96 Dolby® DP570 Multichannel Audio Tool User’s Manual
A Guide to Dolby Metadata Parameter Definitions
Line Mode Compression Profile and RF Mode Compression Profile
Fordetailsoftheavailableprofiles,seeDynamicRangeControlProfilesonpage89.
RF Overmodulation Protection
ThisparameterisdesignedtoprotectagainstovermodulationwhenadecodedDolby
DigitalbitstreamisRFmodulated.Whenenabled,theDolbyDigitalencoderincludes
preemphasisinitscalculationsforRFModecompression.Theparameterhasnoeffect
whendecodingusingLinemodecompression.Exceptinrarecases,thisparametershould
bedisabled.
Center Downmix Level
Whentheencodedaudiohasthreefrontchannels(L,C,R),buttheconsumerhasonlytwo
frontspeakers(leftandright),thisparameterindicatesthenominaldownmixlevelforthe
CenterchannelwithrespecttotheLeftandRightchannels.DolbyDigitaldecodersusethis
Assc.Commentary(C) Thisistypicallyasinglechannelprogramintendedtoconvey
additionalcommentarythatcanbeoptionallydecodedalongwith
themainaudioservice.Thisservicediffersfromadialogueservice
becauseitcontainsanoptional,ratherthanarequired,dialogue
channel.TheCservicemayalsobeacompletemixofallprogram
channels,comprisinguptosixchannels.
Assc.Emergency(E) Thisisasinglechannelservicethatisgivenpriorityin
reproduction.WhentheEserviceappearsinthebitstream,itis
givenpriorityinthedecoderandthemainserviceismuted.
Assc.Voice Over(VO) Thisisasinglechannelserviceintendedtobedecodedandmixed
totheCenterchannel(requiresspecialdecoders).
MainSvKaraoke(K) Thebitstreamisaspecialserviceforkaraokeplayback.Inthiscase,
theLeftandRightchannelscontainmusic,theCenterchannelhasa
guidemelody,andtheLeftandRightSurroundchannelscarry
optionalbackingvocals.
Table D-7 RF Overmodulation Protection Setting

RF Overmodulation

Protection Setting

Enabled
Disabled
Table D-6 itstream Mode Options

Bitstream Mode

Setting Definition