Dolby Laboratories DP570

84 Dolby® DP570 Multichannel Audio Tool User’s Manual

A Guide to Dolby Metadata

DolbyEisaprofessionaltechnologyusedforbroadcastapplications,suchasprogram

originationanddistribution;theDolbyEbitstreamcarriestheentiremetadataparameter

set.DolbyDigital,usedforconsumerapplications,suchastransmissiontothehomeorfor

DVDauthoring,employsasubsetofthefullmetadataparametersetcalledDolbyDigital

metadata;theDolbyDigitalbitstreamcarriesonlythoseparametersnecessaryforproper

decodingbytheconsumer.

Metadataisfirstinsertedduringprogramcreationormastering,andiscarriedthrough

transmissioninabroadcastapplicationordirectlyontoaDVD.Themetadataprovides

controloverhowtheencodedbitstreamistreatedateachsteponthewaytotheconsumer’s

decoder.

Thiscontrol,however,requirestheproducertosetthemetadataparameterscorrectly,since

theyaffectimportantaspectsoftheaudio—andcanseriouslycompromisethefinal

productifsetimproperly.Althoughmostmetadataparametersaretransparentto

consumers,certainparametersaffecttheoutputofahomedecoder,suchasdownmixing

foraspecificspeakerconfiguration,orwhentheconsumerchoosesDynamicRange

Controltoavoiddisturbingfamilyandneighbors.

FigureD‐1showsa5.1+2ProgramConfig,consistingofa5.1‐channelprogramanda

2‐channelsecondaryaudioprogram(SAP).

FigureD‐1

Figure D-1 Metadata Flow from Production to Consumer

ProgramSource

5.1-Channel

Program

Two-Channel

(Stereo)Program

DP570

MultichannelAudio

Tool

in5.1+2 Program Config

DP571

DolbyE Encoder

in5.1+2 Program Config

Multichannel

MonitorSystem

L/R

C/LFE

Ls/Rs

Lt/Rt

TheDolby E bitstream

containsboth the 5.1- and

two-channelprograms’

encodedaudio, and each

program'smetadata.

TheDolby Digital bitstream

containsa single program’s

encodedaudio and

correspondingmetadata.

DP572

DolbyE Decoder

Metadata

DecodedDolby E bitstream

deliversboth the 5.1- and

two-channelprograms’

encodedaudio along with

correspondingmetadata.

DP569

DolbyDigital Encoder

SAPor Visual

Descriptive

Broadcast

Cable,Satellite,

orTerrestrial

Consumer

Dolby

Two-

Channel

Encoder

Metadata

Distribution