Distributed Multimedia

7/24/2019 Distributed Multimedia

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Distributed Multimedia

Application


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Distributed MM applications hasdivided into two categories:

People-to-people applications

Involved at least 2 people

To improve communications betweenhumans

People-to-system applications

Individual / group o peoplecommunicate with a remote system toaccess! receive or interact with MMinormation"


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People-to-peopleapplications

#ro$en down into % ways:

Private applications vs" proessionalapplications

Interpersonal &between two people'!verses group-oriented applications

(eal-time versus asynchronousapplications

)as 2 categories: *ynchronous applications

Asynchronous applications


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People-to-*ystemapplications

Interactive Applications

Distribution Applications


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+omputer *upported+ooperative ,or$ &+*+,'

eneral De.nition:

+*+, is a generic term! which combinesthe understanding o the way peoplewor$ in groups with the enablingtechnologies o computer networ$ing!

and associated hardware! sotware!services and techniues"


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+omputer *upported+ooperative ,or$ &+*+,'

+*+, is a design-oriented academic.eld bringing together socialpsychologists! sociologists! and

computer scientists! among others" +*+, is an identi.able research .eld

ocused on understandingcharacteristics o interdependent group

wor$ with the ob0ective o designingadeuate computer-based technologyto support such cooperative wor$"


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Same time/same place

1ace to ace interaction

(oomware *hared tables! wall displays

Digital whiteboards

lectronic meeting systems *ingle display groupware


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Same time/diferent place

(emote interaction

lectronic meeting systems 3ideoconerencing

(eal-time groupware

Messaging &instant messaging! email!chat'


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Diferent time/same place

+ontinuous tas$

Team rooms! 4arge displays

Post-it


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Diferent time/diferent place

+ommunication 5 +oordination

lectronic meeting systems ,i$i

#logs

,or$6ow 3ersion control


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(euirements onDistributed MM

The distributed MM system should beable to provide support or continuous

media types &such as audio! video andanimation'"

Distributed MM applications is the need

or sophisticated uality o service&7o*' management"


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Distributed MM applications is theneed or a rich set o real-timesynchroni8ation mechanisms about

continuous media transmission"

Distributed MM system able tosupport multiparty communications"


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Issues or DistributedMultimedia

4arge uantities o audio! video andother time-based data elements

*torage

Timely processing

Transmission systems

Availability o standards or multimedianetwor$ing

+ost o transmitting MM inormation


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Application or education!

entertainment and industry 9ample: etwor$ed 3irtual ArtMuseum

+omponents that need to beconsidered:


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*ystemsDefnition:

Distributed multimedia systems consist omultimedia databases! pro9y and

inormation servers! and clients! and are

intended to or the distribution o


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Introduction

Most multimedia is inherently time-based ; the arrival timeand arrivalordero data pac$ets is important

The Internet guarantees is neededwhen transmitting data

1or interactive multimedia over

networ$s! the perormance should bereliableand high-quality


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)istory

=s: Distributed computing researchwith earliest networ$s

?=s: +ompact disc! personal computer

e9plosion

?=s-@=s: Distributed multimedia systemresearch &video conerencing! etc'

@=s-current: +urrent prevalent paradigm&uality o service management'


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oal

)igh uality! reliable! interactivemultimedia

The general Internet structure is not

sucient to accomplish this A distributed multimedia system will

add protocols and architectures on top

o the Internet &or 4A' to guaranteeuality levels! thereby satisying ourneed


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+omponents

#andwidth: data rate through acomponent

4atency: time needed or a pac$et totravel end to end

4oss rate: acceptable drop-rame ratio

7uality o service management:negotiation and allocation ocomputing resources


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(euirement

The reuirements o multimediaapplications signi.cantly diBer rom real-

time applications: Multimedia applications are highly distributed

and thereore compute with other distributedapplications or networ$ bandwidth and

computing resources"The resource reuirements o multimedia

applications are dynamic"

2C


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A distributed multimediasystem

22

Wide area gateway Videoserver

DigitalTV/radioserver

Video cameraand mike

Local network Local network


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*ystem The above .gure illustrates a typicaldistributed multimedia system!capable o supporting a variety o

applications such as des$topconerencing! video-on-demandservices! accessing stored video

seuences using web-basedmultimedia and broadcast digital T3/radio"

2%


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,eb-based multimedia These applicationsprovide best eBort

access to streams o audio and videodata published via the ,eb"

Their perormance is constrained withlimited bandwidth and variablelatencies ound in current networ$s"

These applications are most successulwhen there is little need or thesynchroni8ation o data streams"

2


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etwor$ phone and audioconerencing

These applications have relativelylow bandwidth reuirements whenecient compression techniues are

used"

)owever! its interactive naturedemands low round-trip delays which

are not always achievable"

2E


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3ideo-on-demand services

These supply video inormation indigital orm! retrieving data romlarge online storage systems and

delivering them to userFs display"

These are successul only whendedicated networ$ bandwidth is

available and where the video serverand the receiving stations arededicated"

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Distributed Multimedia

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