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W3C Media Annotation Working Group (MAWG)
Workshop on Euscreen Metadata Schema and Content Selection Strategy, Mykonos, Greece
24.06.2010
Dr. Tobias Bürger
Salzburg Research Forschungsgesellschaft m.b.H.
Invited Expert in the W3C Media Annotation Working Group
[email protected]
www.tobiasbuerger.com
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24.06.2010 T. Bürger: The W3C Media Annotation Working Group, EUScreen Workshop, Mykonos, Greece 2
“Leading the Web to its full potential.”
W3C has more than 400 members in 40 countries, offices in 20
countries, and 3 host sites.
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W3C Video on the Web Workshop (12/2007)
| Topics: <video> HTML 5.0,
codecs and formats, metadata,
content protection, media
fragment, accessibility, tagging,
searchability, synchronization,
temporal properties for styling,
distribution, playlist files
| Participants included Adobe Systems, Apple, CBS Interactive,
Canon, Cisco Systems, Hitachi, MTV Networks, Motorola, Mozilla
Foundation, Nokia Corporation, RealNetworks, Samsung Electronics,
Sony, Sun Microsystems, Thomson, Walt Disney Internet Group,
YouTube
| Outcome: Video in the Web Activity
| Timed Text Working Group, Media Fragments Working Group, Media
Annotation Working Group, Best Practices and Guidelines for Media
Content on the Web (not yet chartered)
24.06.2010 T. Bürger: The W3C Media Annotation Working Group, EUScreen Workshop, Mykonos, Greece 3
Photo credit: Robert Freund
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The MAWG Group
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Total amount of members: 30
Members: Apple, EBU, Opera, Nokia, Samsung, Ercisson, and
research organisations
MA
WG
, F
2F
7, V
ien
na
, A
ustr
ia, 0
4/2
01
0
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Motivation: Interoperability Issues
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EXIF
MPEG-7
DC
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MAWG Purpose: Facilitate Metadata Integration for Media
Resources on the Web
| Mission: „To unify access to selected metadata across a
variety of formats“
| Core outcome:
1. Ontology
| common set of properties
describing basic metadata
for media resources
| mappings of existing
formats to core vocabulary
2. API
| access to the metadata
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Mapping of Metadata Standards
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MA Ontology
MA properties
API (Web Interface Definition Language)
MPEG-7 Dublin Core EBUCORE EXIF…MEDIARDF
MA mapping (expressed as mapping table)
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Ontology for Media Resource 1.0
| Core vocabulary: Common set of properties
| Mappings from different formats
| Descriptive Properties (20)
| Identification (4): ma:identifier, ma:title, ma:language, ma:locator,
| Creation (4): ma:contributor, ma:creator, ma:createDate, ma:location
| Content Description (4) : ma:description, ma:keyword, ma:genre,
ma:rating
| Relational (2): ma:relation, ma:collection
| Rights (2): ma:copyright, ma:policy
| Distribution (2): ma:publisher, ma:targetAudience
| Fragment (2): ma:fragment, ma:namedFragment
| Technical Properties (8)
| ma:frameSize, ma:compression, ma:duration, ma:format,
ma:samplingRate, ma:framerate, ma:averageBitrate, ma:numTracks
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http://www.w3.org/TR/mediaont-10/
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Ontology for Media Resource 1.0
| Core vocabulary: Common set of properties
| Mappings from different formats
| Descriptive Properties (20)
| Identification (4): ma:identifier, ma:title, ma:language, ma:locator,
| Creation (4): ma:contributor, ma:creator, ma:createDate, ma:location
| Content Description (4) : ma:description, ma:keyword, ma:genre,
ma:rating
| Relational (2): ma:relation, ma:collection
| Rights (2): ma:copyright, ma:policy
| Distribution (2): ma:publisher, ma:targetAudience
| Fragment (2): ma:fragment, ma:namedFragment
| Technical Properties (8)
| ma:frameSize, ma:compression, ma:duration, ma:format,
ma:samplingRate, ma:framerate, ma:averageBitrate, ma:numTracks
24.06.2010 T. Bürger: The W3C Media Annotation Working Group, EUScreen Workshop, Mykonos, Greece 9
http://www.w3.org/TR/mediaont-10/
Name Type Definition Description
ma:creator { (identifier:(URI|String)),
(role:String)? }
A tuple identifying the author
of the resource, using either a
URI or plain text…
ma:frameSize { (width:Float), (height:Float),
(unit:String)? }
A tuple defining the frame
size of the resource…
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Mappings: Relating Properties to Existing Formats
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ma:contributor
media:credit@role
in MediaRSS
{XmpDM:artist | xmpDM:composer}
in XMP
relatedmore general
semantic mappings: exact, related, more specific, more general
syntactic mappings, e.g.
“String" in XMP
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Specification of Mappings
| Mappings currently specified in mapping tables as part of „Ontology
for Media Resource 1.0“, http://www.w3.org/TR/mediaont-10/
| Mapping tables available for 17 formats (e.g., DIG, EBUCore, EXIF,
ID3, IPTC, MPEG-7, TVAnytime, XMP)
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MAWG
property
Rel-
ation
EBUCore How to
do the mapping
Datatype XPath
ma:identifier exact dc:identifier DC compliance
requires a string
but it is
recommended.....
string EBUCoreMain/
coreMetadata/
identifier/
dc:identifier
ma:frameSize exact height
width
nonNegat
iveInteger
EBUCoreMain/co
reMetadata/form
at/height or
…/width
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Ontology Implementation
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| Two levels:
1. Basic vocabulary
2. Implementation of the format mappings
| FYI: The Ontology
implementations can currently be
retrieved via the MAWG Wiki.
http://www.w3.org/ns/ma-ont
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Why use RDF and Semantic Technologies?
| XML-based standards do not
explicitely provide their semantics and
are (often) ambiguous.
| Added value of semantic technologies:
| Compliance with the Web.
| Provides us with a simple data model
to make statements about resources
(RDF).
| Allows to embed metadata in HTML
documents (RDFa).
| The use of ontologies (RDFS, OWL)
has positive effects:
| Unique identifiers for conceptualelements to resolve ambiguities.
| Excluding unwanted interpretations by means of formal semantics.
| Inferring implicit facts automatically.
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Mapping Implementation Approaches
| Two types
| expressing mappings using semantic web language (e.g., SKOS or OWL
/SWRL)
| expressing mappings through pivot upper ontology (e.g., format
independent/dependent ontology)
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SKOS OWL +
SWRL
MEON
Ontology
Format
dependent
Ontology
Complexity + + - +
Scalability - - + -
Reasoning - + + -
cf. Stegmaier et al."How to Align Media Metadata Schemas? Design and Implementation of the Media
Ontology" In: Proceedings of SeMuDate 2009, 2009.
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API for Media Resource 1.0
| Client-side API for access to metadata
| Use of media ontology core properties as a pivot vocabulary
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http://www.w3.org/TR/mediaont-api-1.0/
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WebIDL Specification
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API: Usage Example
| Return the genre of the movie „Apocalype Now“
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MAWG: Current Work
| Ontology for Media Resource 1.0 and API for Media Resource 1.0 in LC
status
| Ontology implementation: Currently finalizing the basic OWL ontology
| Mapping implementation: Several proposals under discussion
| API implementation: Started at two groups
| Definition of the test suite: ongoing
| Follow us / Contribute:
| Homepage: http://www.w3.org/2008/WebVideo/Annotations/
| Wiki: http://www.w3.org/2008/WebVideo/Annotations/wiki/Main_Page
| Mailing list (archive): http://lists.w3.org/Archives/Public/public-media-annotation/
| Predecessor: http://www.w3.org/2005/Incubator/mmsem/
|
Nearby initiative:
http://www.w3.org/2008/WebVideo/Fragments/
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Contact
Dr. Tobias Bürger
Salzburg Research Forschungsgesellschaft m.b.H.
Jakob Haringer Straße 5/3 | 5020 Salzburg, Austria
T +43.662.2288-415 | F +43.662.2288-222
[email protected]
www.tobiasbuerger.com
Acknowledgements for some slides to Chris Poppe, Joakim Söderberg, Philippe le Hegaret