TheSeman)csofMPEG‐21DigitalItems
Chris&anTimmerer
KlagenfurtUniversity(UNIKLU)FacultyofTechnicalSciences(TEWI)
DepartmentofInforma&onTechnology(ITEC)Mul&mediaCommunica&on(MMC)h;p://research.)mmerer.comh;p://blog.)mmerer.commailto:chris)an.)[email protected]‐klu.ac.at
Co‐authors:Chris)anTimmerer(UNIKLU)MariaTeresaAndrade,PedroCarvalho(INESC)DavideRogai(Comm.it)GiovanniCordara(TILAB)
ACKNOWLEDGMENTSPartofthisworkissupportedbytheEuropeanCommissioninthecontextoftheAXMEDIS(contractno.511299)andENTHRONE(contractno.038463)projects.Furtherinforma)onisavailableath;p://www.axmedis.organdh;p://www.ist‐enthrone.orgrespec)vely.
Outline
• Introduc)on• MPEG‐21DigitalItems
• UseCasesandDataModels
• Evalua)on(Criteria)andDiscussion• Conclusions
Mainsource:MPEGcoreexperimentconducted
2008/10/31 2Chris)anTimmerer,KlagenfurtUniversity,Austria
(MPEG‐21)Introduc)onGoal• …toenabletransparentandaugmenteduseofmul)mediaresourcesacrossawide
rangeofnetworks,devices,userpreferences,andcommuni)es,notablyfortrading(ofbits)
What?–DigitalItems(DIs)• ADigitalItem(DI)isastructureddigitalobjectwithastandardrepresenta)on,
iden)fica)on,andmetadatawithintheMPEG‐21framework• DigitalItemsare“thecontent”:=(Media)Resources+Metadata+Structure
Who?–Users• AUserisanyen)tythatinteractsintheMPEG‐21environmentormakesuseofa
DigitalItem• Userswillassumerightsandresponsibili)esaccordingtotheirinterac)onwith
otherUsers• Allpar)esthathavearequirementwithinMPEG‐21tointeractarecategorized
equallyasUsers
2008/10/31 Chris)anTimmerer,KlagenfurtUniversity,Austria 3
Introduc)on(cont’d)Issue• …possibletorepresentseman)callysimilar(orequal)DigitalItems
indifferentways– Structureandsyntaxelements
Impactoninteroperabilitywithinandacrossapplica)ondomains(e.g.,automatedproduc)on,delivery,andconsump)onwithinheterogeneousenvironments)
Twotypesofinteroperabilityinves&gated• Interop@DI:access/browsemediaresourcesandmetadata,
process/consumetheDigitalItemassuch• Interop@DID:processingoftheDI’srepresenta)on(parsing,
valida)on)
2008/10/31 Chris)anTimmerer,KlagenfurtUniversity,Austria 4
MPEG‐21DigitalItems
DigitalItemModel:abstracttermsandconceptinEBNF
DigitalItemDeclara)onLanguage(DIDL):XMLschema–buildingblocks Item Component Descriptor Resource Choice/Selec)on
DIDLdocumentakaDID
=>highlyflexible!!!
2008/10/31 Chris)anTimmerer,KlagenfurtUniversity,Austria 5
e.g.,DigitalItemIden)fierreferringtoISBN,ISSN,ISAN,ISRC,etc.e.g.,MPEG‐7,DublinCore,
SMPTE,proprietary,etc.
e.g.,MPEG‐7,DublinCore,SMPTE,proprietary,etc.
(Industry)Adop)onsUPnP–DIDL‐Lite• Containerformat:UPnPspecific(bitrate,resolu)on,etc.)+Dublin
Core
MPEG‐21,Part4–IPMPDIDL• Declara)onofprotectedDigitalItems
MPEGMul&mediaApplica&onFormats(MAFs)• “Profiles”DigitalItems:subsetoftools
MSInterac&veMediaManager(IMM)• ImplementDImodelusingOWL• DublinCore+domainspecificmetadata(IPTC,EXIF,SMPTE)+
customontologypredicates• AdoptsDigitalItemIden)fica)on
2008/10/31 Chris)anTimmerer,KlagenfurtUniversity,Austria 6
=>very/tooflexibleframework!!!
UseCase(s)
• CP:ini)alDI(mediaresource+metadata)• SP:advancedDigitalItemwithrespecttoServiceLevel
Agreements(addi)onalmetadata)• NP:networkconnec)vityservicewithQoS• CC:requestsservice(fromSP)andconsumesit(terminal)
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DataModels
UCS1:AXMEDIS
• CompositeObject
• BasicObject
UCS2:ENTHRONE
• ComposedandFinalItems
2008/10/31 Chris)anTimmerer,KlagenfurtUniversity,Austria 8
Evalua)onCriteria
Interop@DID
C.1ConformancetoDImodel
C.2ConformancetoDIDLC.3Ambiguityofdatamodels
C.4DIDparsingissuesC.5Supportedbuildingblocks
C.6Syntaxrestric)ons
C.7Seman)crestric)ons
Interop@DI
C.8Contentbrowsingissues
C.9DisplaymetadataC.10Mediarenderingissues
C.11Decode/DisplayDIasawhole
2008/10/31 Chris)anTimmerer,KlagenfurtUniversity,Austria 9
Evalua)onandDiscussion
• PlayerscouldsomehowhandleDigitalItems– Metadatanotunderstoodisnotdisplayed(i.e.,ignored)
• Choice/Selec)onnotadopted– Mul)plecomponentsinsteadwithaddi)onalseman)csdefined
– Onlyfirstcomponentisdisplayedforfirstusecase• DigitalItemIden)fica)onarequirement• Interpreta)onofmediaresourcesvs.metadata
– Installmediadecoders–innecessary–on‐demand– Howaboutmetadata?“Metadatadecoder”notdefined!Useproprietarymetadataonlyinternally
• Presenta)onlogicnotmandated
2008/10/31 Chris)anTimmerer,KlagenfurtUniversity,Austria 10
Conclusions
• Flexibility– Applica)onsimplementonlyasubset– Addseman)crestric)onstosimplifyDIhandling– Allowstheuseofproprietarymetadata
• Flexibilityleadstointeroperabilityissues?– DoesnotinvalidDID– Processingmayleadtoalossoffunc)onality– Never(twice)thesameDI(analogoustoNTSC’s“neverthe
samecolor”or“nevertwicethesamecolor”)• Needforaddi)onallayertohomogenizetheuseof
MPEG‐21– DigitalItemProcessing(DIP)– Presenta)onofStructuredInforma)on(PSI)
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Conclusions(cont’d)
• DigitalItemProcessing(DIP)– Sugges)onsofinterac)onwiththeDI– EmbedDigitalItemMethods(ECMAScript,DigitalItemBaseOpera)ons)whicharepresentedtotheUser
• Presenta)onofStructuredInforma)on(PSI)– ExtensionofLASeRtopointtocertainpartsoftheDIDforpresenta)onpurposes
– Actualpresenta)onaccordingtoLASeR• BothrequireextensionofMPEG‐21
2008/10/31 Chris)anTimmerer,KlagenfurtUniversity,Austria 12
Thankyouforyoura;en)on
...ques)ons,comments,etc.arewelcome…>>VisittheITcampusCarinthia<<>>h;p://www.it‐campus.at<<
Ass.‐Prof.Dipl.‐Ing.Dr.Chris)anTimmererKlagenfurtUniversity,DepartmentofInforma)onTechnology(ITEC)
Universitätsstrasse65‐67,A‐9020Klagenfurt,AUSTRIAchris)an.)[email protected]‐klu.ac.at
h;p://research.)mmerer.com/Tel:+43/463/27003621Fax:+43/463/27003699
©Copyright:Chris.anTimmerer
132008/10/31 Chris)anTimmerer,KlagenfurtUniversity,Austria
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