SMPTE ST 391M-2004 Television - Material Exchange Format (MXF) Operational Pattern 1b (Single Item Ganged Packages).pdf

1、 Table of contents 1 Scope 2 Normative references 3 Glossary of acronyms, terms and data types 4 Introduction 5 Application 6 Header metadata specification 7 MXF file interchange: Essence container issues Annex A Bibliography 1 Scope This standard defines operational pattern 1b for the exchange of a

2、 MXF file with a single item contained in multiple, synchronized, playable essence containers, each comprising either a single essence element or interleaved essence elements. It defines the operating restrictions, structural metadata objects and individual attributes that shall be applied to the MX

3、F file format specification to achieve interoperability when exchanging an MXF file as a single, continuously playable item comprising a set of synchronized essence containers. Operational pattern 1b is intended to meet the requirements of acquisition, storage and interchange applications where more

4、 than one essence component is required and it is wished to carry these in two or more essence containers. Operational pattern 1b does require the use of body partitions for internal essence containers. Subdivision of each essence container by using body partitions is optional. 2 Normative reference

5、s 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 parties to agreements based on this standard are encouraged to investiga

6、te the possibility of applying the most recent edition of the standard indicated below. SMPTE 377M-2004, Television Material Exchange Format (MXF) File Format Specification 3 Glossary of acronyms, terms and data types The full glossary of acronyms, terms and data types used in the MXF specification

7、is given in the MXF file format specification. It is not repeated here to avoid any divergence of meaning. Page 1 of 8 pages SMPTE 391M-2004 Copyright 2004 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 595 W. Hartsdale Ave., White Plains, NY 10607 (914) 761-1100 Approved September 22, 20

8、04 SMPTE STANDARD for Television Material Exchange Format (MXF) Operational Pattern 1b (Single Item, Ganged Packages) SMPTE 391M-2004 Page 2 of 8 pages Essence element: An essence container may contain many essence elements interleaved together. An essence element in this standard corresponds to a s

9、eparable part of the interleave which is described by an MXF essence track, such as a picture track, a sound track or a data track. 4 Introduction This standard defines MXF operational pattern 1b. In SMPTE 377M, the properties of the generalized operational patterns are defined. In the MXF engineeri

10、ng guideline (SMPTE EG 41), 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. 4.1 Operational pattern 1b overview Generalized MX

11、F operational patterns are defined as a combination of the two dimensions as defined SMPTE 377M. This operational pattern shall be defined as follows: 4.1.1 Item complexity Single item: The file contains only one item which is made up from two or more ganged essence elements from two or more essence

12、 containers. Each material package SourceClip shall have an identical duration which shall be the same duration as each of the top-level file package(s). 4.1.2 Package complexity Ganged packages: The material package references multiple top-level file packages that are “played” together against a co

13、mmon output timeline. The “ganged” essence streams can be regarded as a single stream that represents a continuous recording as indicated in figure 2. These two dimensions are broadly illustrated in informative figure 1. Item Complexity Ganged Packages Single Item Play-list Items Edit Items Alternat

14、e Packages Single Package Package Complexity MP FP MP FPs MP 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 dtiOnly 1 MP SourcelCip = FP dtiMP1 MP2 OR Any MP track from any

15、FP track 1 2 3 a b c Figure 1 (informative) Item and package complexity SMPTE 391M-2004 Page 3 of 8 pages This operational pattern defines an MXF file as a single item, comprising ganged packages as illustrated in the center-left box of figure 1. 4.2 Material, file and source package relationships T

16、his operational pattern has a number of essence containers that are intended to be synchronized when played. Each essence container is comprised of either a single essence element or interleaved essence elements. The essence containers comprise essence stream data that represents a continuous record

17、ing as indicated in figure 2 . Essence Descriptors e.g. AES audio Sequence (Sound) Track (Sound) SourceClip Material Package Sequence (Picture) Track (Picture) Sequence (defines duration) SourceClip Track (defines start) SourceClip Essence Descriptor e.g. Tape Descriptor SourceClip Parallel tracks s

18、ynchronise the SourceClips. Each SourceClip refers to a different Top-Level File Package. Sequence SourceClip Track (Sound) Sequence SourceClip Track (Picture) Top-Level File Package Top-Level File Package Each Top-level File Package describes an Essence Container with one or more tracks. They are s

19、ynchronised using the timing relationship described by the Material Package Source Packages (File or Physical) Giving historical annotation to the essence Essence Descriptors e.g. MPEG video SourceClip SourceClip Each Top-level File Package describes an Essence Container with one or more tracks. The

20、y are synchronised using the timing relationship described by the Material Package Figure 2 (informative) Outline of operational pattern 1b 5 Application Operational pattern 1b is an extension of the simplest generalized operational pattern (1a) where the single playable essence container is replace

21、d by multiple ganged essence containers which together make up the single audio-visual item. The ganged essence containers may, for example, contain a single shot, a single clip or a single item of program material. The essence containers shall provide for the continuous decoding of contiguous essen

22、ce elements with no additional processing for discontinuities. Operational pattern 1b is intended to meet the requirements of acquisition, storage and interchange applications where more than one essence component is required. In operational pattern 1b, these components are carried in two or more es

23、sence containers in a single file or in multiple files. The minimum implementation of operational pattern 1b will satisfy the requirement for the definition of a single item comprising several synchronized essence containers with metadata support for each essence container and for the resulting sync

24、hronized file. SMPTE 391M-2004 Page 4 of 8 pages NOTE An example of the use of this operational pattern is where a video data stream is carried by one essence container with other essence containers carrying the associated audio data stream. This may be needed where production of the video and audio

25、 are carried out by separate facilities or where audio is produced in both stereo and multi-channel formats. 5.1 Constraints A list of general constraints for this operational pattern is given in table 1. Table 1 General constraints for operational pattern 1b File Kind MXF “Operational Pattern” 1b:

26、(Single item with multiple ganged essence containers) Role Exchange of production items in multiple essence containers Essence Multiple ganged essence containers, operational pattern qualifiers apply (see MXF dormat document SMPTE 377M) Material Packages 1 Number of Material Package SourceClips per

27、Essence Track 1 Top-level File Packages 2 or more shall be referenced by the material package. Any or all of these may be external to the file. Number of Essence Container Types 1 or more Lower-level Source Packages 0 or more Partition limits None Body Partitions Required. If there are N Internal es

28、sence containers, a file shall have at least N-1 body partitions Index Tables Optional, but recommended Editing Support None Streaming Support According to operational pattern qualifiers (see 6.4) 6 Header metadata specification 6.1 General The structural metadata sets and the normative universal la

29、bel used to identify this operational pattern are defined in the MXF file format specification document with specific constraints and additions detailed below. 6.2 Constraints on the MXF packages The material package shall have one SourceClip per essence track. Each top-level file package shall have

30、 one essence track for each essence element in the essence container. All tracks/sequences in the material package and top-level file package shall have the same duration. All tracks/sequences in the material package and top-level file packages shall start and end synchronously (i.e., the normalized

31、 material package start position properties shall have the same value normalized Start Position= (Start Position of Track+Origin of Track)/Edit Rate of Track). SMPTE 391M-2004 Page 5 of 8 pages The material package may have a different start time to the top-level file packages to allow a change to t

32、he initial time code on playback. Lower-level source packages, when present, shall be used to define the historical context of editing. 6.3 Universal label for operational pattern 1b The universal label value to define this operational pattern shall be as defined in the table below. Table 2 Value of

33、 the MXF operational pattern identification universal label Byte No. Description Value (hex) 1-12 Defined in the MXF File Format Specification Operational Patterns Section 13 Operational Pattern: Item Complexity 01h 14 Operational Pattern: Package Container Complexity 02h 15 Operational Pattern: Qua

34、lifiers (application dependent) (see SMPTE 377M) 16 Reserved 0 The meanings of the bytes in this label are specified in the operational pattern section of the MXF file format specification. Bytes 13 and 14 uniquely identify this operational pattern specification. Byte 15 contains generic qualifiers

35、which are defined in the MXF file format specification. 6.4 Operational pattern 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 377M, to reflect the st

36、atus of the essence containers. 6.4.1 Essence container location The essence containers should be embedded in the file body for interchange applications. The essence containers may be externally referenced for certain specialized applications. Example applications might include shared-storage networ

37、ks, archives and other applications where the access to an essence container is localized and the locator value (defined in the locator set in SMPTE 377M) is persistent. If all essence containers are internal to the file, then bit 1 shall be set to zero. Guidance on external essence is given in SMPT

38、E EG 41 (the MXF engineering guideline). 6.4.2 Interleaving of multiple essence tracks Essence containers used in this operational pattern should be streamable. If the essence containers are streamable and have been multiplexed in a way that makes the overall file streamable, then bit 2 shall be set

39、 to zero. Typically, this requires the use of body partitions that provide multiplexing over a relatively short duration. 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 41. SMPTE 391M-2004 Pag

40、e 6 of 8 pages 6.4.3 Number of essence tracks This operational pattern supports multiple essence containers each with one or more essence tracks. If all essence containers have a single essence track, then bit 3 shall be set to zero. 6.5 Minimum implementation All constraints given in the MXF file f

41、ormat specification shall apply unless specifically overridden or extended in this standard. The minimum implementation of operational pattern 1b has the following recommended structural metadata. This section is a recommendation because the exact structure of the sets depends on how many of the top

42、-level file packages reference external data. 1 preface set, 1 or more identification sets and 1 content storage set, 2 or more essence container data sets. One material package including: the sets for the time code track the sets for each picture track as required by the essence containers the sets

43、 for each sound track as required by the essence containers the sets for each data track as required by the essence containers References or two or more top-level file packages. Each package including: the sets for each picture track as required by the essence container the sets for each sound track

44、 as required by the essence container the sets for each data track as required by the essence container NOTE Support for descriptive metadata is optional but at least one scheme should be included in order to get the best from an MXF file. The annexes of the MXF format specification give the propert

45、ies of the sets which should be implemented. All required set properties should be supported by MXF encoders that comply with this operational pattern. 7 MXF file interchange: Essence container issues 7.1 Essence container identification The value of the essence container universal label shall be de

46、fined by the appropriate essence container specification document. This value shall be recorded in the essence containers property of the preface set and all partition packs and in the essence container property of the appropriate essence descriptor set. 7.2 Essence container requirements in operati

47、onal pattern 1b 7.2.1 Number of essence elements There are no constraints on the number of essence elements in an individual essence container. It is not permitted to have a metadata only operational pattern 1b file. There must be at least one essence container type with essence (see table 1). 7.2.2

48、 Interleaving of essence elements For operational pattern 1b, interleaving of essence elements within an essence container is optional. SMPTE 391M-2004 Page 7 of 8 pages 7.2.3 Continuity of essence elements As stated in section 5, each essence container shall provide for the continuous decoding of c

49、ontiguous essence elements. The essence container or essence element specifications may add extra restrictions to this condition. 7.2.4 Number of essence tracks The number of picture, sound and data essence tracks in the material package is determined by the number of picture, sound and data essence elements in all the essence containers. 7.2.5 Use of body partitions This operation pattern requires the use of at least one partition for each internal essence container. If there are N internal essence containers, there will be at least N-1 b