Dolby Laboratories DP570 Surround Downmix Level , Dolby Surround Mode

A Guide to Dolby Metadata Parameter Definitions

Dolby® DP570 Multichannel Audio Tool User’s Manual 97

parameterduringdownmixinginLo/RomodewhenExtendedBSIparametersarenot

active.

Surround Downmix Level

WhentheencodedaudiohasoneormoreSurroundchannels,buttheconsumerdoesnot

havesurroundspeakers,thisparameterindicatesthenominaldownmixlevelforthe

Surroundchannel(s)withrespecttotheLeftandRightfrontchannels.DolbyDigital

decodersusethisparameterduringdownmixinginLo/RomodewhenExtendedBSI

parametersarenotactive.

Dolby Surround Mode

ThisparameterindicatestoaDolbyDigitaldecodingproductthatalsocontainsaDolby

ProLogicdecoder(forexamplea5.1‐channelamplifier),whetherornotthetwo‐channel

encodedbitstreamcontainsaDolbySurround(Lt/Rt)programthatrequiresProLogic

decoding.DecoderscanusethisflagtoautomaticallyswitchonProLogicdecodingas

required.

Table D-8 Center Downmix Level Settings and Definitions

0.707(–3dB)default TheCenterchannelisattenuated3dBandsenttothe

LeftandRightchannels.

0.596(–4.5dB) TheCenterchannelisattenuated4.5dBandsentto

theLeftandRightchannels.

0.500(–6dB) TheCenterchannelisattenuated6dBandsenttothe

LeftandRightchannels.

Table D-9 Surround Downmix Level Settings and Definitions

0.707(–3dB)default TheLeftandRightSurroundchannelsareeachattenuated3

dBandsenttotheLeftandRightfrontchannels,respectively.

0.5(–6dB) Sameasabove,butthesignalisattenuated6dB.

0(–999dB) TheSurroundchannel(s)arediscarded.

Table D-10 Dolby Surround Mode Settings and Definitions

NotDolbySurround Thebitstreamcontainsinformationthatwasnot

encodedinDolbySurround.

DolbySurround Thebitstreamcontainsinformationthatwas

encodedinDolbySurround.AfterDolbyDigital

decoding,thebitstreamisdecodedusingProLogic.

NotIndicated Thereisnoindicationeitherway.