User`s manual

6 Dolby
®
Media Meter 2 User’s Manual
Measuring Loudness
Choosing a Measurement Precision
Youcan change thedisplaytoshowmeasurementsintenthsorintegers(units).Tomake
thischange,rightclickthemeasurementpaneshowninFigure 32,thenchooseUnitsor
Tenthsfromthedisplaycontextmenu.Thecurrentsettingismarked.
Figure32
Figure 3-2 Measurement Pane Showing Tenths
3.2 Measurement Modes: Short Term vs Infinite
TheDolbyMediaMeter2hastwomodesrelatingtothemeasurementperioditself:Infinite
modeandShortTermmode.Thefollowingsectionsdescribetheirbehavior.
3.2.1 Infinite Mode
Infinitemode
1
istypicallyusedwhenitispossibletomeasuretheentiredurationofthe
program(forexample,all30secondsofacommercialoracompletetwohourmovie).
Infinitemodeprovidesthemostaccuratemeasurement,asitisabletoaverageloudness
overthecompleteprogramlength.Thismodeismostof
tenusediningest,qualitycontrol
(QC),andpostproductionapplicationswhereaudiometadataisbeingauthoredandlevels
can,inmostcases,becontrolledandadjusted.
ItisalsopossibletouseInfinitemodetomeasureshorterindividualsectionsofaprogram
ratherthantheentireduration.Thismethodmayallowtheoper
atortofindameasurement
valuemuchmorequickly.Inthiscase,however,theoperatormustensurethattheloudness
levelsofthesectionsbeingmeasuredarerepresentativeoftheentireprogram.
3.2.2 Short-Term Mode
ShortTermmodedisplaysthemeasuredvalueforthepreviousfewsecondsasa“sliding
window”typeoffunction.UsingDialogueIntelligence,forexample,the firstmeasurement
valueisforthetimebetween0and10seconds,thenextbetween1and11seconds,next
between2and12seconds,andsofo
rth.UsingEBUR128,themeasurementsareforthree
seconds,ratherthanten.
AstheShortTermmodemeasuresonlytheimmediatelyprecedingtensecondsofprogram
material,themeasurementvaluehasthepotentialtobemuchmoredynamicthanthevalue
1
EBUR128usesthetermIntegratedinsteadofInfinite.