公开(公告)号：US20250088628A1

公开(公告)日：2025-03-13

申请号：US18961302

申请日：2024-11-26

Applicant: Apple Inc.

Inventor： Alexandros TOURAPIS

IPC: H04N19/117 ,  H04N19/136 ,  H04N19/186 ,  H04N19/44 ,  H04N19/463 ,  H04N19/70 ,  H04N19/82 ,  H04N19/86

Abstract: Offset values, such as Sample Adaptive Offset (SAO) values in video coding standards such as the High Efficiency Video Coding standard (HEVC), may be improved by performing calculations and operations that improve the preciseness of these values without materially affecting the signal overhead needed to transmit the more precise values. Such calculations and operations may include applying a quantization factor to a video sample and at least some of its neighbors, comparing the quantized values, and classifying the video sample as a minimum, maximum, or one of various types of edges based on the comparison. Other sample range, offset mode, and/or offset precision parameters may be calculated and transmitted with metadata to improve the precision of offset values.

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：US20230096567A1

公开(公告)日：2023-03-30

申请号：US17951919

申请日：2022-09-23

Applicant: APPLE INC.

Inventor： Alican NALCI ,  Alexandros TOURAPIS ,  Hsi-Jung WU ,  Jiefu ZHAI ,  Jingteng XUE ,  Jun XIN ,  Mei GUO ,  Xingyu ZHANG ,  Yeqing WU ,  Yunfei ZHENG ,  Jean Begaint

IPC: H04N19/147 ,  H04N19/42 ,  H04N19/172 ,  H04N19/176 ,  H04N19/186 ,  H04N19/119 ,  H04N19/91 ,  H04N19/70 ,  H04N19/124 ,  H04N19/60

Abstract: Improved neural-network-based image and video coding techniques are presented, including hybrid techniques that include both tools of a host codec and neural-network-based tools. In these improved techniques, the host coding tools may include conventional video coding standards such H.266 (VVC). In an aspects, source frames may be partitioned and either host or neural-network-based tools may be selected per partition. Coding parameter decisions for a partition may be constrained based on the partitioning and coding tool selection. Rate control for host and neural network tools may be combined. Multi-stage processing of neural network output may use a checkerboard prediction pattern.

公开(公告)号：US20200177927A1

公开(公告)日：2020-06-04

申请号：US16204792

申请日：2018-11-29

Applicant: Apple Inc.

Inventor： Xiaohua YANG ,  Alexandros TOURAPIS ,  Dazhong ZHANG ,  Hang YUAN ,  Hsi-Jung WU ,  Jae Hoon KIM ,  Jiefu ZHAI ,  Ming CHEN ,  Xiaosong ZHOU

IPC: H04N19/90 ,  H04N21/2343 ,  G06F3/01 ,  H04N19/597 ,  H04N19/52

Abstract: In communication applications, aggregate source image data at a transmitter exceeds the data that is needed to display a rendering of a viewport at a receiver. Improved streaming techniques that include estimating a location of a viewport at a future time. According to such techniques, the viewport may represent a portion of an image from a multi-directional video to be displayed at the future time, and tile(s) of the image may be identified in which the viewport is estimated to be located. In these techniques, the image data of tile(s) in which the viewport is estimated to be located may be requested at a first service tier, and the other tile in which the viewport is not estimated to be located may be requested at a second service tier, lower than the first service tier.

公开(公告)号：US20240040124A1

公开(公告)日：2024-02-01

申请号：US18358094

申请日：2023-07-25

Applicant: Apple Inc.

Inventor： Alican NALCI ,  Yunfei ZHENG ,  Hilmi Enes EGILMEZ ,  Yeqing WU ,  Yixin DU ,  Alexandros TOURAPIS ,  Jun XIN ,  Hsi-Jung WU ,  Arash VOSOUGHI ,  Dzung T. HOANG

IPC: H04N19/13 ,  H04N19/70 ,  H04N19/61 ,  H04N19/176

CPC classification number: H04N19/13 ,  H04N19/70 ,  H04N19/61 ,  H04N19/176

Abstract: A flexible coefficient coding (FCC) approach is presented. In the first aspect, spatial sub-regions are defined over a transform unit (TU) or a prediction unit (PU). These sub-regions organize the coefficient samples residing inside a TU or a PU into variable coefficient groups (VCGs). Each VCG corresponds to a sub-region inside a larger TU or PU. The shape of VCGs or the boundaries between different VCGs may be irregular, determined based on the relative distance of coefficient samples with respect to each other. Alternatively, the VCG regions may be defined according to scan ordering within a TU. Each VCG can encode a 1) different number of symbols for a given syntax element, or a 2) different number of syntax elements within the same TU or PU. Whether to code more symbols or more syntax elements may depend on the type of arithmetic coding engine used in a particular coding specification. For multi-symbol arithmetic coding (MS-AC), a VCG may encode a different number of symbols for a syntax element. For example, to encode absolute coefficient values inside a TU after performing a transform such as the discrete cosine transform (DCT), a VCG region may be defined around lower-frequency transform coefficients and for that VCG M-symbols can be encoded the absolute coefficient values. Another VCG region can be defined around the higher-frequency transform coefficients to encode K-symbols, where K may be different than M. For binary arithmetic coders (BACs), FCC allows for coding a variable number of syntax elements in different VCGs. In this case, one VCG in a TU may code M-syntax elements associated with signaling the absolute coefficient value, where each one of the M-syntax elements may have 2-symbols. Probability models and context derivation rules may be tailored for each VCG in a given TU or PU. Since each VCG may code a different number of symbols or syntax elements in different spatial locations of a TU or PU, different context models may be used for each VCG to provide better granularity for entropy modeling for arithmetic coding. Furthermore, different VCGs may also use different entropy coders including combinations of arithmetic coding, Golomb-Rice coding, Huffman coding.

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：US20210185361A1

公开(公告)日：2021-06-17

申请号：US17188473

申请日：2021-03-01

Applicant: Apple Inc.

Inventor： Xiaohua YANG ,  Alexandros TOURAPIS ,  Dazhong ZHANG ,  Hang YUAN ,  Hsi-Jung WU ,  Jae Hoon KIM ,  Jiefu ZHAI ,  Ming CHEN ,  Xiaosong ZHOU

IPC: H04N19/90 ,  H04N19/52 ,  H04N19/597 ,  G06F3/01 ,  H04N21/2343

Abstract: In communication applications, aggregate source image data at a transmitter exceeds the data that is needed to display a rendering of a viewport at a receiver. Improved streaming techniques that include estimating a location of a viewport at a future time. According to such techniques, the viewport may represent a portion of an image from a multi-directional video to be displayed at the future time, and tile(s) of the image may be identified in which the viewport is estimated to be located. In these techniques, the image data of tile(s) in which the viewport is estimated to be located may be requested at a first service tier, and the other tile in which the viewport is not estimated to be located may be requested at a second service tier, lower than the first service tier.

公开(公告)号：US20210099507A1

公开(公告)日：2021-04-01

申请号：US16825381

申请日：2020-03-20

Applicant: Apple Inc.

Inventor： Fanyi DUANMU ,  Alexandros TOURAPIS ,  Jun XIN ,  Hsi-Jung WU ,  Xiaosong ZHOU

IPC: H04L29/06 ,  H04N13/344 ,  H04N13/161 ,  H04N13/194 ,  H04N13/111

Abstract: Techniques for multi-view video streaming are described in the present disclosure, wherein a viewport prediction may be employed at a client-end based on analysis of pre-fetched media item data and ancillary information. A streaming method may first prefetch a portion of content of a multi-view media item. The method may next identify a salient region from the prefetched content and may then download additional content of the media item that corresponds to the identified salient region.

公开(公告)号：US20210076054A1

公开(公告)日：2021-03-11

申请号：US16561478

申请日：2019-09-05

Applicant: Apple Inc.

Inventor： Mei GUO ,  Jun XIN ,  Yeping SU ,  Hsi-Jung WU ,  Alexandros TOURAPIS

IPC: H04N19/44 ,  H04N19/159 ,  H04N19/46 ,  H04N19/172 ,  H04N19/177

Abstract: Techniques for video exchange are disclosed in which a video source sends redundant copies of video coded at a given presentation time. A decoder may determine, from metadata stored with a first decoded frame, whether other decoded frames have been designated as correlated to the first decoded frame. If so, the decoder may fetch other decoding frames using time indicator values of other decoded frames in metadata stored with the first decoded frame. When other decoded frame(s) are found, the decoder may blend content of the first coded frame and the other decoded frame(s). The decoder may render the blended frame. When one such coded frame is an intra-coded frame, the proposed technique may alleviate beating artifacts by blending recovered data of the intra-coded frame with recovered data of another frame, which may be inter-coded.

公开(公告)号：US20190068992A1

公开(公告)日：2019-02-28

申请号：US16173105

申请日：2018-10-29

Applicant: Apple Inc.

Inventor： Alexandros TOURAPIS ,  David W. SINGER ,  Haitao GUO ,  Hsi-Jung WU ,  Sorin C. CISMAS ,  Xiaohua YANG ,  Yeping SU ,  Dazhong ZHANG

IPC: H04N19/593 ,  H04N19/174 ,  H04N19/156 ,  H04N19/176 ,  H04N19/182 ,  H04N19/117

Abstract: Methods are described for encoding and decoding blocks of image data using intra block copying (IBC). A source block for intra block copying is selected from a source region of a current image that is closer to the current block than a threshold, wherein the source region does not include a portion of the current image that is further from the current block than the threshold.