SMPTE EG41
Page 3 of 74 pages
Part 5a comprises a number of documents for mapping many of the essence and metadata formats used in the
content creation industry into the defined MXF Essence Container.
The MXF document suite makes reference to other documents that contain information required for the
implementation of an MXF system. One such document is the SMPTE Dictionary, RP210, which contains
definitions of parameters, their data types and their Keys when used in a KLV representation. Another is the
SMPTE Labels Registry, RP224, which contains a list of normalized labels that can be used in MXF sets. Annex
B in this MXF Engineering Guideline contains a list of recommended string constants that an application may
use to improve interoperability.
In the unlikely event of conflict or ambiguity between the different parts of the document, the Format document
has precedence over the Operational Patterns, which have precedence over the Essence Containers, which
have precedence over the Descriptive Metadata documents.
Note: During the early development of MXF, a catalogue of enumerated values was created to list SMPTE Labels, Strings
Keys and Tags used within the MXF document suite. The normative definition of the SMPTE Labels is maintained in the
SMPTE Labels Registry and the normative definitions of the SMPTE Keys and Tags are to be found in the MXF document
suite.
2.1 About this document
The information in this document is ordered for the novice reader. Concepts are introduced gradually and
repeated in more detail later in the document. This is done to make the document easier to read, however, it
does make the document somewhat less good as a reference. For that reason, a Table of Contents is provided
at the start of the document to allow “Random Access” to the information within the text.
Section 8 provides MXF worked examples. In order to improve the readability of the text, an arrow is used to
indicate that an example of a certain subject exists for this section. For example (ê8.4) indicates an example for
this subject exists in section 8.4.
3 Introduction
The introduction is constructed as a list of questions. The concepts in MXF can be introduced in a way that gives
an overall view of the specification and the concepts embodied within it. Once the introduction is understood, the
requirements of the file format are discussed. Some specific words and phrases used in the specification are
then defined and finally the Material Exchange Format is introduced in a much more detailed fashion. Although
this entire document is informative, it is hoped that it will give sufficient information for technical and non-
technical readers to understand MXF.
3.1 What problem is the Material Exchange Format trying to solve?
The MXF Specification is intended to encourage an environment where it is convenient to interchange
multimedia information as a file. This will allow users to take advantage of non-real time transfers and to
package together essence and metadata for effective interchange between servers and between businesses.
MXF is not a panacea, but is an aid to automation and machine-machine communication. It allows essence and
metadata transfer without the metadata elements having to be manually re-entered.
The MXF Specification is intended to allow the interchange of captured, ingested, finished or “almost finished”
material. It is not intended to be an authoring format. Despite this, careful thought has gone into SMPTE 377M
to ensure that authoring tools such as those based on AAF Association technology are able to directly open and
use an MXF file efficiently without having to convert the file.
The MXF Specification has also been carefully crafted to ensure that it can be efficiently stored on a variety of
media, as well as transported over communications links. The MXF Format has not forgotten about tape. There
are structures and mechanisms within the file that make MXF appropriate for data tape storage and archiving of
content.
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