1、 Copyright 2011 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue., White Plains, NY 10601 (914) 761-1100 Approved March 31, 2011 Table of Contents Page Foreword . 2 Intellectual Property 2 Introduction 2 1 Scope . 3 2 Conformance Notation . 3 3 Normative Reference . 4 4 Glos
2、sary of Acronyms, Terms and Data Types . 4 5 Operational Pattern Overview 4 5.1 Material Package Complexity 5 6 Application 5 6.1 Constraints . 5 7 Header Metadata Specification 6 7.1 General. 6 7.2 Constraints on the MXF Packages 6 7.3 Universal Label for Operational Pattern “OP-Atom” 6 8 MXF File
3、Interchange: Essence Container Issues 8 8.1 Essence Container Identification . 8 8.2 Essence Container Requirements . 8 9 Recommended Partitioning of OP-Atom Files . 9 9.1 Partitioning OP-Atom with CBR Index Tables 9 9.2 Partitioning OP-Atom with VBR Index Tables 9 Annex A Bibliography (Informative)
4、 10 Annex B Examples of using Material Package Tracks to Add Synchronization Data to OP-Atom Files (Informative) . 11 B.1 Introduction 11 B.2 Parallel OP-Atom files 11 B.3 Sequence of OP-Atom files 12 Page 1 of 12 pages SMPTE ST 390:2011 Revision of SMPTE 390M-2004 SMPTE STANDARD Material Exchange F
5、ormat (MXF) Specialized Operational Pattern “OP-Atom” (Simplified Representation of a Single Item) SMPTE ST 390:2011 Page 2 of 12 pages Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized standards developing organization. Headquartered and incorp
6、orated in the United States of America, SMPTE has members in over 80 countries on six continents. SMPTEs Engineering Documents, including Standards, Recommended Practices, and Engineering Guidelines, are prepared by SMPTEs Technology Committees. Participation in these Committees is open to all with
7、a bona fide interest in their work. SMPTE cooperates closely with other standards-developing organizations, including ISO, IEC and ITU. SMPTE Engineering Documents are drafted in accordance with the rules given in Part XIII of its Administrative Practices. SMPTE ST 390 was prepared by Technology Com
8、mittee 31FS. Intellectual Property At the time of publication no notice had been received by SMPTE claiming patent rights essential to the implementation of this Standard. However, attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. S
9、MPTE shall not be held responsible for identifying any or all such patent rights. Introduction This section is entirely informative and does not form an integral part of this Engineering Document. This standard defines MXF Operational Pattern “Atom”. In the MXF file format specification (SMPTE ST 37
10、7-1), the concepts of Operational Patterns and the general conditions for audio-visual material interchange and interoperability are described in outline form. The introductory sections of these documents are not repeated here. SMPTE ST 390:2011 Page 3 of 12 pages 1 Scope This standard defines the s
11、pecialized Operational Pattern “OP-Atom” or OP-Atom for the storage and exchange of an MXF file with a tightly defined structure for a single item of essence described by a single Essence Track. It defines the operating restrictions, Structural Metadata objects and individual attributes applied to t
12、he MXF file format specification to achieve interoperability when exchanging a single item of audio-visual material. Operational Pattern “OP-Atom” is intended to satisfy the demands of applications where there is a requirement for exchange of material and associated metadata together in a single fil
13、e with an open and standardized format, yet also a demand for a simple, predictable, layout with minimum scope for variation. OP-Atom is specifically intended for applications where each Essence Track is held separately. Operational Pattern “OP-Atom” provides for a subset of MXF features. The provis
14、ions of OP-Atom make it unsuitable for certain applications, in these cases a generalized Operational Pattern or a different specialized Operational Pattern is used. In all cases, the suitability of this pattern needs to be judged on a per-application basis. Some specific areas to consider are: OP-A
15、tom is optimized for applications where the record (file creation) process is completed before a playout (file read) process is started. Therefore, it is unsuitable in applications where the record/playout (file creation/file reading) processes occur concurrently. This Operational Pattern places a f
16、ull Index Table in the Footer Partition which, with VBR essence, makes it impossible to use as a streaming format where stream delivery requires advanced knowledge of frame boundaries. With VBR essence, it also requires the (possibly very large) Index Table to be stored separately until the file rec
17、ording ends. Each OP-Atom file holds a single track of essence data therefore many applications will need an external mechanism to synchronize essence among multiple files. This standard does not define such a synchronization method; however, it does include an annex detailing a method of informativ
18、ely recording synchronization among files created as a group. 2 Conformance Notation Normative text is text that describes elements of the design that are indispensable or contains the conformance language keywords: “shall“, “should“, or “may“. Informative text is text that is potentially helpful to
19、 the user, but not indispensable, and can be removed, changed, or added editorially without affecting interoperability. Informative text does not contain any conformance keywords. All text in this document is, by default, normative, except: the Introduction, any section explicitly labeled as “Inform
20、ative“ or individual paragraphs that start with “Note:” The keywords “shall“ and “shall not“ indicate requirements strictly to be followed in order to conform to the document and from which no deviation is permitted. The keywords, “should“ and “should not“ indicate that, among several possibilities,
21、 one is recommended as particularly suitable, without mentioning or excluding others; or that a certain course of action is preferred but not necessarily required; or that (in the negative form) a certain possibility or course of action is deprecated but not prohibited. The keywords “may“ and “need
22、not“ indicate courses of action permissible within the limits of the document. The keyword “reserved” indicates a provision that is not defined at this time, shall not be used, and may be defined in the future. The keyword “forbidden” indicates “reserved” and in addition indicates that the provision
23、 will never be defined in the future. SMPTE ST 390:2011 Page 4 of 12 pages A conformant implementation according to this document is one that includes all mandatory provisions (“shall“) and, if implemented, all recommended provisions (“should“) as described. A conformant implementation need not impl
24、ement optional provisions (“may“) and need not implement them as described. Unless otherwise specified, the order of precedence of the types of normative information in this document shall be as follows: Normative prose shall be the authoritative definition; Tables shall be next; followed by formal
25、languages; then figures; and then any other language forms. 3 Normative Reference Note: All references in this document to other SMPTE documents use the current numbering style (e.g. SMPTE ST 377-1:2009) although, during a transitional phase, the document as published (printed or PDF) may bear an ol
26、der designation (such as SMPTE 377-1-2009). Documents with the same root number (e.g. 377-1) and publication year (e.g. 2009) are functionally identical. The following standard contains provisions which, through reference in this text, constitute provisions of this standard. At the time of publicati
27、on, the edition indicated was 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 standard indicated below. SMPTE ST 377-1:2009, Television Material Exchange Format (MX
28、F) File Format Specification 4 Glossary of Acronyms, Terms and Data Types The full glossary of acronyms, terms and data types used in the MXF specification is given in the MXF file format specification. It is not repeated here to avoid any divergence of meaning. 5 Operational Pattern Overview Specia
29、lized Operational Pattern “OP-Atom” adds the following constraints to the format defined in the MXF file format specification: There shall be one Top-Level File Package (which references the essence in the single Essence Container). There is no restriction on the number of Lower-Level Source Package
30、s. There shall be only one Essence Track in the Top-Level File Package. There shall be exactly one Essence Container and it shall only contain essence from a single instance of an MXF essence mapping. This Essence Container shall be internal to the file. The value of the Primary Package Property of
31、the Preface Set shall be set and shall reference the Top-Level File Package. The size of the run-in shall be zero bytes. The Header Partition shall be closed and complete. Open or incomplete Header Partitions shall not be used. Section 8.2.5 gives advice on this issue. There shall be an Index Table
32、in the Footer Partition and it shall not be sparse. There shall only be Header Metadata in the Header Partition (there shall be no Header Metadata repetitions). Each Partition shall contain data from no more than one data stream. Each data stream shall be contained in a single Partition. SMPTE ST 39
33、0:2011 Page 5 of 12 pages Note: Although each copy of an Index Table has the same stream ID, they are regarded as separate, alternate, data streams. An instance of an Index Table is not split between two or more Partitions, but other copies of the same Index Table (complete or sparse) can exist in d
34、ifferent Partitions. 5.1 Material Package Complexity The Top-Level File Package in OP-Atom is highly constrained; however, no constraints are placed on the Material Package. The Material Package stores informative data about the synchronization of the essence in this file to essence stored in other
35、files. An example is where audio and video are captured together and written to two OP-Atom files. More detailed examples are given in Annex B. In the simplest case, the Material Package stores no extra data and so contains a single Essence Track with a single Source Clip that references the whole o
36、f the essence in the Top-Level File Package. More complex Material Packages may have more than one Essence Track, more than one Source Clip per Essence Track, or both. The Material Package complexity is indicated in the OP label (see Section 7.3). Note: The complexity of the Material Package does no
37、t affect basic decoding of an OP-Atom file as the Primary Package property allows a simple decoder to jump directly to the Top-Level File Package when parsing. 6 Application The specialized Operational Pattern defined in this standard describes the audio-visual item as a single playable Essence Cont
38、ainer. This Essence Container may, for example, contain a single clip or a single item of program material. The Essence Container shall provide for the continuous decoding of contiguous Essence Elements with no additional processing for discontinuities. This Operational Pattern is intended only for
39、applications where it is desirable to have a simple overall file layout requiring minimum parsing to separate the essence and metadata. It is also specifically intended for applications where each Essence Track is held separately. OP-Atom provides for a subset of MXF features. The minimum implementa
40、tion of OP-Atom satisfies the requirement for the definition of a single clip with minimum metadata support. 6.1 Constraints A list of general constraints for OP-Atom is given in Table 1. SMPTE ST 390:2011 Page 6 of 12 pages Table 1 Summary of Operational Pattern constraints File Kind MXF “Operation
41、al Pattern” OP-Atom Role Continuous Recording, exchange of a single audio-visual item. Essence Single Essence Container Number of Essence Track 1 Primary Package Top-Level File Package Material Packages 1 Number of Material Package Source Clips per Essence Track 1 or more Top-Level File Packages 1 N
42、umber of Essence Container Types 1 Lower-Level Source Packages 0 or more Partition Limits closed and complete Header Partition closed and complete Footer Partition Also see Section 9 Body Partitions See Section 9 Index Tables Required Editing Support None (but see informative Annex B) Streaming Supp
43、ort Depends solely on the Essence Container 7 Header Metadata Specification 7.1 General The Structural Metadata Sets and the normative Universal Label used to identify this Operational Pattern are defined in the MXF file format specification with specific constraints and additions detailed below. 7.
44、2 Constraints on the MXF Packages There shall be only one Top-Level File Package; The “Primary Package”, as indicated in the Preface, shall be the Top-Level File Package; The Primary Package shall have a single Essence Track; There shall be only one Material Package; Lower-Level Source Packages, whe
45、n present, shall be used to define the historical context of editing. 7.3 Universal Label for Operational Pattern “OP-Atom” The Universal Label value to define this Operational Pattern shall be as defined in Table 2. SMPTE ST 390:2011 Page 7 of 12 pages Table 2 Value of the MXF Operational Pattern i
46、dentification Universal Label Byte No. Description Value (hex) 1-12 Defined in the MXF file format specification Operational Patterns section 13 Operational Pattern: Specialized Operational Pattern “OP-Atom” 10h 14 Material Package complexity See Table 3 15-16 Reserved 00h Note: The Universal Label
47、for Operational Pattern “OP-Atom” was added to RP 224 at Registry Version 2. Therefore, the value of byte 8 (Registry Version Number) is 2. Byte 13 uniquely identifies this Operational Pattern specification. The Material Package complexity is indicated by the value of byte 14: Table 3 Material Packa
48、ge complexity value Bit No. Value 0 0 = Each Material Package Essence Track contains a single Source Clip 1 = One or more Material Package Essence Track contains more than one Source Clip 1 0 = The Material Package contains a single Essence Track 1 = The Material Package contains more than one Essen
49、ce Track 2-7 Reserved (set to 0) 7.3.1 Minimum implementation recommendation All constraints given in the MXF file format specification shall apply unless specifically overridden or extended in this standard. The minimum implementation of the specialized Operational Pattern defined by this standard has the following limits in reference to the MXF file format specification: 1 Preface Set, 1 or more Identification Sets, 1 Content Storage Set, and 1 Essence Container Data Set One Top-Level File Package in
