公开(公告)号：US20240040120A1

公开(公告)日：2024-02-01

申请号：US18358111

申请日：2023-07-25

Applicant: Apple Inc.

Inventor： Hilmi Enes EGILMEZ ,  Yunfei ZHENG ,  Alican NALCI ,  Yeqing WU ,  Yixin DU ,  Guoxin JIN ,  Alexandros TOURAPIS ,  Jun XIN ,  Hsi-Jung WU

IPC: H04N19/122 ,  H04N19/61 ,  H04N19/176 ,  H04N19/70 ,  H04N19/159 ,  H04N19/136 ,  H04N19/18 ,  H04N19/186

CPC classification number: H04N19/122 ,  H04N19/61 ,  H04N19/176 ,  H04N19/70 ,  H04N19/159 ,  H04N19/136 ,  H04N19/18 ,  H04N19/186

Abstract: Video coders and decoders perform transform coding and decoding on blocks of video content according to an adaptively selected transform type. The transform types are organized into a hierarchy of transform sets where each transform set includes a respective number of transforms and each higher-level transform set includes the transforms of each lower-level transform set within the hierarchy. The video coders and video decoders may exchange signaling that establishes a transform set context from which a transform set that was selected for coding given block(s) may be identified. The video coders and video decoders may exchange signaling that establishes a transform decoding context from which a transform that was selected from the identified transform set to be used for decoding the transform unit. The block(s) may be coded and decoded by the selected transform.

公开(公告)号：US20240340438A1

公开(公告)日：2024-10-10

申请号：US18593281

申请日：2024-03-01

Applicant: Apple Inc.

Inventor： Yeqing WU ,  Yunfei ZHENG ,  Yixin DU ,  Alican NALCI ,  Hilmi E. EGILMEZ ,  Guoxin JIN ,  Alexandros TOURAPIS ,  Jun XIN ,  Hsi-Jung WU

IPC: H04N19/52 ,  H04N19/105 ,  H04N19/124 ,  H04N19/127 ,  H04N19/154 ,  H04N19/172 ,  H04N19/176

CPC classification number: H04N19/52 ,  H04N19/105 ,  H04N19/124 ,  H04N19/127 ,  H04N19/154 ,  H04N19/172 ,  H04N19/176

Abstract: Techniques are proposed to improve temporal motion projection in video coding. Candidate reference frames available for use in temporal motion projection are sorted in processing order according to scores assigned based on estimates of the reference frames' suitability for prediction. Such estimates may be based on temporal distance between each candidate reference frame and that reference frame's prediction references. Estimates may be based, for each reference frame, based on an estimate of coding quality of a reference frame from which the respective candidate reference frame makes a prediction reference. Once sorted, the candidate reference frames may be processing in the sorting order to supply prediction data to a current frame that is to be coded from the candidate reference frames. Additionally, hardware friendly designs of motion field hole filling and motion vector smoothing operations are proposed. Such designs can reduce hardware implementation complexity and benefit hardware parallel processing in several aspects: by removing the dependency among different processing block rows for hole filling and motion vector smoothing so that it is becomes easier and friendlier to achieve hardware parallel processing; by reducing the hardware bandwidth loading overhead; by improving hardware pipeline throughput; and/or by avoiding adding a line buffer to store the data from the above row since a line buffer will increase hardware cost.

公开(公告)号：US20240129472A1

公开(公告)日：2024-04-18

申请号：US18468900

申请日：2023-09-18

Applicant: Apple Inc.

Inventor： Yeqing WU ,  Yunfei ZHENG ,  Alican NALCI ,  Yixin DU ,  Hilmi Enes EGILMEZ ,  Guoxin JIN ,  Alexandros TOURAPIS ,  Jun XIN ,  Hsi-Jung WU

IPC: H04N19/13 ,  H04N19/129 ,  H04N19/176

CPC classification number: H04N19/13 ,  H04N19/129 ,  H04N19/176

Abstract: Improved lossless entropy coding techniques for coding of image data include selecting a context for entropy coding based on an ordered scan path of possible context locations. A symbol for a current location within a source image may be entropy coded based on a context of prior encoded symbols of other locations within source images, where the context is selected based on an ordered scan path enumerating a series of potential context locations within one or more source images. To select a context, a predetermined number of prior symbols may be selected by qualifying or disqualifying locations in the scan path, and then the current symbol may be encoded with a context based on prior symbols corresponding to the first qualifying context locations in the order of the scan path.

公开(公告)号：US20250080759A1

公开(公告)日：2025-03-06

申请号：US18794601

申请日：2024-08-05

Applicant: APPLE INC.

Inventor： Guoxin JIN ,  Yeqing WU ,  Yunfei ZHENG ,  Dazhong ZHANG ,  Dzung T. HOANG ,  Felix C. FERNANDES ,  Van Luong PHAM ,  Jiancong LUO ,  Yixin DU ,  Hilmi Enes EGILMEZ ,  Alican NALCI ,  Jun XIN ,  Hsi-Jung WU

IPC: H04N19/176 ,  H04N19/117 ,  H04N19/159 ,  H04N19/46 ,  H04N19/70 ,  H04N19/82

Abstract: Techniques are disclosed for coding video in applications where regions of video are inactive on a frame to frame basis. According to the techniques, coding processes update and reconstruct only a subset of pixel blocks of pixels within a frame, while other pixel blocks are retained from a previously coded frame stored in a coder's or decoder's reference frame buffer. The technique is called Backward Reference Updating (or “BRU”) for convenience. At a desired pixel block granularity, based on the activity between a current frame to be coded and its reference frame(s), BRU will only perform prediction, transform, quantization, and reconstruction on selected regions that are determined to be active. The reconstructed pixels in these active regions are directly placed onto a specified reference frame in memory instead of creating a new frame. Therefore, fewer memory transfers need to be performed.

公开(公告)号：US20240073438A1

公开(公告)日：2024-02-29

申请号：US18452194

申请日：2023-08-18

Applicant: Apple Inc.

Inventor： Yeqing WU ,  Yunfei ZHENG ,  Guoxin JIN ,  Yixin DU ,  Alican NALCI ,  Hilmi Enes EGILMEZ ,  Jun XIN ,  Hsi-Jung WU

IPC: H04N19/513 ,  H04N19/176

CPC classification number: H04N19/513 ,  H04N19/176

Abstract: Techniques are disclosed for improved video coding with virtual reference frames. A motion vector for prediction of a pixel block from a reference may be constrained based on the reference. In as aspect, if the reference is a temporally interpolated virtual reference frame with corresponding time close to the time of the current pixel block, the motion vector for prediction may be constrained magnitude and/or precision. In another aspect, a bitstream syntax for encoding the constrained motion vector may also be constrained. In this manner, the techniques proposed herein contribute to improved coding efficiencies.