SB based motion compensation on the at least one sub-block to generate a SB based prediction within each SB; obtaining a spatial gradient for the prediction within each SB; determining a MV offset for each pixel in each SB; obtaining an intensity change in each SB based on the spatial gradients and MV offsets via an optical flow equation; and refining the prediction within each SB based on the obtained intensity changes.

Methods and apparatus for prediction refinement for decoder side motion vector refinement with optical flow

The present disclosure provides systems and methods for transform-skip residual video data coding and decoding. One exemplary method comprises: performing a first pass of scanning a transform coefficient of a sub-block of a video frame, wherein the first pass of scanning comprises: bypass coding a parity level flag for the transform coefficient, the parity level flag indicating a parity of an absolute value of a level of the transform coefficient.

Transform-skip residual coding of video data

The present disclosure provides systems and methods for performing residual coding of video data. According to certain disclosed embodiments, the methods include: receiving control information for coding a video sequence; and determining, based on the control information, a coding method for coding a prediction residual signal of a coding block in the video sequence. The coding method is one of a transform residual coding and a transform-skip residual coding.

Lossless coding of video data

The present disclosure provides methods and apparatuses for processing video content. The method can include: determining whether a picture-header (PH) network-abstraction-layer (NAL) unit is present in a picture unit (PU); in response to the PH NAL unit being present in the PU, determining a first video-coding-layer (VCL) NAL unit of the PU to be a first VCL NAL unit following the PH NAL unit, or in response to the PH NAL unit being not present in the PU, determining that the PU has only one VCL NAL unit and the first VCL NAL unit of the PU is the VCL NAL unit in the PU; and determining whether the first VCL NAL unit of the PU is the first VCL NAL unit of an access unit (AU) containing the PU.

Methods and apparatuses for signaling picture header

The present disclosure provides a computer-implemented method for encoding video. The method includes: determining whether a coded video sequence (CVS) contains equal number of profile, tier and level (PTL) syntax structures and output layer sets (OLSs); and in response to the CVS containing equal number of PTL syntax structures and OLSs, coding the bitstream without signaling a first PTL syntax element specifying an index, to a list of PTL syntax structures in the VPS, of a PTL syntax structure that applies to a corresponding OLS in the VPS.

Growing community of inventors

Skillman, NJ, United States of America

Jiancong Luo