US-12621476-B2 - Coding enhancement in cross-component sample adaptive offset

US12621476B2US 12621476 B2US12621476 B2US 12621476B2US-12621476-B2

Abstract

An electronic apparatus performs a method of decoding video data, including: receiving, a plurality of frames, each including a first component and a second component; determining, for a first frame, one or more classifiers for the second component respectively from one or more samples of the first component associated with a respective sample of the second component; and when a received syntax element indicates that differential pulse-code modulation (DPCM) is enabled for signalling a first group of differential sample offsets for the second component of a second frame according to the one or more classifiers: determining a second group of sample offsets for the second component of the second frame by adding the first group of differential sample offsets of the second frame to a first group of sample offsets for the second component of the first frame according to the one or more classifiers.

Inventors

Che-Wei KUO
Xiaoyu Xiu
Wei Chen
Xianglin Wang
Yi-Wen Chen
HONG-JHENG JHU
Ning Yan
Bing Yu

Assignees

Beijing Dajia Internet Information Technology Co., Ltd.

Dates

Publication Date: 20260505
Application Date: 20240126

Claims (14)

1 . A method of decoding video bitstream, comprising: receiving, from the video bitstream, a plurality of frames, each frame including a first component and a second component; determining, for a first frame of the plurality of frames, one or more classifiers for the second component respectively from one or more samples of the first component associated with a respective sample of the second component; receiving, from the video bitstream, a first group of sample offsets for the second component of the first frame according to the one or more classifiers; determining whether differential pulse-code modulation (DPCM) is enabled for signalling a first group of differential sample offsets for the second component of a second frame of the plurality of frames according to the one or more classifiers, wherein the first group of differential sample offsets represent the differences between the first group of sample offsets in the first frame and a second group of sample offsets for the second component of the second frame; in response to determining the DPCM being enabled: receiving, from the video bitstream, the first group of differential sample offsets for the second component of the second frame according to the one or more classifiers; and modifying a set of one or more samples of the second component of the second frame based on the first group of differential sample offsets of the second frame and the first group of sample offsets of the first frame, wherein the first component is a luma component and the second component is a chroma component, or the first component is a chroma component and the second component is a luma component, or the first component is a first chroma component and the second component is a second chroma component.
2 . The method of claim 1 , wherein the determining whether the DPCM is enabled comprises: receiving, from the video bitstream, a syntax element, wherein the syntax element indicates whether the DPCM is enabled.
3 . The method of claim 1 , wherein the modifying the set of one or more samples of the second component of the second frame based on the first group of differential sample offsets of the second frame and the first group of sample offsets of the first frame comprises: determining the second group of sample offsets by adding the first group of differential sample offsets of the second frame to the first group of sample offsets of the first frame; and modifying the set of one or more samples of the second component of the second frame based on the second group of sample offsets.
4 . The method of claim 3 , further comprising in response to determining the DPCM being enabled, modifying a set of one or more samples of the second component of the first frame based on the first group of sample offsets.
5 . The method of claim 1 , wherein the first group of sample offsets for the second component according to the one or more classifiers is stored in adaptation parameter set (APS).
6 . The method of claim 1 , wherein the first group of differential sample offsets is received from signalling in fixed length code (FLC), truncated unary (TU) code, or exponential-golomb code with order k (EGk).
7 . The method of claim 3 , wherein the first group of differential sample offsets for the second component of the second frame is in a quantized format and is dequantized before adding the first group of differential sample offsets to the first group of sample offsets.
8 . The method of claim 4 , wherein the first group of sample offsets for the second component of the first frame is in a quantized format and is dequantized before modifying the set of one or more samples of the second component of the first frame based on the first group of sample offsets.
9 . The method of claim 1 , wherein the receiving the first group of differential sample offsets for the second component of the second frame according to the one or more classifiers further comprises: receiving an index for the first group of differential sample offsets that refers to the first group of sample offsets to which the first group of differential sample offsets is applied for updating.
10 . The method of claim 1 , wherein the receiving, from the video bitstream, the first group of differential sample offsets for the second component of the second frame according to the one or more classifiers further comprises: receiving a flag that indicates whether (1) to update the first group of differential sample offsets only or (2) to update both the first group of differential sample offsets and corresponding classifiers associated with the first group of differential sample offsets.
11 . The method of claim 3 , wherein the adding the first group of differential sample offsets to the first group of sample offsets comprises adding each value of the first group of differential sample offsets of the second frame to each value of the first group of sample offsets of the first frame.
12 . The method of claim 1 , wherein the each frame comprises a picture frame or a slice in the picture frame.
13 . An electronic apparatus comprising: one or more processing units; a memory coupled to the one or more processing units; and a plurality of programs stored in the memory that, when executed by the one or more processing units, cause the electronic apparatus to perform acts comprising: receiving, from a video bitstream, a plurality of frames, each frame including a first component and a second component; determining, for a first frame of the plurality of frames, one or more classifiers for the second component respectively from one or more samples of the first component associated with a respective sample of the second component; receiving, from the video bitstream, a first group of sample offsets for the second component of the first frame according to the one or more classifiers; determining whether differential pulse-code modulation (DPCM) is enabled for signalling a first group of differential sample offsets for the second component of a second frame of the plurality of frames according to the one or more classifiers, wherein the first group of differential sample offsets represent the differences between the first group of sample offsets in the first frame and a second group of sample offsets for the second component of the second frame; in response to determining the DPCM being enabled: receiving, from the video bitstream, the first group of differential sample offsets for the second component of the second frame according to the one or more classifiers; and modifying a set of one or more samples of the second component of the second frame based on the first group of differential sample offsets of the second frame and the first group of sample offsets of the first frame, wherein the first component is a luma component and the second component is a chroma component, or the first component is a chroma component and the second component is a luma component, or the first component is a first chroma component and the second component is a second chroma component.
14 . A non-transitory computer readable storage medium having stored therein a bitstream comprising video information to be decoded by acts comprising: receiving, from the video bitstream, a plurality of frames, each frame including a first component and a second component; determining, for a first frame of the plurality of frames, one or more classifiers for the second component respectively from one or more samples of the first component associated with a respective sample of the second component; receiving, from the video bitstream, a first group of sample offsets for the second component of the first frame according to the one or more classifiers; determining whether differential pulse-code modulation (DPCM) is enabled for signalling a first group of differential sample offsets for the second component of a second frame of the plurality of frames according to the one or more classifiers, wherein the first group of differential sample offsets represent the differences between the first group of sample offsets in the first frame and a second group of sample offsets for the second component of the second frame; in response to determining the DPCM being enabled: receiving, from the video bitstream, the first group of differential sample offsets for the second component of the second frame according to the one or more classifiers; and modifying a set of one or more samples of the second component of the second frame based on the first group of differential sample offsets of the second frame and the first group of sample offsets of the first frame, wherein the first component is a luma component and the second component is a chroma component, or the first component is a chroma component and the second component is a luma component, or the first component is a first chroma component and the second component is a second chroma component.

Description

CROSS-REFERENCE TO THE RELATED APPLICATIONS The present application is a continuation application of PCT International Application No. PCT/US2022/038497 filed Jul. 27, 2022, which claims priority to U.S. Provisional Patent Application No. 63/226,088, entitled “CROSS-COMPONENT SAMPLE ADAPTIVE OFFSET” filed Jul. 27, 2021, the entire contents of each of which are incorporated herein by reference. TECHNICAL FIELD The present application generally relates to video coding and compression, and more specifically, to methods and apparatus on improving both the luma and the chroma coding efficiency. BACKGROUND Digital video is supported by a variety of electronic devices, such as digital televisions, laptop or desktop computers, tablet computers, digital cameras, digital recording devices, digital media players, video gaming consoles, smart phones, video teleconferencing devices, video streaming devices, etc. The electronic devices transmit and receive or otherwise communicate digital video data across a communication network, and/or store the digital video data on a storage device. Due to a limited bandwidth capacity of the communication network and limited memory resources of the storage device, video coding may be used to compress the video data according to one or more video coding standards before it is communicated or stored. For example, video coding standards include Versatile Video Coding (VVC), Joint Exploration test Model (JEM), High-Efficiency Video Coding (HEVC/H.265), Advanced Video Coding (AVC/H.264), Moving Picture Expert Group (MPEG) coding, or the like. AOMedia Video 1 (AV1) was developed as a successor to its preceding standard VP9. Audio Video Coding (AVS), which refers to digital audio and digital video compression standard, is another video compression standard series. Video coding generally utilizes prediction methods (e.g., inter-prediction, intra-prediction, or the like) that take advantage of redundancy inherent in the video data. Video coding aims to compress video data into a form that uses a lower bit rate, while avoiding or minimizing degradations to video quality. SUMMARY The present application describes implementations related to video data encoding and decoding and, more particularly, to methods and apparatus on improving the coding efficiency of both luma and chroma components, including improving the coding efficiency by exploring cross-component relationship between luma component and chroma component. According to a first aspect of the present application, a method of decoding video bitstream, includes: receiving, from the video bitstream, a plurality of frames, each frame including a first component and a second component; determining, for a first frame of the plurality of frames, one or more classifiers for the second component respectively from one or more samples of the first component associated with a respective sample of the second component; receiving, from the video bitstream, a first group of sample offsets for the second component of the first frame according to the one or more classifiers; determining whether differential pulse-code modulation (DPCM) is enabled for signalling a first group of differential sample offsets for the second component of a second frame of the plurality of frames according to the one or more classifiers; in response to the DPCM being enabled for the signalling the first group of differential sample offsets: receiving, from the video bitstream, the first group of differential sample offsets for the second component of the second frame according to the one or more classifiers; and modifying a set of one or more samples of the second component of the second frame based on the first group of differential sample offsets of the second frame and the first group of sample offsets of the first frame. In some embodiments, the determining whether the DPCM is enabled for signalling the first group of differential sample offsets for the second component of the second frame of the plurality of frames according to the one or more classifiers comprises: receiving, from the video bitstream, a syntax element, wherein the syntax element indicates whether the DPCM is enabled for signalling the first group of differential sample offsets for the second component of the second frame of the plurality of frames according to the one or more classifiers. In some embodiments, the modifying the set of one or more samples of the second component of the second frame based on the first group of differential sample offsets of the second frame and the first group of sample offsets of the first frame comprises: determining a second group of sample offsets for the second component of the second frame by adding the first group of differential sample offsets of the second frame to the first group of sample offsets of the first frame; and modifying the set of one or more samples of the second component of the second frame based on the second group of sample offsets. In some embodi