SIST EN 60958-4-2:2016

SLOVENSKI STANDARD
SIST EN 60958-4-2:2016
01-december-2016
1DGRPHãþD
SIST EN 60958-4:2004
Digitalni avdio vmesnik - 4-2. del: Profesionalna uporaba - Metapodatki in subkoda
(IEC 60958-4-2:2016)
Digital audio interface - Part 4-2: Professional applications - Metadata and subcode (IEC
60958-4-2:2016)
Digitalton-Schnittstelle - Teil 4-2: Professioneller Gebrauch - Metadaten und Subcode
(IEC 60958-4-2:2016)
Interface audionumérique - Partie 4-2: Applications professionnelles - Métadonnées et
sous-code (IEC 60958-4-2:2016)
Ta slovenski standard je istoveten z: EN 60958-4-2:2016
ICS:
33.160.30 Avdio sistemi Audio systems
35.200 Vmesniška in povezovalna Interface and interconnection
oprema equipment
SIST EN 60958-4-2:2016 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 60958-4-2:2016

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SIST EN 60958-4-2:2016


EUROPEAN STANDARD EN 60958-4-2

NORME EUROPÉENNE

EUROPÄISCHE NORM
July 2016
ICS 33.160.30 Supersedes EN 60958-4:2003 (partially)
English Version
Digital audio interface -
Part 4-2: Professional applications -
Metadata and subcode
(IEC 60958-4-2:2016)
Interface audionumérique -  Digitalton-Schnittstelle -
Partie 4-2: Applications professionnelles -  Teil 4-2: Professioneller Gebrauch -
Métadonnées et sous-code Metadaten und Subcode
(IEC 60958-4-2:2016) (IEC 60958-4-2:2016)
This European Standard was approved by CENELEC on 2016-04-28. CENELEC members are bound to comply with the CEN/CENELEC
Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC
Management Centre or to any CENELEC member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.


European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
 Ref. No. EN 60958-4-2:2016 E

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SIST EN 60958-4-2:2016
EN 60958-4-2:2016
European foreword
The text of document 100/2453/CDV, future edition 1 of IEC 60958-4-2, prepared by Technical Area 4
"Digital system interfaces and protocols", of IEC/TC 100 "Audio, video and multimedia systems and
equipment" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
EN 60958-4-2:2016.
The following dates are fixed:
• latest date by which the document has to be implemented at (dop) 2017-01-28
national level by publication of an identical national
standard or by endorsement
(dow) 2019-04-28
• latest date by which the national standards conflicting with
the document have to be withdrawn

This document, together with EN 60958-4-1:2016 and EN 60958-4-4:2016, supersedes EN 60958-4:2003.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.
Endorsement notice
The text of the International Standard IEC 60958-4-2:2016 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60958 NOTE Harmonized in EN 60958 series.
IEC 62365:2009 NOTE Harmonized as EN 62365:2009 (not modified).
IEC 62537 NOTE Harmonized as EN 62537.

2

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SIST EN 60958-4-2:2016
EN 60958-4-2:2016
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
NOTE 1 When an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is
available here: www.cenelec.eu.

Publication Year Title EN/HD Year
IEC 60958-1 2008 Digital audio interface - EN 60958-1 2008
Part 1: General
+ A1 2014 + A1 2014
IEC 60958-3 -  Digital audio interface - EN 60958-3 -
Part 3: Consumer applications
IEC 60958-4-1 -  Digital audio interface - EN 60958-4-1 -
Part 4-1: Professional applications -
Audio content
IEC 60958-4-4 -  Digital audio interface - EN 60958-4-4 -
Part 4-4: Professional applications -
Physical and electrical parameters
ISO/IEC 646 -  Information technology - ISO 7-bit coded - -
character set for information interchange
ITU-R -  Transmission standards for FM sound - -
Recommendation broadcasting at VHF
BS.450-3
ITU-T -  Pre-emphasis used on sound- - -
Recommendation programme circuits
J.17

3

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SIST EN 60958-4-2:2016



IEC 60958-4-2

®


Edition 1.0 2016-03




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE











Digital audio interface –

Part 4-2: Professional applications – Metadata and subcode




Interface audionumérique –

Partie 4-2: Applications professionnelles – Métadonnées et sous-code
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE


INTERNATIONALE




ICS 33.160.30 ISBN 978-2-8322-3247-7



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

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SIST EN 60958-4-2:2016
– 2 – IEC 60958-4-2:2016 © IEC 2016
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references. 7
3 Terms, definitions and abbreviations . 7
3.1 Terms and definitions . 7
3.2 Abbreviations . 8
4 User data format . 8
5 Channel status format . 8
5.1 Channel status bit . 8
5.2 Channel status block . 8
5.3 Implementation . 9
5.3.1 Implementation levels . 9
5.3.2 Transmitter requirement . 9
5.3.3 Receiver requirement . 9
5.4 Documentation . 9
5.5 Channel status content . 9
5.5.1 General . 9
5.5.2 Byte 0: Basic audio parameters . 11
5.5.3 Byte 1: Channel modes, user bits management . 12
5.5.4 Byte 2: Auxiliary bits, word length and alignment level . 12
5.5.5 Byte 3: Multichannel modes . 13
5.5.6 Byte 4: DARS, hidden information, multiple-rate sampling frequencies . 14
5.5.7 Byte 5: Reserved . 15
5.5.8 Bytes 6 to 9: Alphanumeric channel origin . 16
5.5.9 Bytes 10 to 13: Alphanumeric channel destination . 16
5.5.10 Bytes 14 to 17: Local sample address code . 16
5.5.11 Bytes 18 to 21: Time-of-day sample address code . 16
5.5.12 Byte 22: Reserved . 16
5.5.13 Byte 23: Channel status data CRCC . 17
5.6 Channel status when non-PCM audio is flagged . 17
6 Auxiliary bits . 17
6.1 Availability of auxiliary bits . 17
6.2 Use of auxiliary bits . 17
Annex A (informative) Channel modes . 18
Annex B (informative) Provision of additional, voice-quality channels . 19
Annex C (informative) Generation of CRCC (byte 23) for channel status . 20
Bibliography . 22

Figure 1 – Channel status data format . 10
Figure B.1 – Frame and block structure . 19
Figure C.1 – Flow diagram including exclusive or gates . 20

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Table 1 – Non-PCM audio, protected status bits . 17

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INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

DIGITAL AUDIO INTERFACE –

Part 4-2: Professional applications – Metadata and subcode

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.
International Standard IEC 60958-4-2 has been prepared by technical area 4: Digital system
interfaces and protocols, of IEC technical committee 100: Audio, video and multimedia
systems and equipment.
This first edition, together with IEC 60958-4-1 and IEC 60958-4-4, cancels and replaces
IEC 60958-4 published in 2003 and its Amendment 1:2008 and constitutes a technical
revision.
This edition includes the following significant technical changes with respect to
IEC 60958-4:2003 with its Amendment 1:2008:
a) support for a wider range of physical media;
b) support for a wider range of audio sampling frequencies;
c) deprecation of “minimum implementation” of channel status data.

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SIST EN 60958-4-2:2016
IEC 60958-4-2:2016 © IEC 2016 – 5 –
The text of this standard is based on the following documents:
CDV Report on voting
100/2453/CDV 100/2582/RVC

Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
A list of all parts in the IEC 60958 series, published under the general title Digital audio
interface, can be found on the IEC website.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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INTRODUCTION
The two-channel digital audio interface has been widely used in a variety of professional
audio applications that have reached beyond the vision of the original standard. In particular,
applications using increased sampling frequencies and alternative physical media.
Separating the standard into independently-maintainable parts allows, for example, additional
transmission media to be introduced in the future by revising IEC 60958-4-4 without affecting
the other parts of the IEC 60958-4 series. The parts comprise:
Part 4-1: Audio content: defines the format for coding audio used for the audio content. It
specifies the semantics of the audio data, including the "validity" flag. It also
specifies the sampling frequency by reference to AES5.
Part 4-2: Metadata and subcode: specifies the format for information, metadata, or subcode
transmitted with the audio data: principally the "channel status" but also user data
and the auxiliary bits. Implementors will note that the current implementation
options ("Standard" and "Enhanced") both require that status data be
implemented correctly in compliant equipment.
Part 4-4: Physical and electrical parameters: specifies the physical signals that convey the
bit stream specified in IEC 60958-1. The transport format is intended for use with
shielded twisted-pair cable of conventional design over distances of up to 100 m
at frame rates of up to 50 kHz. Longer cable lengths and higher frame rates may
be used, but with a rapidly increasing requirement for care in cable selection and
possible receiver equalization, or the use of active repeaters. Provision is made in
this standard for adapting the balanced terminals to use 75 Ω coaxial cable.
Transmission by fibre-optic cable is under consideration.

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IEC 60958-4-2:2016 © IEC 2016 – 7 –
DIGITAL AUDIO INTERFACE –

Part 4-2: Professional applications – Metadata and subcode



1 Scope
This part of IEC 60958 specifies the format for coding metadata, or subcode, that relates to
the audio content and is carried with it. This part of IEC 60958, together with IEC 60958-1,
IEC 60958-4-1, and IEC 60958-4-4, specifies an interface for serial digital transmission of two
channels of periodically sampled and linearly represented digital audio data from one
transmitter to one receiver.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60958-1:2008, Digital audio interface – Part 1: General
IEC 60958-1:2008/AMD1:2014
IEC 60958-3, Digital audio interface – Part 3: Consumer applications
IEC 60958-4-1, Digital audio interface – Part 4-1: Professional applications – Audio content
IEC 60958-4-4, Digital audio interface – Part 4-4: Professional applications – Physical and
electrical parameters
ISO 646, Information technology – ISO 7-bit coded character set for information interchange
ITU-R Recommendation BS.450, Transmission standards for FM sound broadcasting at
1
VHF
ITU-T Recommendation J.17, Pre-emphasis used on sound program circuits
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60958-1 and the
following apply.
3.1.1
channel status
bits carrying, in a fixed format aligned with the block, specified in IEC 60958-1, information
associated with each audio channel which is decodable by any interface user
_____________
1
 Previously CCIR Recommendation 450-1.

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3.1.2
metadata
information relating to the audio content in the same channel
3.1.3
subframe
smallest structural element in a digital audio interface transport stream, carrying one PCM
sample and ancillary information
Note 1 to entry: The format of a subframe is specified in 4.1.1 of IEC 60958-1:2008.
3.2 Abbreviations
DARS Digital Audio Reference Signal
IRV International Reference Version
4 User data format
One bit of user data may be carried in each subframe. Different user data may be carried in
each channel and may be related to the associated audio or not. Its capacity in kbit/s is
therefore equal to the sampling frequency in use, in kilosamples/s, for each channel.
User data bits may be used in any way desired by the user.
Known possible formats for the user data channel are indicated by the channel status byte 1,
bits 4 to 7.
Other possible formats may be used and may or may not be standardized in future.
The default value of the user data bit is logic 0.
5 Channel status format
5.1 Channel status bit
One bit of channel status data shall be carried in each sub-frame. Different channel status
data may be carried in each channel. Their capacity in kbit/s is therefore equal to the
sampling frequency in use, in kilosamples/s.
NOTE The channel status for each audio signal carries information associated with that audio signal, and thus it
is possible for different channel status data to be carried in the two subframes of the digital audio signal. Examples
of information to be carried in the channel status are: length of audio sample words, number of audio channels,
sampling frequency, sample address code, alphanumeric source and destination codes, and emphasis.
5.2 Channel status block
Channel status information shall be organized in 192-bit blocks, subdivided into 8-bit bytes
nd
numbered from 0 to 23. The transmission format shall mark every 192 frame to show that it
carries the first bit of a block. Within each byte, the bits are numbered from 0 to 7, 0 being the
first bit transmitted, so bit 0 of byte 0 is the first bit in the block. Where a byte holds a
numerical value, bit 0 is the least significant bit.
NOTE In IEC 60958-1, the frame that begins with preamble Z contains the first bit of a block in both channels. In
other transports (for example AES10 and IEC 62365) a block start flag is used to mark the first subframe in a block,
and may be applied to each channel independently.

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5.3 Implementation
5.3.1 Implementation levels
5.3.1.1 General
The following two implementations are defined: standard and enhanced. These terms are
used to communicate in a simple manner the level of implementation of the interface
transmitter involving the many features of channel status. Irrespective of the level of
implementation, all reserved states of bits defined in 5.5 shall remain unchanged.
5.3.1.2 Standard level
The standard implementation provides a fundamental level of implementation which should
prove sufficient for general applications in professional audio or broadcasting. In standard
implementation, transmitters shall correctly encode and transmit all channel status bits in
byte 0, byte 1, byte 2, and byte 23 (CRCC) in the manner specified in this standard.
NOTE This note applies to the French language only.
5.3.1.3 Enhanced level
In addition to conforming to the requirements described in 5.3.1.2 for the standard
implementation, the enhanced implementation shall provide further capabilities.
5.3.2 Transmitter requirement
Transmitters shall encode channel status to follow all the formatting and channel coding rules
to one of the two specified implementation levels. All transmitters shall correctly encode and
transmit channel status with the correct juxtaposition with respect to the Z preamble or block
start (see IEC 60958-1).
5.3.3 Receiver requirement
Receivers shall decode channel status as required by their application. Receivers shall
interpret CRCC errors as needing to reject the channel status block with the error. Receivers
shall not interpret any errors in a channel status block such as CRCC or block length errors
as a reason to mute or alter the audio content.
The purpose of the CRCC in byte 23 is to indicate corruption of the channel status block due
to switching or editing effects (for example). Due consideration should be given to the
implications of any action on downstream equipment and the associated system in general.
5.4 Documentation
Documentation shall be provided describing the channel status features supported by
interface transmitters and receivers.
To promote compatible operation between items of equipment built to this standard it is
necessary to establish which information bits and operational bits shall be encoded and sent
by a transmitter and decoded by an interface receiver.
5.5 Channel status content
5.5.1 General
The specific organization is presented in Figure 1. Multiple-bit quantities are shown in the
tables with the most significant bit to the left. Note that the order in which the bits are
transmitted is therefore from right to left.

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Byte Bit
7 6 5 4 3 2 1 0
0 e d c b a
1 g f
2 j i h
3 n = 0 k
3 n = 1 m l
4 r q p o
5 s
6
Alphanumeric
7
channel origin date
8
9
10
Alphanumeric
11
channel destination data
12
13
14
Local sample address code
15
(32-bit binary)
16
17
18
Time-of-day sample address code
19
(32-bit binary)
20
21
22 Reliability flags
23 Cyclic redundancy check character

IEC
Key
a Use of channel status block j Indication of alignment level
b Linear PCM identification k Channel number
c Audio signal pre-emphasis l Channel number
d Lock indication m Multichannel mode number
e Sampling frequency n Multichannel mode
f Channel mode o Digital audio reference signal
g User bits management p Reserved but undefined
h Use of auxiliary sample bits q Sampling frequency
i Source word length r Sampling frequency scaling flag
 s Reserved but undefined
Figure 1 – Channel status data format

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5.5.2 Byte 0: Basic audio parameters
Bit 0 Use of channel status block.
a
0 Consumer use of channel status block.
state
1 Professional use of channel status block.
a
The significance of byte 0, bit 0 is such that a transmission from an interface conforming to IEC 60958-3
consumer use can be identified, and a receiver conforming only to IEC 60958-3 consumer use will correctly
identify a transmission from a professional-use interface as defined in this standard. Connection of a
professional-use transmitter with a consumer-use receiver or vice versa might result in unpredictable
operation. Thus, the following byte definitions only apply when bit 0 = logic 1 (professional use of the
channel status block).

Bit 1 Linear PCM identification
0 Audio sample word represents linear PCM samples.
state
1 Audio sample word used for purposes other than linear PCM samples.

Bits 4 3 2 Audio signal emphasis
0 0 0 Emphasis not indicated. Receiver defaults to no emphasis with manual override
enabled.
0 0 1 No emphasis. Receiver manual override is disabled.
states 0 1 1 50 µs + 15 µs emphasis, see ITU-R BS.450. Receiver manual override is disabled.
1 1 1 ITU-T J.17 emphasis (with 6,5 dB insertion loss at 800 Hz). Receiver manual
override is disabled
All other states of bits 2 to 4 are reserved and are not to be used until further defined.

Bit 5 Lock indication
0 Default. Lock condition not indicated.
state
1 Source sampling frequency unlocked.

Bits 7 6 Sampling frequency
0 0 Sampling frequency not indicated. Receiver default to interface frame rate and
manual override or auto set is enabled.
1 0 48-kHz sampling frequency. Manual override or auto set is disabled.
states
0 1 44,1-kHz sampling frequency. Manual override or auto set is disabled.
1 1 32-kHz sampling frequency. Manual override or auto set is disabled.

The following considerations for basic audio parameters have to be taken into account.
• The indication that the audio sample words are not in linear PCM form requires that the
validity bit be set for
...