公开(公告)号：US20240276015A1

公开(公告)日：2024-08-15

申请号：US18641482

申请日：2024-04-22

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  James Zern ,  Linfeng Zhang ,  Ching-Han Chiang ,  Yaowu Xu

IPC: H04N19/60 ,  H04N19/129 ,  H04N19/13 ,  H04N19/184 ,  H04N19/88

CPC classification number: H04N19/60 ,  H04N19/129 ,  H04N19/13 ,  H04N19/184 ,  H04N19/88

Abstract: An encoded bitstream is decodable by a processor configured to execute instructions to store, in a first line buffer, first values of a first scan-order diagonal line scanned immediately before a current scan-order diagonal line of a transform block; and store, in a second line buffer, second values of a second scan-order diagonal line scanned immediately before the first scan-order diagonal line. The first values of the first line buffer and the second values of the second line buffer are interleaved in a destination buffer. Using the destination buffer, a probability distribution is selected for coding a current value of the current scan-order diagonal line. The current value is entropy decoded from the bitstream using the probability distribution. One of the second line buffer or the first line buffer is replaced with current values of the current scan-order diagonal line for coding values of an immediately subsequent scan-order diagonal line.

公开(公告)号：US12047606B2

公开(公告)日：2024-07-23

申请号：US17866612

申请日：2022-07-18

Applicant: Google LLC

Inventor： Yaowu Xu ,  Jingning Han ,  Ching-Han Chiang

IPC: H04N11/02 ,  G06N7/01 ,  G06N20/10 ,  H04N19/12 ,  H04N19/137 ,  H04N19/176 ,  H04N19/463 ,  H04N19/60 ,  H04N11/04 ,  H04N19/127 ,  H04N19/157

CPC classification number: H04N19/60 ,  G06N7/01 ,  G06N20/10 ,  H04N19/12 ,  H04N19/137 ,  H04N19/176 ,  H04N19/463 ,  H04N11/044 ,  H04N19/127 ,  H04N19/157

Abstract: Transform kernel candidates including a vertical transform type associated with a vertical motion and a horizontal transform type associated with a horizontal motion can be encoded or decoded. During a decoding operation, a probability model for decoding encoded bitstream video data associated with a transform kernel candidate for an encoded transform block is identified based on one or both of a first transform kernel candidate selected for an above neighbor transform block of the encoded transform block or a second transform kernel candidate selected for a left neighbor transform block of the encoded transform block. The encoded bitstream video data associated with the transform kernel candidate is decoded using the probability model.

公开(公告)号：US20240171733A1

公开(公告)日：2024-05-23

申请号：US18424445

申请日：2024-01-26

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Bohan Li ,  Jingning Han

IPC: H04N19/105 ,  H04N19/139 ,  H04N19/172 ,  H04N19/573

CPC classification number: H04N19/105 ,  H04N19/139 ,  H04N19/172 ,  H04N19/573

Abstract: A motion field estimate determined using motion vector information of two or more reference frames of a current/encoded frame is used to derive a motion vector for inter-prediction of the current/encoded frame. Motion trajectory information, including concatenated motion vectors and locations of the current/encoded frame at which those concatenated motion vectors point, is determined by concatenating motion vectors of the reference frames. A motion field estimate is determined using the motion trajectory information and, in some cases, by interpolating unavailable motion vectors using neighbors. The motion field estimate is used to determine a co-located reference frame for the current/encoded frame, and an inter-prediction process is performed for the current/encoded frame using a motion vector derived using the co-located reference frame. During decoding, the motion field estimate may be determined using motion vectors signaled within a bitstream and without additional side information, thereby improving prediction coding efficiency.

公开(公告)号：US20240155121A1

公开(公告)日：2024-05-09

申请号：US18406816

申请日：2024-01-08

Applicant: Google LLC

Inventor： Yaowu Xu ,  Jingning Han ,  Cheng Chen

IPC: H04N19/117 ,  H04N19/176 ,  H04N19/186 ,  H04N19/46

CPC classification number: H04N19/117 ,  H04N19/176 ,  H04N19/186 ,  H04N19/46

Abstract: A bitstream that stores encoded image data is described. In addition to the compressed data for color planes of the image, signals identifying respective deblocking filters is identified for the different color planes of the image. The deblocking filters may include those having different lengths for a luma plane as compared to one or more chroma planes of the image. One or more of the color planes, such as the luma plane, may have different filters for filtering reconstructed pixels vertically as compared to filtering the reconstructed pixels horizontally.

公开(公告)号：US20220377364A1

公开(公告)日：2022-11-24

申请号：US17868011

申请日：2022-07-19

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Yaowu Xu ,  James Bankoski ,  Jia Feng

IPC: H04N19/51 ,  H04N19/196 ,  H04N19/182 ,  H04N19/176 ,  H04N19/513 ,  H04N19/433 ,  H04N19/55

Abstract: Decoding a current block of a current frame includes obtaining motion trajectories between the current frame and at least one previously coded frame by projecting motion vectors from the at least one previously coded frame onto the current frame. A motion field is obtained between the current frame and a reference frame used for coding the current frame. The motion field is obtained by extending the motion trajectories from the current frame towards the reference frame. A motion vector for the current block is identified based on the motion field. A prediction block is obtained for the current block using a reference block of the reference frame identified using the motion vector.

公开(公告)号：US11405631B2

公开(公告)日：2022-08-02

申请号：US16983342

申请日：2020-08-03

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Yaowu Xu ,  James Bankoski ,  Jia Feng

IPC: H04N19/00 ,  H04N19/51 ,  H04N19/196 ,  H04N19/182 ,  H04N19/176 ,  H04N19/513 ,  H04N19/433 ,  H04N19/55

Abstract: Decoding a current frame includes identifying a first reference frame and a second reference frame for decoding the current frame; storing reference motion vectors of reference blocks of the first reference frame, where other reference frames are used to decode the first reference frame; identifying motion trajectories that pass through the current frame by projecting the reference motion vectors of the reference blocks of the first reference frame onto the current frame using at least a third reference frame of the other reference frames, where the projecting identifies, for a first current block of the current frame a corresponding first reference block in the first reference frame, and a corresponding reference motion vector of the reference motion vectors is associated with the corresponding first reference block; and projecting the corresponding reference motion vector onto the second reference frame to obtain a second reference block in the second reference frame.

公开(公告)号：US11218737B2

公开(公告)日：2022-01-04

申请号：US16042261

申请日：2018-07-23

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  Aki Kuusela ,  Stanislav Vitvitskyy ,  Yaowu Xu ,  Ching-Han Chiang ,  Dake He

IPC: H04N19/91 ,  H04N19/44 ,  H04N19/61 ,  H04N19/70

Abstract: Asymmetric probability model updating and entropy coding includes using different numbers of bits for storing probabilities of a probability model and for entropy coding symbols using that probability model. The probabilities of a probability model are updated according to values of syntax elements decoded from a bitstream. The probabilities are associated with possible values of the syntax elements and are stored using a first bit precision. Based on the updated probabilities, a second bit precision to use to entropy decode the syntax elements is determined. The second bit precision is less than the first bit precision. The syntax elements are then entropy decoded using the second bit precision, such as to produce quantized transform coefficients, which may be further processed and output to an output video stream. Using the first bit precision to entropy decode the syntax elements results in a lower compression throughput than using the second bit precision.

公开(公告)号：US11102477B2

公开(公告)日：2021-08-24

申请号：US16838544

申请日：2020-04-02

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Jingning Han ,  Ching-Han Chiang

IPC: H04N19/105 ,  H04N19/13 ,  H04N19/167 ,  H04N19/18 ,  H04N19/91

Abstract: A sign value of a DC coefficient of a current block is determined using neighbor blocks of the current block. First and second sign values are identified as respectively corresponding to an above neighbor block of the current block and a left neighbor block of the current block. A context value is calculated by applying a first weighting value to the first sign value and a second weighting value to the second sign value. The first weighting value is based on a boundary between the above neighbor block and the current block, and the second weighting value is based on a boundary between the left neighbor block and the current block. A probability value is selected based on the context value. The sign value of the DC coefficient of the current block is then determined using the probability model.

公开(公告)号：US20210144364A1

公开(公告)日：2021-05-13

申请号：US17090094

申请日：2020-11-05

Applicant: GOOGLE LLC

Inventor： Bohan Li ,  Yaowu Xu ,  Jingning Han

IPC: H04N19/105 ,  H04N19/139 ,  H04N19/573 ,  H04N19/172

Abstract: A motion field estimate determined using motion vector information of two or more reference frames of a current/encoded frame is used to derive a motion vector for inter-prediction of the current/encoded frame. Motion trajectory information, including concatenated motion vectors and locations of the current/encoded frame at which those concatenated motion vectors point, is determined by concatenating motion vectors of the reference frames. A motion field estimate is determined using the motion trajectory information and, in some cases, by interpolating unavailable motion vectors using neighbors. The motion field estimate is used to determine a co-located reference frame for the current/encoded frame, and an inter-prediction process is performed for the current/encoded frame using a motion vector derived using the co-located reference frame. During decoding, the motion field estimate may be determined using motion vectors signaled within a bitstream and without additional side information, thereby improving prediction coding efficiency.

公开(公告)号：US20200267391A1

公开(公告)日：2020-08-20

申请号：US16866591

申请日：2020-05-05

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Bohan Li ,  Jingning Han

IPC: H04N19/139 ,  H04N19/537 ,  H04N19/172 ,  H04N19/573 ,  H04N19/577 ,  H04N19/105

Abstract: Decoding a current block of a current frame includes selecting a first reference frame for forward inter prediction of the current frame; selecting a second reference frame for backward inter prediction of the current frame; generating an optical flow reference frame portion for inter prediction of the current block by performing an optical flow estimation using the first reference frame and the second reference frame, where the optical flow estimation produces a respective motion field for pixels of the current block; and performing a prediction process for the current block using the optical flow reference frame portion by: using a motion vector used to encode the current block to identify a reference block; adjusting boundaries of the reference block using a subpixel interpolation filter length; and identifying blocks encompassing pixels within the adjusted boundaries of the reference block.