Digital audio - Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 - Part 2: Burst-info

IEC 61937-2:2021 is available as IEC 61937-2:2021 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.IEC 61937-2:2021 specifies the digital audio interface to convey non-linear PCM encoded audio bitstreams applying IEC 60958-1 and IEC 60958-3. This document specifies burst-info, which defines content information about the data contained in the burst-payload. IEC 61937-2:2021 cancels and replaces the second edition published in 2007, Amendment 1:2011 and Amendment 2:2018. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) new audio data-types of MPEG-D USAC, ACX, ACX HBR2, ACX HBR4 and ACX HBR8 have been added;
b) extended data-type field in Pe has been activated.

Audionumérique - Interface pour les flux de bits audio à codage MIC non linéaire selon l'IEC 60958 - Partie 2: Informations relatives à la salve

IEC 61937-2:2021 est disponible sous forme de IEC 61937-2:2021 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.L'IEC 61937-2:2021 spécifie l'interface audionumérique pour l'acheminement des flux de bits audio à codage MIC non linéaire selon l'IEC 60958-1 et l'IEC 60958-3. Le présent document spécifie les informations relatives à la salve, qui définissent les informations de contenu concernant les données contenues dans la charge utile de la salve. L'IEC 61937-2:2021 annule et remplace la deuxième édition parue en 2007, l'Amendement 1:2011 et l'Amendement 2:2018. Cette édition constitue une révision technique. Cette édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente:
a) les nouveaux types de données audio MPEG-D USAC, ACX, ACX HBR2, ACX HBR4 et ACX HBR8 ont été ajoutés;
b) le champ de type de données étendu dans Pe a été activé.

General Information

Status
Published
Publication Date
07-Mar-2021
Current Stage
PPUB - Publication issued
Completion Date
08-Mar-2021
Ref Project

Buy Standard

Standard
IEC 61937-2:2021 - Digital audio - Interface for non-linear PCM encoded audio bitstreams applying IEC 60958 - Part 2: Burst-info
English and French language
32 pages
sale 15% off
Preview
sale 15% off
Preview

Standards Content (sample)

IEC 61937-2
Edition 3.0 2021-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Digital audio – Interface for non-linear PCM encoded audio bitstreams applying
IEC 60958 –
Part 2: Burst-info
Audionumérique – Interface pour les flux de bits audio à codage MIC non
linéaire selon l'IEC 60958 –
Partie 2: Informations relatives à la salve
IEC 61937-2:2021-03(en-fr)
---------------------- Page: 1 ----------------------
THIS PUBLICATION IS COPYRIGHT PROTECTED
Copyright © 2021 IEC, Geneva, Switzerland

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 IEC or IEC's member National Committee in the country of the requester. If you have any questions about IEC

copyright or have an enquiry about obtaining additional rights to this publication, please contact the address below or

your local IEC member National Committee for further information.

Droits de reproduction réservés. Sauf indication contraire, aucune partie de cette publication ne peut être reproduite

ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie

et les microfilms, sans l'accord écrit de l'IEC ou du Comité national de l'IEC du pays du demandeur. Si vous avez des

questions sur le copyright de l'IEC ou si vous désirez obtenir des droits supplémentaires sur cette publication, utilisez

les coordonnées ci-après ou contactez le Comité national de l'IEC de votre pays de résidence.

IEC Central Office Tel.: +41 22 919 02 11
3, rue de Varembé info@iec.ch
CH-1211 Geneva 20 www.iec.ch
Switzerland
About the IEC

The International Electrotechnical Commission (IEC) is the leading global organization that prepares and publishes

International Standards for all electrical, electronic and related technologies.
About IEC publications

The technical content of IEC publications is kept under constant review by the IEC. Please make sure that you have the

latest edition, a corrigendum or an amendment might have been published.

IEC publications search - webstore.iec.ch/advsearchform IEC online collection - oc.iec.ch

The advanced search enables to find IEC publications by a Discover our powerful search engine and read freely all the

variety of criteria (reference number, text, technical publications previews. With a subscription you will always

committee, …). It also gives information on projects, replaced have access to up to date content tailored to your needs.

and withdrawn publications.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
The world's leading online dictionary on electrotechnology,
Stay up to date on all new IEC publications. Just Published
containing more than 22 000 terminological entries in English
details all new publications released. Available online and
and French, with equivalent terms in 18 additional languages.
once a month by email.
Also known as the International Electrotechnical Vocabulary
(IEV) online.
IEC Customer Service Centre - webstore.iec.ch/csc
If you wish to give us your feedback on this publication or
need further assistance, please contact the Customer Service
Centre: sales@iec.ch.
A propos de l'IEC

La Commission Electrotechnique Internationale (IEC) est la première organisation mondiale qui élabore et publie des

Normes internationales pour tout ce qui a trait à l'électricité, à l'électronique et aux technologies apparentées.

A propos des publications IEC

Le contenu technique des publications IEC est constamment revu. Veuillez vous assurer que vous possédez l’édition la

plus récente, un corrigendum ou amendement peut avoir été publié.
Recherche de publications IEC - IEC online collection - oc.iec.ch

webstore.iec.ch/advsearchform Découvrez notre puissant moteur de recherche et consultez

La recherche avancée permet de trouver des publications IEC gratuitement tous les aperçus des publications. Avec un

en utilisant différents critères (numéro de référence, texte, abonnement, vous aurez toujours accès à un contenu à jour

comité d’études, …). Elle donne aussi des informations sur adapté à vos besoins.
les projets et les publications remplacées ou retirées.
Electropedia - www.electropedia.org
IEC Just Published - webstore.iec.ch/justpublished
Le premier dictionnaire d'électrotechnologie en ligne au
Restez informé sur les nouvelles publications IEC. Just
monde, avec plus de 22 000 articles terminologiques en
Published détaille les nouvelles publications parues.
anglais et en français, ainsi que les termes équivalents dans
Disponible en ligne et une fois par mois par email.
16 langues additionnelles. Egalement appelé Vocabulaire
Electrotechnique International (IEV) en ligne.
Service Clients - webstore.iec.ch/csc
Si vous désirez nous donner des commentaires sur cette
publication ou si vous avez des questions contactez-nous:
sales@iec.ch.
---------------------- Page: 2 ----------------------
IEC 61937-2
Edition 3.0 2021-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Digital audio – Interface for non-linear PCM encoded audio bitstreams applying
IEC 60958 –
Part 2: Burst-info
Audionumérique – Interface pour les flux de bits audio à codage MIC non
linéaire selon l'IEC 60958 –
Partie 2: Informations relatives à la salve
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.160.30 ISBN 978-2-8322-9522-9

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 61937-2:2021 © IEC 2021
CONTENTS

FOREWORD ........................................................................................................................... 3

1 Scope .............................................................................................................................. 5

2 Normative references ...................................................................................................... 5

3 Terms and definitions ...................................................................................................... 6

4 Burst-info ......................................................................................................................... 8

4.1 General ................................................................................................................... 8

4.2 Data-type, subdata-type and extended data-type .................................................... 8

4.3 Audio data-bursts .................................................................................................. 10

4.3.1 General ......................................................................................................... 10

4.3.2 AC-3 .............................................................................................................. 10

4.3.3 MPEG-1 layer-1 ............................................................................................. 11

4.3.4 MPEG-1 layer-2 or layer-3 or MPEG-2 without extension ............................... 11

4.3.5 MPEG-2 with extension ................................................................................. 11

4.3.6 MPEG-2 AAC ................................................................................................. 11

4.3.7 MPEG-2 layer-1 low sampling frequency........................................................ 11

4.3.8 MPEG-2 layer-2 low sampling frequency........................................................ 11

4.3.9 MPEG-2 layer-3 low sampling frequency........................................................ 11

4.3.10 DTS type I ..................................................................................................... 11

4.3.11 DTS type II .................................................................................................... 11

4.3.12 DTS type III ................................................................................................... 12

4.3.13 DTS type IV ................................................................................................... 12

4.3.14 ATRAC .......................................................................................................... 12

4.3.15 ATRAC 2/3 .................................................................................................... 12

4.3.16 ATRAC-X ....................................................................................................... 12

4.3.17 MPEG-2 AAC low sampling frequency ........................................................... 12

4.3.18 MPEG-4 AAC ................................................................................................. 12

4.3.19 Windows Media Audio professional ................................................................ 12

4.3.20 Enhanced AC-3 ............................................................................................. 13

4.3.21 MAT .............................................................................................................. 13

4.3.22 MPEG-4 ALS ................................................................................................. 13

4.3.23 MPEG-4 AAC LC in LATM/LOAS ................................................................... 13

4.3.24 MPEG-4 HE AAC in LATM/LOAS ................................................................... 13

4.3.25 DRA .............................................................................................................. 14

4.3.26 ATRAC-X low latency .................................................................................... 14

4.3.27 MPEG-H 3D Audio ......................................................................................... 14

4.3.28 AC-4, AC-4 HBR4, AC-4 HBR16 and AC-4 LD ............................................... 14

4.3.29 MPEG-4 ALS in LATM/LOAS ......................................................................... 14

4.3.30 MPEG-D USAC in LATM/LOAS ...................................................................... 14

4.3.31 ACX, ACX HBR2, ACX HBR4 and ACX HBR8 ................................................ 15

Bibliography .......................................................................................................................... 16

Table 1 – Fields of burst-info .................................................................................................. 8

Table 2 – Data-types............................................................................................................... 9

Table 3 – Extended data-types ............................................................................................. 10

---------------------- Page: 4 ----------------------
IEC 61937-2:2021 © IEC 2021 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
DIGITAL AUDIO – INTERFACE FOR NON-LINEAR PCM
ENCODED AUDIO BITSTREAMS APPLYING IEC 60958 –
Part 2: Burst-info
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international

co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and

in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,

Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their

preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with

may participate in this preparatory work. International, governmental and non-governmental organizations liaising

with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for

Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence between

any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.

5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity

assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any

services carried out by independent certification bodies.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.

8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent

rights. IEC shall not be held responsible for identifying any or all such patent rights.

IEC 61937-2 has been prepared by technical area 20: Analogue and digital audio, of IEC

technical committee 100: Audio, video and multimedia systems and equipment. It is an

International Standard.
This third edition cancels and replaces the second edition published in 2007,

Amendment 1:2011 and Amendment 2:2018. This edition constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:

a) new audio data-types of MPEG-D USAC, ACX, ACX HBR2, ACX HBR4 and ACX HBR8 have

been added;
b) extended data-type field in Pe has been activated.
---------------------- Page: 5 ----------------------
– 4 – IEC 61937-2:2021 © IEC 2021
The text of this International Standard is based on the following documents:
Draft Report on voting
100/3459/CDV 100/3541/RVC

Full information on the voting for its approval can be found in the report on voting indicated in

the above table.
The language used for the development of this International Standard is English.

This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in

accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available

at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are

described in greater detail at www.iec.ch/standardsdev/publications.

The list of all the parts of the IEC 61937 series, under the general title Digital audio – Interface

for non-linear PCM encoded audio bitstreams applying IEC 60958, can be found on the IEC

website.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under webstore.iec.ch in the data related to the

specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
---------------------- Page: 6 ----------------------
IEC 61937-2:2021 © IEC 2021 – 5 –
DIGITAL AUDIO – INTERFACE FOR NON-LINEAR PCM
ENCODED AUDIO BITSTREAMS APPLYING IEC 60958 –
Part 2: Burst-info
1 Scope

This part of IEC 61937 specifies the digital audio interface to convey non-linear PCM encoded

audio bitstreams applying IEC 60958-1 and IEC 60958-3. This document specifies burst-info,

which defines content information about the data contained in the burst-payload.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements 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.
IEC 60958-1, Digital audio interface – Part 1: General
IEC 60958-3, Digital audio interface – Part 3: Consumer applications

IEC 61937-1:2021, Digital audio – Interface for non-linear PCM encoded audio bitstreams

applying IEC 60958 – Part 1: General

IEC 61937-3, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 3: Non-linear PCM bitstreams according to the AC-3 format

IEC 61937-4, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 4: Non-linear PCM bitstreams according to the MPEG audio format

IEC 61937-5, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 5: Non-linear PCM bitstreams according to the DTS (Digital Theater Systems)

format(s)

IEC 61937-6, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 6: Non-linear PCM bitstreams according to the MPEG-2 AAC and MPEG-4

AAC audio formats

IEC 61937-7, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 7: Non-linear PCM bitstreams according to the ATRAC, ATRAC2/3 and

ATRAC-X formats

IEC 61937-8, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 8: Non-linear PCM bitstreams according to the Windows Media Audio (WMA)

Professional format

IEC 61937-9, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 9: Non-linear PCM bitstreams according to the MAT format
---------------------- Page: 7 ----------------------
– 6 – IEC 61937-2:2021 © IEC 2021

IEC 61937-10, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 10: Non-linear PCM bitstreams according to the MPEG-4 audio lossless

coding (ALS) format

IEC 61937-11, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 11: MPEG-4 AAC and its extensions in LATM/LOAS

IEC 61937-12, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 12: Non-linear PCM bitstreams according to the DRA formats

IEC 61937-13, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 13: MPEG-H 3D Audio

IEC 61937-14, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 14: Non-linear PCM bitstreams according to the AC-4 format

IEC 61937-15, Digital audio – Interface for non-linear PCM encoded audio bitstreams applying

IEC 60958 – Part 15: Non-linear PCM bit streams according to Auro-Cx format
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following

addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
audio data-burst
data-burst with an encoded audio frame as burst-payload
3.2
audio data-word
16-bit data-word
3.3
audio frame
fixed number of audio samples

Note 1 to entry: The number of samples in an audio frame is dependent on the particular encoding system that is

used to encode the audio frame into the encoded audio frame.
3.4
audio gap

period in the sequence of baseband audio samples where valid samples of audio are not

available
3.5
bitstream
non-linear PCM encoded audio source, represented in a sequence of bits

Note 1 to entry: In this interface, the bitstream consists of a sequence of data-bursts.

3.6
data-burst

packet of data, including the burst-preamble, to be transmitted across the interface

---------------------- Page: 8 ----------------------
IEC 61937-2:2021 © IEC 2021 – 7 –
3.7
burst-payload
information content of the data-burst
3.8
burst-preamble

header for the data-burst, containing synchronization and information about the data contained

in the burst-payload
3.9
data-type
reference to the type of payload of the data-bursts
3.10
encoded audio frame
minimum decodable unit of an encoded data sequence

Note 1 to entry: Each encoded audio frame is the encoded representation of a fixed number of audio samples (for

each original audio channel). The number of samples that are encoded into an encoded audio frame depends on the

particular encoding system used to encode the audio frame into the encoded audio frame.

3.11
length-code
length of the data-burst-payload in bits, bytes or 8-byte units
3.12
repetition period

period between the reference point of the current data-burst, and the reference point of the

immediately following data-burst of the same data-type
3.13
sampling frequency

frequency of the encoded PCM audio samples (i.e. before encoding and after decoding)

3.14
sampling period

period related to the sampling frequency of the PCM audio samples, represented in the encoded

bitstream
3.15
stuffing
occupation of the unused data capacity of the interface
3.16
stuffing sub-frame
occupation of the unused data capacity in 16-bit audio data-words
3.17
stream gap

period within the encoded audio bitstream without any audio frame; a discontinuity in the

bitstream

Note 1 to entry: Typically, a stream gap will occur between encoded audio frames.

---------------------- Page: 9 ----------------------
– 8 – IEC 61937-2:2021 © IEC 2021
4 Burst-info
4.1 General

The 16-bit burst-info contains information about the data found in the data-burst. Fields of burst-

info are specified in Table 1.
Table 1 – Fields of burst-info
Bits of Pc Value Contents
0 to 6 Data-type (defined in IEC 61937-1)
0 to 4 Conventional data-type
0 to 31 See Table 2
5 to 6 Subdata-type
0 to 3 See Table 2
7 Error-flag
0 Error-flag indicating a valid burst-payload
1 Error-flag indicating that the burst-payload may contain errors
8 to 2 Data-type-dependent info
13 to 15 0 to 7 Bit-stream-number
NOTE Refer to IEC 61937-1:2021, 6.1.8.1 and 6.1.8.2.
4.2 Data-type, subdata-type and extended data-type

Data-type defined in Pc bits 0-6 in IEC 61937-1 consists of conventional data-type (0 to 4) and

sub-data-type (5 to 6) for historical reasons. All conventional data-types and subdata-types are

defined in Table 2.

Extended data-type is defined in Pe bits 0 to 15 in IEC 61937-1. All extended data-types are

defined in Table 3.
---------------------- Page: 10 ----------------------
IEC 61937-2:2021 © IEC 2021 – 9 –
Table 2 – Data-types
Data-type Contents Reference Repetition period Units of
value of Pc bit 0 to 6 point R of data-burst Pd
measured in
Conventional Subdata-
IEC 60958 frames
data-type type
Value of data- Value of
type bits data-
type bits
0 to 4
5 to 6
0 0 Null data
1 0 AC-3 data R-AC-3 1 536 bits
2 0 to 3 Refer to SMPTE ST 338 bits
3 0 Pause bit 0 of Pa bits
4 0 MPEG-1 layer 1 data bit 0 of Pa 384 bits
MPEG-1 layer 2 or 3 data or bits
5 0 bit 0 of Pa 1 152
MPEG-2 without extension
6 0 MPEG-2 data with extension bit 0 of Pa 1 152 bits
7 0 MPEG-2 AAC bit 0 of Pa 1 024 bits
MPEG-2, layer-1 low sampling bits
8 0 bit 0 of Pa 768
frequency
MPEG-2, layer-2 low sampling bits
9 0 bit 0 of Pa 2 304
frequency
MPEG-2, layer-3 low sampling bits
10 0 bit 0 of Pa 1 152
frequency
11 0 DTS type I bit 0 of Pa 512 bits
12 0 DTS type II bit 0 of Pa 1 024 bits
13 0 DTS type III bit 0 of Pa 2 048 bits
14 0 ATRAC bit 0 of Pa 512 bits
15 0 ATRAC 2/3 bit 0 of Pa 1 024 bits
0 ATRAC-X bit 0 of Pa 2 048 bits
1 ATRAC-X low latency bit 0 of Pa 512 bits
2 ATRAC-X low latency bit 0 of Pa 256 bits
3 ATRAC-X low latency bit 0 of Pa 128 bits
17 0 DTS type IV bit 0 of Pa See IEC 61937-5 bytes
bits
0 WMA professional type I bit 0 of Pa 2 048
1 WMA professional type II bit 0 of Pa 2 048 bits
2 WMA professional type III bit 0 of Pa 1 024 bits
3 WMA professional type IV bit 0 of Pa 512 bits
MPEG-2 AAC low sampling bits
0 bit 0 of Pa 2 048
frequency
MPEG-2 AAC low sampling bits
19 1 bit 0 of Pa 4 096
frequency
MPEG-2 AAC low sampling bits
2 to 3 reserved reserved
frequency
0 MPEG-4 AAC bit 0 of Pa 1 024 bits
1 MPEG-4 AAC bit 0 of Pa 2 048 bits
2 MPEG-4 AAC bit 0 of Pa 4 096 bits
3 MPEG-4 AAC bit 0 of Pa 512 bits
21 0 Enhanced AC-3 bit 0 of Pa 6 144 bytes
22 0 MAT R-MAT 15 360 bytes
0 MPEG-4 ALS bit 0 of Pa See IEC 61937-10 8-bytes
1 MPEG-4 AAC LC in LATM/LOAS bit 0 of Pa See IEC 61937-11 bits
2 MPEG-4 HE AAC in LATM/LOAS bit 0 of Pa See IEC 61937-11 bits
3 DRA bit 0 of Pa See IEC 61937-12 bits
---------------------- Page: 11 ----------------------
– 10 – IEC 61937-2:2021 © IEC 2021
Data-type Contents Reference Repetition period Units of
value of Pc bit 0 to 6 point R of data-burst Pd
measured in
Conventional Subdata-
IEC 60958 frames
data-type type
Value of data- Value of
type bits data-
type bits
0 to 4
5 to 6
0 AC-4 bit 0 of Pa See IEC 61937-14 bytes
1 AC-4 HBR4 bit 0 of Pa See IEC 61937-14 bytes
2 AC-4 HBR16 bit 0 of Pa See IEC 61937-14 8-bytes
3 AC-4 LD bit 0 of Pa See IEC 61937-14 bytes
0 MPEG-H 3D Audio bit 0 of Pa See IEC 61937-13 bytes
1 MPEG-H 3D Audio HBR bit 0 of Pa See IEC 61937-13 8-bytes
2 MPEG-4 ALS in LATM/LOAS bit 0 of Pa See IEC 61937-10 8-bytes
3 MPEG-D USAC bit 0 of Pa See IEC 61937-11 bits
0 ACX bit 0 of Pa See IEC 61937-15 bytes
1 ACX HBR2 bit 0 of Pa See IEC 61937-15 bytes
2 ACX HBR4 bit 0 of Pa See IEC 61937-15 bytes
3 ACX HBR8 bit 0 of Pa See IEC 61937-15 bytes
27 to 30 0 to 3 Refer to SMPTE ST 338 bits
0 Extended data-type (see table 3)
Extended data-type (do not use
1 to 3
until defined)
Refer to IEC 61937-1:2021, 7.4.

The repetition period of pause data-bursts depends on the application. The repetition period of pause data-

bursts is defined for each audio data-burst.
Refer to IEC 61937-8:2006, 4.2.
Table 3 – Extended data-types
Extended data-type Contents Reference Repetition period of Units of Pd
value of Pe bit 0 to 15 point R data-burst measured
in IEC 60958 frames
0 to 65 535 Reserved for future use
4.3 Audio data-bursts
4.3.1 General

Subclause 4.3 specifies the audio data-bursts. Specific properties such as reference points,

repetition period, the method of filling stream gaps, and decoding latency are specified for each

data-type.

The decoding latency (or delay), indicated for the data-types, shall be used by the transmitter

to schedule data-bursts as necessary to establish synchronization between picture and

decoded audio.
4.3.2 AC-3

The AC-3 bitstream consists of a sequence of AC-3 syncframes. The data-type of an AC-3 data-

burst is 1 and the subdata-type of an AC-3 data-burst is 0. An AC-3 syncframe represents

1 536 samples of each encoded audio channel (left, centre, etc.). The data-burst is headed with

a burst-preamble, followed by the burst-payload. The burst-payload of each data-burst of AC-3

data shall contain one complete AC-3 syncframe.
---------------------- Page: 12 ----------------------
IEC 61937-2:2021 © IEC 2021 – 11 –

The length of the AC-3 data-burst will depend on the encoded bit rate (which determines the

AC-3 syncframe length). The specification for the AC-3 bitstream is specified in IEC 61937-3.

4.3.3 MPEG-1 layer-1

An MPEG-1 layer-1 MPEG-frame represents 384 samples of each encoded channel and can be

transferred using data-type 4 and the subdata-type 0. The data-burst is headed with a burst-

preamble, followed by the burst-payload; see IEC 61937-4.
4.3.4 MPEG-1 layer-2 or layer-3 or MPEG-2 without extension

The burst-payload of MPEG-1 layer-2, or layer-3, or MPEG-2 without extension, represents

1 152 samples of each encoded channel and can be transferred using data-type 5 and sub-

data-type 0. The data-burst is headed with a burst-preamble, followed by the burst-payload;

see IEC 61937-4.
4.3.5 MPEG-2 with extension

The burst-payload of MPEG-2 with extension represents 1 152 samples of each encoded

channel and can be transferred using data-type 6 and subdata-type 0. The data-burst is headed

with a burst-preamble, followed by the burst-payload; see IEC 61937-4.
4.3.6 MPEG-2 AAC

The payload of MPEG-2 AAC represents 1 024 samples of each encoded channel and can be

transferred using data-type 7 and sub-data-type 0. The data-burst is headed wi
...

Questions, Comments and Discussion

Ask us and Technical Secretary will try to provide an answer. You can facilitate discussion about the standard in here.