公开(公告)号：US12244818B2

公开(公告)日：2025-03-04

申请号：US18542997

申请日：2023-12-18

Applicant: GOOGLE LLC

Inventor： Yaowu Xu ,  Bohan Li ,  Jingning Han

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

Abstract: A motion vector for a current block of a current frame is decoded from a compressed bitstream. A location of a reference block within an un-generated reference frame is identified. The reference block is generated using a forward reference frame and a backward reference frame without generating the un-generated reference frame. The reference block is generated by identifying an extended reference block by extending the reference block at each boundary of the reference block by a number of pixels related to a filter length of a filter used in sub-pixel interpolation; and generating pixel values of only the extended reference block by performing a projection using the forward reference frame and the backward reference frame without generating the whole of the un-generated reference frame. The current block is then decoded based on the reference block and the motion vector.

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：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.

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：US20240214607A1

公开(公告)日：2024-06-27

申请号：US18594121

申请日：2024-03-04

Applicant: GOOGLE LLC

Inventor： Bohan Li ,  Ching-Han Chiang ,  Jingning Han ,  Yao Yao

IPC: H04N19/597 ,  H04N19/139 ,  H04N19/167 ,  H04N19/176 ,  H04N19/182 ,  H04N19/52 ,  H04N19/57 ,  H04N19/583 ,  H04N19/80

CPC classification number: H04N19/597 ,  H04N19/139 ,  H04N19/167 ,  H04N19/176 ,  H04N19/182 ,  H04N19/52 ,  H04N19/57 ,  H04N19/583 ,  H04N19/80

Abstract: Mapping-aware coding tools for 360 degree videos adapt conventional video coding tools for 360 degree video data using parameters related to a spherical projection of the 360 degree video data. The mapping-aware coding tools perform motion vector mapping techniques, adaptive motion search pattern techniques, adaptive interpolation filter selection techniques, and adaptive block partitioning techniques. Motion vector mapping includes calculating a motion vector for a pixel of a current block by mapping the location of the pixel within a two-dimensional plane (e.g., video frame) onto a sphere and mapping a predicted location of the pixel on the sphere determined based on rotation parameters back onto the plane. Adaptive motion searching, adaptive interpolation filter selection, and adaptive block partitioning operate according to density distortion based on locations along the sphere. These mapping-aware coding tools contemplate changes to video information by the mapping of 360 degree video data into a conventional video format.

公开(公告)号：US20200092576A1

公开(公告)日：2020-03-19

申请号：US16131133

申请日：2018-09-14

Applicant: GOOGLE LLC

Inventor： Bohan Li ,  Yaowu Xu ,  Jingning Han

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

Abstract: Video coding may include generating, by a processor executing instructions stored on a non-transitory computer-readable medium, an encoded frame by encoding a current frame from an input bitstream, by generating a reference coframe spatiotemporally corresponding to the current frame, wherein the current frame is a 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, and encoding the current frame using the reference coframe. Video coding may include including the encoded frame in an output bitstream and outputting the output bitstream.

公开(公告)号：US20250071319A1

公开(公告)日：2025-02-27

申请号：US18811455

申请日：2024-08-21

Applicant: Google LLC

Inventor： Yunqing Wang ,  Jingning Han ,  Bohan Li ,  Yaowu Xu

IPC: H04N19/52 ,  H04N19/105 ,  H04N19/139 ,  H04N19/176 ,  H04N19/182 ,  H04N19/46

Abstract: Techniques are described for motion vector resolution based motion vector prediction for video coding. A motion vector precision level for coding a current block is determined, a motion vector reference list is generated using the motion vector precision level, an index into the motion vector reference list is determined, where the index identifies a motion vector candidate from the motion vector reference list, and a motion vector for inter prediction of the current block is coded using the motion vector candidate. The motion vector precision level can indicate a single resolution for generating the motion vector reference list or a first resolution for generating the motion vector reference list and a second resolution for coding motion vector residuals of the motion vector.

公开(公告)号：US20240422309A1

公开(公告)日：2024-12-19

申请号：US18820598

申请日：2024-08-30

Applicant: GOOGLE LLC

Inventor： Lin Zheng ,  Yaowu Xu ,  Lester Lu ,  Jingning Han ,  Bohan Li

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

Abstract: Methods, systems and apparatuses are disclosed including computer readable medium storing instructions used to encode or decode a video or a bitstream encodable or decodable using disclosed steps. The steps include reconstructing a first reference frame and a second reference frame for a current frame to be encoded or decoded, projecting motion vectors of the first reference frame and the second reference frame onto pixels of a current reference frame resulting in a first pixel in the current reference frame being associated with a plurality of projected motion vectors, and selecting a first projected motion vector from the plurality of projected motion vectors as a selected motion vector associated with the first pixel to be used for determining a pixel value of the first pixel, the selection based on magnitudes of the respective ones of the plurality of projected motion vectors.

公开(公告)号：US20240380924A1

公开(公告)日：2024-11-14

申请号：US18635323

申请日：2024-04-15

Applicant: GOOGLE LLC

Inventor： Bohan Li ,  Debargha Mukherjee ,  Yaowu Xu ,  Jingning Han

IPC: H04N19/60 ,  H04N19/159 ,  H04N19/176 ,  H04N19/70

Abstract: Decoding a current block of a current frame includes decoding, from a compressed bitstream, one or more syntax elements indicating that a geometric transformation is to be applied; applying the geometric transformation to at least a portion of the current frame to obtain a transformed portion; and obtaining a prediction of the current block based on the transformed portion and an intra-prediction mode.