ISO/IEC 23003-2:2010

INTERNATIONAL ISO/IEC
STANDARD 23003-2
First edition
2010-10-01
Information technology —
MPEG audio technologies —
Part 2:
Spatial Audio Object Coding (SAOC)
Technologies de l'information — Technologies audio MPEG —
Partie 2: Codage d'objet audio spatial (SAOC)

Reference number
©
ISO/IEC 2010
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ii © ISO/IEC 2010 – All rights reserved

Contents Page
Foreword .v
Introduction.vi
1 Scope.1
2 Normative references.1
3 Terms and definitions .1
4 Symbols, notation and abbreviated terms.3
4.1 Notation .3
4.2 Operations.3
4.3 Constants .3
4.4 Variables.3
4.5 Abbreviated terms.5
5 SAOC overview.7
5.1 Introduction.7
5.2 Basic structure of the SAOC transcoder/decoder .7
5.3 Tools and functionality .9
5.4 Delay and synchronization.10
5.5 SAOC Profiles and Levels .15
6 Syntax.17
6.1 Payloads for SAOC.17
6.2 Definition .29
7 SAOC processing.34
7.1 Compressed data stream decoding and dequantization of SAOC data .34
7.2 Compressed data stream encoding and quantization of MPS data.38
7.3 Time/frequency transforms .39
7.4 Post(processing) downmix compensation.39
7.5 Signals and parameters.39
7.6 Transcoding modes .41
7.7 Decoding modes.49
7.8 EAO processing.53
7.9 DCU processing.61
7.10 MBO processing .65
7.11 MCU Combiner.66
7.12 Effects.67
7.13 Low Power SAOC processing.70
7.14 Low Delay SAOC processing .70
8 Transport of SAOC side information.73
8.1 Overview.73
8.2 Transport and signalling in an MPEG environment.73
8.3 Transport of SAOC data over PCM channels .77
9 Transport of predefined rendering information .78
9.1 Introduction.78
9.2 Rendering information description file format.79
Annex A (normative) Tables .80
Annex B (normative) Low Delay MPEG Surround.109
Annex C (informative) Effects processing.119
Annex D (informative) Encoder .121
© ISO/IEC 2010 – All rights reserved iii

Annex E (informative) Guidelines for rendering matrix specification .125
Annex F (informative) MCU Combiner.127
Annex G (informative) Patent statement.129
Bibliography .130

iv © ISO/IEC 2010 – All rights reserved

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. In the field of information
technology, ISO and IEC have established a joint technical committee, ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as
an International Standard requires approval by at least 75 % of the national bodies casting a vote.
ISO/IEC 23003-2 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information.
ISO/IEC 23003 consists of the following parts, under the general title Information technology — MPEG audio
technologies:
— Part 1: MPEG Surround
— Part 2: Spatial Audio Object Coding (SAOC)

© ISO/IEC 2010 – All rights reserved v

Introduction
The International Organization for Standardization (ISO) and International Electrotechnical Commission (IEC)
draw attention to the fact that it is claimed that compliance with this document may involve the use of patents.
ISO and IEC take no position concerning the evidence, validity and scope of these patent rights.
The holders of these patent rights have assured ISO and IEC that they are willing to negotiate licences under
reasonable and non-discriminatory terms and conditions with applicants throughout the world. In this respect,
the statements of the holders of these patent rights are registered with ISO and IEC. Information may be
obtained from the companies listed in Annex G.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights other than those identified in Annex G. ISO and IEC shall not be held responsible for identifying any or
all such patent rights.
vi © ISO/IEC 2010 – All rights reserved

INTERNATIONAL STANDARD ISO/IEC 23003-2:2010(E)

Information technology — MPEG audio technologies —
Part 2:
Spatial Audio Object Coding (SAOC)
1 Scope
This part of ISO/IEC 23003 specifies the reference model of the Spatial Audio Object Coding (SAOC)
technology that is capable of recreating, modifying and rendering a number of audio objects based on a
smaller number of transmitted channels and additional parametric data. In the preferred modes of operating
the SAOC system, the transmitted signal can be either mono or stereo. The audio objects can be represented
by a mono and stereo signal or have the MPEG Surround (MPS) Multi-channel Background Object (MBO)
format. The additional parametric data exhibits a significantly lower data rate than required for transmitting all
objects individually, making the coding very efficient. At the same time this ensures compatibility of the
transmitted signal with legacy devices.
When a multi-channel rendering setup (e.g. a 5.1 loudspeaker setup) is required, the SAOC system acts as a
transcoder, converting the additional parametric data to MPS parameters, and interfaces to the MPS decoder
that acts as rendering device. For certain rendering setups (e.g. a binaural or plain stereo setup), the SAOC
system behaves as a decoder, using its own rendering engine. Another key feature is that the SAOC
parametric data from different streams can be merged at parameter level to allow for the combination of
SAOC streams, similar to the functionality of a Multi-point Control Unit (MCU).
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO/IEC 13818-7:2006, Information technology — Generic coding of moving pictures and associated audio
information — Part 7: Advanced Audio Coding (AAC)
ISO/IEC 14496-3:2009, Information technology — Coding of audio-visual objects — Part 3: Audio
ISO/IEC 23003-1:2007, Information technology — MPEG audio technologies — Part 1: MPEG Surround
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
audio object
input audio signal consisting of one, two or multiple channels, including Multi-channel Background Object
(MBO)
3.2
frame
time segment to which SAOC processing is applied according to the data conveyed in the corresponding
SAOCFrame() syntax element
© ISO/IEC 2010 – All rights reserved 1
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