公开(公告)号：US20190158843A1

公开(公告)日：2019-05-23

申请号：US15817369

申请日：2017-11-20

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Bohan Li ,  Jingning Han

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

Abstract: An optical flow reference frame portion (e.g., a block or an entire frame) is generated that can be used for inter prediction of blocks of a current frame in a video sequence. A forward reference frame and a backward reference frame are used in an optical flow estimation that produces a respective motion field for pixels of a current frame. The motion fields are used to warp some or all pixels of the reference frames to the pixels of the current frame. The warped reference frame pixels are blended to form the optical flow reference frame portion. The inter prediction may be performed as part of encoding or decoding portions of the current frame.

公开(公告)号：US20190068991A1

公开(公告)日：2019-02-28

申请号：US15683684

申请日：2017-08-22

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Bohan Li ,  Jingning Han

IPC: H04N19/587 ,  H04N19/80 ,  H04N19/176 ,  H04N19/182 ,  H04N19/44

Abstract: An optical flow reference frame is generated that can be used for inter prediction of blocks of a current frame in a video sequence. A first (e.g., forward) reference frame and a second (e.g., backward reference frame) are used in an optical flow estimation that produces a respective motion field for pixels of the current frame. The motion fields are used to warp the reference frames to the current frame. The warped reference frames are blended to forms the optical flow reference frame.

公开(公告)号：US20190020900A1

公开(公告)日：2019-01-17

申请号：US15648500

申请日：2017-07-13

Applicant: GOOGLE LLC

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

IPC: H04N19/70 ,  H04N19/176 ,  H04N19/50 ,  H04N19/44 ,  H04N19/13

Abstract: Video syntax elements are coded using a context tree. Context information used for coding previously-coded syntax elements is identified. A context tree is produced by separating the previously-coded syntax elements into data groups based on the context information. The context tree includes nodes representing the data groups. Separating the previously-coded syntax elements can include applying separation criteria against values of the context information to produce at least some of the nodes. Context information is then identified for another set of syntax elements to be coded. One of the nodes of the context tree is identified based on values of the context information associated with one of the other set of syntax elements. That syntax element is then coded according to a probability model associated with the identified node. The context tree can be used to encode or decode syntax elements.

公开(公告)号：US20250142050A1

公开(公告)日：2025-05-01

申请号：US18927278

申请日：2024-10-25

Applicant: Google LLC

Inventor： Jingning Han ,  Bohan Li ,  Yaowu Xu ,  In Suk Chong

IPC: H04N19/105 ,  H04N19/137 ,  H04N19/159 ,  H04N19/172 ,  H04N19/176 ,  H04N19/80

Abstract: Filtering an interpolated reference frame is described. The interpolated reference frame is generated by determining, from a motion field, a motion vector pointing towards a forward reference frame and a motion vector pointing towards a backward reference frame. Expanded prediction blocks, compared to the size of the block of the interpolated reference frame, are determined using the motion vectors and reference frames. The expanded prediction blocks form overlapping areas with adjacent blocks of the interpolated reference frame. The overlapping areas are filtered to mitigate discontinuities.

公开(公告)号：US20230232001A1

公开(公告)日：2023-07-20

申请号：US18188364

申请日：2023-03-22

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Paul Gordon Wilkins ,  James Bankoski

IPC: H04N19/122 ,  H04N19/13

CPC classification number: H04N19/122 ,  H04N19/13 ,  H04N19/61

Abstract: A system, apparatus, and method for encoding and decoding a video image having a plurality of frames is disclosed. Encoding and decoding the video image can include selecting, for a current block, a prediction mode from a plurality of prediction modes; identifying, for the current block, a quantization value; selecting, for the current block, a probability distribution from a plurality of probability distributions based on the identified quantization value using a processor; and entropy encoding the selected prediction mode using the selected probability distribution.

公开(公告)号：US11647223B2

公开(公告)日：2023-05-09

申请号：US17132065

申请日：2020-12-23

Applicant: GOOGLE LLC

Inventor： Jingning Han ,  James Bankoski ,  Yaowu Xu

IPC: H04N19/00 ,  H04N19/573 ,  H04N19/70 ,  H04N19/567 ,  H04N19/52

CPC classification number: H04N19/573 ,  H04N19/52 ,  H04N19/567 ,  H04N19/70

Abstract: Dynamic motion vector referencing is used to predict motion within video blocks. A motion trajectory is determined for a current frame including a video block to encode or decode based on a reference motion vector used for encoding or decoding one or more reference frames of the current frame. One or more temporal motion vector candidates are then determined for predicting motion within the video block based on the motion trajectory. A motion vector is selected from a motion vector candidate list including the one or more temporal motion vector candidates and used to generate a prediction block. The prediction block is then used to encode or decode the video block. The motion trajectory is based on an order of video frames indicated by frame offset values encoded to a bitstream. The motion vector candidate list may include one or more spatial motion vector candidates.

公开(公告)号：US11405646B2

公开(公告)日：2022-08-02

申请号：US17106898

申请日：2020-11-30

Applicant: GOOGLE LLC

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

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

Abstract: A processor is configured to maintain, for encoding current values related to the transform coefficients a first line buffer and a second line buffer. The current values are arranged along a current scan-order anti-diagonal line. The first line buffer includes first values of a first scan-order anti-diagonal line. The second line buffer includes second values of a second scan-order anti-diagonal line. The processor is further configured to interleave the first values and the second values in a destination buffer; select, using the destination buffer, a probability distribution for coding a current value of the current values; entropy encode, in a compressed bitstream, the current value using the probability distribution; and replace, for coding values of an immediately subsequent scan-order anti-diagonal line to the current scan-order anti-diagonal line, one of the second line buffer or the first line buffer with the current scan-order anti-diagonal line.

公开(公告)号：US11375240B2

公开(公告)日：2022-06-28

申请号：US16221853

申请日：2018-12-17

Applicant: GOOGLE LLC

Inventor： James Bankoski ,  Paul Wilkins ,  Yaowu Xu

IPC: H04N7/12 ,  H04N19/80 ,  H04N19/105 ,  H04N19/139 ,  H04N19/176 ,  H04N19/172 ,  H04N19/61 ,  H04N19/107 ,  H04N19/117 ,  H04N19/127 ,  H04N19/179 ,  H04N19/23 ,  H04N19/527

Abstract: Video coding using a constructed reference frame may include generating, by a processor in response to instructions stored on a non-transitory computer readable medium, an encoded video and outputting an output bitstream. Generating the encoded video includes receiving an input video stream, generating a constructed reference frame, generating an encoded constructed reference frame by encoding the constructed reference frame, including the encoded constructed reference frame in an output bitstream such that the constructed reference frame is a non-showable frame, generating an encoded frame by encoding a current frame from the input video stream using the constructed reference frame as a reference frame, and including the encoded frame in the output bitstream.

公开(公告)号：US20220014744A1

公开(公告)日：2022-01-13

申请号：US17340293

申请日：2021-06-07

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Paul Gordon Wilkins ,  James Bankoski

IPC: H04N19/122 ,  H04N19/13

Abstract: Generating, by a processor in response to instructions stored on a non-transitory computer readable medium, a reconstructed frame, may include generating a reconstructed block of the reconstructed frame by decoding from an encoded bitstream. Decoding may include decoding a value from the encoded bitstream, identifying, in accordance with the value, a probability distribution for generating the reconstructed block, wherein the value indicates the probability distribution among a plurality of probability distributions determined independently of generating the reconstructed frame, entropy decoding an encoded prediction mode from the encoded bitstream using the probability distribution to identify a prediction mode for generating the reconstructed block, generating a prediction block in accordance with the prediction mode; combining the prediction block and a reconstructed residual block to obtain the reconstructed block, and including the reconstructed block in the reconstructed frame.

公开(公告)号：US10750171B2

公开(公告)日：2020-08-18

申请号：US16016768

申请日：2018-06-25

Applicant: GOOGLE LLC

Inventor： Cheng Chen ,  Jingning Han ,  Yaowu Xu

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

Abstract: Systems and methods are disclosed for encoding and decoding video. For example, methods may include: accessing an encoded bitstream; reconstructing an image including multiple color planes based on data from the encoded bitstream; decoding a first filter level from the encoded bitstream, wherein the first filter level specifies one or more thresholds that are used to select a length for a deblocking filter; decoding a second filter level from the encoded bitstream, wherein the second filter level specifies one or more thresholds that are used to select a length for a deblocking filter; after reconstruction of the image, applying a deblocking filter to a first color plane of the image using the first filter level; and, after reconstruction of the image, applying a deblocking filter to a second color plane of the image using the second filter level.