公开(公告)号：US12003754B2

公开(公告)日：2024-06-04

申请号：US17573331

申请日：2022-01-11

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram Sethuraman ,  Jeeva Raj A ,  Sagar Kotecha

IPC: H04N19/513 ,  H04N19/523

CPC classification number: H04N19/513 ,  H04N19/523

Abstract: Given that decoder side motion vector refinement/derivation is a normative aspect of a coding system, the encoder will also have to perform the same error surface technique in order to not have any drift between the encoder's reconstruction and the decoder's reconstruction. Hence, all aspects of all embodiments are applicable to both encoding and decoding systems. In template matching, the refinement movement occurs only in the reference starting from the sub-pixel accurate center that is derived based on the explicitly signaled merge index or implicitly through cost evaluations. In bilateral matching (with or without averaged template), the refinements start in the reference lists L0 and L1 starting from the respective sub-pixel accurate centers that are derived based on the explicitly signaled merge index or implicitly through cost evaluations.

公开(公告)号：US11310521B2

公开(公告)日：2022-04-19

申请号：US17100924

申请日：2020-11-22

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram Sethuraman ,  Jeeva Raj A ,  Sagar Kotecha

IPC: H04N19/513 ,  H04N19/523

Abstract: Given that decoder side motion vector refinement/derivation is a normative aspect of a coding system, the encoder will also have to perform the same error surface technique in order to not have any drift between the encoder's reconstruction and the decoder's reconstruction. Hence, all aspects of all embodiments are applicable to both encoding and decoding systems. In template matching, the refinement movement occurs only in the reference starting from the sub-pixel accurate center that is derived based on the explicitly signaled merge index or implicitly through cost evaluations. In bilateral matching (with or without averaged template), the refinements start in the reference lists L0 and L1 starting from the respective sub-pixel accurate centers that are derived based on the explicitly signaled merge index or implicitly through cost evaluations.

公开(公告)号：US20220116648A1

公开(公告)日：2022-04-14

申请号：US17556594

申请日：2021-12-20

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram SETHURAMAN ,  Sagar KOTECHA ,  Jeeva Raj A ,  Semih ESENLIK

IPC: H04N19/52 ,  H04N19/172 ,  H04N19/577 ,  H04N19/70 ,  H04N19/174 ,  H04N19/176

Abstract: It is provided a method of decoding a video bitstream implemented by a decoding device, the video bitstream including coded data for a plurality of pictures. The decoding method comprises: parsing an enabling flag for decoder motion vector refinement (DMVR) from a sequence parameter set of the video bitstream; parsing a disabling flag for DMVR from a syntax structure of a lower hierarchic syntax structure level than the sequence parameter set (SPS) level of the video bitstream; and performing DMVR based inter bi-prediction for a current block within at least one region of the current picture to obtain predicted sample values of the current block when at least one pre-defined condition is fulfilled, and wherein the at least one pre-defined condition comprises that the parsed value of the disabling flag specifies that DMVR based inter bi-prediction is enabled for at least one region of the current picture.

公开(公告)号：US20220014776A1

公开(公告)日：2022-01-13

申请号：US17467785

申请日：2021-09-07

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram Sethuraman ,  Sagar Kotecha ,  Jeeva Raj A

IPC: H04N19/513 ,  H04N19/176 ,  H04N19/139 ,  H04N19/132 ,  H04N19/107

Abstract: A bidirectional optical flowing prediction method includes obtaining an initial motion vector pair for a current block, obtaining a forward and a backward prediction block according to the forward motion vector and a backward prediction block according to the initial motion vector pair, and calculating gradient parameters for a current sample in the current block. The method further includes obtaining at least two sample optical flow parameters, including a first parameter and a second parameter, for the current sample based on the gradient parameters, obtaining block optical flow parameters based on sample optical flow parameters of samples in the current block, and obtaining a prediction value of the current block. One of the block optical flow parameters is obtained by multiplying the first parameter and a sign function of the second parameter, and the sign function is a piecewise function with at least three subintervals.

公开(公告)号：US20210409754A1

公开(公告)日：2021-12-30

申请号：US17467794

申请日：2021-09-07

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram SETHURAMAN ,  Sagar KOTECHA ,  Jeeva Raj A ,  Semih ESENLIK

IPC: H04N19/52 ,  H04N19/533 ,  H04N19/57 ,  H04N19/176 ,  H04N19/567 ,  H04N19/172 ,  H04N19/105 ,  H04N19/56

Abstract: A method for determining a motion vector to be used in inter-prediction of a current block of a video picture, the method comprising: obtaining an initial motion vector; obtaining at least two groups of points according to the initial motion vector, wherein a first group of the at least two groups of points only includes a first point corresponding to the initial motion vector and additional N points with N≥0 and wherein each point of the first group is closer to the first point than any point of the points of a second group of the at least two groups; and obtaining the motion vector for the current block according to the at least two groups of points and a cost function.

公开(公告)号：US20210368202A1

公开(公告)日：2021-11-25

申请号：US17394598

申请日：2021-08-05

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram Sethuraman ,  Jeeva Raj A

IPC: H04N19/557 ,  G06T3/40 ,  H04N19/573 ,  H04N19/53 ,  H04N19/513

Abstract: Methods and apparatuses of determining an alignment level between motion compensated reference patches for reducing motion vector refinement steps are provided. According to one method, obtaining, by a decoder, motion compensated interpolated samples based on sub-pixel accurate merge motion vectors from a bilinear motion compensated interpolation; computing, by the decoder, a sum of absolute differences (SAD) between two motion compensated reference patches using a subset of the motion compensated interpolated samples; determining, by the decoder, whether the SAD is less than a coding unit (CU) size-dependent threshold value; when the SAD is less than the CU size-dependent threshold value: skipping remaining decoder-side motion vector refinement (DMVR) process steps; and performing final motion compensation; and when the SAD is not less than the CU size-dependent threshold value: performing the remaining DMVR process steps; and performing the final motion compensation.

公开(公告)号：US20210084328A1

公开(公告)日：2021-03-18

申请号：US17103822

申请日：2020-11-24

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram SETHURAMAN ,  Jeeva Raj A

IPC: H04N19/557 ,  H04N19/53 ,  H04N19/513 ,  H04N19/573 ,  G06T3/40

Abstract: Methods and apparatuses of determining an alignment level between motion compensated reference patches for reducing motion vector refinement steps are provided. According to one method, obtaining, by a decoder, motion compensated interpolated samples based on sub-pixel accurate merge motion vectors from a bilinear motion compensated interpolation; computing, by the decoder, a sum of absolute differences (SAD) between two motion compensated reference patches using a subset of the motion compensated interpolated samples; determining, by the decoder, whether the SAD is less than a coding unit (CU) size-dependent threshold value; when the SAD is less than the CU size-dependent threshold value: skipping remaining decoder-side motion vector refinement (DMVR) process steps; and performing final motion compensation; and when the SAD is not less than the CU size-dependent threshold value: performing the remaining DMVR process steps; and performing the final motion compensation.

公开(公告)号：US12212777B2

公开(公告)日：2025-01-28

申请号：US18423846

申请日：2024-01-26

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram Sethuraman ,  Jeeva Raj A ,  Sagar Kotecha

IPC: H04N19/577 ,  H04N19/132 ,  H04N19/172 ,  H04N19/176

Abstract: In some embodiments, a video encoder or a video decoder obtains a pair of motion vectors for a current coding block of a video signal with respect to two reference frames. Predictions of the current block are generated using the pair of motion vectors from respective reference frames. The video encoder or video decoder further determine an optical flow for the current coding block based on samples values in the predictions. One component of the optical flow is determined based on the other component of the optical flow. Bi-predictive optical flow (BPOF) can be performed on the current coding block using the determined optical flow.

公开(公告)号：US12206860B2

公开(公告)日：2025-01-21

申请号：US18592849

申请日：2024-03-01

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Semih Esenlik ,  Sriram Sethuraman ,  Jeeva Raj A ,  Sagar Kotecha

IPC: H04N19/132 ,  H04N19/117 ,  H04N19/159 ,  H04N19/176 ,  H04N19/82

Abstract: It is provided a method of video coding implemented in a decoding device or an encoding device, the method comprising: obtaining initial motion vectors for a current block; obtaining first predictions for a sample value in the current block based on the initial motion vectors; calculating a first matching cost according to the first predictions; determining whether an optical flow refinement process should be performed or not, according to at least one preset condition, the at least one preset condition comprising a condition of whether the calculated first matching cost is equal to or larger than a threshold value; and performing an optical flow refinement process for obtaining a final inter prediction for the sample value in the current block, when it is determined that the optical flow refinement process should be performed.

公开(公告)号：US20240259583A1

公开(公告)日：2024-08-01

申请号：US18613596

申请日：2024-03-22

Applicant: HUAWEI TECHNOLOGIES CO., LTD.

Inventor： Sriram SETHURAMAN ,  Sagar KOTECHA ,  Jeeva Raj A

IPC: H04N19/513 ,  H04N19/107 ,  H04N19/132 ,  H04N19/139 ,  H04N19/176

CPC classification number: H04N19/513 ,  H04N19/107 ,  H04N19/132 ,  H04N19/139 ,  H04N19/176

Abstract: A bidirectional optical flowing prediction method includes obtaining an initial motion vector pair for a current block, obtaining a forward and a backward prediction block according to the forward motion vector and a backward prediction block according to the initial motion vector pair, and calculating gradient parameters for a current sample in the current block. The method further includes obtaining at least two sample optical flow parameters, including a first parameter and a second parameter, for the current sample based on the gradient parameters, obtaining block optical flow parameters based on sample optical flow parameters of samples in the current block, and obtaining a prediction value of the current block. One of the block optical flow parameters is obtained by multiplying the first parameter and a sign function of the second parameter, and the sign function is a piecewise function with at least three subintervals.