Dolby Laboratories Multichannel Audio Tool DP570 - Manual (Page 20)

4 Dolby ® DP570 Multichannel Audio Tool User’s Manual
Overview
The Cat. No. 548 Analog Output Card provides an analog monitor section and some
additional features to ease interfacing to existing mixing and monitoring environments.
This optional analog monitor section provides features including multiple
speaker‐configuration outputs, a master volume control, speaker trim controls, and an
input for a console solo bus.
1.4 Main Applications
The DP570 can be successfully deployed wherever there is a need to monitor the quality of
digital audio, and to review existing metadata. It is currently most common in two
applications:
• DVD mastering
• Creation and broadcast of DTV content
1.4.1 Use in DVD Mastering
A DVD author is typically preparing mixed audio for writing to the DVD: generating
metadata, verifying levels, and auditioning downmixes. This process is described in detail
in
Chapter 5 .
1.4.2 Use in Digital Television
Here’s an example of the process flow in DTV:
In a broadcast truck parked outside a football stadium, the program mixer chooses the
appropriate metadata for the audio program being created. The resulting audio program,
together with metadata, is encoded as Dolby E data and sent to the television station via
fiber, microwave, or other transmission link. This process is discussed in detail in
Chapter 6 .
At the receiving end of this transmission, the Dolby E stream is decoded back to baseband
audio and metadata. The audio program and the metadata are monitored, altered, or
re‐created as other elements of the program are added in preparation for broadcast. This
process is discussed in detail in
Chapter 7 .
This new audio program/metadata pair, reencoded as Dolby E data, leaves the
postproduction studio and passes through the television station to Master Control, where
many incoming Dolby E streams are once again decoded back to their individual baseband
digital audio/metadata programs. The audio program/metadata pair that is selected to air
is sent to the transmission Dolby Digital encoder, which encodes the incoming audio
program according to the metadata stream associated with it, thereby simplifying the
transmission process. This process is discussed in detail in
Chapter 8 .
Finally, the Dolby Digital signal is decoded in the consumer’s home, with metadata
providing the information for that decoding process. Through the use of metadata, the
mixer in the truck has been able to control the home decoder for the sporting event, while
segments such as news breaks, commercials, and station IDs are similarly decoded, each
using its own metadata.