Tencent America LLC

Sharp Kabushiki Kaisha Corporation

Fg Innovation Company Limited

Other

Byeongdoo Choi

Shan Liu

Stephan Wenger

Xiaozhong Xu

Xiang Yang Li

Sehoon Yea

Arash Vosoughi

Iraj Sodagar

Xiang Li

Wei Jiang

Xin Zhao

Wei W Wang

Shuai Zhao

Zeqiang Li

Sachin G Deshpande

Christopher A Segall

Yixin Du

Frank Bossen

Guichun Li

Ling Li

Kiran Mukesh Misra

Jie Zhao

Wei Wang

Weijia Zhu

Philip Cowan

Weiwei Feng

Liang Zhao

Jing Ye

Rohit Abhishek

An approach for reconstructing a current Network Abstraction Layer (NAL) unit for video decoding using at least one processor includes determining the current NAL unit to be an Intra Random Access Picture (IRAP) NAL unit; determining whether a previous NAL unit decoded immediately before the current NAL unit indicates an end of a coded video sequence (CVS); based on determining that the previous NAL unit indicates the end of the CVS, decoding the current NAL unit as one from among an Instantaneous Decoder Refresh (IDR) NAL unit or a Broken Link Access (BLA) NAL unit; and based on determining that the previous NAL unit does not indicate the end of the CVS, decoding the current NAL unit as a Clean Random Access (CRA) NAL unit, and reconstructing the decoded current NAL unit.

Identification of random access point and picture types

A method, computer program, and computer system is provided for aligning across layers in a coded video stream. A video bitstream having multiple layers is decoded. One or more subpicture regions are identified from among the multiple layers of the decoded video bitstream, the subpicture regions including a background region and one or more foreground subpicture regions. An enhanced subpicture is decoded and displayed based on a determination that a foreground subpicture region is selected. The background region is decoded and displayed based on a determination that a foreground subpicture region was not selected.

Method for alignment across layers in coded video stream

A method, computer program, and computer system is provided for video coding. The method may include decoding coded syntax elements corresponding to a wrap-around padding process based on shifting a reference block by a width value that is determined based on luma samples in the reference block; and reconstructing at least one coded current picture using the wrap-around padding process, wherein the wrap-around padding process is applied at boundaries of subpictures.

Method for padding processing with sub-region partitions in video stream

A method of video encoding includes determining whether a plurality of constraint flags of a constraint information group are to be signaled for a subset of coding blocks, and signaling a gate flag indicating whether the plurality of constraint flags of the constraint information group are signaled. The gate flag is signaled in constraint information in a syntax structure of a coded video bitstream. In accordance with the signaled gate flag indicating that the plurality of constraint flags of the constraint information group are signaled, the method further includes signaling the plurality of constraint flags of the constraint information group in the constraint information in the syntax structure of the coded video bitstream. In accordance with the plurality of constraint flags being signaled in the constraint information, the method further includes encoding the subset of coding blocks based on the plurality of constraint flags.

Constraint flags in general constraints information

Aspects of the disclosure provide methods and apparatuses for video data processing. In some examples, an apparatus for video data processing includes processing circuitry. For example, the processing circuitry determines a first syntax element for coding control in a first scope of coded video data in a bitstream. The first syntax element is associated with a coding tool of a slice based Rice coding for a residual coding in a transform skip mode. The coding tool provides a Rice parameter at a slice level for the residual coding in the transform skip mode. In response to the first syntax element being a first value indicative of disabling of the coding tool in the first scope, the processing circuitry decodes the first scope of coded video data that includes one or more second scopes of coded video data without invoking the coding tool.

General constraints information for transform skip

A method of decoding an encoded video bitstream using at least one processor includes obtaining a coded video sequence including a plurality of output layer sets from the encoded video bitstream; obtaining a first flag indicating whether each output layer set of the plurality of output layer sets includes more than one layer; based on the first flag indicating that the each output layer set includes more than the one layer, obtaining a first syntax element indicating an output layer set mode; selecting at least one layer from among layers included in the plurality of output layer sets as at least one output layer based on at least one of the first flag and the first syntax element; and outputting the at least one output layer.

Signaling of output layer set for scalable video stream

A method of generating a coded video bitstream including setting a flag pps_ref_wraparound_enabled_flag, wherein the flag pps_ref_wraparound_enabled_flag being equal to 1 specifies that a horizontal wrap-around motion compensation is enabled for pictures referring to a picture parameter set (PPS) in a coded video stream; determining whether the reference picture is to be scaled based on whether reference picture resampling is enabled; in response to the reference picture being not scaled, setting a second flag refWraparoundEnabledFlag to be equal to a value of the flag pps_ref_wraparound_enabled_flag; and encoding the coded video bitstream comprising at least the current picture and the flag pps_ref_wraparound_enabled_flag.

Method for wrap around motion compensation with reference picture resampling

A method and system for decoding a coded video sequence may include obtaining the coded video sequence, and decoding the coded video sequence. A a value of a temporal sublayer identifier of a video coding layer (VCL) network abstraction layer (NAL) unit in the coded video sequence is constrained to be less than or equal to a value of vps_max_sublayers_minus1, that specifies a maximum number of temporal sublayers that may be present in a layer in each coded video sequence referring to the video parameter set (VPS), in the VPS referred to by the VCL NAL unit.

Derivation on sublayer-wise output layer set

Aspects of the disclosure provide methods and apparatuses for video data processing. In some examples, an apparatus for video data processing includes processing circuitry. For example, the processing circuitry determines a first syntax element for coding control in a first scope of coded video data in a bitstream. The first syntax element is associated with a coding tool for coding a position of a last significant coefficient during an entropy coding of transform coefficients. Then, in response to the first syntax element being a first value indicative of disabling of the coding tool in the first scope, the processing circuitry decodes the first scope of coded video data in the bitstream that includes one or more second scopes of coded video data without invoking the coding tool.

Techniques for constraint flag signaling for range extension with coding for last significant coefficient

Systems and methods for decoding a coded video stream are provided. A method includes receiving a coded video stream that includes an access unit, including a picture; signaling a first flag that indicates whether the access unit includes either or neither one from among an intra random access point (IRAP) picture and a gradual decoding refresh (GDR) picture; signaling a second flag that indicates whether the picture is the IRAP picture; and decoding the picture, as a current picture, based on the signaling of the first flag and the second flag, wherein a value of the first flag and a value of the second flag are aligned.

Techniques for random access point indication and picture output in coded video stream

A method of decoding an encoded video bitstream using at least one processor, including obtaining a first flag indicating whether a constant picture size is used in a coded video sequence including a current picture; based on the first flag indicating that the constant picture size is used, decoding the current picture without performing reference picture resampling; based on the first flag indicating that the constant picture size is not used, obtaining a second flag indicating whether a conformance window size is signaled; based on the second flag indicating that the conformance window size is signaled: obtaining the conformance window size, determining a resampling ratio between the current picture and a reference picture based on the conformance window size, and performing the reference picture resampling on the current picture using the resampling ratio.

Signaling of reference picture resampling with constant window size in video bitstream

There is included a method and apparatus comprising computer code configured to cause a processor or processors to perform acquiring an input bitstream comprising metadata and video data, decoding the video data, determining whether the metadata comprises at least one flag signaling at least one component of a picture size of at least one picture of the video data, and signaling, in a case where it is determined that the metadata comprises the at least one flag, a display device to display the at least one picture from the video data according to the at least one flag.

Signaling output picture size for reference picture resampling

A method, computer program, and computer system is provided for decoding a video sequence. Video information corresponding to one or subpictures within a picture is received and the video information includes at least one output layer set corresponding to one or more output layers and a plurality of flags. A first subpicture is identified from among the subpictures as a region of interest based on the output layer set. The first subpicture corresponding to the region of interest is decoded in a high quality mode from an enhancement layer of the picture and remaining subpictures are decoded in a low quality mode from a base layer of the picture.

Method for signaling output subpicture layer set

A method of generating an encoded video bitstream, including obtaining an IRAP AU from a video bitstream; determining whether the IRAP AU is a first AU in a decoding order, whether each picture is an IDR picture, or whether each picture is a first picture of a layer following an EOS NAL unit; if so, setting a first flag for the IRAP AU equal to one; if not, determining whether a second flag for the IRAP AU is externally set to an external value; if so, setting the first flag for the IRAP AU equal to the external value; and if not, setting the first flag for the IRAP AU and the second flag for the IRAP AU equal to zero; encoding the video bitstream based on the first flag and the second flag; and transmitting the encoded video bitstream.

Method for layerwise random access in a coded video stream

A method is provided that includes obtaining a coded bitstream that includes an access unit (AU); and decoding at least one picture of the coded bitstream based on the AU. The AU includes at least one picture unit (PU) that includes: a picture header network abstraction layer (NAL) unit; and at least one video coding layer (VCL) NAL unit that is after the picture header NAL unit within the AU.

Growing community of inventors

Palo Alto, CA, United States of America

Byeongdoo Choi