公开(公告)号：US20230308679A1

公开(公告)日：2023-09-28

申请号：US18323613

申请日：2023-05-25

Applicant: GOOGLE LLC

Inventor： Bohan Li ,  Yaowu Xu ,  Jingning Han

IPC: H04N19/52 ,  H04N19/176 ,  H04N19/577

CPC classification number: H04N19/52 ,  H04N19/176 ,  H04N19/577

Abstract: Video coding using motion prediction coding with coframe motion vectors includes generating a reference coframe spatiotemporally concurrent with a current frame from a sequence of input frames, wherein each frame from the sequence of input frames has a respective sequential location in the sequence of input frames, and wherein the current frame has a current sequential location in the sequence of input frames, generating an encoded frame by encoding the current frame using the reference coframe, including the encoded frame in an encoded bitstream, and outputting the encoded bitstream.

公开(公告)号：US20220264109A1

公开(公告)日：2022-08-18

申请号：US17738105

申请日：2022-05-06

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Bohan Li ,  Jingning Han

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

Abstract: Motion prediction using optical flow is determined to be available for a current frame in response to determining that a reference frame buffer includes, with respect to the current frame, a forward reference frame and a backward reference frame. A flag indicating whether a current block is encoded using optical flow is decoded. Responsive to determining that the flag indicates that the current block is encoded using optical flow, a motion vector is decoded for the current block; a location of an optical flow reference block is identified within an optical flow reference frame based on the motion vector; subsequent to identifying the location of the optical flow reference block, the optical flow reference block is generated using the forward reference frame and the backward reference frame without generating the optical flow reference frame; and the current block is decoded based on the optical flow reference block.

公开(公告)号：US11350102B2

公开(公告)日：2022-05-31

申请号：US16866591

申请日：2020-05-05

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Bohan Li ,  Jingning Han

IPC: H04N19/00 ,  H04N19/139 ,  H04N19/105 ,  H04N19/577 ,  H04N19/573 ,  H04N19/172 ,  H04N19/537

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.

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.