ISO/IEC 14496-26:2010
(Main)Information technology — Coding of audio-visual objects — Part 26: Audio conformance
Information technology — Coding of audio-visual objects — Part 26: Audio conformance
ISO/IEC 14496-26:2010 specifies how tests can be designed to verify whether compressed data and decoders meet requirements specified by ISO/IEC 14496-3. In ISO/IEC 14496-26:2010, encoders are not addressed specifically. An encoder may be said to be an ISO/IEC 14496 encoder if it generates compressed data compliant with the syntactic and semantic bitstream payload requirements specified in ISO/IEC 14496-3. Characteristics of compressed data and decoders are defined for ISO/IEC 14496-3. The compressed data characteristics define the subset of the standard that is exploited in the compressed data. Examples are the applied values or range of the sampling rate and bitrate parameters. Decoder characteristics define the properties and capabilities of the applied decoding process. An example of a property is the applied arithmetic accuracy. The capabilities of a decoder specify which compressed data the decoder can decode and reconstruct, by defining the subset of the standard that may be exploited in the decodable compressed data. Compressed data can be decoded by a decoder if the characteristics of the compressed data are within the subset of the standard specified by the decoder capabilities. Procedures are described for testing conformance of compressed data and decoders to the requirements defined in ISO/IEC 14496-3. Given the set of characteristics claimed, the requirements that must be met are fully determined by ISO/IEC 14496-3. ISO/IEC 14496-26:2010 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
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INTERNATIONAL ISO/IEC
STANDARD 14496-26
First edition
2010-05-01
Information technology — Coding of
audio-visual objects —
Part 26:
Audio conformance
Technologies de l'information — Codage des objets audiovisuels —
Partie 26: Conformité audio
Reference number
ISO/IEC 14496-26:2010(E)
©
ISO/IEC 2010
---------------------- Page: 1 ----------------------
ISO/IEC 14496-26:2010(E)
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ISO/IEC 14496-26:2010(E)
These DVDs contain:
1) the publication ISO/IEC 14496-26:2010 in portable document format (PDF), which can be viewed
using Adobe® Acrobat® Reader;
2) electronic attachments for audio conformance.
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© ISO
...
INTERNATIONAL ISO/IEC
STANDARD 14496-26
First edition
2010-05-01
Information technology — Coding of
audio-visual objects —
Part 26:
Audio conformance
Technologies de l'information — Codage des objets audiovisuels —
Partie 26: Conformité audio
Reference number
ISO/IEC 14496-26:2010(E)
©
ISO/IEC 2010
---------------------- Page: 1 ----------------------
ISO/IEC 14496-26:2010(E)
PDF disclaimer
This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but
shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation
parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In
the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2010
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or
ISO's member body in the country of the requester.
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Published in Switzerland
ii © ISO/IEC 2010 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC 14496-26:2010(E)
Contents Page
Foreword .v
Introduction.vii
1 Scope.1
2 Normative references.1
3 Terms and definitions .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.14
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.44
7.7 CELP.52
7.8 ER CELP.56
7.9 HVXC.61
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.102
7.18 PS (Parametric Stereo).113
7.19 SSC (SinuSoidal Coding).115
7.20 DST (Lossless coding of oversampled audio) .121
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.131
8 Audio EP tool .134
8.1 Compressed data .134
8.2 Decoders.137
9 Audio Composition .142
9.1 AudioBIFS v1.142
9.2 Advanced Audio BIFS nodes .153
9.3 AudioBIFS v3 Nodes .179
10 MPEG-4 audio transport stream .197
10.1 General.197
10.2 Compressed Data.198
10.3 Decoders.198
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ISO/IEC 14496-26:2010(E)
11 Upstream.199
11.1 Compressed data.199
11.2 Decoders.200
12 Conformance test sequence assignment to profiles and levels .200
12.1 Overview.200
12.2 Audio.200
12.3 Systems.216
Annex A (informative) Complexity measurement criteria and tool for level definitions of
algorithmic synthesis and AudioFX Object Type.221
Annex B (informative) Test bitstreams for the CELP object type .242
iv © ISO/IEC 2010 – All rights reserved
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ISO/IEC 14496-26:2010(E)
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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 14496-26 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information.
This part of ISO/IEC 14496 cancels and replaces:
⎯ ISO/IEC 14496-4:2004, Clause 6,
⎯ ISO/IEC 14496-4:2004/Cor.5,
⎯ ISO/IEC 14496-4:2004/Cor.6,
⎯ ISO/IEC 14496-4:2004/Amd.8:2005, including ISO/IEC 14496:2004/Amd.8:2005/Cor.1:2008,
⎯ ISO/IEC 14496-4:2004/Amd.11:2006, including ISO/IEC 14496-4:2004/Amd.11:2006/Cor.1:2008,
⎯ ISO/IEC 14496-4:2004/Amd.11:2006/Cor.2:2007,
⎯ ISO/IEC 14496-4:2004/Amd.11:2006/Cor.3:2008,
⎯ ISO/IEC 14496:2004-4/Amd.13:2007, including ISO/IEC 14496-4:2004/Amd.13:2007/Cor.1:2007,
⎯ ISO/IEC 14496:2004-4/Amd.13:2007/Cor.2:2007,
⎯ ISO/IEC 14496-4:2004/Amd.14:2007,
⎯ ISO/IEC 14496-4:2004/Amd.15:2007,
⎯ ISO/IEC 14496-4:2004/Amd.18:2007,
⎯ ISO/IEC 14496-4:2004/Amd.19:2007, including ISO/IEC 14496-4:2004/Amd.19:2007/Cor.1:2008,
⎯ ISO/IEC 14496-4:2004/Amd.20:2008, and
⎯ ISO/IEC 14496-4:2004/Amd.22:2008.
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ISO/IEC 14496-26:2010(E)
ISO/IEC 14496 consists of the following parts, under the general title Information technology — Coding of
audio-visual objects:
⎯ Part 1: Systems
⎯ Part 2: Visual
⎯ Part 3: Audio
⎯ Part 4: Conformance testing
⎯ Part 5: Reference software
⎯ Part 6: Delivery Multimedia Integration Framework (DMIF)
⎯ Part 7: Optimised reference software for coding of audio-visual objects
⎯ Part 8: Carriage of ISO/IEC 14496 contents over IP networks
⎯ Part 9: Reference hardware description
⎯ Part 10: Advanced Video Coding
⎯ Part 11: Scene description and application engine
⎯ Part 12: ISO base media file format
⎯ Part 13: Intellectual Property Management and Protection (IPMP) extensions
⎯ Part 14: MP4 file format
⎯ Part 15: Advanced Video Coding (AVC) file format
⎯ Part 16: Animation Framework eXtension (AFX)
⎯ Part 17: Streaming text format
⎯ Part 18: Font compression and streaming
⎯ Part 19: Synthesized texture stream
⎯ Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF)
⎯ Part 21: MPEG-J Graphics Framework eXtensions (GFX)
⎯ Part 22: Open Font Format
⎯ Part 23: Symbolic Music Representation
⎯ Part 24: Audio and systems interaction [Technical Report]
⎯ Part 25: 3D Graphics Compression Model
⎯ Part 26: Audio conformance
⎯ Part 27: 3D Graphics conformance
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ISO/IEC 14496-26:2010(E)
Introduction
ISO/IEC 14496-3 specifies coded representations of audio information. ISO/IEC 14496-3 allows for large
flexibility, achieving suitability of ISO/IEC 14496 for many different applications. The flexibility is obtained by
including parameters in the bitstream that define the characteristics of coded bitstreams. Examples are the
audio sampling frequency bitrate parameters, synchronisation timestamps, the association of bitstreams and
synthetic objects within objects.
This part of ISO/IEC 14496 specifies how tests can be designed to verify whether bitstreams and decoders
meet the requirements as specified in ISO/IEC 14496-3 and allow interoperability with remote terminals in
interactive, broadcast and local (with stored contents) sessions. These tests can be used for various purposes
such as
⎯ manufacturers of encoders, and their customers, can use the tests to verify whether the encoder
produces bitstreams compliant with ISO/IEC 14496-3,
⎯ manufacturers of decoders and their customers can use the tests to verify whether the decoder meets the
requirements specified in ISO/IEC 14496-3 for the claimed decoder capabilities,
⎯ manufacturers and customers of terminals supporting interactive, broadcast and local sessions over a
multitude of transport protocols and networks, can use the tests to verify whether the claimed
functionalities are compliant with ISO/IEC 14496-6,
⎯ manufacturers of test equipments, and their customers can use the tests to verify compliance with
ISO/IEC 14496-3.
© ISO/IEC 2010 – All rights reserved vii
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INTERNATIONAL STANDARD ISO/IEC 14496-26:2010(E)
Information technology — Coding of audio-visual objects —
Part 26:
Audio conformance
1 Scope
This part of ISO/IEC 14496 specifies how tests can be designed to verify whether compressed data and
decoders meet requirements specified by ISO/IEC 14496-3. In this part of ISO/IEC 14496, encoders are not
addressed specifically. An encoder may be said to be an ISO/IEC 14496 encoder if it generates compressed
data compliant with the syntactic and semantic bitstream payload requirements specified in ISO/IEC 14496-3.
Characteristics of compressed data and decoders are defined for ISO/IEC 14496-3. The compressed data
characteristics define the subset of the standard that is exploited in the compressed data. Examples are the
applied values or range of the sampling rate and bitrate parameters. Decoder characteristics define the
properties and capabilities of the applied decoding process. An example of a property is the applied arithmetic
accuracy. The capabilities of a decoder specify which compressed data the decoder can decode and
reconstruct, by defining the subset of the standard that may be exploited in the decodable compressed data.
Compressed data can be decoded by a decoder if the characteristics of the compressed data are within the
subset of the standard specified by the decoder capabilities.
Procedures are described for testing conformance of compressed data and decoders to the requirements
defined in ISO/IEC 14496-3. Given the set of characteristics claimed, the requirements that must be met are
fully determined by ISO/IEC 14496-3. This part of ISO/IEC 14496 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).
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 11172-3, Information technology — Coding of moving pictures and associated audio for digital
storage media at up to about 1,5 Mbit/s — Part 3: Audio
ISO/IEC 11172-4, Information technology — Coding of moving pictures and associated audio for digital
storage media at up to about 1,5 Mbit/s — Part 4: Compliance testing
ISO/IEC 13818-3, Information technology — Generic coding of moving pictures and associated audio
information — Part 3: Audio
ISO/IEC 13818-4, Information technology — Generic coding of moving pictures and associated audio
information — Part 4: Conformance testing
ISO/IEC 13818-7, Information technology — Generic coding of moving pictures and associated audio
information — Part 7: Advanced Audio Coding (AAC)
© ISO/IEC 2010 – All rights reserved 1
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ISO/IEC 14496-26:2010(E)
ISO/IEC 14496-1, Information technology — Coding of audio-visual objects — Part 1: Systems
ISO/IEC 14496-3, Information technology — Coding of audio-visual objects — Part 3: Audio
ISO/IEC 14496-11, Information technology — Coding of audio-visual objects — Part 11: Scene description
and application engine
3 Terms and definitions
For the purposes of this document the terms, defintions, symbols and abbreviated terms given in
ISO/IEC 14496-1, ISO/IEC 14496-3 and the following apply.
3.1
conformance data
conformance test sequences and conformance tools
3.2
conformance tool
tool to check certain conformance criteria
NOTE Conformance tools are provided in the electronic attachments to this part of ISO/IEC 14496.
3.3
conformance test sequence
superset of compressed data and its reference waveforms
NOTE Examples of conformance test sequences are provided in the electronic attachments to this part of
ISO/IEC 14496.
3.4
compressed data
data encoded in accordance with ISO/IEC 14496-3
3.5
reference waveform
decoded counterparts of the compressed data
4 Conformance Points
All audio decoders except the LATM-based decoders are part of the MPEG-4 framework. Table 1 gives an
overview about the interfaces that have to be provided to test the audio decoders using the MPEG-4 System.
Table 1 — Conformance points
conformance point/interface data flow description/reference
direction
AudioSpecificConfig in audio related decoder specific information, see ISO/IEC 14496-3:2009, (1.6.2.1
AudioSpecificConfig)
audio access units in audio related bitstream payload, see ISO/IEC 14496-1:2004 (7.1.2.3 Access Units (AU))
BIFS/AudioSource node in see ISO/IEC 14496-11: 2005 (7.2.2.15 Audio Source)
private test info in to control some elements which are usually generated by random number generators
audio composition units out see ISO/IEC 14496-1: 2004 (7.2.8 Composition Units (CU))
2 © ISO/IEC 2010 – All rights reserved
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ISO/IEC 14496-26:2010(E)
Figure 1 gives an overview about the test bench (MPEG-4 System), the system under test (Audio decoder),
and the interfaces between them. Figure 2 gives a more detailed view on the audio decoder, consisting of
error protection (EP) decoder and audio core decoder.
MPEG-4 System
AudioSpecificConfig private test info
*.mp4 audio presentation
BIFS(AudioSource)
file format
Node fields
Audio Decoder
audio composition units
audio access units
(incl. time stamps for SA, TTS)
Figure 1 — Audio Conformance Points
Audio Decoder
2
EP Decoder Audio
directMapping
0
3
Core
epConfig
2/3
1
1
Decoder
0
Figure 2 — Audio decoder structure
Clause 7 describes:
The conformance criteria of the audio core decoder.
The conformance criteria of the compressed data not requiring the EP decoder (epConfig == 0 || epConfig
== 1).
The properties of the examples of compressed data with (epConfig == 0 || epConfig == 1).
Clause 8 describes:
The conformance criteria of the EP decoder
The conformance criteria of the compressed data requiring the EP decoder (epConfig == 2 || epConfig == 3).
The properties of the examples of compressed data with (epConfig == 2 || epConfig == 3).
Compressed data with different epConfig settings might be available referring to the same reference
waveforms. Here, the output of a conforming decoder shall be equal, independently of the used epConfig
setting.
© ISO/IEC 2010 – All rights reserved 3
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ISO/IEC 14496-26:2010(E)
For some of the compressed data containing scalable configurations, conformance points are defined at the
PCM output of the decoder for m layers being decoded from an n-layer input, where m is an integer in the
range 0 (base layer conformance) to n-1. The reference PCM decoder output signals corresponding to these
conformance points are listed in the respective conformance tables.
5 Profiles
ISO/IEC 14496-3 defines several profiles and several levels within each profile. Conformance is always tested
against a certain level within a certain profile. Audio profiles always comprise a set of audio object types.
Nevertheless the conformance criteria as described within this document are based on audio object types.
The assignment of object types to profiles as well as the level definitions can be found in ISO/IEC 14496-3.
The conformance of a certain level within a certain profile is fulfilled, if the conformance of each object type
belonging to this profile is fulfilled. The assignment of the provided test sequences to profiles and levels can
be found in Clause 12.
6 Conformance data
6.1 File name conventions
For all conformance test sequences, the file name convention given in Table 2 is used.
Table 2 — File name conventions
object type name/ tool name File Name (compressed) File Name (uncompressed)
AdvancedAudioBIFS aabper -- not applicable --
- perceptual apporach
AdvancedAudioBIFS aabphy -- not applicable --
- physical approach
AudioBIFS ab_ ab_
AudioBIFS v3 ABv3_ -- not applicable --
AAC scalable ac ac[_lay]
AAC LC al_ al_[_cut_boost]
[_level][_]
AAC main am_ am_[_cut_boost]
[_level][_]
AAC LTP ap_ ap_
AAC SSR as_ as_[_]
CELP ce ce[_lay]
ER AAC scalable er_ac_ep er_ac[_lay]
[]
ER AAC LD er_ad__ep er_ad_
[]
ER AAC LC er_al__ep er_al_
[]
ER AAC LTP er_ap__ep er_ap_
[]
SBR (+AAC LC) al_sbr___[_fsaac al_sbr____
][_sig] [_fsaac][_sig][_]
SBR (+AAC LC with al960_sbr___ al960_sbr____
960 samples per frame ) [_fsaac][_sig] [_fsaac][_sig][_]
PS (+SBR+AAC LC) al_sbr_ps_ al_sbr_ps_[_]
SSC ssc__[_sig] ssc___[_sig][_]
DST dst__[_sig] dst___[_sig][_]
Layer-3 l3_ l3_
4 © ISO/IEC 2010 – All rights reserved
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ISO/IEC 14496-26:2010(E)
ER BSAC er_bs__ep er_bs_[_lay]
[]
ER CELP er_ce_ep er_ce[_lay]
[]
ER HILN er_hi_ep er_hi[_lay]
[] [_s][_p
ER HVXC er_hv_ep er_hv[_lay]_
[]
ER Parametric er_pa_ep er_pa[_lay]_
[]
ER Twin VQ er_tv_ep er_tv[_lay]
[]
HVXC hv hv[_lay]_ref
Algorithmic Synthesis sy sy
and Audio FX
TTSI tts tts
TwinVQ tv tv[_lay]
ALS als__ als__
SLS sls__ sls__
Layer-1 l1_ l1_
Layer-2 l2_ l2_
ER AAC ELD er_eld__ep er_eld_
[]
can be 16 or 24 and indicates the bit resolution of the coded wavefile
indicates the channel for multi-channel sequences (f - number of the front channel,
b- number of the back channel, s - number of the side channel, l - number of
the LSF channel).
indicates the coder used to encode the content (ce – CELP, sa – Structured Audio, pcm – PCM)
refers to a certain audio coder setup. It is most likely a number, but might also contain
characters.
refers to the decoder delay, it can become “ld” (low delay) or “nd” (normal delay).
can be 0, 1, 2 or 3, depending on epConfig (defined in AudioSpecificConfig).
is required if (epConfig==2 || epConfig==3). It refers to a certain error protection setup.
sampling frequency (08, 11, 12, 16, 22, 24, 32, 44, 48, 64, 88 or 96).
_level refers to the level with regard to DRC.
_cut_boost referes to the cut and boost factors with regard to DRC.
_lay is required for any scalable configuration. It marks the highest layer of the scalable
configuration used for decoding (starting with 0 for the core layer).
_p is a number refering to the decoder configuration with regard to the pitch factor.
_ref is a number refering to the decoder configuration with regard to delay mode, speed and pitch
change.
_s is a number refering to the decoder configuration with regard to the speed factor.
© ISO/IEC 2010 – All rights reserved 5
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ISO/IEC 14496-26:2010(E)
indicates the SBR module mainly targeted by the test sequence. Possible values are “e” for testing the
envelope adjuster “s” for testing sine addition, “gh” for testing time-grid transitions in combination with changes
of SBR header data, “i” for testing inverse filtering, “qmf” for testing the QMF implementation, “cm” for testing
various channel modes, “sig” for testing SBR signaling, “twi” for QMF identification, and “sr” for testing various
combinations of sampling rates.
is the abbreviation of one of the AudioBIFS v3 node names.
corresponds to the number of channels present in the conformance test sequence. It is either a
single integer, in which case it refers to the number of main audio channels, or two integers separated by a “.”,
in which case the first integer equals the number of main audio channels, while the second number equals the
number of low frequency enhancement channels.
fsaac corresponds to the sampling rate of the und
...
INTERNATIONAL ISO/IEC
STANDARD 14496-26
First edition
2010-##-##
Information technology — Coding of
audio-visual objects —
Part 26:
Audio conformance
Technologies de l'information — Codage des objets audiovisuels —
Partie 26: Conformité audio
PROOF/ÉPREUVE
Reference number
ISO/IEC 14496-26:2010(E)
©
ISO/IEC 2010
---------------------- Page: 1 ----------------------
ISO/IEC 14496-26:2010(E)
PDF disclaimer
PDF files may contain embedded typefaces. In accordance with Adobe's licensing policy, such files may be printed or viewed but shall
not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In
downloading a PDF file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat
accepts no liability in this area.
Adobe is a trademark of Adobe Systems Incorporated.
Details of the software products used to create the PDF file(s) constituting this document can be found in the General Info relative to
the file(s); the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the files are suitable for
use by ISO member bodies. In the unlikely event that a problem relating to them is found, please inform the Central Secretariat at the
address given below.
COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2010
All rights reserved. Unless required for installation or otherwise specified, no part of these DVDs may be reproduced, stored in a retrieval
system or transmitted in any form or by any means without prior permission from ISO. Requests for permission to reproduce this product
should be addressed to
ISO copyright office • Case postale 56 • CH-1211 Geneva 20 • Switzerland
Internet copyright@iso.org
Reproduction may be subject to royalty payments or a licensing agreement.
Violators may be prosecuted.
Published in Switzerland
ii PROOF/ÉPREUVE © ISO/IEC 2010 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/IEC 14496-26:2010(E)
These DVDs contain:
1) the publication ISO/IEC 14496-26:2010 in portable document format (PDF), which can be viewed
using Adobe® Acrobat® Reader;
2) electronic attachments for audio conformance.
Adobe and Acrobat are trademarks of Adobe Systems Incorporated.
Installation
If this publication has been packaged as a zipped file, do NOT open the file from the DVD, but copy it to the
desired location in your local environment. Once the file has been copied to your local environment, open the
file to unzip its contents. For compound documents (e.g. HTML documents comprising several files or folders,
documents that have been subdivided owing to the total file size, etc.), in order for the links between
documents to function properly, the file and folder names must be maintained and all the files stored in the
same folder.
Where the zip file contains a Readme file, it is essential to consult this file to understand the way in which the
document has been structured.
© ISO/IEC 2010 – All righ
...
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 14496-26
ISO/JTC 1/SC 29
Information technology — Coding of
Secretariat: ANSI
audio-visual objects —
Voting begins on:
2010-02-24
Part 26:
Audio conformance
Voting terminates on:
2010-04-24
Technologies de l'information — Codage des objets audiovisuels —
Partie 26: Conformité audio
Please see the administrative notes on page iii
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ISO/FDIS 14496-26:2010(E)
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NATIONAL REGULATIONS. ISO 2010
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ISO/FDIS 14496-26:2010(E)
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ii © ISO 2010 – All rights reserved
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ISO/IEC FDIS 14496-26:2010(E)
In accordance with the provisions of Council Resolution 21/1986, this document is circulated in the
English language only.
© ISO/IEC 2010 – All rights reserved iii
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ISO/IEC FDIS 14496-26:2010(E)
Contents Page
Foreword. vi
Introduction . viii
1 Scope.1
2 Normative references.1
3 Terms and definitions .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.14
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.44
7.7 CELP.52
7.8 ER CELP.56
7.9 HVXC.61
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.102
7.18 PS (Parametric Stereo).113
7.19 SSC (SinuSoidal Coding) .115
7.20 DST (Lossless coding of oversampled audio).121
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.131
8 Audio EP tool .134
8.1 Compressed data.134
8.2 Decoders.137
9 Audio Composition.142
9.1 AudioBIFS v1.142
9.2 Advanced Audio BIFS nodes.153
9.3 AudioBIFS v3 Nodes .179
10 MPEG-4 audio transport stream.197
10.1 General.197
10.2 Compressed Data.198
10.3 Decoders.198
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ISO/IEC FDIS 14496-26:2010(E)
11 Upstream.199
11.1 Compressed data .199
11.2 Decoders.200
12 Conformance test sequence assignment to profiles and levels .200
12.1 Overview.200
12.2 Audio.200
12.3 Systems.216
Annex A (informative) Complexity measurement criteria and tool for level definitions of
algorithmic synthesis and AudioFX Object Type .221
Annex B (informative) Test bitstreams for the CELP object type .242
© ISO/IEC 2010 – All rights reserved v
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ISO/IEC FDIS 14496-26:2010(E)
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.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 14496-26 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 29, Coding of audio, picture, multimedia and hypermedia information.
This part of ISO/IEC 14496 cancels and replaces:
⎯ ISO/IEC 14496-4:2004, Clause 6,
⎯ ISO/IEC 14496-4:2004/Cor.5,
⎯ ISO/IEC 14496-4:2004/Cor.6,
⎯ ISO/IEC 14496-4:2004/Amd.8:2005, including ISO/IEC 14496:2004/Amd.8:2005/Cor.1:2008,
⎯ ISO/IEC 14496-4:2004/Amd.11:2006, including ISO/IEC 14496-4:2004/Amd.11:2006/Cor.1:2008,
⎯ ISO/IEC 14496-4:2004/Amd.11:2006/Cor.2:2007,
⎯ ISO/IEC 14496-4:2004/Amd.11:2006/Cor.3:2008,
⎯ ISO/IEC 14496:2004-4/Amd.13:2007, including ISO/IEC 14496-4:2004/Amd.13:2007/Cor.1:2007,
⎯ ISO/IEC 14496:2004-4/Amd.13:2007/Cor.2:2007,
⎯ ISO/IEC 14496-4:2004/Amd.14:2007,
⎯ ISO/IEC 14496-4:2004/Amd.15:2007,
⎯ ISO/IEC 14496-4:2004/Amd.18:2007,
⎯ ISO/IEC 14496-4:2004/Amd.19:2007, including ISO/IEC 14496-4:2004/Amd.19:2007/Cor.1:2008,
⎯ ISO/IEC 14496-4:2004/Amd.20:2008, and
⎯ ISO/IEC 14496-4:2004/Amd.22:2008.
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ISO/IEC FDIS 14496-26:2010(E)
ISO/IEC 14496 consists of the following parts, under the general title Information technology — Coding of
audio-visual objects:
⎯ Part 1: Systems
⎯ Part 2: Visual
⎯ Part 3: Audio
⎯ Part 4: Conformance testing
⎯ Part 5: Reference software
⎯ Part 6: Delivery Multimedia Integration Framework (DMIF)
⎯ Part 7: Optimised reference software for coding of audio-visual objects
⎯ Part 8: Carriage of ISO/IEC 14496 contents over IP networks
⎯ Part 9: Reference hardware description
⎯ Part 10: Advanced Video Coding
⎯ Part 11: Scene description and application engine
⎯ Part 12: ISO base media file format
⎯ Part 13: Intellectual Property Management and Protection (IPMP) extensions
⎯ Part 14: MP4 file format
⎯ Part 15: Advanced Video Coding (AVC) file format
⎯ Part 16: Animation Framework eXtension (AFX)
⎯ Part 17: Streaming text format
⎯ Part 18: Font compression and streaming
⎯ Part 19: Synthesized texture stream
⎯ Part 20: Lightweight Application Scene Representation (LASeR) and Simple Aggregation Format (SAF)
⎯ Part 21: MPEG-J Graphics Framework eXtensions (GFX)
⎯ Part 22: Open Font Format
⎯ Part 23: Symbolic Music Representation
⎯ Part 24: Audio and systems interaction [Technical Report]
⎯ Part 25: 3D Graphics Compression Model
⎯ Part 26: Audio conformance
⎯ Part 27: 3D Graphics conformance
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ISO/IEC FDIS 14496-26:2010(E)
Introduction
ISO/IEC 14496-3 specifies coded representations of audio information. ISO/IEC 14496-3 allows for large
flexibility, achieving suitability of ISO/IEC 14496 for many different applications. The flexibility is obtained by
including parameters in the bitstream that define the characteristics of coded bitstreams. Examples are the
audio sampling frequency bitrate parameters, synchronisation timestamps, the association of bitstreams and
synthetic objects within objects.
This part of ISO/IEC 14496 specifies how tests can be designed to verify whether bitstreams and decoders
meet the requirements as specified in ISO/IEC 14496-3 and allow interoperability with remote terminals in
interactive, broadcast and local (with stored contents) sessions. These tests can be used for various purposes
such as
⎯ manufacturers of encoders, and their customers, can use the tests to verify whether the encoder
produces bitstreams compliant with ISO/IEC 14496-3,
⎯ manufacturers of decoders and their customers can use the tests to verify whether the decoder meets the
requirements specified in ISO/IEC 14496-3 for the claimed decoder capabilities,
⎯ manufacturers and customers of terminals supporting interactive, broadcast and local sessions over a
multitude of transport protocols and networks, can use the tests to verify whether the claimed
functionalities are compliant with ISO/IEC 14496-6,
⎯ manufacturers of test equipments, and their customers can use the tests to verify compliance with
ISO/IEC 14496-3.
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FINAL DRAFT INTERNATIONAL STANDARD ISO/IEC 14496-26:2010(E)
Information technology — Coding of audio-visual objects —
Part 26:
Audio conformance
1 Scope
This part of ISO/IEC 14496 specifies how tests can be designed to verify whether compressed data and
decoders meet requirements specified by ISO/IEC 14496-3. In this part of ISO/IEC 14496, encoders are not
addressed specifically. An encoder may be said to be an ISO/IEC 14496 encoder if it generates compressed
data compliant with the syntactic and semantic bitstream payload requirements specified in ISO/IEC 14496-3.
Characteristics of compressed data and decoders are defined for ISO/IEC 14496-3. The compressed data
characteristics define the subset of the standard that is exploited in the compressed data. Examples are the
applied values or range of the sampling rate and bitrate parameters. Decoder characteristics define the
properties and capabilities of the applied decoding process. An example of a property is the applied arithmetic
accuracy. The capabilities of a decoder specify which compressed data the decoder can decode and
reconstruct, by defining the subset of the standard that may be exploited in the decodable compressed data.
Compressed data can be decoded by a decoder if the characteristics of the compressed data are within the
subset of the standard specified by the decoder capabilities.
Procedures are described for testing conformance of compressed data and decoders to the requirements
defined in ISO/IEC 14496-3. Given the set of characteristics claimed, the requirements that must be met are
fully determined by ISO/IEC 14496-3. This part of ISO/IEC 14496 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).
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 11172-3, Information technology — Coding of moving pictures and associated audio for digital
storage media at up to about 1,5 Mbit/s — Part 3: Audio
ISO/IEC 11172-4, Information technology — Coding of moving pictures and associated audio for digital
storage media at up to about 1,5 Mbit/s — Part 4: Compliance testing
ISO/IEC 13818-3, Information technology — Generic coding of moving pictures and associated audio
information — Part 3: Audio
ISO/IEC 13818-4, Information technology — Generic coding of moving pictures and associated audio
information — Part 4: Conformance testing
ISO/IEC 13818-7, Information technology — Generic coding of moving pictures and associated audio
information — Part 7: Advanced Audio Coding (AAC)
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ISO/IEC FDIS 14496-26:2010(E)
ISO/IEC 14496-1, Information technology — Coding of audio-visual objects — Part 1: Systems
ISO/IEC 14496-3, Information technology — Coding of audio-visual objects — Part 3: Audio
ISO/IEC 14496-11, Information technology — Coding of audio-visual objects — Part 11: Scene description
and application engine
3 Terms and definitions
For the purposes of this document the terms, defintions, symbols and abbreviated terms given in
ISO/IEC 14496-1, ISO/IEC 14496-3 and the following apply.
3.1
conformance data
conformance test sequences and conformance tools
3.2
conformance tool
tool to check certain conformance criteria
NOTE Conformance tools are provided in the electronic attachments to this part of ISO/IEC 14496.
3.3
conformance test sequence
superset of compressed data and its reference waveforms
NOTE Examples of conformance test sequences are provided in the electronic attachments to this part of
ISO/IEC 14496.
3.4
compressed data
data encoded in accordance with ISO/IEC 14496-3
3.5
reference waveform
decoded counterparts of the compressed data
4 Conformance Points
All audio decoders except the LATM-based decoders are part of the MPEG-4 framework. Table 1 gives an
overview about the interfaces that have to be provided to test the audio decoders using the MPEG-4 System.
Table 1 — Conformance points
conformance point/interface data flow description/reference
direction
AudioSpecificConfig in audio related decoder specific information, see ISO/IEC 14496-3:2009, (1.6.2.1
AudioSpecificConfig)
audio access units in audio related bitstream payload, see ISO/IEC 14496-1:2004 (7.1.2.3 Access Units (AU))
BIFS/AudioSource node in see ISO/IEC 14496-11: 2005 (7.2.2.15 Audio Source)
private test info in to control some elements which are usually generated by random number generators
audio composition units out see ISO/IEC 14496-1: 2004 (7.2.8 Composition Units (CU))
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ISO/IEC FDIS 14496-26:2010(E)
Figure 1 gives an overview about the test bench (MPEG-4 System), the system under test (Audio decoder),
and the interfaces between them. Figure 2 gives a more detailed view on the audio decoder, consisting of
error protection (EP) decoder and audio core decoder.
MPEG-4 System
AudioSpecificConfig private test info
*.mp4 audio presentation
BIFS(AudioSource)
file format
Node fields
Audio Decoder
audio composition units
audio access units
(incl. time stamps for SA, TTS)
Figure 1 — Audio Conformance Points
Audio Decoder
2
EP Decoder Audio
directMapping
0
3
Core
epConfig
2/3
1
1
Decoder
0
Figure 2 — Audio decoder structure
Clause 7 describes:
The conformance criteria of the audio core decoder.
The conformance criteria of the compressed data not requiring the EP decoder (epConfig == 0 || epConfig
== 1).
The properties of the examples of compressed data with (epConfig == 0 || epConfig == 1).
Clause 8 describes:
The conformance criteria of the EP decoder
The conformance criteria of the compressed data requiring the EP decoder (epConfig == 2 || epConfig == 3).
The properties of the examples of compressed data with (epConfig == 2 || epConfig == 3).
Compressed data with different epConfig settings might be available referring to the same reference
waveforms. Here, the output of a conforming decoder shall be equal, independently of the used epConfig
setting.
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ISO/IEC FDIS 14496-26:2010(E)
For some of the compressed data containing scalable configurations, conformance points are defined at the
PCM output of the decoder for m layers being decoded from an n-layer input, where m is an integer in the
range 0 (base layer conformance) to n-1. The reference PCM decoder output signals corresponding to these
conformance points are listed in the respective conformance tables.
5 Profiles
ISO/IEC 14496-3 defines several profiles and several levels within each profile. Conformance is always tested
against a certain level within a certain profile. Audio profiles always comprise a set of audio object types.
Nevertheless the conformance criteria as described within this document are based on audio object types.
The assignment of object types to profiles as well as the level definitions can be found in ISO/IEC 14496-3.
The conformance of a certain level within a certain profile is fulfilled, if the conformance of each object type
belonging to this profile is fulfilled. The assignment of the provided test sequences to profiles and levels can
be found in Clause 12.
6 Conformance data
6.1 File name conventions
For all conformance test sequences, the file name convention given in Table 2 is used.
Table 2 — File name conventions
object type name/ tool name File Name (compressed) File Name (uncompressed)
AdvancedAudioBIFS aabper -- not applicable --
- perceptual apporach
AdvancedAudioBIFS aabphy -- not applicable --
- physical approach
AudioBIFS ab_ ab_
AudioBIFS v3 ABv3_ -- not applicable --
AAC scalable ac ac[_lay]
AAC LC al_ al_[_cut_boost]
[_level][_]
AAC main am_ am_[_cut_boost]
[_level][_]
AAC LTP ap_ ap_
AAC SSR as_ as_[_]
CELP ce ce[_lay]
ER AAC scalable er_ac_ep er_ac[_lay]
[]
ER AAC LD er_ad__ep er_ad_
[]
ER AAC LC er_al__ep er_al_
[]
ER AAC LTP er_ap__ep er_ap_
[]
SBR (+AAC LC) al_sbr___[_fsaac al_sbr____
][_sig] [_fsaac][_sig][_]
SBR (+AAC LC with al960_sbr___ al960_sbr____
960 samples per frame ) [_fsaac][_sig] [_fsaac][_sig][_]
PS (+SBR+AAC LC) al_sbr_ps_ al_sbr_ps_[_]
SSC ssc__[_sig] ssc___[_sig][_]
DST dst__[_sig] dst___[_sig][_]
Layer-3 l3_ l3_
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ISO/IEC FDIS 14496-26:2010(E)
ER BSAC er_bs__ep er_bs_[_lay]
[]
ER CELP er_ce_ep er_ce[_lay]
[]
ER HILN er_hi_ep er_hi[_lay]
[] [_s][_p
ER HVXC er_hv_ep er_hv[_lay]_
[]
ER Parametric er_pa_ep er_pa[_lay]_
[]
ER Twin VQ er_tv_ep er_tv[_lay]
[]
HVXC hv hv[_lay]_ref
Algorithmic Synthesis sy sy
and Audio FX
TTSI tts tts
TwinVQ tv tv[_lay]
ALS als__ als__
SLS sls__ sls__
Layer-1 l1_ l1_
Layer-2 l2_ l2_
ER AAC ELD er_eld__ep er_eld_
[]
can be 16 or 24 and indicates the bit resolution of the coded wavefile
indicates the channel for multi-channel sequences (f - number of the front channel,
b- number of the back channel, s - number of the side channel, l - number of
the LSF channel).
indicates the coder used to encode the content (ce – CELP, sa – Structured Audio, pcm – PCM)
refers to a certain audio coder setup. It is most likely a number, but might also contain
characters.
refers to the decoder delay, it can become “ld” (low delay) or “nd” (normal delay).
can be 0, 1, 2 or 3, depending on epConfig (defined in AudioSpecificConfig).
is required if (epConfig==2 || epConfig==3). It refers to a certain error protection setup.
sampling frequency (08, 11, 12, 16, 22, 24, 32, 44, 48, 64, 88 or 96).
_level refers to the level with regard to DRC.
_cut_boost referes to the cut and boost factors with regard to DRC.
_lay is required for any scalable configuration. It marks the highest layer of the scalable
configuration used for decoding (starting with 0 for the core layer).
_p is a number refering to the decoder configuration with regard to the pitch factor.
_ref is a number refering to the decoder configuration with regard to delay mode, speed and pitch
change.
_s
...
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