SIST EN 62261-2:2007

Television METADATA -- Part 2: Data encoding protocol using key-length-value

This part of IEC 62261 defines an octet-level data encoding protocol for representing data items and data groups. This protocol defines a data structure which is independent of the application or transportation method used. The standard defines a key-length-value (KLV) triplet as a data interchange protocol for data items where the key identifies the data, the length specifies the length of the data, and the value is the data itself. The KLV protocol provides a common interchange for all compliant applications irrespective of the method of implementation or transport. The standard also provides methods for combining associated KLV triplets in data sets where the set of KLV triplets is itself coded with KLV data coding protocol. Such sets can be coded in either full form (universal sets) or in one of four increasingly bit-efficient forms (global sets, local sets, variable-length packs, and fixed-length packs). The standard provides a definition of each of these data constructs. The encoding octet range (length of the payload) specified in this standard may generate unusually large volumes of data. Consequently, a specific application of KLV encoding is capable of only a limited operating data range and those details shall be defined in a relevant application document. Of necessity, keys and other reference data have to be globally unique if clashes are to be avoided. The IEC will therefore, from time to time, designate other bodies to act as its registration authority and agent in this respect; it is important to note that, as a result of this, registrations will always contain the designator of the registration authority acting at the time of registration and not that of the IEC (unless the IEC was acting directly as its own registration authority). A mixture of registration authority designators is therefore to be expected.

Fernseh-Metadaten -- Teil 2: Protokoll zur Datencodierung mit Schlüssellängenwert

Métadonnées des applications télévision -- Partie 2: Protocole de codage des données par méthode de longueur de clés

Televizijski metapodatki – 2. del: Protokol za kodiranje podatkov z uporabo vrednosti dolžine ključa (IEC 62261-2:2005)

General Information

• Status: Published
• Publication Date: 28-Feb-2007
• Withdrawal Date: 28-Feb-2007
• ICS: 33.160.01 - Audio, video and audiovisual systems in general
• ICS: 35.040.40 - Coding of audio, video, multimedia and hypermedia information
• Technical Committee: AVM - Audio, video and multimedia systems and equipment
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Mar-2007
• Due Date: 01-Mar-2007
• Completion Date: 01-Mar-2007
• Ref Project: EN 62261-2:2006 - Television METADATA - Part 2: Data encoding protocol using key-length-value

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 62261-2:2007
01-marec-2007
7HOHYL]LMVNLPHWDSRGDWNL±GHO3URWRNRO]DNRGLUDQMHSRGDWNRY]XSRUDER
YUHGQRVWLGROåLQHNOMXþD,(&
Television METADATA -- Part 2: Data encoding protocol using key-length-value
Fernseh-Metadaten -- Teil 2: Protokoll zur Datencodierung mit Schlüssellängenwert
Métadonnées des applications télévision -- Partie 2: Protocole de codage des données
par méthode de longueur de clés
Ta slovenski standard je istoveten z: EN 62261-2:2006
ICS:
33.160.01 Avdio, video in avdiovizualni Audio, video and audiovisual
sistemi na splošno systems in general
35.040 Nabori znakov in kodiranje Character sets and
informacij information coding
SIST EN 62261-2:2007 en,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------

EUROPEAN STANDARD
EN 62261-2

NORME EUROPÉENNE
December 2006
EUROPÄISCHE NORM

ICS 33.160; 35.040


English version


Television METADATA
Part 2: Data encoding protocol using key-length-value
(IEC 62261-2:2005)


Métadonnées des applications télévision Fernseh-Metadaten
Partie 2: Protocole de codage des Teil 2: Protokoll zur Datencodierung mit
données par méthode de longueur de clés Schlüssellängenwert
(CEI 62261-2:2005) (IEC 62261-2:2005)




This European Standard was approved by CENELEC on 2006-12-01. 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 Central Secretariat or to any CENELEC member.

This European Standard exists in two official versions (English and 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
Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62261-2:2006 E

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EN 62261-2:2006 - 2 -
Foreword
The text of the International Standard IEC 62261-2:2005, prepared by Technical Area 6: Higher data rate
storage media, data structure and equipment, of IEC TC 100, Audio, video and multimedia systems and
equipment, was submitted to the formal vote and was approved by CENELEC as EN 62261-2 on
2006-12-01 without any modification.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2007-12-01
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2009-12-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 62261-2:2005 was approved by CENELEC as a European
Standard without any modification.
__________

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- 3 - EN 62261-2:2006
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

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.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

ISO/IEC 8825-1 2002 Information technology - -
ASN.1 encoding rules: Specification of Basic
Encoding Rules (BER), Canonical Encoding
Rules (CER) and Distinguished Encoding
Rules (DER)


ANSI/SMPTE 1997 Television - Universal Labels for Unique - -
298M Identification of Digital Data

---------------------- Page: 4 ----------------------

INTERNATIONAL IEC


STANDARD 62261-2





First edition
2005-08


Television METADATA –
Part 2:
Data encoding protocol using key-length-value

 IEC 2005  Copyright - all rights reserved
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 the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale V
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
For price, see current catalogue

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– 2 – 62261-2  IEC:2005(E)
CONTENTS
FOREWORD.4

1 Scope.6
2 Normative references .6
3 KLV protocol.6
3.1 General .6
3.2 ANSI/SMPTE 298M universal label key .7
3.3 Encoding of the KLV length field.10
3.4 Encoding of data values .11
3.5 Empty metadata items.12
4 KLV coding of individual data items .12
4.1 General .12
4.2 Identification of value data representations .12
5 KLV group coding .13
5.1 General .13
5.2 Universal sets .14
5.3 Global sets .14
5.4 Local sets.16
5.5 Variable-length packs.19
5.6 Fixed-length packs .22
6 Labels .24

Annex A (normative)  Glossary of terms.25
Annex B (informative) Example usage of Universal Label Key.27
Annex C (informative) Example of the KLV encoding of a single metadata item .28
Annex D (informative) Example of a universal set .29
Annex E (informative) Example of a global set .30
Annex F (informative) Example of a local set .31
Annex G (informative) Example of a variable-length pack .32
Annex H (informative) Example of a fixed-length pack .33
Annex I (informative)  Example of a label.34

Bibliography.35

Figure 1 – KLV encoding.7
Figure 2 – KLV coded universal set data structure .15
Figure 3 – KLV coded global set data structure.17
Figure 4 – KLV coded local set structure.18
Figure 5 – Informative illustration of local set label to global key linking.20
Figure 6 – KLV coded variable-length pack structure .21
Figure 7 – KLV coded fixed-length pack structure .23
Figure 8 – UL key for labels .24
Figure B.1 – Example of universal label fields for metadata encoding in the SMPTE
namespace .27

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62261-2  IEC:2005(E) – 3 –

Table 1 – KLV fields for encoding of data.7
Table 2 – Field descriptions for the universal label key for the KLV encoding of data .8
Table 3 – UL designators for octets 5 through 7.9
Table 4 – Field descriptions for the UL key for the KLV encoding of universal sets .15
Table 5 – Field descriptions for the UL key for global set encoding .17
Table 6 – Coding of registry designator (octet 6) for global set syntax .18
Table 7 – Field descriptions for the UL key for local set encoding .18
Table 8 – Coding of registry designator (octet 6) for local set syntax .19
Table 9 – Field descriptions for the UL key for variable-length pack encoding.21
Table 10 – Coding of registry designator (octet 6) for variable-length pack syntax .21
Table 11 – Field descriptions for the UL key for fixed-length pack encoding.23
Table 12 – Field descriptors for the UL key for labels.24
Table B.1 – Expanded example of SMPTE universal label fields for metadata encoding.27
Table C.1 – Informative example of KLV individual value encoding of metadata.28
Table D.1 – Informative example of KLV universal set encoding of metadata (octets
separated by spaces for readability) .29
Table E.1 – Informative example of KLV global set encoding of metadata (octets
separated by spaces for readability) .30
Table F.1 – Informative example of KLV local set encoding of metadata (octets
separated by spaces for readability) .31
Table G.1 – Informative example of KLV variable-length pack encoding of metadata
(octets separated by spaces for readability) .32
Table H.1 – Informative example of KLV fixed-length pack encoding of metadata
(octets separated for readability) .33
Table I.1 – Example of a label.34

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– 4 – 62261-2  IEC:2005(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

TELEVISION METADATA –

Part 2: Data encoding protocol using key-length-value


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 provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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 62261-2 has been prepared by Technical Area 6: Higher data rate
storage media, data structures and equipment, of IEC technical committee 100: Audio, video
and multimedia systems and equipment
This standard cancels and replaces IEC/PAS 62261 published in 2001.
This first edition constitutes a technical revision.
The text of this standard is based on the following documents:
CDV Report on voting
100/854/CDV 100/955/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.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

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62261-2  IEC:2005(E) – 5 –
IEC 62261 consists of the following parts, under the general title Television metadata:
Part 1: Metadata dictionary structure
Part 2: Data encoding protocol using key-length-value
Part 3: Universal labels for unique identification of digital data
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site 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.
A bilingual version of this publication may be issued at a later date.

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– 6 – 62261-2  IEC:2005(E)
TELEVISION METADATA –

Part 2: Data encoding protocol using key-length-value


1 Scope
This part of IEC 62261 defines an octet-level data encoding protocol for representing data
items and data groups. This protocol defines a data structure which is independent of the
application or transportation method used.
The standard defines a key-length-value (KLV) triplet as a data interchange protocol for data
items where the key identifies the data, the length specifies the length of the data, and the
value is the data itself. The KLV protocol provides a common interchange for all compliant
applications irrespective of the method of implementation or transport.
The standard also provides methods for combining associated KLV triplets in data sets where
the set of KLV triplets is itself coded with KLV data coding protocol. Such sets can be coded
in either full form (universal sets) or in one of four increasingly bit-efficient forms (global sets,
local sets, variable-length packs, and fixed-length packs). The standard provides a definition
of each of these data constructs. The encoding octet range (length of the payload) specified
in this standard may generate unusually large volumes of data. Consequently, a specific
application of KLV encoding is capable of only a limited operating data range and those
details shall be defined in a relevant application document.
Of necessity, keys and other reference data have to be globally unique if clashes are to be
avoided. The IEC will therefore, from time to time, designate other bodies to act as its
registration authority and agent in this respect; it is important to note that, as a result of this,
registrations will always contain the designator of the registration authority acting at the time
of registration and not that of the IEC (unless the IEC was acting directly as its own
registration authority). A mixture of registration authority designators is therefore to be
expected.
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 8825-1:2002, (ITU-T X.690), Information Technology – ASN.1 Encoding Rules –
Specification of Basic Encoding Rules (BER), Canonical Encoding Rules (CER), and
Distinguished Encoding Rules (DER)
ANSI/SMPTE 298M:1997, Television – Universal Labels for Unique Identification of Digital
Data
3 KLV protocol
3.1 General
Table 1 and Figure 1 present an introductory view of the KLV protocol for encoding data. The
data encoded may be a single data item or a data group. The coding of data items is
described in Clause 4 while the coding of data groups is described in Clause 5 of this
standard.

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62261-2  IEC:2005(E) – 7 –
The KLV coding protocol is composed of a universal label (UL) identification key (UL key),
followed by a numeric length (value length), followed by the data value.
The composition of the UL key is described in 3.2 of this standard. The length of the full UL
key shall be 16 octets. The length field is described in 3.3 of this standard. The value is
described in 3.4 of this standard. The value is a sequence of octets of the data type as
specified in a relevant standard and is not further specified by the KLV protocol. The length of
the value field is variable and any limitations are defined in a relevant defining standard.
Table 1 – KLV fields for encoding of data
Field Description Length Content/Format
UL key Universal label for identification of 16 octets Subclause 3.2
the value
Length Length of the value field Defined in a relevant dictionary, essence, Subclause 3.3
application standard, but variable length
Value Value associated with the UL key Variable Subclause 3.4


Length

UL Key Length Value

16 octets BER Variable Length Octets

IEC  1161/05


Figure 1 – KLV encoding
The bit-order (lsb or msb first) for KLV encoding shall be that of the transport used to carry
the information.
3.2 ANSI/SMPTE 298M universal label key
3.2.1 General
KLV coding protocol shall use a 16-word universal label (UL) generated according to
ANSI/SMPTE 298M as the UL key to identify the data in the value field but with the
appropriate registration authority’s 4-octet prefix following the OID tag and length byte.
Each word in the ANSI/SMPTE 298M UL is coded using the basic encoding rules (BER) for
the encoding of an object identifier value specified in ISO/IEC 8825-1, 8.19. Each word of the
UL key shall be limited to the range 0x00 to 0x7F and shall be represented by a single octet.
The UL key shall have left-to-right significance with the first octet as the most significant. The
leftmost octet of value 0x00 in the UL key shall define the termination of the label and all
octets of lower significance shall also be set to 0x00. Octets of value 0x00 shall have no
significance to the meaning of the UL key.
The full UL key consists of a 16-octet field including an object ID (OID) and the UL size (0x0E
indicating a total UL key size of 16 octets) followed by a UL code and a series of sub-
identifiers which shall define the UL designators. The first two UL designators shall have
reserved values for the KLV coding protocol according to this standard.

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– 8 – 62261-2  IEC:2005(E)
NOTE The ANSI/SMPTE UL itself adopts KLV coding with the object ID as the key, the UL size as the length, and
the UL designators as the value.
When applying the ANSI/SMPTE UL to the coding of data according to this standard, these
fields shall be categorized as the UL header, UL designators, and item descriptor as shown in
Table 2.
Annex B shows an informative example of a metadata UL key in tabular and figure formats.
Note that decoders which recognize the UL key but do not want to, or cannot, decode the
associated value, may ignore the item and shall continue the decoding process of subsequent
items using the length value to skip the value of the undecoded item. If decoders only store or
forward the item, they shall forward the item unaltered.
3.2.2 UL designators
Table 3 defines octet values for the designators to be used in octets 5 through 7 of the UL
designators. Standards and recommended practices which define a UL key with the value of
octet 5 (registry category designator) in the range 0x01 to 0x04 shall register the full UL key
or keys used with the IEC’s designated registration authority in the registry identified by octets
6 and 7 (registry designator and structure designator).
Table 2 – Field descriptions for the universal label key for the KLV encoding of data
No. Field Description Length Content/format
UL header
1 OID Object identifier 1 octet Always 0x06
2 UL size 16-octet size of the UL 1 octet Always 0x0E
UL designators
3 UL code Concatenated subidentifiers ISO, ORG 1 octet Always 0x0B
4 Registration Registration authority subidentifier 1 octet Dependant on
authority designator Registration Authority
(for example, 0x34 for
SMPTE)
5 Registry category Registry category designator identifying the 1 octet See Table 3
designation category of registry described (for example,
dictionaries)

6 Registry designator Registry designator identifying the specific 1 octet See Table 3
registry in a category (for example, metadata
dictionary)

7 Structure Designator of the structure variant within the 1 octet Subclause 3.2.3
designator given registry

8 Version number Version of the given registry which first defines 1 octet Incrementing number
the item specified by the item designator
9-16 Item descriptor Unique identification of the particular item within 8 See relevant standard
the context of the UL designator octets
and version

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62261-2  IEC:2005(E) – 9 –
Table 3 – UL designators for octets 5 through 7
Registry
Registry Structure
category Described in
Octet 6 Octet 7
Octet 5
01 - Dictionaries Clause 4
01 – Metadata dictionaries 0x01-0x07F – Structure designator Other standard/practice
02 – Essence dictionaries 0x01-0x07F – Structure designator Other standard/practice
03 – Control dictionaries 0x01-0x07F – Structure designator Other standard/practice
04 – Types dictionaries 0x01-0x07F – Structure designator Other standard/practice
02 – Groups (sets and packs) Clause 5
01 – Universal sets 0x01-0x07F – Structure designator Subclause 5.2
02 – Global sets (default) 0x01-0x07F – Structure designator Subclause 5.3
03 – Local sets (default) 0x01-0x07F – Structure designator Subclause 5.4
04 – Variable-length packs 0x01-0x07F – Structure designator Subclause 5.5
(default)
05 – Fixed-length packs 0x01-0x07F – Structure designator Subclause 5.6
03 – Wrappers and containers
01 – Simple wrappers 0x01-0x07F – Structure designator Other standard/practice
02 – Complex wrappers 0x01-0x07F – Structure designator Other standard/practice
04 – Labels Clause 6
01 – Labels dictionary 0x01-0x07F – Structure designator Other standard/practice

3.2.2.1 Dictionaries
Standards and recommended practices which define the value of word 5 of the UL key as
0x01 are dictionary standards and shall be used to define single data items with the KLV data
construct. The coding of individual items is defined in Clause 4.
3.2.2.2 Sets and packs
Standards and recommended practices which define the value of word 5 of the UL key as
0x02 are set and pack standards and shall be used to define groups of KLV coded data items.
The coding of data groups is defined in Clause 5.
3.2.2.3 Wrappers and containers
Standards and recommended practices which define the value of word 5 of the UL key as
0x03 are wrapper and container standards and use the UL key to identify the wrapper or
container and its contents. Wrappers and containers differ from sets and packs in that they do
not necessarily employ an overall KLV data construct for the entire contents of the wrapper or
container. It is recommended that individual parts of a wrapper or container encode data
using the KLV coding protocol, but these parts may be bound together by other techniques. In
some cases, a wrapper or container may employ an overall KLV construct in certain
applications (such as a streaming interface) but employ another technique in other
applications (such as a storage container). In these cases, the wrapper or container is not
redefined as a set or a pack but retains the definition as a container or wrapper for
consistency of identification.
Simple wrappers and containers are defined as embedding all the data into a single
framework with no external references. Complex containers and wrappers are defined by
frameworks where individual data items may be included in a file by reference rather than
embedding. Complex containers and wrappers can be more efficient and are suited to local
environments where references can be easily resolved. The definition of wrappers and
containers is outside the scope of this standard and can be found in other documents.

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– 10 – 62261-2  IEC:2005(E)
3.2.3 Structure designator
Octet 7 shall contain the structure designator for the given registry. Structure designators are
allocated to distinguish between incompatible versions of the same registry. They may be
thought of as a major version number.
NOTE Different structure designators may be assigned when a registry becomes so cluttered that it has outlived
its usefulness
...