Dolby Laboratories DP570 D.6 Parameter Definitions

92 Dolby® DP570 Multichannel Audio Tool User’s Manual

A Guide to Dolby Metadata

ThereareseparatemetadataparametersthatgoverntheLo/RoandLt/Rtdownmixes.

Certainmetadataparametersallowtheengineertoselecthowthestereodownmixis

constructedandwhichstereoanalogsignalispreferred,butLt/Rtisthedefaultselection

inallconsumerdecoders.SeeParameterDefinitionsonpage 92forthedefinitionof

individualparameters.

Duringdownmixing,aswehaveseen,theadjustmentofDynamicRangeControl

parametersislimited.Broadlyspeaking,thestereooutputsusetheLinemodecompression

profilewhilethemonosignalusesRFmodecompression.Aswithdynamicrangecontrol,

downmixingisultimatelydependentuponeachconsumer’suniquelistening

environment.

Whiletheengineermustoptimizethemultichannelmixforreproductioninanideal

listeningenvironment,itisalsoimportanttopreviewthemixindownmixingconditions

toensurecompatibilitywithdifferentplaybacksystemswhenselectingthedownmixing

metadataparameters.ThesepreviewscanbeachievedinrealtimeusingtheDP570

MultichannelAudioTool.

D.6 Parameter Definitions

Thissectionexplainsbothprofessionalandconsumermetadataparametersingreater

detail.

Metadataparametersinclude:

•Universalparameters

•ExtendedBitstreamInformation(ExtendedBSI)parameters

ExtendedBSIparametersareactiveonlywhenboththeproducerchoosestousethemand

theconsumer’sdecoderiscapableofreadingthem.Alldecoderscansuccessfullydecodea

metadatastreamwithoutExtendedBSIparameters,andExtendedBSIparameterstranslate

seamlesslytodecodersthatreadonlyuniversalparameters.

AlluniversalparametersaresupportedbyDolbyEencodersanddecoders;allexcept

ProgramConfigurationandProgramDescriptionTextaresupportedbyallDolbyDigital

encodersanddecoders.

ThisparameterdetermineshowtheaudiochannelsaregroupedwithinaDolbyE

bitstream.Uptoeightchannelscanbegroupedtogetherinindividualprograms,where

Note: Universalparametersincludebothprofessionalandconsumermetadata.Table D‐1

onpage 85distinguishesbetweenprofessionalandconsumerparameters.