Dolby Laboratories DP570 Using Infinite Measurements, Using Short-term Measurements

Measuring and Setting the Dialogue Level
Dolby® DP570 Multichannel Audio Tool User’s Manual 29
valuewithinDolbyEandDolbyDigitalbitstreams.TheDP570measurementfeaturewill
yieldbestresultswhentheoperatormeasuresportionsoftheprogramthatcontainonly
minimalnondialoguematerial.
Using Infinite Measurements
InfinitemeasurementmodeconformstothespecificationsofITU‐RRec.BS.1770.Inthis
mode,thecalculatedvalueisthelong‐termlevel,integratedovertheentireperiodsincethe
measurementwaslastreset.
Infinitemodeistypicallyusedtomeasuretheentiredurationoftheprogram,orseveral
longsectionsofaprogram,tofindthelong‐termlevel.SinceDialogueIntelligence™is
availableonlyintheDolbyLM100BroadcastLoudnessMeter,wesuggestusingthe
followingstepstoobtainanestimatedvaluefortheentireprogram:
1. Reviewtheprogram,notingthelocationsofseveralrepresentativesectionswhere
dialogueispresent.
2. Cuethebeginningofthefirstselectedsegment.
3. ClickResettoclearpastmeasurements.
4. Measurethefirstsegment,thenclickPausetopausemeasurement.
5. Cuethesecondsegment.
6. ClickPauseagaintoresumemeasurement.
7. Continueinthisfashion,pausingmeasurementbetweenselectedsegmentsuntilthe
programiscompleted.
Thisprocessallowsyoutoaccuratelyestimatetheaveragelevelofalloftheindividual
dialoguesections.1
Thetermrepresentativesectionindicatesashortersectionoftheprogrambeingmeasured
thatcontainsspokendialoguelevelsthatarerepresentativeofthespeechlevelsfound
throughouttheentireprogram.
Infinite���modeismostoftenusediningest,QC,andpostproductionapplicationswhere
audiometadataisbeingauthored,thewholepieceofcontentisavailable,andlevelscan
usuallybecontrolledand/oradjusted.Infinitemodeshouldbeusedinautomatedand
semi‐automatedapplications.
Using Short-term Measurements
Short‐termmeasurementmodedisplaysthemeasuredvalueforonlytheprevious
10‐secondperiod.Forexample,thefirstmeasurementvalueisforthetimeintervalbetween
0and10seconds,thenextbetween1and11seconds,thenextbetween2and12seconds,
andsoforth.Figure 4‐5illustratesthesemeasurements.
1Theenergyaverageoftwoormorequantitiesexpressedonadecibelscalediffersfromthearithmetic
averageofthequantities.TheDP570Pausefeatureallowstheusertoproperlyaveragemeasurements(in
dB)acrossmultiplesectionsofprogramming.