AS-AP Archive and Preservation Early Draft Oliver Morgan Metaglue Corporation August 2010.
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AS-AP Archive and Preservation Early Draft Oliver Morgan Metaglue Corporation August 2010
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Transcript of AS-AP Archive and Preservation Early Draft Oliver Morgan Metaglue Corporation August 2010.
AS-AP Archive and PreservationEarly Draft
Oliver MorganMetaglue Corporation
August 2010
2
AS-AP Archive and Preservation
• Goals– define a standard MXF format for A&P– discuss and reach consensus on image formats, file
structure, and metadata– reconcile with implementation practice– review and publish through AMWA– eventually, due-process standardization
3
Profiling MXF
• MXF is a massive standard– wide coverage– many details– many options– needs focus to specific applications
• Application Specification– defines broad choices for an application area– ex: Program Delivery, Versioning, Craft Editing,
Contribution,...
• Shim– detailed constraints for specific uses
4
the universe of media formats
media formats that can be carried in MXF
Archive and Preservation
Umatic
(Application Spec)
(Shim)
5
the universe of media formats
media formats that can be carried in MXF
Archive and Preservation
Umatic
(Application Spec)
(Shim)Film
NAVCC? (Sub-Shim)
6
the universe of media formats
media formats that can be carried in MXF
Archive and Preservation
Umatic
(Application Spec)
(Shim)Film
NAVCC? (Sub-Shim)
Photo
NARA?
7
Details and AS-AP Topics
• AS-03 case study/example– slides follow below
• AS-AP Strawman– “AMWA-AS-AP-Archive&Preservation-Spec-1a-20100811.doc”
AS-03 Program Delivery
Oliver MorganMetaglue Corporation
June 2009
9
AS-03 MXF Program Delivery
• File-Based Workflow• Which file format?
– Based on SMPTE Material Exchange Format (MXF)– The SMPTE MXF standards cover a very wide range of
parameters and user needs– AS-03 is a vendor-neutral interoperability profile of
MXF
– The NGIS HD and NGIS SD “shims” focus the AS-03 profile on PBS programming distribution requirements
– Other “shims” are anticipated for other organizations
10
Why MXF?
• There are many file formats to choose from– almost as many formats as there are recording devices– that is fine so long as we all use the same server…
• The industry has been searching for a format that can become as ubiquitous as SDI– Goal is a non-proprietary specification – SMPTE started work in earnest in 1997– Universal Wrapper
• Compression Agnostic, Bitrate Agnostic• Application Agnostic• Allow Mix and Match
– Universal Metadata• Both Standard and User-Defined
11
MXF History
• MXF was published in 2004– 700 pages of specifications– a disruptive technology
• Developed 1997 to 2003 with lots of testing– published documents needed corrigenda & amendment– initial implementations were rough
• Nonetheless, user uptake gathered momentum
12
MXF Today
• Libraries of AAF and MXF files exist today– have existed since 2002
• Primarily essence files– also include valuable customer metadata
• Some examples– Digital Cinema Releasing: 50,000 per year ?– Digital Cinema Post Production: scads– Commercial TV: 50,000 per month ?– Shoah Foundation: 50,000 per year– Culpeper Archive: will be 250,000 per year– Government: 1 per minute per aircraft
13
Some of the (many) kinds of MXF Files
MasterMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
EssenceData
UMID
FileSourceMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
MasterMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
FileSourceMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
MasterMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
EssenceData
UMID
FileSourceMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
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FileSourceMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
Some more…
FileSourceMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
EssenceData
UMID
EssenceData
UMID
MasterMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
PhysicalSourceMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
MasterMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
PhysicalSourceMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
15
AS-03 File (MXF OP1a)
MasterMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
EssenceData
UMID
FileSourceMob
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
16
Overall View Of An AS-03 File
File Footer Body Index
Header Partition
Header Metadata
Footer Partition
File Header File Body with interleaved Video, Audio, Captions
Video
A Header Metadata
Body Partition
C Video
A C Video
A C Index
Body Partition
17
MXF “Package”
Package
V1
A2
A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
Tracksany number –Picture, Sound –Descriptive Metadata – Data, User-defined –
Sequences– any length
Descriptive Metadata (DM)– any number, any scheme
– SMPTE, MXF, User-defined
Timecodesany number, any frame rate –SMPTE, Keycode, GPS –
Links to other Mobs– as needed
– internal or external
Media Object
Package IdentifierSMPTE UMID –Software GUID –User-defined –
18
AS-03 Goals
• The goal of the AS-03 Program Delivery project is create specifications and sample files for MXF distribution of finished programs and program segments with associated metadata.
• The content of these files is not intended for further processing before delivery to the consumer – Direct Playout, from any server
• Specifications will be composed of a set of general constraints plus one or more "shims" that are directed to specific applications
19
How?
• AS-03 defines sets of constraints upon the use of the features of the MXF file format for use in the program delivery chain.
• The intent of these constraints is to minimize the number of options that must be considered by implementers of individual devices within the system, thus increasing the reliability and interoperability of the overall system.
20
Specification
• A set of general constraints plus one or more "shims" that are directed to specific applications: for example, one for "NGIS HD", one for "NGIS SD", one for "Broadcaster A", and so on.
• This allows us to remain flexible while maintaining our focus on delivering this project according to the proposed schedule
• We can move issues between the general text and the "shims" to optimize the split between generality and specific application requirements
21
AS-03 Coverage
• The specifications will cover both SD and HD program content encoded in long GOP MPEG2 or H.264 constrained to specific bit rates and GOP structures.
• Captioning and VBI data will be carried separately from video.• Program audio will be constrained to specific channel
repertoires and bit rates.• Essence will be interleaved to ensure preservation of sync
during distribution– MPEG V-ES in SMPTE 381– PCM in SMPTE 382– AC-3 ES in SMPTE 339 in SMPTE 382– VBI in SMPTE 436– Alll multiplexed in SMPTE 379M Generic Container
22
AS-03 Metadata
• Different metadata sets appropriate to each distribution application will be carried in the MXF header
• A small summary metadata set will be present in all files– will carry a few metadata items gathered from the application-specific metadata– to facilitate content identification, routing and multiplexing – DMS-AS-03
• For NGIS HD and SD– Slate metadata
• Program ID (P123456-001)• Total Run Time (TRT)• Start/End of Message (SOM and EOM) pairs• Active Format Description (AFD)• Feature Indicators (CC, DVS, SAP, Vchip, Rating)• Language Codes• NOLA code• Title• Media type (signal type)
– Optional PB/Core
23
AS-03 Constraint Tabulation - Picture
Dimension Description AS-03Constraint
AS-03Values
NGIS HD Constraint
NGIS HD Values
Segment Duration
what is the range of program items to be covered
Gentle 0:00:01:00 and up
Moderate 0:00:05:00 to 3:00:00:00
Program bitrate
how many bits per second at real time
Gentle ~3Mbps to ~50 Mbps
Strong 25 Mbps + Audio @ 1.5 Mpbs for HD
Picture format Picture raster and aspect ratio
Moderate
480i 4:3,1080i 16:9
Strong 1080i 16:9 for HD
Transport Bitrate
how many bits per second in transit
None N/A Strong <35 Mbps
Picture Essence Schemes
what picture signal schemes (compression or sampling or other) are encountered in programs
Gentle MPEG2 all GOPsAVC all GOPs4:2:0 or 4:2:2
Strong ATSC &MPEG 2 long GOP
24
AS-03 Constraint Tabulation - Sound
Dimension Description AS-03Constraint
AS-03Values
NGIS HD Constraint
NGIS HD Values
Sound Essence Schemes
what sound signal schemes
Moderate
PCMAC-3
-same- -same-
Sound Language repertoire
what primary sound languages may be present
None any Moderate en-usone other ?
Track Listings what combinations of picture sound and data tracks are encountered in programs
Strong 1 x Main Sound(stereo or 5.1)1 x SAP (opt)1 x DVS (opt)Others opt up to a total 8 pairsPCM pairs shall be used for Stereo programming
Strong PBS Published Audio Configuration (surround plus 4 pairs)
25
More Constraints – Captions, Metadata
Dimension Description AS-03Constraint
AS-03Values
NGIS HD Constraint
NGIS HD Values
Caption Essence Schemes
what captions signals schemes
Strong CEA-608, CEA-708 & SMPTE 436M
-same- -same-
Caption Languages
what captions languages
None any Strong en-us and one other
Program identification
what identifiers are required
Gentle One of: ISAN Ad-ID House (per shim) UUID
Strong House (PODS)
Intimate metadata
what metadata must be carried with the program item
Moderate
Program Ident (reqd)Track Ident (reqd)Language Ident (reqd)other per shim
Program Segmentation (opt)
Moderate PODS summary (reqd)PBCore (opt)
26
More Constraints – MXF-specific
Dimension Description AS-03Constraint
AS-03Values
NGIS HD Constraint
NGIS HD Values
Segment Duration
what is the range of program items to be covered
Gentle 0:00:01:00 and up Moderate 0:00:05:00 to 3:00:00:00
MXF Structure MXF-specificOperational Pattern
Strong OP1A internal -same- -same-
MXF Structure (continued)
MXF-specificIndex Tables
Strong Full Index Tables -same- -same-
MXF Structure (continued)
MXF-specificPartitioning
None N/A -same- -same-
27
Reference Implementation
• Utilities have been produced to wrap test essence and metadata into AS-03 files, to unwrap the files and compare the inputs and outputs. These will be used throughout the project to illuminate design issues and to perform regression testing
• Using mxflib open source – scripts to wrap and unwrap– design testing is performed with a custom scripting
application• simpler functions will be included in NGIS workflow
28
Sample Files
• Test files will be created during the development, including “golden” (engineered good), and “silver” (real-world, proven good)
• Silver streams encoded by users– for NGIS HD and SD encoded by PBS
• Several encoders• Actual “Cringely” and other programming
• Golden test streams– Golden test sequence uses synthetic test patterns
• MPEG Video, AC3, PCM, CEA 608 and 708
29
AS-03 Testing
• AS-03 builds on earlier work on AS-PBS• Basic methodology
– make specs and sample files available to all vendors– regular telephone discussion– iterative testing– eventually, publish via the AMWA
• Server vendors– Omneon, Harris, Thomson, Seachange,
GVG, 360 Systems , Sony, Pinnacle, …
• Now starting testing with transcoder vendors
30
Segmentation
• Some files cut to length– SOM = 0, EOM = total duration– e.g. AS-03 NGIS
• Some files include preroll/postroll– SOM, EOM traditionally specified using timecode– Duration is less error-prone than EOM
• SOM and EOM/Duration pairs– sequence of non-overlapping segments– may be separated by black fill, or back-to-back
• (not AS-03) Segments may be in individual files
31
MXF “Package”
Package
V1
A2
A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
Tracksany number –Picture, Sound –Descriptive Metadata – Data, User-defined –
Sequences– any length
Descriptive Metadata (DM)– any number, any scheme
– SMPTE, MXF, User-defined
Timecodesany number, any frame rate –SMPTE, Keycode, GPS –
Links to other Mobs– as needed
– internal or external
Media Object
Package IdentifierSMPTE UMID –Software GUID –User-defined –
32
The Package Derivation Chain
CompositionPkg
FXV1
A2A1
V2
UMID
EssenceData
UMID
PhysicalSourcePkg
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
EssenceData
UMID
FileSourcePkg
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
MasterPkg
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
FileSourcePkg
V1
A2A1
TC 23 24 00 01 02 03
AX
DM
UMID UMID
33
MXF Operational Patterns
Item Complexity
Ganged Packages
Single Item Play-list Items Edit Items
Alternate 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 SourceClip = entire FP
seq. MP1
MP2
OR
MP1
MP2
OR
Each MP SourcelCip = entire FP
Only 1 MP SourceClip = FP
duration
Only 1 MP SourcelCip = FP
duration
MP1
MP2
OR
Any MP track from any FP track
1 2 3
a
b
c
34
SOM/EOM in MXF Structural Metadata (1)
Material Package 01:00:00:00 01:05:00:00 01:10:00:00 01:15:00:00
File Package
Composition Package
PictureSound
Timecode
PictureSound
PictureSound
Descriptive Metadata
Descriptive Metadata
<!--partial Reg-XML--><compositionpackage> <track> <sequence> <datadefinition> Picture </datadefinition> <fill> <duration> 2:00:00 </duration> </fill> <sourceclip> <duration> 4:30:00 </duration> </sourceclip> <fill> <duration> 1:00:00 </duration> </fill> <sourceclip> <duration> 6:00:00 </duration> </sourceclip> <sourceclip> <duration> 1:20:00 </duration> </sourceclip> <fill> <duration> 20:00 </duration> </fill> <sourceclip> <duration> 2:20:00 </duration> </sourceclip> </sequence> </track> <track> … </track></compositionpackage>
35
SOM/EOM in MXF Structural Metadata (2)
Material Package 01:00:00:00 01:05:00:00 01:10:00:00 01:15:00:00
<!--partial Reg-XML--><materialpackage> <track> <sequence> <datadefinition> Descriptive Metadata </datadefinition> <fill> <duration> 2:00:00 </duration> </fill> <dmsegment> <duration> 4:30:00 </duration> </dmsegment> <fill> <duration> 1:00:00 </duration> </fill> <dmsegment> <duration> 6:00:00 </duration> </dmsegment> <dmsegment> <duration> 1:20:00 </duration> </dmsegment> <fill> <duration> 20:00 </duration> </fill> <dmsegment> <duration> 2:20:00 </duration> </dmsegment> </sequence> </track> <track> … </track></materialpackage>
File Package
PictureSound
Timecode
PictureSound
Descriptive Metadata
36
CRC and Signature
• Requirements for verification of file content?– transport/storage/delivery errors– authentication– file corruption during processing– integrity of repurposing (e.g. track swapping)
• Techniques in AS-02– MD5– CCITT CRC-16– Castagnoli CRC-32
• Techniques from SMPTE 429-6 DCP Encryption– SHA-256/SHA-512 Secure Hash– full MIC and encryption
• Other techniques– Signature– Hash essence together with the author’s public key
Thank YouQuestions?
Oliver Morgan
http://www.metaglue.com
