- Dolby Multichannel Audio Tool User's Manual

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.
Figure D‐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
Program Source
5.1-Channel
Program
Two-Channel
(Stereo) Program
DP570
Multichannel Audio
Tool
in 5.1+2 Program Config
DP571
Dolby E Encoder
in 5.1+2 Program Config
Multichannel
Monitor System
L/R
C/LFE
Ls/Rs
Lt/Rt
The Dolby E bitstream
contains both the 5.1- and
two-channel programs’
encoded audio, and each
program's metadata.
The Dolby Digital bitstream
contains a single program’s
encoded audio and
corresponding metadata.
DP572
Dolby E Decoder
Metadata
Decoded Dolby E bitstream
delivers both the 5.1- and
two-channel programs’
encoded audio along with
corresponding metadata.
DP569
Dolby Digital Encoder
SAP or Visual
Descriptive
Broadcast
Cable, Satellite,
or Terrestrial
Consumer
Dolby
Two-
Channel
Encoder
Metadata
Distribution