SMPTE RDD 44-2017 Material Exchange Format - Mapping and Application of Apple ProRes.pdf

1、 Copyright 2017 by THE SOCIETY OF MOTION PICTURE AND TELEVISION ENGINEERS 3 Barker Avenue, White Plains, NY 10601 (914) 761-1100 Approved April 4, 2017 The attached document is a Registered Disclosure Document prepared by the sponsor identified below. It has been examined by the appropriate SMPTE Te

2、chnology Committee and is believed to contain adequate information to satisfy the objectives defined in the Scope, and to be technically consistent. This document is NOT a Standard, Recommended Practice or Engineering Guideline, and does NOT imply a finding or representation of the Society. Every at

3、tempt has been made to ensure that the information contained in this document is accurate. Errors in this document should be reported to the proponent identified below, with a copy to engsmpte.org. All other inquiries in respect of this document, including inquiries as to intellectual property requi

4、rements that may be attached to use of the disclosed technology, should be addressed to the proponent identified below. Proponent contact information: ProRes Program Office Apple Inc. 1 Infinite Loop, MS: 77-2YAK Cupertino, CA 95014 USA Email: ProR Apple is a trademark of Apple Inc., registered in t

5、he U.S. and other countries. Page 1 of 15 pages SMPTE RDD 44:2017 SMPTE REGISTERED DISCLOSURE DOCUMENT Material Exchange Format Mapping and Application of Apple ProRes SMPTE RDD 44:2017 Page 2 of 15 pages Table of Contents Page Introduction. 3 1 Scope . 3 2 Conformance Notation . 3 3 Normative Refer

6、ences . 3 4 Glossary of Acronyms, Terms and Data Types . 4 5 ProRes Mapping Specifications and Application Considerations 4 5.1 Essence Containers . 4 5.2 Generic Container Mapping . 5 5.3 Essence Segmentation and Index Tables 5 5.4 Random Index Pack . 6 5.5 Header Metadata and Descriptor Property V

7、alues 6 5.6 KAG and KLV Fill Items 7 5.7 Run-In . 7 5.8 Mapping Track Numbers to Generic Container Elements 7 6 KLV Coding and Universal Label Specifications 7 6.1 ProRes Profiles . 7 6.2 ProRes Essence Element KLV Coding 8 6.3 ProRes Picture Element Key 8 6.4 ProRes Essence Container Label 9 6.5 Pr

8、oRes Picture Essence Coding Label 9 7 MXF Descriptors. 11 7.1 File and Structural Descriptors . 11 7.2 ProRes Compression of Television Formats 11 7.3 Generic Picture Essence Descriptor 11 7.4 CDCI (Color Difference Component Image) Picture Essence Descriptor 13 7.5 Color Items for MXF Descriptors (

9、Informative) . 13 Bibliography (Informative) 15 SMPTE RDD 44:2017 Page 3 of 15 pages Introduction This section is entirely informative and does not form an integral part of this Registered Disclosure Document (RDD). ProRes is a picture-by-picture (intra-frame) compression scheme. This RDD specifies

10、the mapping of ProRes bitstreams (SMPTE RDD 36) into a subset of the MXF Generic Container (SMPTE ST 379-2). This RDD also describes application considerations. MXF file encoders (file writers) require a ProRes bitstream for each picture, each pictures bitstream length, and additional technical meta

11、data items. This metadata can be provided by a ProRes encoder or an application that synthesizes or acquires a ProRes bitstream from another source. The goals for this MXF specification are to be straightforward to implement, to be as constrained as possible to maximize interoperability, but to be s

12、ufficient for the needs of: Video camera recording. Use in broadcast environments, including playout servers and asset management systems. Use in professional video editing and preview, which require: fast file-open time, efficient file playback, and ability to edit while file is being recorded. Com

13、patibility considerations for possible future application efforts such as IMF and AS-11. References to other documents have the section or table number and the section title or table caption in parentheses. 1 Scope This Registered Disclosure Document (RDD) specifies the mapping of ProRes bitstreams

14、into a subset of the MXF Generic Container (SMPTE ST 379-2). This document also defines application restrictions. The ProRes bitstream is documented by SMPTE RDD 36:2015. ProRes bitstreams are mapped into a Picture Essence Track of the MXF Generic Container with Frame Wrapping. This RDD defines the

15、KLV coding, the required Keys (Universal Labels) and MXF Picture Essence Descriptor items. 2 Conformance Notation This RDD uses the conformance notation specified in SMPTE ST 377-1. 3 Normative References The following standards and related documents contain provisions that, through reference in thi

16、s text, constitute provisions of this RDD. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this RDD are encouraged to investigate the possibility of applying the most recent edition of the standards indicated be

17、low. SMPTE ST 377-1:2011, Material Exchange Format (MXF) File Format Specification Amendment 1:2012 to SMPTE ST 377-1:2011 Amendment 2:2012 to SMPTE ST 377-1:2011 SMPTE ST 379-2:2010, Television Material Exchange Format (MXF) MXF Constrained Generic Container SMPTE ST 2067-5:2013, Interoperable Mast

18、er Format Essence Component Amendment 1:2016 to SMPTE ST 2067-5:2013 SMPTE RDD 44:2017 Page 4 of 15 pages 4 Glossary of Acronyms, Terms and Data Types The general glossary of acronyms, terms and data types used in the MXF specification is given in SMPTE ST 377-1 and is supplemented in SMPTE ST 379-2

19、. These glossaries are not repeated here to avoid any divergence of meaning. In this document, terms are used as defined by SMPTE ST 377-1 in preference to any definition specific to SMPTE ST 379-2. 5 ProRes Mapping Specifications and Application Considerations The ProRes container shall be complian

20、t with SMPTE ST 379-2 with constraints defined in the following sections. 5.1 Essence Containers 5.1.1 Files with a Single Picture Essence Track A Content Item is comprised of one or more Content Element(s), each of which shall contain a single picture (one full video frame) as illustrated in Figure

21、 1. Figure 1 Frame Wrapping of Picture Elements in the Generic Container 5.1.2 Files with Multiple Essence Tracks The ProRes pictures may be interleaved with other essence components (Sound or Data) in the Frame Wrapped Essence Container as illustrated in Figure 2. Other essence components shall be

22、as defined by an MXF mapping standard or a SMPTE RDD. All Essence Elements (Generic Container Content Elements) shall be Frame Wrapped. Each Picture (one full video frame) should contain essence data that is independent of adjacent pictures. Other MXF standards may place additional requirements on t

23、he Content Element sequences in a Content Package. Note: The term Frame Wrapping is defined by SMPTE ST 379-2 as the individual wrapping of one Content Package having a basic sample unit. This basic sample unit is defined by the ProRes bitstream and can be the result of compression of two fields fro

24、m an interlaced scanned picture or one frame from a progressively scanned picture. V 1 f ra m e K L P ic tu re Ite m Cod e str e a m V 1 f ra m e K L P ic tu re Ite m Cod e str e a m V 1 f ra m e K L P ic tu re Ite m Cod e str e a m SMPTE RDD 44:2017 Page 5 of 15 pages Figure 2 Frame Wrapping of int

25、erleaved items and elements in the Generic Container Note: Interleaving Essence Elements sometimes involve timing tolerances whose specification is beyond the scope of this RDD. However, the design of the frame based interleaved Generic Container is well established for time aligned Essence Elements

26、 within each Content Package. 5.2 Generic Container Mapping All Content Elements shall use Frame Wrapping as defined in the Generic Container (SMPTE ST 379-2). Each Picture Element shall contain an individual KLV wrapped picture (one progressive video frame or two interlaced video fields). All pictu

27、res in a track shall have the same image characteristics described from the linked Picture Essence Descriptor. Each Frame Wrapped Generic Container Content Package is a separate editable unit with synchronized System, Picture, Sound and Data Items. A System Item may be included in a Content Package.

28、 Note: SMPTE ST 379-2 Section 8.2 (Content Items and Content Elements) has additional information. 5.3 Essence Segmentation and Index Tables Application requirements need to be considered when selecting one of the file Essence segmentation and Index Table specifications described below. One of the p

29、artition segmentation and index table rules from the following subsections of 5.3 shall be used. 5.3.1 Files That Are Not Segmented A file that includes Essence in only one Partition (and does not break Essence into multiple Partitions) shall use a Header Partition or a Body Partition for the Essenc

30、e. An Essence Container in a single Partition may be of any duration. In such a file, all Index Tables shall be stored in the Footer Partition, the Header Partition, or both. 5.3.2 Files with Essence Segmented into Fixed Duration Partitions The first Partition containing Essence shall be a Body Part

31、ition. The duration of all Body Partitions, with the possible exception of the final Body Partition, should be approximately 10 seconds and all Body Partitions shall be less than or equal to 10.01 seconds in duration. The duration of the final Body Partition may be less than the other Body Partition

32、s. The duration of all Body Partitions shall be constant (measured in time or Edit Units) with the possible exception of the final Body Partition. SMPTE RDD 44:2017 Page 6 of 15 pages Body Partition durations in Edit Units and seconds should follow the values documented in Table 1. Table 1 Partition

33、 Durations (Informative) Frame Rate Partition Duration (Edit Units) Partition Duration (seconds) 24/1.001p 240 10.01 24p 240 10 25p and 25i 240 9.6 30/1.001p and 30/1.001i 300 10.01 50p 480 9.6 60/1.001p 600 10.01 Note: The Partition durations are chosen as a compromise between Partition size and Pa

34、rtition durations based on established MXF implementations to facilitate interoperability. Each Body Partition with the exception of the first Body Partition shall include an Index Table for the previous Body Partition from the same Essence Container. All Index Table Segments shall be repeated at th

35、e end of the file. Files with a single File Package shall repeat all Index Table Segments in the Footer Partition. Files with multiple File Packages shall repeat all Index Table Segments for all streams in the last Partition of each stream that includes Index Table Segments. Notes: 1) Files with seg

36、mented Essence Containers can be decoded while being recorded. 2) If an application normally requires that Essence Containers be segmented, short files (less than 10 seconds), can be encoded using the rules in this section. 3) SMPTE ST 377-1 Section 5.2.2 (Partition Rules Summary) summarizes the use

37、 of partitions in MXF files. 4) SMPTE EG 377-3 provides examples of how Index Tables can be created for both mono-essence and multi-essence mappings and for both constant and variable length Edit Unit sizes. 5.3.3 Additional Segmentation Specifications Partition segmentation and Index Table rules de

38、fined by SMPTE ST 2067-5 shall be used for IMF files. 5.4 Random Index Pack The file shall include a Random Index Pack. See SMPTE ST 377-1. 5.5 Header Metadata and Descriptor Property Values 5.5.1 Local Set and Pack Tags If Static Local Tags have been previously defined, these should be used for KLV

39、 Sets and Packs. Static Local Tags are defined in SMPTE ST 377-1. Dynamic Local Tags shall be used when Static Local Tags have not been defined. SMPTE RDD 44:2017 Page 7 of 15 pages 5.5.2 Edit Rate The Edit Rate for ProRes essence in Header Metadata, Index Table Segments and Descriptors shall be cal

40、culated based on one frame (or two fields). For additional information see SMPTE ST 377-1 Section 9.5.3 (Material Package), Section 11.2.3 (Index Table Segment), Annex B.12 (Timeline Track) and Annex G.2.2 (Sample Rate and Edit Rate). Note: The Edit Rate for other Essence Tracks in Header Metadata i

41、s defined in SMPTE ST 377-1 Section 9.4 (Structural Metadata Semantics). 5.5.3 Sample Rate The Sample Rate item for ProRes essence in Header Metadata, Index Table Segments and Essence Descriptors shall be calculated based on one frame (or two fields). For additional information see SMPTE ST 377-1 An

42、nex F.2 (File Descriptor) and Annex G.2.2 (Sample Rate and Edit Rate). 5.6 KAG and KLV Fill Items MXF encoders and decoders shall comply with the KAG rules defined in SMPTE ST 377-1 Section 6.4.1 (KLV Alignment Grid). The KLV Fill item can be used to maintain a constant Content Package size. A KAG v

43、alue of 1 should be used. Other KAG values may be used within the range allowed by SMPTE ST 377-1 Section 6.4.1 (KLV Alignment Grid). Note: The KLV Fill item can be used to provide a constant Edit Unit size for all pictures. 5.7 Run-In The file shall not include an MXF file Run-In. 5.8 Mapping Track

44、 Numbers to Generic Container Elements Each Track Number value for an Essence Element defined in this RDD shall be derived as described in the MXF Generic Container standard (SMPTE ST 379-2). 6 KLV Coding and Universal Label Specifications 6.1 ProRes Profiles ProRes is an intra-frame codec that can

45、encode either progressive or interlaced frames with arbitrary dimensions and either 4:2:2 or 4:4:4 chroma sampling. The compressed size of each frame is variable and dependent on image content, resolution, and the ProRes profile. The 4:4:4 profiles can optionally support an alpha channel with either

46、 8 or 16-bit sample depth. Table 2 defines the ProRes profile names, their attributes and values. Note: Nominal bit rates are provided for 1920 x 1080 and 3840 x 2160 pictures at 24 fps. Actual bit rates are variable and content dependent. Alpha channel compression is lossless and does not have a no

47、minal bit rate. SMPTE RDD 44:2017 Page 8 of 15 pages Table 2 ProRes Profiles Profile name Chroma sampling Alpha sample depth Nominal bit rate (informative) 1920 x 1080 at 24 fps 3840 x 2160 at 24 fps 422 Proxy 4:2:2 No alpha 36 Mb/s 145 Mb/s 422 LT 4:2:2 No alpha 82 Mb/s 329 Mb/s 422 4:2:2 No alpha

48、117 Mb/s 472 Mb/s 422 HQ 4:2:2 No alpha 176 Mb/s 707 Mb/s 4444 4:4:4 No alpha 264 Mb/s 1.06 Gb/s 4444 4:4:4 8 or 16 4444 XQ 4:4:4 No alpha 396 Mb/s 1.59 Gb/s 4444 XQ 4:4:4 8 or 16 6.2 ProRes Essence Element KLV Coding 6.2.1 ProRes Picture Element Key ProRes Picture Essence is Frame Wrapped and the K

49、ey (Universal Label) defined in Section 6.3 shall be used. 6.2.2 Essence Element Length The KLV length field BER coding for ProRes video Content Elements shall be five bytes. Note: The five byte KLV length field is needed for high resolution with high data rates. 6.2.3 Essence Element Value The Essence Element KLV value for progressive pictures shall be one video frame, and for interlaced pictures the KLV value shall be two fields from a single video frame. 6.3 ProRes Picture Element Key The values of the bytes of