Dolby Laboratories DP600 User Manual

DP600 Program Optimizer—Postproduction

Dolby DP600 and DP600-C Program Optimizer
Overview for Postproduction Facilities

Summary

The Dolby® DP600 Program Optimizer is an innovative and
flexible system offering intelligent file-based audio loudness
analysis and correction compatible with many of the broad­cast and video-on-demand (VOD) media file formats in use
today. Expanding upon the technology developed for the
award-winning Dolby LM100 Broadcast Loudness Meter with
Dialogue Intelligence™, the Dolby DP600 enables cable and
IPTV broadcasters to automatically normalize the loudness of
all file-based programming and commercials without impact­ing the original dynamic range.

For compressed audio formats that include metadata (Dolby E,
Dolby Digital, and Dolby Digital Plus, for example), the Dolby
DP600 can automatically set the dialnorm parameter and
automatically correct a previously set dialnorm parameter.

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Note: This document assumes the DP600 includes the optional file-based audio coding package.

The DP600-C version additionally offers faster-than-real-time
file-based encoding and decoding of Dolby Digital, Dolby
Digital Plus, and Dolby E content, and enables transcoding be­tween Dolby E and Dolby Digital or Dolby Digital Plus formats.

Taking advantage of the features of Dolby Digital Plus, the
DP600-C can perform high-quality, single-step transcoding
of Dolby Digital to Dolby Digital Plus without having to de­code and reencode.

To ensure the highest possible work-flow integration and ef­ficiency, the DP600 offers open access (via Web Services) to
Dolby’s unique audio processing engines as well as coding
technologies traditionally found only in real-time hardware.

For example, the DP600 feature set complements several
types of third-party applications and products, including the
following:

• Archiving

• Automation

• Content conversion

• Content transport

• Distribution

• Media asset management

• Production

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In very rare cases involving extreme loudness corrections, “soft clipping” can occur.

A Quick Look Under the Hood

The DP600 includes a number of audio and media file processing engines for utilization in many applications,
as shown in Figure 1.

DP600 Processing Engines and
Supported Media File Types

Media File Types Supported

• MPEG-2 Transport Stream

• MPEG-2 Program Stream

• GXF (SMPT E 360M)

• WAV and Broadcast WAV

• Dolby E

• Dolby Digital (AC-3)

• Dolby Digital Plus (E-AC-3)

Loudness Analysis and Correction

• Dolby E

• Dolby Digital

• MPEG-1 LII

• LPCM via WAV and Broadcas t WAV

Direct Transcoding

• Dolby Digital to Dolby Digital Plus

Figure 1 DP600 Processing Engines and Supported Media File Types

Audio Encoders *

• Dolby E

• Dolby Digital

• Dolby Digital Plus

• MPEG-1 LII

Audio Decoders *

• Dolby E

• Dolby Digital

• Dolby Digital Plus

• MPEG-1 LII

* DP600 -C only.

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DP600 Program Optimizer—Postproduction

DP600 and DP600-C for Postproduction

The DP600 Program Optimizer can be utilized in several
postproduction and content creation applications:

• Automated fi le analysis and loudness correction

• Automated fi le transcoding
° MPEG-1 LII to Dolby Digital (AC-3)
° Dolby Digital to Dolby Digital Plus

• Automated broadcast media fi le (GXF, others) audio
transcoding

° Dolby E to Dolby Digital
° Dolby E to Dolby Digital Plus
° Dolby Digital to Dolby Digital Plus

File-based Dolby E, Dolby Digital, and Dolby Digital Plus bit­streams can be encoded and decoded to and from multichan­nel WAV or Broadcast WAV fi les with metadata (included in
the Dolby audio metadata “chunk”).2 File-based media and
audio assets can be analyzed, logged, and (if necessary) cor­rected in faster than real time before delivery to clients.

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For more infor mation on the Dolby audio metadata chunk, please contact us.

Automated Broadcast Media File QC and Loudness
Correction

The Dolby DP600 platform facilitates a variety of applica­tions, including archiving, automated QC, content conversion,
and media asset management, and it offers considerable po­tential for integration with third-party systems through a Web
Services interface. Three control methods help meet specifi c
user requirements:

• Manual control—Users can set up and initiate
“processing jobs” on an individual basis from a simple­to-use Web browser interface.

• Third-party control via Web Services—The DP600’s
processing engines are also available as a set of Web
Services. Manufacturers can integrate these engines,
at any level, directly into their work fl ow to create a
seamless user experience without impacting day-to-day
operations.

• Automatic hot-folder ingest process—Users can create
“hot folders” and predefi ne a work order profi le for each
one. The profi le governs the DP600’s behavior with
specifi c broadcast media types. All media fi les moved
to a hot folder are automatically processed based on the
folder’s profi le and delivered to a user-defi ned folder
upon completion. Hot folders are easy to set up and use
and can greatly speed integration within some facilities.

Asset

Manager

Client

Ingest

Client/Server

Dolby DP600

10/100/1000 Ethernet

Archive Client Play-out

Server

Figure 2 DP600 Integration Over view

Satellite
Delivery

Clients

Media

Storage

Library

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Incoming Content

• Programs

• Commercials

• Interstitials

Content
Archive

DP600 Program Optimizer—Postproduction

Dolby DP600 Program Optimizer

Analyze l Correct l Log

Ingested File

DP600 Control

• Automatic “hot folder,”

• User-driven Web interface, or

• Third-party via Web Services

Media

Storage

Library

VOD

Media File Network, GigE

Figure 3 Example of Media File Work Flow (Loudness Analysis and Correction)

Integration and Control

The DP600 integrates easily into an existing fi le-based, post­production network infrastructure. Once connected and con­fi gured, the DP600 becomes an intelligent processing node
that can be readily adapted to day-to-day operations and
work fl ow (see Figure 2), including:

• Postproduction QC and correction—File-based media
and/or audio assets can be analyzed, logged, and, if
necessary, corrected in faster than real time before
being delivered to your clients.

Analyzed and
Corrected File

To Air

Destination

• Postproduction fi le encoding and decoding—File-based
Dolby E, Dolby Digital, or Dolby Digital Plus bitstreams
can be encoded and decoded to/from multichannel WAV
or Broadcast WAV fi les with or without a Dolby audio
metadata WAV chunk.

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Intelligent Loudness Normalization Process

DP600 Program Optimizer—Postproduction

The DP600 expands upon the technology developed for the
award-winning Dolby LM100 Broadcast Loudness Meter with
Dialogue Intelligence. The DP600 intelligently closes the loop
on the measurement and correction process and gives us­ers the ability to automatically normalize the loudness of all
their file-based content without impacting dynamic range, in
a faster-than-real-time manner.

This unique process guarantees that important metadata
parameters such as dialnorm are set properly for every file
(program) without user intervention, and without the time­consuming measurement and correction processes that were
previously done in real time.

Dolby DP600 Program Optimizer

For example, for coded audio data types that include metadata,
such as Dolby E and Dolby Digital, loudness normalization is
achieved by automatically analyzing the audio bitstream and
then comparing this analysis with the stream’s metadata. If
a mismatch is detected, the DP600 will automatically correct
the metadata values without having to decode and reencode
the audio stream (see Figure 4).

The DP600 can also correct coded and/or linear audio data
types that do not include metadata, such as MPEG-1 LII and
LPCM. For these audio data types, loudness normalization is
achieved by automatically analyzing the audio bitstream and
then comparing this analysis with a user-defined target loud­ness value. If a mismatch is detected, the DP600 will auto­matically scale the loudness to match the target value (see
Figure 5).

Uncorrected File

Broadcast Media File with

Dolby E or Dolby Digital

Analyze Audio

Analyze Dolby Metadata

01101010011010100111001101110000

Yes

Error = 0?

No

Update/Correc t

Metadata

Figure 4 Coded Audio with Metadata Analysis and Correction

Audio Stream

and Metadata Are

Already OK

Analyzed and
Corrected File

Broadcast Media File with

Dolby E or Dolby Digital

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DP600 Program Optimizer—Postproduction

Dolby DP600 Program Optimizer

Uncorrected File

Broadcast Media or

Multichannel WAV File

Without Metadata

n channels

Analyze Digital Audio

User-Defined Target Level

–(xx) dBFS

Audio Loudness

Yes

Error = 0?

No

Scale Loudness

Level

Figure 5 Audio Analysis and Correction for Audio Types Without Metadata

Already at Target

Level (No Correction

Needed)

Analyzed and
Corrected File

Broadcast Media or

Multichannel WAV File

Without Metadata

n channels

File-Based Encoding and Decoding

The DP600-C additionally offers direct access to Dolby tech­nologies typically found in real-time hardware. These include:

• Dolby E

• Dolby Digital

• Dolby Digital Plus

These processes can be easily combined with each other or
with our intelligent loudness analysis and correction engine to
adapt to a wide range of content needs, including file-based
transcoding of content stored in Dolby E format to Dolby
Digital or Dolby Digital Plus.

The Dolby audio decoder engines generate a multichannel
and/or multiprogram Broadcast WAV file with a Dolby audio
metadata chunk. The audio encoder engines accept multi­channel and/or multiprogram WAV files (including Broadcast
WAV and multichannel WAV formats) with or without a Dolby
audio metadata chunk.

File-Based Dolby Digital to Dolby Digital Plus Transcoder

The DP600-C supports a unique, quality-preserving Dolby
Digital to Dolby Digital Plus transcoder. This transcoding can
provide a simple migration path for next-generation services
utilizing existing file-based content. For example, VOD files
that currently include a multichannel Dolby Digital audio
elementary stream can be processed by the DP600-C to add a
Dolby Digital Plus audio elementary stream without having to
demux, decode, reencode, and remux the files.

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DP600 Program Optimizer—Postproduction

Supported File Formats

The DP600 supports several of the most common broadcast media file formats and audio types found today.

MPEG-2 Transport System
MPEG-2 Program System
GXF (SMPTE 360M)

Supported Broadcast

Media File Types

Dolby E
Dolby Digital (AC-3)
Dolby Digital Plus (E-AC-3)
MPEG-1 Layer II
LPCM via WAV and Broadcast WAV

Supported Audio

Data Types

Figure 6 DP600 Supported File Formats and Audio Data Types

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Wootton Bassett, Wiltshire SN4 8QJ England Telephone [phone] Fax [phone]
Dolby and the double-D symbol are registered trademarks of Dolby Laboratories. Dialogue Intelligence is a trademark of Dolby Laboratories.

© 2007 Dolby Laboratories, Inc. All rights reserved. S07/18099/18820

www.dolby.com

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