SMPTE ST 392-2012 Material Exchange Format (MXF) - Operational Pattern 2a (Play-List Items Single Package).pdf

1、 Copyright 2013 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved February 5, 2012 Table of Contents Page Foreword . 2 Intellectual Property 2 1 Scope . 3 2 Conformance Notation . 3 3 Normative Reference . 3 4 Glossary of Acrony

2、ms, Terms and Data Types . 4 5 Introduction 4 5.1 Operational Pattern 2a Definition 4 5.2 Material, File and Source Package Relationships 5 6 Application 6 6.1 Constraints 6 7 Header Metadata Specification 7 7.1 General . 7 7.2 Constraints on the MXF Packages . 7 7.3 Universal Label for Operational

3、Pattern 2a . 8 7.4 Operational Pattern Qualifiers . 8 7.5 Qualifiers Specific to this Operational Pattern 9 7.6 Minimum Implementation Recommendation 9 8 Essence Container Requirements in Operational Pattern 2a 10 8.1 Number of Essence Elements 10 8.2 Interleaving of Essence Elements . 10 8.3 Contin

4、uity of Essence Elements . 10 8.4 Number of Essence Tracks . 11 8.5 Use of Body Participations 11 Annex A MPEG Example of an Operational Pattern 2a File (Informative) 12 Annex B Bibliography (Informative) . 14 Page 1 of 14 pages SMPTE ST 392:2013 Revision of SMPTE 392M-2004 SMPTE STANDARD Material E

5、xchange Format (MXF) Operational Pattern 2a (Play-List Items, Single Package) SMPTE ST 392:2013 Page 2 of 14 pages Foreword SMPTE (the Society of Motion Picture and Television Engineers) is an internationally-recognized standards developing organization. Headquartered and incorporated in the United

6、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 a bona fide interest

7、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 Operations Manual. SMPTE ST 392 was prepared by Technology Committee 31FS. Intellectual Pr

8、operty 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. SMPTE shall not be held respo

9、nsible for identifying any or all such patent rights. SMPTE ST 392:2013 Page 3 of 14 pages 1 Scope This standard defines operational pattern 2a for the exchange of an MXF file with a play-list of playable essence containers, each comprising either a single essence element or interleaved essence elem

10、ents. It defines the operating restrictions, structural metadata objects and individual attributes that must be applied to the MXF file format specification to achieve interoperability when exchanging an MXF file as a list of continuously playable items of audio-visual material. Operational pattern

11、2a is intended to meet the requirements of acquisition, storage and interchange applications that are satisfied by a play-list of individual items of content packaged in two or more essence containers each of the same type. Operational pattern 2a requires the use of body partitions for internal esse

12、nce containers. Subdivision of each essence container by using body partitions is optional. 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

13、that is potentially helpful to 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

14、 explicitly labeled as “Informative“ 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

15、, among several possibilities, 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.

16、 The keywords “may“ and “need 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 additio

17、n indicates that the provision will never be defined in the future. 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 implement o

18、ptional 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 languag

19、es; then figures; and then any other language forms. 3 Normative Reference The following standard contains provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the edition indicated was valid. All standards are subject to revision and

20、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 377-1:2011, Material Exchange Format (MXF) File Format Specification SMPTE ST 392:2013 Page 4 of 14 pages 4 Glossary of Acronyms, T

21、erms and Data Types The full glossary of acronyms, terms and data types is given in the MXF file format specification, SMPTE ST 377-1. It is not repeated here to avoid any divergence of meaning. 5 Introduction This standard defines MXF operational pattern 2a. In SMPTE ST 377-1, the properties of all

22、 generalized operational patterns are defined. In the MXF engineering guideline, SMPTE EG 377-3, 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

23、not repeated here. 5.1 Operational Pattern 2a Definition Generalized MXF operational patterns are defined as a combination of the two dimensions as defined in SMPTE 377-1. This operational pattern shall be defined as follows: 5.1.1 Item complexity - Play-list items: The file contains two or more con

24、catenated items. Each item shall be defined by a top-level file package. There shall be one material package having SourceClips each of which has a duration that is equal to the corresponding top-level file package. 5.1.2 Package complexity - Single package: The material package can only access a si

25、ngle top-level file package at a time. The two dimensions of operational patterns are illustrated in informative Figure 1. SMPTE ST 392:2013 Page 5 of 14 pages Item Complexity Ganged Packages Single Item Play-list Items Edit Items Alternate Packages Single Package Package Complexity MP FP MP FPs MP

26、FPs MP FPs AND MP FPs MP FPs AND Any MP track from any FP track Each MP SourcelCip = entire FP MP1 MP2 OR MP1 MP2 OR Each MP SourcelCip = entire FP Only 1 MP SourcelCip = FP d ti Only 1 MP SourcelCip = FP d ti MP1 MP2 OR Any MP track from any FP track 1 2 3 a b c Figure 1 Item and package complexity

27、 (Informative) This operational pattern defines an MXF file as a single package of play-list items, as illustrated in the center-top box of Figure 1. All other standard operational patterns to the right or below this box are notionally a superset of the functionality of this operational pattern. 5.2

28、 Material, File and Source Package Relationships This operational pattern has multiple essence containers which shall be all of the same type, and may comprise either a single essence element or interleaved essence elements. The essence containers shall each comprise essence stream data that represe

29、nts a continuous recording as illustrated in Figure 2. SMPTE ST 392:2013 Page 6 of 14 pages Material Package Sequence (Picture) Track (Picture) Sequence SourceClip SourceClip Track (Picture) SourceClip SourceClip SourceClip Parallel tracks synchronise the SourceClips. Each SourceClip refers to a dif

30、ferent Top-Level File Package. Sequence (duration) SourceClip Track (Picture) Sequence SourceClip Track (Picture) 3 Top-Level File Packages The Top-level File Packages describe a play list of Essence Containers Essence Descriptors e.g. MPEG video Ganged packages are aligned Sequence (defines duratio

31、n) SourceClip Track (defines start) SourceClip Essence Descriptor e.g. Tape Descriptor Source Packages (File or Physical) Giving historical annotation to the essence Figure 2 Outline of operational pattern 2a (Informative) 6 Application Operational pattern 2a represents a play-list of items as a con

32、tiguous sequence of playable essence containers. Each essence container may, for example, contain a single clip or a single item of program material. Each essence container shall be of the same type. The sequence of essence containers shall provide for the continuous decoding of contiguous essence e

33、lements. Operational pattern 2a is intended to satisfy the requirements of simple cuts-only editing and finished program interchange applications. The minimum implementation of operational pattern 2a will satisfy the requirement for a concatenation of multiple clips as a program, with metadata suppo

34、rt for each clip as well as metadata support for the program as a whole. 6.1 Constraints A list of general constraints for this operational pattern is given in Table 1. SMPTE ST 392:2013 Page 7 of 14 pages Table 1 General constraints for operational pattern 2a File Kind MXF “Operational Pattern” 2a:

35、 (Play-list items, single package) Role Interchange of programs with simple edits. Essence Multiple essence containers of the same type. Operational pattern qualifiers apply (see MXF file format specification, SMPTE ST 377-1) Material Packages 1 Number of Material Package SourceClips for each Essenc

36、e Track 1 Top-Level File Packages Number of material package SourceClips per track Number of Essence Container Types 1 Lower-Level Source Packages 0 or more Partition limits None Body Partitions Required. If there are N internal essence containers, a file shall have at least N-1 body partitions. Ind

37、ex Tables Optional, but recommended Editing Support Simple play-list output Streaming Support According to operational pattern qualifiers (see Section 6.4) Notes: 1. The “number of material package SourceClips” in Table 1 refers only to essence tracks. Operational patterns are intended to constrain

38、the essence handling of an MXF application. So in the case where the essence is continuous and only the metadata in a file has multiple SourceClips, it is likely that the file is an operational pattern lower than 2a. 2. The “1” essence container type is also subject to the continuity of essence cond

39、ition in Section 8.3. When using the MXF generic container, it is possible that there will be several different essence container labels being signaled in a file (e.g., one for the audio; another for the video). Each and every track is subject to the continuity conditions in Section 8.3. 7 Header Me

40、tadata 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 document with specific constraints and additions detailed below. 7.2 Constraints on the MXF Packages The material

41、 package shall have more than one SourceClip per essence track. The material package SourceClips shall start and end synchronously for each and every material package essence track. The material package may define a different start time-code value to the first top-level file package to allow a chang

42、e to the initial time-code on playout. Each top-level file package shall have one track for each utilized essence element in the associated essence container. Lower-level source packages, where present, shall be used to define the historical context of editing. SMPTE ST 392:2013 Page 8 of 14 pages 7

43、.3 Universal Label for Operational Pattern 2a The universal label value to define this operational pattern shall be as defined in Table 2. Table 2 Value of the MXF operational pattern identification Universal label Byte No. Description Value (hex) 1-12 Defined in the MXF File Format Specification Op

44、erational Patterns Section See SMPTE ST 377-1 13 Operational Pattern: Item Complexity 02h 14 Operational Pattern: Package Complexity 01h 15 Operational Pattern: Qualifiers (application dependent) See SMPTE ST 377-1 16 Operational Pattern: OP2a qualifiers See Table 3 The meanings of the bytes in this

45、 label are specified in the operational pattern section of the MXF file format specification (SMPTE ST 377-1). Bytes 13 and 14 uniquely identify this operational pattern specification and byte 15 contains generic qualifiers that are defined in the MXF file format specification. 7.4 Operational Patte

46、rn Qualifiers This operational pattern shall support the qualifiers as specified in byte 15 of the operational pattern universal label. Each bit of byte 15 shall be correctly set, as defined by SMPTE ST 377-1, to reflect the status of the essence container. 7.4.1 Essence container location The essen

47、ce containers should be embedded in the file body for interchange applications. The essence containers may be externally referenced for certain specialized applications. Example applications include shared-storage networks, archives and other applications where the access to an essence container is

48、localized and the locator value (defined by a locator set in SMPTE ST 377-1) is persistent. If all the essence containers are internal to the file, then bit 1 shall be set to zero. Guidance on using external essence is given in SMPTE EG 377-3. 7.4.2 Interleaving of multiple essence tracks All essenc

49、e containers used in this operational pattern should be streamable. If all the essence containers are streamable, and have been multiplexed in a way that makes the overall file streamable, then bit 2 shall be set to zero. If the primary package references any external essence, then the file shall not be indicated as streamable. Guidance on streamability is given in SMPTE EG 377-3. SMPTE ST 392:2013 Page 9 of 14 pages 7.4.3 Number of essence tracks This operational pattern supports multiple essence containers, each with one or