ISO/IEC 14496-26:2024
(Main)Information technology — Coding of audio-visual objects — Part 26: Audio conformance
Information technology — Coding of audio-visual objects — Part 26: Audio conformance
This document specifies how tests can be designed to verify whether compressed data and decoders meet requirements specified by ISO/IEC 14496-3. Encoders are not addressed specifically. An ISO/IEC 14496 encoder generates compressed data compliant with the syntactic and semantic bitstream payload requirements specified in ISO/IEC 14496-3. This document summarises the requirements, cross references them to characteristics, and defines how conformance with them can be tested. Guidelines are given on constructing tests to verify decoder conformance. Some examples of compressed data implemented according to these guidelines are provided as an electronic annex to this document usually together with their uncompressed counterparts (reference waveforms).
Technologies de l'information — Codage des objets audiovisuels — Partie 26: Conformité audio
General Information
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Standards Content (Sample)
International
Standard
ISO/IEC 14496-26
Second edition
Information technology — Coding of
audio-visual objects —
2024-11
Part 26:
Audio conformance
Technologies de l'information — Codage des objets
audiovisuels —
Partie 26: Conformité audio
Reference number
© ISO/IEC 2024
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© ISO/IEC 2024 – All rights reserved
ii
Contents Page
Foreword . v
Introduction . vii
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
3.1 Conformance Data . 2
3.2 Conformance Tools . 2
3.3 Conformance Test Sequences . 2
3.4 Compressed Data . 2
3.5 Reference Waveforms . 2
4 Conformance Points . 2
5 Profiles . 4
6 Conformance data . 4
6.1 File name conventions . 4
6.2 Content . 6
7 Audio Object Types . 7
7.1 General . 7
7.2 Null . 13
7.3 AAC-based scalable configurations . 14
7.4 AAC (main, LC, ER LC, SSR, LTP, ER LTP, ER LD, scalable, ER scalable) . 15
7.5 TwinVQ and ER_TwinVQ . 40
7.6 ER BSAC . 43
7.7 CELP . 51
7.8 ER CELP . 55
7.9 HVXC . 60
7.10 ER HVXC . 71
7.11 ER HILN and ER Parametric . 74
7.12 TTSI . 89
7.13 General MIDI . 91
7.14 Wavetable Synthesis . 92
7.15 Algorithmic Synthesis and AudioFX . 93
7.16 Main Synthetic . 100
7.17 SBR . 101
7.18 PS (Parametric Stereo) . 113
7.19 SSC (SinuSoidal Coding) . 115
7.20 DST (Lossless coding of oversampled audio) . 120
7.21 Layer-3 . 123
7.22 ALS (Audio lossless coding) . 125
7.23 SLS (Scalable Lossless Coding) . 127
7.24 Layer-1 and Layer 2 . 130
7.25 Low Delay SBR . 132
8 Audio EP tool . 143
8.1 Compressed data . 143
8.2 Decoders . 145
9 Audio Composition . 151
9.1 AudioBIFS v1 . 151
9.2 Advanced Audio BIFS nodes . 162
9.3 AudioBIFS v3 Nodes . 188
© ISO/IEC 2024 – All rights reserved
iii
10 MPEG-4 audio transport stream . 205
10.1 General . 205
10.2 Compressed Data . 205
10.3 Decoders . 206
11 Upstream . 207
11.1 Compressed data . 207
11.2 Decoders . 207
12 Conformance test sequence assignment to profiles and levels . 207
12.1 Overview . 207
12.2 Audio . 208
12.3 Systems . 224
Annex A (informative) Complexity measurement criteria and tool for level definitions of algorithmic
synthesis and AudioFX Object Type . 229
Annex B (informative) Test bitstreams for the CELP object type . 250
© ISO/IEC 2024 – All rights reserved
iv
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 Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information.
This second edition cancels and replaces the first edition (ISO/IEC 14496-26:2010), which has been
technically revised. It also incorporates the Amendments ISO/IEC 14496-26:2010/Amd 2:2010,
ISO/IEC
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