Dolby Laboratories DP570 Bitstream Mode

A Guide to Dolby Metadata Parameter Definitions
Dolby® DP570 Multichannel Audio Tool User’s Manual 95
Channelparametercanbeset.Youmusthaveatleastthreechannelstobeabletoaddan
LFEchannel.
Bitstream Mode
ThisparameterdescribestheaudioservicecontainedwithintheDolbyDigitalbitstream.
Acompleteaudioprogrammayconsistofamainaudioservice(acompletemixofallthe
programaudio),anassociatedaudioservicecomprisingacompletemix,oronemain
servicecombinedwithanassociatedservice.Toformacompleteaudioprogram,itmaybe
(butrarelyis)necessarytodecodebothamainserviceandanassociatedserviceusinga
maximumtotalbitrateof512kbps.RefertotheGuidetotheUseoftheATSCDigitalTele vis ion 
Standard,DocumentA/54forfurtherinformation.Althoughadetaileddescriptionofeach
optionfollows,inpractice,mostprogrammingusesthedefaultsetting,CompleteMain.An
exampleofanexceptiontothisruleisaspecialkaraokeDVD,oranemergencyservice
withindigitaltelevision.
Table D-5 LFE Channel Settings
LFE Channel Setting
Enabled
Disabled
Table D-6 itstream Mode Options
Bitstream Mode
Setting Definition
CompleteMain(CM) CMflagsthebitstreamasthemainaudioservicefortheprogram
andindicatesthatallelementsarepresenttoformacompleteaudio
program.Currently,thisisthemostcommonsetting.TheCM
servicemaycontainfromone(mono)tosix(5.1)channels.
MainM&E(ME) Thebitstreamisthemainaudioservicefortheprogram,minusa
dialoguechannel.Thedialoguechannel,ifany,isintendedtobe
carriedbyanassociateddialogueservice.Differentdialogue
servicescanbeassociatedwithasingleMEservicetosupport
multiplelanguages.
Assc.VisualImp.(VI) Thisistypicallyasingle‐channelprogramintendedtoprovidea
narrativedescriptionofthepicturecontenttobedecodedalong
withthemainaudioservice.TheVIservicemayalsobeacomplete
mixofallprogramchannels,comprisinguptosixchannels.
Assc.HearImp.(HI) Thisistypicallyasingle‐channelprogramintendedtoconveyaudio
thathasbeenprocessedforincreasedintelligibilityanddecoded
alongwiththemainaudioservice.TheHIservicemayalsobea
completemixofallprogramchannels,comprisinguptosix
channels.
Assc.Dialogue(D) Thisistypicallyasingle‐channelprogramintendedtoprovidea
dialoguechannelforanMEservice.IftheMEservicecontainsmore
thantwochannels,theDserviceislimitedtoonlyonechannel;ifthe
MEserviceistwochannels,theDservicecanbeastereopair.The
appropriatechannelsofeachservicearemixedtogether(requires
specialdecoders).