Dolby Laboratories Program Optimizer DP600 - Manual (Page 4)

DP600 Program Optimizer—Postproduction

Intelligent Loudness Normalization Process
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 us-
ers 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 time-
consuming measurement and correction processes that were
previously done in real time.
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 loud-
ness value. If a mismatch is detected, the DP600 will auto-
matically scale the loudness to match the target value (see
Figure 5).
Figure  Coded Audio with Metadata Analysis and Correction
Analyzed and
Corrected File
Uncorrected File
Dolby DP600 Program Optimizer
Broadcast Media File with
Dolby E or Dolby Digital
Analyze Dolby Metadata
01101010011010100111001101110000
Broadcast Media File with
Dolby E or Dolby Digital
Analyze Audio
Update/Correct
Metadata
Audio Stream
and Metadata Are
Already OK
Error = 0?
Yes
No