公开(公告)号：US11979593B2

公开(公告)日：2024-05-07

申请号：US17728392

申请日：2022-04-25

Applicant: MEDIATEK INC.

Inventor： Shih-Chun Chiu ,  Tzu-Der Chuang ,  Ching-Yeh Chen ,  Chun-Chia Chen ,  Chih-Wei Hsu ,  Yu-Wen Huang

IPC: H04N7/12 ,  G06T3/02 ,  H04N19/117 ,  H04N19/136 ,  H04N19/139 ,  H04N19/172 ,  H04N19/184 ,  H04N19/463 ,  H04N19/52 ,  H04N19/635 ,  H04N19/82

CPC classification number: H04N19/463 ,  G06T3/02 ,  H04N19/117 ,  H04N19/136 ,  H04N19/139 ,  H04N19/172 ,  H04N19/184 ,  H04N19/52 ,  H04N19/635 ,  H04N19/82

Abstract: Method and apparatus for affine CPMV or ALF refinement are mentioned. According to this method, statistical data associated with the affine CPMV or ALF refinement are collected over a picture area. Updated parameters for the affine CPMV refinement or the ALF refinement are then derived based on the statistical data, where a process to derive the updated parameters includes performing multiplication using a reduced-precision multiplier for the statistical data. The reduced-precision multiplier truncates at least one bit of the mantissa part. In another embodiment, the process to derive the updated parameters includes performing reciprocal for the statistical data using a lookup table with (m−k)-bit input by truncating k bits from the m-bit mantissa part, and contents of the lookup table includes m-bit outputs. m and k are positive integers.

公开(公告)号：US11838557B2

公开(公告)日：2023-12-05

申请号：US17726713

申请日：2022-04-22

Applicant: MEDIATEK INC.

Inventor： Shih-Chun Chiu ,  Chih-Wei Hsu ,  Ching-Yeh Chen ,  Chun-Chia Chen ,  Tzu-Der Chuang ,  Yu-Wen Huang

IPC: H04N19/82 ,  H04N19/117 ,  H04N19/124 ,  H04N19/186 ,  H04N19/147

CPC classification number: H04N19/82 ,  H04N19/117 ,  H04N19/124 ,  H04N19/147 ,  H04N19/186

Abstract: Video encoding methods and apparatuses include receiving reconstructed video samples, determining an initial clipping setting for ALF coefficients, deriving clipping setting candidates from the initial clipping setting. ALF coefficients for the initial clipping setting and the clipping setting candidates are derived by solving inverse matrices, where partial intermediate results of solving ALF coefficients are shared by two or more clipping settings. A distortion value corresponds to the derived ALF coefficients for each clipping setting is computed, and final clipping indices for final ALF coefficients are determined according to the distortion values. ALF filtering is applied to the reconstructed video samples based on the final ALF coefficients and the final clipping indices.