ISO/IEC 23008-6:2025

Information technology - High efficiency coding and media delivery in heterogeneous environments - Part 6: 3D audio reference software

This document contains simulation software for the MPEG-H 3D audio standard as defined in ISO/IEC 23008-3.

Technologies de l'information — Codage à haut rendement et fourniture de supports dans les environnements hétérogènes — Partie 6: Logiciel de référence 3D Audio

General Information

• Status: Published
• Publication Date: 23-Oct-2025
• ICS: 35.040.40 - Coding of audio, video, multimedia and hypermedia information
• Technical Committee: ISO/IEC JTC 1/SC 29 - Coding of audio, picture, multimedia and hypermedia information
• Drafting Committee: ISO/IEC JTC 1/SC 29/WG 6 - MPEG Audio coding
• Current Stage: 6060 - International Standard published
• Start Date: 24-Oct-2025
• Due Date: 21-Jan-2026
• Completion Date: 24-Oct-2025

Relations

• Revises: ISO/IEC 23008-6:2021/Amd 1:2024 - Information technology - High efficiency coding and media delivery in heterogeneous environments - Part 6: 3D audio reference software - Amendment 1: Corrections for closest loudspeaker playout and increased software resilience
• Effective Date: 17-Aug-2024
• Revises: ISO/IEC 23008-6:2021 - Information technology - High efficiency coding and media delivery in heterogeneous environments - Part 6: 3D audio reference software
• Effective Date: 17-Aug-2024

Overview

ISO/IEC 23008-6:2025 specifies reference simulation software for the MPEG‑H 3D audio system defined in ISO/IEC 23008-3. This fourth edition provides the normative bitstream decoding reference implementation and informative encoding and utility tools as source code. The package is intended as a definitive software model that correctly implements the MPEG‑H 3D audio decoding processes and to support development, testing and conformance activities.

Keywords: ISO/IEC 23008-6, MPEG‑H 3D audio, reference software, 3D audio decoder, reference model encoder, immersive audio.

Key Topics

• Normative decoding software
  • Reference implementation of the MPEG‑H 3D audio decoder (modules/3DAudioCoder/3DAudioDecoder).
  • Decoder is normative in behavior (correctly implements ISO/IEC 23008-3), though implementation techniques are not prescriptive.
• Informative encoding software (Annex A)
  • Reference model encoder (RM) for creating compliant bitstreams; implementation quality and complexity are not optimized.
• Utility software (Annex B)
  • Tools and libraries for WAV handling, channel/object separation, channel merger/splitter, sample cutter, filter banks, QMF (qmflib), FFT (fftlib), bitstream reader/writer, and helpers for loudspeaker configurations.
• Reference software structure & licensing
  • Source code package available from the ISO standards repository.
  • Each source module includes a copyright disclaimer and a royalty-free licence for use in conformant implementations; implementers are advised to check patent status.
• Conformance and normative scope
  • The software is derived from models used during development of ISO/IEC 23008-3 and is intended as a normative reference for decoding behavior, not as the only permitted implementation.

Applications

This standard and its reference software are practical for:

• Codec developers implementing MPEG‑H 3D audio decoders/encoders.
• Product engineers building playback devices, receivers, and media players that support 3D audio.
• Content producers and post‑production teams validating object/channel rendering and loudspeaker configurations.
• Test labs and conformance bodies verifying bitstream compliance with ISO/IEC 23008-3.
• Researchers and educators studying MPEG‑H 3D audio algorithms and reference models.

Source code and software modules are provided by ISO at: https://standards.iso.org/iso-iec/23008/-6/ed-4/en

Related Standards

• ISO/IEC 23008-3 - High efficiency coding and media delivery in heterogeneous environments - Part 3: 3D audio (normative companion standard defining syntax and decoding processes).
• Other parts of the ISO/IEC 23008 series (for related coding and delivery topics).

Standards Content (Sample)

International
Standard
ISO/IEC 23008-6
Fourth edition
Information technology — High
2025-10
efficiency coding and media
delivery in heterogeneous
environments —
Part 6:
3D audio reference software
Technologies de l'information — Codage à haut rendement et
fourniture de supports dans les environnements hétérogènes —
Partie 6: Logiciel de référence 3D Audio
Reference number
© ISO/IEC 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
© ISO/IEC 2025 – All rights reserved
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Reference software structure . 1
4.1 General .1
4.2 Copyright disclaimer for software modules .2
5 Bitstream decoding software . 2
5.1 General .2
5.2 MPEG-H 3D audio decoding software .2
Annex A (informative) Bitstream encoding software . 3
Annex B (informative) Additional utility software . 4

© ISO/IEC 2025 – All rights reserved
iii
Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical activity.
ISO and IEC technical committees collaborate in fields of mutual interest. Other international organizations,
governmental and non-governmental, in liaison with ISO and IEC, also take part in the work.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of document should be noted. This document was drafted in accordance with the editorial rules of the ISO/
IEC Directives, Part 2 (see www.iso.org/directives or www.iec.ch/members_experts/refdocs).
ISO and IEC draw attention to the possibility that the implementation of this document may involve the
use of (a) patent(s). ISO and IEC take no position concerning the evidence, validity or applicability of any
claimed patent rights in respect thereof. As of the date of publication of this document, ISO and IEC had not
received notice of (a) patent(s) which may be required to implement this document. However, implementers
are cautioned that this may not represent the latest information, which may be obtained from the patent
database available at www.iso.org/patents and https://patents.iec.ch. ISO and IEC shall not be held
responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT) see www.iso.org/iso/foreword.html.
In the IEC, see www.iec.ch/understanding-standards.
This document was prepared by Technical Committee ISO/IEC JTC 1, Information technology, Subcommittee
SC 29, Coding of audio, picture, multimedia and hypermedia information.
This fourth edition cancels and replaces the third edition (ISO/IEC 23008-6:2021), which has been
technically revised. It also incorporates the Amendment ISO/IEC 23008-6:2021/Amd 1:2024.
The main changes are as follows:
— various software fixes without change of technical scope.
A list of all parts in the ISO 23008 series can be found on the ISO and IEC websites.
Any feedback or questions on this document should be directed to the user’s national standards
body. A complete listing of these bodies can be found at www.iso.org/members.html and
www.iec.ch/national-committees.

© ISO/IEC 2025 – All rights reserved
iv
International Standard ISO/IEC 23008-6:2025(en)
Information technology — High efficiency coding and media
delivery in heterogeneous environments —
Part 6:
3D audio reference software
1 Scope
This document contains simulation softwar
...