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ensurethatnochangesweremadetothevideoistousethesameprojectpresetforexportthatwas
usedforimport,whichisthedefaultbehaviorinAdobePremierePro.
‐Thereisoneexceptiontoexportingwiththesourcecodec:whenthesourceisDV25andcontainsa
numberofmotiongraphicsorcompositing.
‐Whenyoupreprocess,choosethehighestframerateandlargestframesizethatyouwilluse.Ifyou
aretargetingwebcodecs,usesquarepixels(pixelaspectratioof1).
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Choosingafileformatforrendering
‐ThemostcommonformatsareQuickTimeandAVI;bothoffergood‐qualityintermediatecodecs.
‐YoucanalsouseMPEG‐2athighdatarates.
‐Itisessentialtomakesurethattheencodingtoolsupportsthefileformat.
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Choosingacodecforexporting
‐Whenyouexportanintermediatefile,pickacodecandadataratethatdoesn’tintroduce
compressionartifacts.
‐Whenyouarenotpreprocessing,it’stypicaltousethesourcecodecorMotion
JPEG.WhenyouuseMotionJPEG,useitinsinglefieldwhenyouexportasprogressivescan,or
interlacedwhenyouexportasinterlaced.
‐ForAVIfilesonWindows,theHuffyuvcodecisquitepopular.
Understandingpreprocessing
‐Preprocessingisthemiddlestepofvideocompressionandinvolvestransformingthedecodedframe
ofthesourcevideointotheoptimizedframegiventothecodec.–Goal=totransformthevideointo
thefinalformat.
‐Preprocessingisveryimportantforquality,andgettingitrightcandramaticallyimprovethequality
ofthefinalvideo.Awellpreprocessedvideocanlookbetterthanthesamesourcefilepoorly
preprocessed,butcanbeencodedattwicethedatarate.