GB/T 46271-2025 Information technology—3D audio technology—Coding, distribution and presentation English, Anglais, Englisch, Inglés, えいご
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ICS 35.040 CCS L 71
People's Republic of China National Standard
GB/T 46271-2025
Information technology - 3D audio technology - Coding, distribution and presentation
Issued on 2025-08-29 Implemented on 2026-03-01
Issued by State Administration for Market Regulation, Standardization Administration of China
Contents
1 Scope
2 Normative References
3 Terms and Definitions
4 Abbreviations
5 Conventions
5.1 Arithmetic Operators
5.2 Logical Operators
5.3 Relational Operators
5.4 Bitwise Operators
5.5 Assignment Operators
5.6 Mnemonics
5.7 Mathematical Functions
5.8 Bitstream Syntax Rules
6 3D Audio Coding and Rendering Framework
7 Universal Full Rate Audio Decoding
8 Lossless Audio Decoding
9 Metadata Decoding
1 Scope
This document describes methods for coding, distribution and presentation of 3D audio, compatible with mono, stereo, surround sound and other audio formats.
This document applies to 3D audio coding, distribution and presentation in broadcasting, streaming media, network audiovisual, real-time communication, virtual/augmented reality, and digital storage media.
2 Normative References
The following documents contain provisions which, through reference in this text, constitute essential provisions of this document. For dated references, only the edition cited applies; for undated references, the latest edition (including amendments) applies.
GB/T 17191 (all parts) Information technology - Coding of moving pictures and associated audio for digital storage media at up to 1.5 Mbit/s
GB/T 33475.3-2018 Information technology - Efficient multimedia coding - Part 3: Audio
GB/T 44115.3-2025 Information technology - Virtual reality content representation - Part 3: Audio
GY/T 262-2012 Program loudness and true peak audio level measurement algorithm
GY/T 316-2018 Advanced sound system for program production
GY/T 404-2024 Audio definition model
ITU-R BS.2094:2025 Common definitions for the audio definition model
ETSIT S126445 V18.1.0 Universal Mobile Telecommunications System (UMTS); LTE; 5G; Codec for Enhanced Voice Services (EVS)
3 Terms and Definitions
Terms and definitions defined in GB/T 33475.3-2018 and the following apply to this document.
3.1
Coded bitstream
The encoded representation of audio signals.
3.2
Object
In 3D audio signals, sounds perceived as a whole or independent sounds emitted by a single sound source from the environment.
3.3
Stereo audio
An audio format using two channels to carry audio signals with phase, amplitude, or mixed relationships.
NOTE: Typically reproduced through two symmetrically placed speakers in front of the listener to create a wider sound field.
3.4
Surround audio
An audio format using multiple channels to carry multi-channel audio signals constituting complete audio content.
NOTE: Reproduced through multiple speakers surrounding the listener at ear height to create a surrounding sound field.
3.5
3D audio
An audio format using multiple channels to carry multi-channel audio signals constituting complete audio content.
NOTE: Reproduced directly through speakers at different height levels surrounding the listener, or after rendering to simulate 3D audio experience, providing higher spatial resolution and immersive sound fields.
4 Abbreviations
The following abbreviations apply to this document.
AASF: AVS Audio Storage Format
AATF: AVS Audio Transport Format
ADM: Audio Definition Model
AVS: Audio Video coding Standard
BWE: Bandwidth Extension
CDF: Cumulative-probability Density Function
CNN: Convolutional Neural Network
CRC: Cyclic Redundancy Check
DRC: Dynamic Range Control
EQ: Equalizer
FFT: Fast Fourier Transform
FOA: First Order Ambisonics
HOA: Higher Order Ambisonics
ILD: Inter-channel Level Difference
LFE: Low Frequence Effect
LPC: Linear Prediction Coefficients
LSF: Line Spectral Frequencies
LSP: Line Spectral Pairs
MCAC: MultiChannel Adaptive Coupling
MCR: Maximum Correlation Rotation
MDCT: Modified Discrete Cosine Transform
M/S: Middle/Side
PAR: Peak-to-Average Ratio
SFB: Scale Factor Band
SFM: Spectral Flatness Measure
TNS: Temporal Noise Shaping
VBAP: Vector-based Amplitude Panning
VQ: Vector Quantization
5 Conventions
5.1 Arithmetic Operators
Arithmetic operators are defined in Table 1.
