Dolby Laboratories Multichannel Audio Tool DP570 - Manual (Page 100)

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