1 Scope
This standard defines an octet-level data encoding
protocol for representing data items and data groups.
This protocol defines a data structure which is inde-
pendent 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 pro-
tocol. Such sets can be coded in either full form
(universal sets) or in one of four increasingly bit-effi-
cient forms (global sets, local sets, variable-length
packs, and fixed-length packs). The standard pro-
vides 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 appli-
cation of KLV encoding is capable of only a limited
operating data range and those details shall be de-
fined in a relevant application document.
2 Normative references
The following standards contain provisions which,
through reference in this text, constitute provisions
of this standard. At the time of publication, the
editions indicated were valid. All standards are subject
to revision, and parties to agreements based on this
standard are encouraged to investigate the possibility
of applying the most recent edition of the standards
indicated below.
ANSI/SMPTE 298M-1997, Television — Universal
Labels for Unique Identification of Digital Data
ISO/IEC 8825-1:1998 (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)
3 Key-length-value (KLV) protocol
Table 1 and figure 1 present an introductory view of
the key-length-value (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.
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 3.1
of this standard. The length of the full UL key shall
be 16 octets. The length field is described in 3.2 of
this standard. The value is described in 3.3 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.
Approved
March 28, 2001
Copyright © 2001 by THE SOCIETY OF
MOTION PICTURE AND TELEVISION ENGINEERS
595 W. Hartsdale Ave., White Plains, NY 10607
(914) 761-1100
for Television —
Data Encoding Protocol
using Key-Length-Value
SMPTE 336M-2001
SMPTE STANDARD
Page 1 of 25 pages
剩余24页未读，继续阅读
资源评论
