- Dolby Multichannel Audio Tool User's Manual

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estima te theaveragelevelofalloftheindividual
dialoguesections.
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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.
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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us ertoproperlyaveragemeasurements(in
dB)acrossmultiplesectionsofprogramming.