1、BRITISH STANDARDBS EN 62261-2:2006Television METADATA Part 2: Data encoding protocol using key-length-valueThe European Standard EN 62261-2:2006 has the status of a British StandardICS 33.160.01; 35.040g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g
2、40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Licensed Copy: Wang Bin, na, Fri Sep 14 02:46:11 GMT+00:00 2007, Uncontrolled Copy, (c) BSIBS EN 62261-2:2006This British Standard was published under the authority of the Standards Policy and Strat
3、egy Committee on 31 May 2007 BSI 2007ISBN 978 0 580 50819 6National forewordThis British Standard was published by BSI. It is the UK implementation of EN 62261-2:2006. It is identical with IEC 62261-2:2005.The UK participation in its preparation was entrusted to Technical Committee EPL/100, Audio, v
4、ideo and multimedia systems and equipment.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a Bri
5、tish Standard cannot confer immunity from legal obligations.Amendments issued since publicationAmd. No. Date CommentsLicensed Copy: Wang Bin, na, Fri Sep 14 02:46:11 GMT+00:00 2007, Uncontrolled Copy, (c) BSIEUROPEAN STANDARD EN 62261-2 NORME EUROPENNE EUROPISCHE NORM December 2006 CENELEC European
6、Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr 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 CEN
7、ELEC members. Ref. No. EN 62261-2:2006 E ICS 33.160; 35.040 English version Television METADATA Part 2: Data encoding protocol using key-length-value (IEC 62261-2:2005) Mtadonnes des applications tlvision Partie 2: Protocole de codage des donnes par mthode de longueur de cls(CEI 62261-2:2005) Fernse
8、h-Metadaten Teil 2: Protokoll zur Datencodierung mit Schlssellngenwert (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 s
9、tatus 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 v
10、ersion 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 Czec
11、h 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. Licensed Copy: Wang Bin, na, Fri Sep 14 0
12、2:46:11 GMT+00:00 2007, Uncontrolled Copy, (c) BSIForeword 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 forma
13、l 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 national standard or by endorsement (dop) 2007-12-01 latest date by which the na
14、tional standards conflicting with the EN have to be withdrawn (dow) 2009-12-01 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. _ EN 62261-2:2006 2 Licensed Copy:
15、Wang Bin, na, Fri Sep 14 02:46:11 GMT+00:00 2007, Uncontrolled Copy, (c) BSICONTENTS 1 Scope.5 2 Normative references .5 3 KLV protocol.5 3.1 General .5 3.2 ANSI/SMPTE 298M universal label key .6 3.3 Encoding of the KLV length field .9 3.4 Encoding of data values 10 3.5 Empty metadata items.11 4 KLV
16、 coding of individual data items 11 4.1 General .11 4.2 Identification of value data representations .11 5 KLV group coding.12 5.1 General .12 5.2 Universal sets .13 5.3 Global sets13 5.4 Local sets15 5.5 Variable-length packs18 5.6 Fixed-length packs 21 6 Labels 23 Annex A (normative) Glossary of t
17、erms24 Annex B (informative) Example usage of Universal Label Key26 Annex C (informative) Example of the KLV encoding of a single metadata item .27 Annex D (informative) Example of a universal set 28 Annex E (informative) Example of a global set .29 Annex F (informative) Example of a local set .30 A
18、nnex G (informative) Example of a variable-length pack 31 Annex H (informative) Example of a fixed-length pack .32 Annex I (informative) Example of a label33 Bibliography34 Figure 1 KLV encoding.6 Figure 2 KLV coded universal set data structure 14 Figure 3 KLV coded global set data structure.15 Figu
19、re 4 KLV coded local set structure.17 Figure 5 Informative illustration of local set label to global key linking19 Figure 6 KLV coded variable-length pack structure 20 Figure 7 KLV coded fixed-length pack structure .22 Figure 8 UL key for labels 23 Figure B.1 Example of universal label fields for me
20、tadata encoding in the SMPTE namespace .26 EN 62261-2:2006 3 Annex ZA (normative) Normative references to international publications with theircorresponding European publications 35Licensed Copy: Wang Bin, na, Fri Sep 14 02:46:11 GMT+00:00 2007, Uncontrolled Copy, (c) BSITable 1 KLV fields for encod
21、ing of data6 Table 2 Field descriptions for the universal label key for the KLV encoding of data 7 Table 3 UL designators for octets 5 through 78 Table 4 Field descriptions for the UL key for the KLV encoding of universal sets .14 Table 5 Field descriptions for the UL key for global set encoding .16
22、 Table 6 Coding of registry designator (octet 6) for global set syntax 17 Table 7 Field descriptions for the UL key for local set encoding .17 Table 8 Coding of registry designator (octet 6) for local set syntax 18 Table 9 Field descriptions for the UL key for variable-length pack encoding.20 Table
23、10 Coding of registry designator (octet 6) for variable-length pack syntax 20 Table 11 Field descriptions for the UL key for fixed-length pack encoding22 Table 12 Field descriptors for the UL key for labels23 Table B.1 Expanded example of SMPTE universal label fields for metadata encoding26 Table C.
24、1 Informative example of KLV individual value encoding of metadata27 Table D.1 Informative example of KLV universal set encoding of metadata (octets separated by spaces for readability) .28 Table E.1 Informative example of KLV global set encoding of metadata (octets separated by spaces for readabili
25、ty) .29 Table F.1 Informative example of KLV local set encoding of metadata (octets separated by spaces for readability) .30 Table G.1 Informative example of KLV variable-length pack encoding of metadata (octets separated by spaces for readability)31 Table H.1 Informative example of KLV fixed-length
26、 pack encoding of metadata (octets separated for readability) 32 Table I.1 Example of a label.33 EN 62261-2:2006 4 Licensed Copy: Wang Bin, na, Fri Sep 14 02:46:11 GMT+00:00 2007, Uncontrolled Copy, (c) BSITELEVISION METADATA Part 2: Data encoding protocol using key-length-value 1 Scope This part of
27、 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
28、 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 fo
29、r 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-leng
30、th 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 r
31、ange 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 re
32、spect; 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 author
33、ity 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 am
34、endments) 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 Digita
35、l 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 st
36、andard. EN 62261-2:2006 5 Licensed Copy: Wang Bin, na, Fri Sep 14 02:46:11 GMT+00:00 2007, Uncontrolled Copy, (c) BSIThe 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
37、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
38、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 the value 16 octets Subclause
39、 3.2 Length Length of the value field Defined in a relevant dictionary, essence, application standard, but variable length Subclause 3.3 Value Value associated with the UL key Variable Subclause 3.4 ValueUL Key Length 16 octets BER Variable Length Octets LengthIEC 1161/05Figure 1 KLV encoding The bi
40、t-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 th
41、e value field but with the appropriate registration authoritys 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
42、 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
43、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
44、-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. EN 62261-2:2006 6 Licensed Copy: Wang Bin, na, Fri Sep 14 02:46:11 GMT+00:00 2007, Uncontrolled Copy, (c) BSINOTE The ANSI/SMPTE UL itse
45、lf 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 Ta
46、ble 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 v
47、alue 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 def
48、ine 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 IECs designated registration authority in the registry identified by octets 6 and 7 (registry designator and structure designator). Table 2 Field descr
49、iptions 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 authority designator Registration authority subidentifier 1 octet Dependant on Registration Authority (for example, 0x34 for SMPTE) 5 Registry category des
