Canon XL1 3CCD Manual

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‐MotionJPEGis4:2:2,andmostimplementationsallowyoutospecifyadatarateorqualitylevel.

‐Typically,dataratesof50Mbpsorgreaterareconsideredbroadcastquality.

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3.Uncompressedcodecs

‐Moreandmorecardssupporttrue4:2:2uncompressedvideo.Thedataratesarelarge,andthe

qualityisnobetterthanalosslesscompression.

‐Onesignificantadvantageofsomeuncompressedcodecsissupportfor10‐bit‐per‐channelcaptures,

whichcanperformbetterforanalogandespeciallySDIsources.‐High‐endvideoediting

applications,suchasAfterEffectsProfessional,areabletoprocessvideoinmorethan8bitsper

channel,improvingthequality.

‐Becauseuncompressedcodecshavesuchhighdatarates,youshoulduseafastdrivesystem,suchas

aRAID(redundantarrayofindependentdisks)system.

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Exportingvideo

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‐Iffeaturesinotherencodingtoolsarerequired,forexample,volumeencodingtomultipleoutput

formats,itisusefultoexportanintermediatefilefromthetimelineandusetheexportedfilefor

furtherprocessing.

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Exportingtofile

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Afileyouexportforlaterprocessingiscalledanintermediatefile.(Reasonforthis=toprovidehigh

qualityinthemostusefulformatwithoutintroducinganycompressionartifacts).

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Choosingwhethertopreprocessortoavoidrendering

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Whentoapplypreprocessing?Duringtherenderingphaseorlater?

‐Preprocessingduringrenderinggenerallyresultsinasmallerfile,butaddsmorerenderingtime.

‐Basically,toavoidrendering,youusethesamecodecandfileformatasyoursourcevideo.

‐Ifyoudon’tpreprocess,youdon’tneedtouncompressandthenrecompressunmodifiedframes—

instead,youcopythemfromthesourceintotheoutput.‐InAdobePremierePro,you’dturnoff

theRecompressoptionintheVideo

paneoftheExportMovieSettingsdialogbox.Forthisprocesstowork,thevideomusttrulybe

unchangedwiththesameframerate,framesize,pixelaspectratio,andsoon.Thesimplestwayto