Dolby Laboratories DP570 LFE Channel , Bitstream Mode

94 Dolby® DP570 Multichannel Audio Tool User’s Manual

A Guide to Dolby Metadata

FigureD‐3

LFE Channel

ThestatusoftheLFEChannelparameterindicatestoaDolbyDigitalencoderwhetheran

LFEchannelispresentwithinthebitstream.ChannelmodedetermineswhethertheLFE

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-4 Channel Mode Definition and Data Rates

1+1 Dualmono(notvalidfor

DTVbroadcastorDVD

production)

1/0Mono From56kbps,usually

96kbps

2/0Stereo From96kbps,usually

192kbps

3/0 From256kbps

2/1 From256kbps

3/1 From320kbps

2/2 From320kbps

3/2 From384kbps,often

448kbps

Table D-5 LFE Channel Settings

Enabled

Disabled

Table D-6 Bitstream Mode Options

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.