公开(公告)号：US20240114128A1

公开(公告)日：2024-04-04

申请号：US18526481

申请日：2023-12-01

Applicant: Apple Inc.

Inventor： Alexandros TOURAPIS ,  Jungsun KIM ,  Krishnakanth RAPAKA ,  David William SINGER

IPC: H04N19/105 ,  H04N19/172 ,  H04N19/174 ,  H04N19/184 ,  H04N19/513 ,  H04N19/70

CPC classification number: H04N19/105 ,  H04N19/172 ,  H04N19/174 ,  H04N19/184 ,  H04N19/513 ,  H04N19/70

Abstract: Techniques for encoding video with motion compensation include a compressed bitstream syntax that includes a list of all motion prediction reference frames without distinguishing between short-term reference frame and long-term reference frames. The list of reference frames may be provided in a slice header and may apply to encoded data video data within the corresponding slice. The list may be prefaced with a single number indicating the total number of reference frames. In an aspect delta POC reference numbers may be encoded with a flag indicating the sign of the delta POC when the absolute value of the POC is not equal to zero. In another aspect, a flag may be encoded for every reference frame indicating if POC information should be used when scaling prediction references, and a weighting parameter may be included when POC information should be used.

公开(公告)号：US20210400273A1

公开(公告)日：2021-12-23

申请号：US17234596

申请日：2021-04-19

Applicant: Apple Inc.

Inventor： Krishnakanth RAPAKA ,  Jaehong CHON ,  Alexandros TOURAPIS ,  David W. SINGER

IPC: H04N19/124 ,  H04N19/82 ,  H04N19/186 ,  H04N19/172

Abstract: Improved video coding and decoding techniques are described, including techniques to derive quantization step sizes adaptively with quantization step size table templates. Quantization techniques described provide finer-grained control over quantization with a more flexible quantization step size especially at higher degrees of quantization. This may result in improved overall compression quality. Other coding parameters, such as in-loop filtering parameters, may be derived based on the more flexible quantization parameters.