第6章电子信息类专业英语(李白萍).ppt

UnitSixMultimedia,PassageAWhatIsMultimedia?PassageBCharacteristicsPassageCMultimedia,PassageAWhatIsMultimedia?Interestinmultimediaiscurrentlypervasiveentertainmentandeducationalgroupsareexploringnewapplications,andthecomputer,telecommunications,andconsumerelectronicsindustriesareactivelydevelopingunderlyingtechnology.Asaterm,“multimedia”frequentlyusedbutrarelydefined.Amonghardwareandsoftwareengineers,attemptstoprovideameaningrangefromthewhimsical“multimediadefinition”(multimediaiswhenyouhavetoomanycables)tothoseemphasizingcommunicationorinteraction(GrimesandPotel,1991).Itisdifficulttopindowntheessenceofmultimediasincethetermappearsinnumerouscontexts,eachwithitsownnuances.Computerusershavemultimediapresentation,multimediaworkstations,andmultimediadatabases,butthepeopleinvolvedthepresentationauthors,workstationsdesigners,anddatabaseresearchersviewmultimediafromdifferentperspectives.Onepointwheretheyagree,however,isontheessentialroleplayedbymultimediadata.1Forinstance,multimediapresentations,astheirnamesuggests,involvethepresentationofmultimediadata,multimediaworkstationsdealwiththeprocessingofmultimediadata,andmultimediadatabaseswithitsstorageandretrieval.Perhaps,then,thenotionofmultimediadataisaunifyingthreadtodigitalmultimedia.,Sowhatismultimediadata?Letsfirstlookattherelatednotionofmediadata.McLuhan,inUnderstandingMedia,considersmediaas“extensionstoman”,astechnologiesandproductsgivingoursensesaccesstofurtherformsofinformation.2Thisverybroaddefinitionencompassestwomorespecificviews.Thefirstrelatesthetermmediatohowinformationisconveyedanddistributed;forinstance,wehaveprintandbroadcastmedia.Second,wealsousethetermmediawhendescribingthematerialsandformsofartisticexpression.Thisoccurswhenwespeakofdigitalmedia,notinthesenseofdigitalstoragemedia,butinthesenseofdigitalcounterpartstonaturalmedia.,Thedistinctionbetweennaturalanddigitalmediamaynotalwaysbeclearcut,buttheideaisthatnaturalmediarelyonphysicalelementspaper,stone,inksandpaints,musicalinstruments,andthestagewhiledigitalmediarelyonthecomputer.Supposewecallartifactstheobjectsproducedinaparticularmedium;wecanthendefinemediadataasmachine-readablerepresentationsofartifacts.Forinstance,prints,paintings,musicalperformances,musicalrecordings,films,andvideoclipsareallartifacts;mediadatacorrespondingtotheseartifactsconsistofdigitalimages,digitalvideorecordings,anddigitalaudiorecordings.,Wehavedescribedthreerelatedterms:media,bothnaturaldigital;artifacts,objectsproducedinmedia;andmediadata,digitalrepresentationsofartifacts.Someexamplesareshownbelow:Althoughmediadataarebitsandbytesusedbythecomputer,thisdatacanrepresentartifactsfrombothnaturalanddigitalmedia.Digitalimagesproducedbyscanningeitherphotographicprintsorhanddrawingsarerepresentationsofnaturalartifacts,whiledigitalimagesproducedbyacomputerpaintprogramarerepresentationsofdigitalartifacts.,Nowthatwehavethenotionsofmedia,mediadataandartifacts,wedefinemultimediaartifactsasthecompositionofartifactsfromvariousmedia.Differentcompositiontechniquesarepossibleandwilldependuponthemediainvolved.Compositionissometimesdividedintotwobroadcategories:spatialcomposition,forinstance,oneimagebeingjuxtaposedwithasecond,andtemporalcomposition,aswhenanaudiotrackisaddedtoavisualsequence.Inanalogywiththedefinitionofmediadata,wedefinemultimediadataasmachine-readablerepresentationsofmultimediaartifacts.Noticethattheartifactsbeingrepresentedmaybenatural,digital,oramixofbothnaturalanddigital.,KEYWORDSpervasive扩大的，渗透的whimsical古怪的，反复无常的pin钉住，扣住，抓住nuance微小的差别(色彩等)presentation赠与，图像，呈现，演示perspective透视，角度，远景convey运输，传递，转换counterpart伙伴，副本，对应物artifact人工制品video-clip录像剪辑audiorecording唱片juxtapose并置，并列,NOTES1Onepointwheretheycanagree,however,isontheessentialroleplayedbymultimediadata.但是有一个看法是能取得一致的，即多媒体的主要角色是由多媒体数据来扮演的。本句主语是onepoint，where引导的定语从句用来修饰onepoint，是指可以取得一致看法的一点。介词短语ontheessentialrole意为：论及重要作用方面(表示条件),谓语动词为isplayed,表被动语态。,2Mcluhan,inUnderstandingMedia,considersmediaas“extensiontoman”,astechnologiesandproductsgivingoursensesaccesstofurtherformsofinformation.McLuhan在他的了解多媒体一书中，把多媒体看作是人类感官的延伸，其技术和产品为人们提供进一步接触各种形式的知觉。本句是简单句，McLuhan为主语，considers为谓语，media为宾语。第一个as引导的短语补充说明宾语media。第二个as引导的是一个现在分词短语，分词短语的逻辑主语是technologiesandproducts,oursenses是giving的宾语。,EXERCISES1.True/False.(1)Thisexistingtraditionisbeingenlargedbyanewtypeofmultimedia.()(2)Asaterm,multimediaisfrequentlyusedbutrarelydefined.()(3)Peopleinvolvedinpresentationauthors,multimediaworkstations,andmultimediadatabasesresearchershavethesameviewonmultimedia.()(4)Althoughmediadataarebitsandbytesusedbythecomputer,thisdatacanrepresentartifactsbothnaturalanddigitalmedia.()(5)Inanalogwiththedefinitionofmediadata,wedefinemultimediadataasmachine-readablerepresentationsofmultimediaartifacts.(),(6)Noticethatartifactsbeingrepresentedmaybenatural,digital,oramixofbothnaturalanddigital.()(7)Themultimediahardwareneededbyaparticularapplicationwilldependonthebasisofapplicationcharacteristics.()(8)Thesimultaneouspresentationandmanipulationofmultiplemediaoftendoesnotdemandhardwareassistance.()(9)Currentmultimediaplatformsincludeordinaryworkstations,andPCs,withbuilt-insupportforseveralmedia.()(10)Manycurrentnetworksareappropriateforthetransferofaudioandvideodata.()(11)BISDNandATMareexamplesofrelevanttechnologiesandthebasisofinternationalstandardsforfuturemultimedianetworks.(),2.Fillintheblanks.(1)Digitalmediaarereadilycombinedandprocessed,andtheyareaskeyelementsofmoderntechnology.(2)Multimediacombinesaudioandvisualmaterialtoenhancecommunicationandits.(3)Itisdifficulttotheessenceofmultimediasincethetermappearsinnumerouscontexts,eachwithitsownnuances.(4)Perhaps,then,thenotionofmultimediadataisatodigitalmultimedia.(5)Thisoccurswhenwespeakofdigitalmedia,notinthesenseofdigitalstoragemedia,butinthesenseofdigitaltonaturalmedia.,(6)Thebetweennaturalanddigitalmediamaynotalwaysbeclear,buttheideaisthatnaturalmediarelyonphysicalelements,whiledigitalmediarelyonthecounter.(7)Compositionissometimesdividedintotwocategories:compositionandcomposition.(8)Theprocessofcreatingadigitalpresentationofamediaartifactsiscalled.(9)Inotherwords,wecandividemediaspecificdigitalhardwareintothree.(10)Forinstance,areusedtomeasurebothaudiosignalsandvideosignals.,3.Answerthequestions.(1)WhataretwoideasofMcLuhanonMedia?(2)Inwhatconditionaretheartifactsobjectsproduced?(3)Whataredigitalimagesproducedby?(4)Whataretheexamplesofinteractivedevices?(5)Inwhatwaydomultimediadifferfromcurrentlocalandwideareanetwork?(6)Whataredigitalimagesproducedby?(7)Howmanyframescanavideodischoldatnormalplaybackspeedin30minutes?,(8)Whataretheexamplesthatissomewhatnebulouscategoryoverlappingwithpreviouscategories,inparticularhypermediabrowsersandelectronicgames?(9)Whatisauthoring?(10)Whatisthebasisofdesktopconferencing?(11)Whatisthedifferencebetweentextandhypertext?(12)Whatisalink?(13)Whatisbrowsingornavigating?(14)Whataretypicalmediainhypermedianodes?,4.Fillintheblankswiththebestchoice.(1)Whichoneofthefollowingisnotanexampleofdigitalmediadevices?a.Printerb.MIDIsynthesizerc.audiotapeplayerd.frame-buffer(2)Whichoneofthefollowingisnotanexampleofanalogmediadevices?a.speakerb.MIDIkeyboardc.microphoned.videodiskplayer(3)Whichoneofthefollowingisnotanexampleofinteractivedevices?a.mouseandjoystickb.electronicpensc.3Dtrackersd.keyboards(4)Whichoneofthefollowingisnotanexampleofinputdevices?a.joysticksb.buttonsc.audiotapeplayerd.triggergrips,PassageBCharacteristicsMultimediaisoneofthemostinnovativewaysofusingatelecommunicationsnetworktoachieveeffectivecommunications(1)betweenpeopleand(2)foraccesstoinformation.Thischapterdescribestheessentialingredientsofmultimediaandgivesawidevarietyofexamplesofapplicationsinawiderangeofindustrialsettings.,FourKeyIngredientsMultimediacommunicationsisdefinedhereasthecombinationoffourkeyingredients:Twoormoreofthefivemediaofcommunication(audio,data,fax,image,andvideo);Interactivecapabilitiesbetweenthecommunicatingparties;CommunicationswithHumanUsers.Multimediasystemsinvolvecommunicationswithhumanusersassendersorreceiversofinformation,orboth.Bycontrast,singlemediumsystems,suchasdataandfax,caninvolveinter-machinecommunicationswithnohumanuserpresentwhilethecommunicationisunderway.Itisthehumanelementthatbenefitsfrommorethanonemediumofcommunication,andalsofromtheinteractivecapabilitiesofmultimediasystems.1,Synchronization.Multimediasystemsrequiretwotypesofsynchronizationbetweenthedifferentmedia.Continuoussynchronizationisrequiredforaudio/video,forinstance,tocoordinatelipmovementwithspeech.Syntheticsynchronizationisrequiredbythedesignerofthesystemtoorganizethepresentationofmaterialinthedesiresmanner(e.g.,thesequencingofvideoclipswithdataandgraphics).Videoconferencingisatypicalexampleofmultimedia,combiningtwomedia(audioandvideo),interaction,humanusers,andsynchronization.Bycontrast,broadcasttelevisionallowsnobackwardchannelfortheinformationreceivertointeractwiththeinformationprovider,anditisthereforenotregardedasamultimediacommunication.,Thetypesofinteractioninmultimediasystemsareasfollows:Searchandbrowse.Thesecorrespondtodatabaseaccessfunctionsforextractingtherequiredmultimediainformationfromstorage.Interactive“buttons”.Aframeofinformation(i.e.,ascreenorportionofascreen)maycontainbuttonsthatcanbeselected(e.g.,usingacursor)tocontrolthepresentationofinformation,andtopassontoanotherframe.Examplesof“buttons”arelistsofoptions,menuselections,andportionsofthedisplayedinformationthatcanbeselectedtoobtainadditionalinformationonthatsubject.Windowing.Oneframeofinformationoverlapsabackgroundframe,andthesizeofframescanbechangedbytheusersoastoviewportionsofseveralframessimultaneously.,FastForward,rewind,pause,andskip.“Taperecorder”commandstocontrolthesequenceandspeedofpresentationofinformationcanbeused,notjustwithaudioandvideoinformationbutalsotocontrolasequenceofframesofdata,fax,andimage.2Conversationalinteraction.Whenahumanuserispresentateachendofthecommunicationchannel,awiderangeofconversationalinteractionsarepossible,includingaudiodiscussion,displayingdataandimagesinsharedscreens,andpointingto,editingandannotatingthecontentsofthesharedscreen.,EnablingTechnologiesMultimediacommunicationshascomeaboutasaresultofthedevelopmentofanumberoftechnologicalcapabilities.Thesecapabilitiesaredescribedinthefollowingsubsections.Fast-PacketNetworks.Thehighbandwidth,burstnatureofmultimediacommunicationsmakesitparticularlysuitedtofast-packettelecommunicationcapabilitiessuchasthoseprovidedbyATMandDQDB.Untilthesenetworksarewidelydeployed,multimediacommunicationscanbebasedoncircuitcapabilitiesatarangeofbandwidthsandlowerbandwidthpacketcapabilities.suchasX.25andframerelay.3,HighCapacityStorageSystems.Thepredominanceofstorageintensivemedia,suchasaudio,video,andhighresolutionimageinmultimediacommunicationsrequireshighcapacitystoragesystems,suchasopticaldisks.PowerfulProcessingCapability.Theencoding/decodingofavarietyofmediaplusthesynchronizationoftheirpresentationtotheuserrequirepowerfulprocessors.CompressionCoding.Thedevelopmentofcodingtechniquesforaudio,image,andvideohasenabledmultimediacommunicationstobecompressedintoavailablebandwidth.Thisenabledmanymultimediasystemstobedevelopedbeforetheavailabilityofbroadbandnetworks.Broadbandcommunicationsresultsinimprovedqualityandlowerend-to-enddelay.,Hypertext.Hypertextisaprecursortomultimediathatwasdevelopedseveralyearsbeforethetechnologynecessaryformultimediabecameavailable.4Usingonlyonemediumimageitprovidedmanyoftheinteractivecapabilitiesofmultimediasystemsandservedtoprimethemarketforthetruemultimediathatisbecomingavailabletoday.Windowing.Windowingsoftwaregivesaninterfaceinwhichtheusercaninteractwithseveralfilesorsoftwareprocessesusingasinglescreen.Itwasoriginallydevelopedinasinglemediumsituationnamely,imageandwasrapidlyextendedtocaterformotionvideo.Itgreatlyenhancestheinteractivecapabilitiesofmanymultimediasystemstoday.,BusinessAdvantagesofMultimediaCommunicationsThereisastronglatentdemandformultimediacommunicationsasevidencedby:theuseofvideoconferencingtodisplayatechnicaldrawingorotherobjectofdiscussionaswellastheheadandshouldersofthediscussant.Thisisessentiallytheuseofmotionvideotoprovideastill-imagecapability.theuseoffaxanddatacommunicationequipmentduringthecourseofavideoconferencing;theuseofmodemsthatallowvoiceanddatacommunicationsoveronevoice-gradeline.,Theseexamplesimplyademandforinteractivecombinationsofallfivecommunicationsmedia:audio,data,image,fax,andvideo.Thebusinesseffectivenessofmultimediacommunicationscanbeestimatedfromtheeffectivenessofearlierformsofcomputermediatedcommunications(CMC)inwhichusersexchangedata,sometimesasanaccompanimenttoatelephoneconversation.BusinessexperienceofCMC,andresearchintoitsbenefits,ismoreestablishedthanformultimediasinceithasbeenusedsincethemid-1970s.TheeffectivenessofCMChasbeenanalyzedinbusinessgroupdecision-makingsituationsandineducationalsettingsasaninstructionaltool.,GroupDecisionMakingStudieshaveshownthatthereareadvantagestoCMCingroupdecision-makingsituationscomparedtoface-to-facemeetings.Table6.1givesacomparisonbetweencomputer-mediatedcommunicationsandface-to-facemeetings.,TheresultinTable6.1canbesummarizedbythestatementthatcomputermediationallowsfor(1)moreopinionstobegivenbymoregroupmembersand(2)morewillingnesstochangeopinioninordertocometoaqualitydecision.Face-to-facemeetingscanresultinpoorerdecisions,resultingfromthebandwagoneffectofdominantpersonalities.TheseadvantagesofCMCcanbeexpectedtoapplywithgreaterforceinthecaseofmultimediacommunications,wherethecomputer-mediatedelementhasmoreimpactonthehumansensesthaninthedata/text-basedsituations.5,EducationATprovideseasyaccesstolargequantitiesofinformation,suchasindustrialtrainingmanuals,dictionaries,andencyclopedias;oftenutilizesasmallstoragedevice,suchasanopticaldisk;byearly1990shadbeguntorevolutionizethecomputer,withstrongimplicationsforcommunication,education,andentertainment.Intheearly1990s,manufacturersbeganproducinginexpensiveCD-ROMdrivesthatcouldaccessmorethan650megabytesofdatafromasingledisc.Thisdevelopmentstartedamultimediarevolutionthatmaycontinuefordecades.Thetermmultimediaencompassesthecomputersabilitytomergesounds,video,text,music,animations,charts,maps,etc.,intocolorful,interactivepresentations,abusinessadvertisingcampaign,orevenaspace-wararcadegame.,Audioandvideoclipsrequireenormousamountsofstoragespace,andforthisreason,untilrecently,programscouldnotuseanybutthemostrudimentaryanimationsandsounds.Floppyandharddiskswerejusttoosmalltoaccommodatethehundredsofmegabytesofrequireddata.TheenermousstoragepotentialofCD-ROMchangedallthat.Drivingsimulations,forexample,cannowshowactualfootageoftheIndianapolisSpeedwayastheuserplaysthegame.Themanufacturerfirstdigitizesv