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.)mmerer@itec.uni‐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

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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)

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MPEG‐21DigitalItems

DigitalItemModel:abstracttermsandconceptinEBNF

DigitalItemDeclara)onLanguage(DIDL):XMLschema–buildingblocks Item Component Descriptor Resource Choice/Selec)on

DIDLdocumentakaDID

=>highlyflexible!!!

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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

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=>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

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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

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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

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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.)mmerer@itec.uni‐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