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WO-2026094280-A1 - SYSTEMS AND METHODS FOR SIGNALING CROSS-COMPONENT ADAPTIVE LOOP FILTER COEFFICIENTS IN VIDEO CODING

WO2026094280A1WO 2026094280 A1WO2026094280 A1WO 2026094280A1WO-2026094280-A1

Abstract

A device may be configured to signal a cross-component adaptive loop filter coefficients. In one example, a device may be configured to signal cross-component adaptive loop filter coefficients for a number of cross-component filters for a chroma component using a continuous Huffman coded bit string. A device may be configured to parse a continuous bit string and calculate filter coefficient values for filter coefficients for each of a number of cross-component filters by applying a Huffman decoding process.

Inventors

  • TAKADA, KEIICHIRO
  • DESHPANDE, SACHIN G.

Assignees

  • SHARP KABUSHIKI KAISHA

Dates

Publication Date
20260507
Application Date
20250206
Priority Date
20241030

Claims (3)

  1. A device comprising one or more processors configured to: parse a syntax element specifying a number of cross-component filters for a chroma component signalled in a current filter data syntax structure; and parse a continuous bit string and calculate filter coefficient values for filter coefficients for each of the number of cross-component filters by applying a Huffman decoding process.
  2. The device of claim 1, wherein the device includes a video decoder.
  3. A method for decoding video data, the method comprising: parsing a syntax element specifying a number of cross-component filters for a chroma component signalled in a current filter data syntax structure; and parsing a continuous bit string and calculating filter coefficient values for filter coefficients for each of the number of cross-component filters by applying a Huffman decoding process.

Description

SYSTEMS AND METHODS FOR SIGNALING CROSS-COMPONENT ADAPTIVE LOOP FILTER COEFFICIENTS IN VIDEO CODING This disclosure relates to video coding and more particularly to techniques for signaling cross-component adaptive loop filter information for coded video. Digital video capabilities can be incorporated into a wide range of devices, including digital televisions, laptop or desktop computers, tablet computers, digital recording devices, digital media players, video gaming devices, cellular telephones, including so-called smartphones, medical imaging devices, and the like. Digital video may be coded according to a video coding standard. Video coding standards define the format of a compliant bitstream encapsulating coded video data. A compliant bitstream is a data structure that may be received and decoded by a video decoding device to generate reconstructed video data. Video coding standards also define the decoding process and decoders that follow the decoding process can be said to be conforming decoders. Video coding standards may incorporate video compression techniques. Examples of video coding standards include ISO/IEC MPEG-4 Visual and ITU-T H.264 (also known as ISO/IEC MPEG-4 AVC), High-Efficiency Video Coding (HEVC), and Versatile video coding (VVC). HEVC is described in High Efficiency Video Coding, Rec. ITU-T H.265, November 2019, which is referred to herein as ITU-T H.265. VVC is described in Versatile Video Coding, Rec. ITU-T H.266, April 2022, which is incorporated by reference, and referred to herein as ITU-T H.266. Extensions and improvements for ITU-T H.266 are currently being considered for the development of next generation video coding standards. For example, the ITU-T Video Coding Experts Group (VCEG) and ISO/IEC (Moving Picture Experts Group (MPEG) (collectively referred to as the Joint Video Exploration Team (JVET)) are working to standardized enhanced video coding technology beyond the capabilities of the VVC standard. The Enhanced Compression Model 14 (ECM 14), Algorithm Description of Enhanced Compression Model 14 (ECM 14), ISO/IEC JTC1/SC29 Document: JVET-AI2025,12-19 July 2024, Sapporo JP, which is incorporated by reference herein, describes the coding features that were under coordinated test model study by as potentially enhancing video coding technology beyond the capabilities of ITU-T H.266. It should be noted that the coding features of ECM 14 are implemented in ECM reference software. As used herein, the term ECM may collectively refer to algorithms included in ECM 14 and implementations of ECM reference software. Video compression techniques enable data requirements for storing and transmitting video data to be reduced. Video compression techniques may reduce data requirements by exploiting the inherent redundancies in a video sequence. Video compression techniques may sub-divide a video sequence into successively smaller portions (i.e., groups of pictures within a video sequence, a picture within a group of pictures, regions within a picture, sub-regions within regions, etc.). Intra prediction coding techniques (e.g., spatial prediction techniques within a picture) and inter prediction techniques (i.e., inter-picture techniques (temporal)) may be used to generate difference values between a unit of video data to be coded and a reference unit of video data. The difference values may be referred to as residual data. Residual data may be coded as quantized transform coefficients. Syntax elements may relate residual data and a reference coding unit (e.g., intra-prediction mode indices, and motion information). Residual data and syntax elements may be entropy coded. Entropy encoded residual data and syntax elements may be included in data structures forming a compliant bitstream. In general, this disclosure describes various techniques for coding video data. In particular, this disclosure describes techniques for signaling cross-component adaptive loop filter information in video coding. It should be noted that although techniques of this disclosure are described with respect to ITU-T H.264, ITU-T H.265, ITU-T H.266, and ECM, the techniques of this disclosure are generally applicable to video coding. For example, the coding techniques described herein may be incorporated into video coding systems, (including video coding systems based on future video coding standards) including video block structures, intra prediction techniques, inter prediction techniques, transform techniques, filtering techniques, and/or entropy coding techniques other than those included in ITU-T H.264, ITU-T H.265, ITU-T H.266, and ECM. Thus, reference to ITU-T H.264, ITU-T H.265, ITU-T H.266, and/or ECM is for descriptive purposes and should not be construed to limit the scope of the techniques described herein. Further, it should be noted that incorporation by reference of documents herein is for descriptive purposes and should not be construed to limit or create ambiguity with re