US-12621498-B2 - Systems and methods for signaling source picture timing information for temporal sublayers in video coding

US12621498B2US 12621498 B2US12621498 B2US 12621498B2US-12621498-B2

Abstract

A device may be configured to decode video data based on information included in a source picture timing information message. In one example, a source picture timing information message includes a syntax element specifying a highest temporal sublayer that the source picture timing information message includes source picture timing information about, wherein when not present the value of the second syntax element is inferred to be equal to an indicated sublayer temporal identifier. In one example, a source picture timing information message includes respective instances of a syntax element specifying a scale factor used in determining a source picture interval of corresponding consecutive pictures in output order for each temporal sublayers to the specified highest temporal sublayer starting with 0 or the indicated sublayer temporal identifier.

Inventors

Jonatan Alfred SAMUELSSON-ALLENDES
Sachin G. Deshpande

Assignees

SHARP KABUSHIKI KAISHA

Dates

Publication Date: 20260505
Application Date: 20240905

Claims (3)

1 . A method of decoding video data, the method comprising: receiving a source picture timing information message; parsing a first syntax element in the source picture timing information message, wherein the first syntax element indicates whether timing of source pictures is the same as timing of corresponding decoded output pictures; conditionally parsing a second syntax element in the source picture timing information message based on a value of the first syntax element, wherein the second syntax element equal to 1 indicates a third syntax element is present in the source picture timing information message; and conditionally parsing the third syntax element in the source picture timing information message based on a value of the second syntax element being equal to 1, wherein the third syntax element indicates the timing relationship between source pictures and corresponding decoded output pictures.
2 . A device comprising one or more processors configured to: receive a source picture timing information message; parse a first syntax element in the source picture timing information message, wherein the first syntax element indicates whether timing of source pictures is the same as timing of corresponding decoded output pictures; conditionally parse a second syntax element in the source picture timing information message based on a value of the first syntax element, wherein the second syntax element equal to 1 indicates a third syntax element is present in the source picture timing information message; and conditionally parse the third syntax element in the source picture timing information message based on a value of the second syntax element being equal to 1, wherein the third syntax element indicates the timing relationship between source pictures and corresponding decoded output pictures.
3 . The device of claim 2 , wherein the device includes a video decoder.

Description

RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Application No. 63/544,484, filed on Oct. 17, 2023, which is incorporated by reference in its entirety. TECHNICAL FIELD This disclosure relates to video coding and more particularly to techniques for signaling source picture timing information for coded video. BACKGROUND 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 7 (ECM 7), Algorithm Description of Enhanced Compression Model 7 (ECM 7), ISO/IEC JTC1/SC29 Document: JVET-AB2025, Oct. 20-28, 2022, Mainz, DE, 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 7 are implemented in ECM reference software. As used herein, the term ECM may collectively refer to algorithms included in ECM 7 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. SUMMARY In general, this disclosure describes various techniques for coding video data. In particular, this disclosure describes techniques for signaling source picture timing 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 shou