Specifications

Standards and Practices for Authoring Dolby
®
Digital and Dolby E Bitstreams
7
listening. Additionally, when enjoying a television broadcast or DVD in an
environment with a high level of ambient noise, quieter portions of the program are
drowned out by the ambient noise. When these “Dynamic Range Profiles” are
asserted within the decoder, the decoder raises the level of the softer portions of the
program and lowers the level of the louder portions, allowing the user to enjoy the
movie without having to reach for the volume control constantly.
Input Level
Low High
Boost
Range
Null
Band
Centered at
the Dialogue
Level Parameter
Cut
Range
Early
Cut
Range
Dialogue Level
Setting
Low
High
Ouput Level
Figure 1 Dynamic Range Control within a Dolby Digital Decoder
There are two dynamic range metadata profiles to set within a Dolby Digital data stream.
Each of these two profiles has six presets available to choose from, including None.
Music Light (No early cut range)
Max Boost: 12 dB (below –65 dB)
Boost Range: –65 dB to –41 dB (2:1 ratio)
Null Band Width: 20 dB (–41 dB to –21 dB)
Cut Range: –21 dB to +9 dB (2:1 ratio)
Music Standard
Max Boost: 12 dB (below –55 dB)
Boost Range: –55 dB to –31 dB (2:1 ratio)
Null Band Width: 5 dB (–31 dB to –26 dB)
Early Cut Range: –26 dB to –16 dB (2:1 ratio)
Cut Range: –16 dB to +4 dB (20:1 ratio)
Film Light
Max Boost: 6 dB (below –53 dB)
Boost Range: –53 dB to –41 dB (2:1 ratio)
Null Band Width: 20 dB (–41 dB to –21 dB)
Early Cut Range: –26 dB to –11 dB (2:1 ratio)
Cut Range: –11 dB to +4 dB (20:1 ratio)
Film Standard
Max Boost: 6 dB (below –43 dB)
Boost Range: –43 dB to –31 dB (2:1 ratio)
Null Band Width: 5 dB (–31 dB to –26 dB)
Early Cut Range: –26 dB to –16 dB (2:1 ratio)
Cut Range: –16 dB to +4 dB (20:1 ratio)
Speech
Max Boost: 15 dB (below –50 dB)
Boost Range: –50 dB to –31 dB (5:1 ratio)
Null Band Width: 5 dB (–31 dB to –26 dB)
Early Cut Range: –26 dB to –16 dB (2:1 ratio)
Cut Range: –16 dB to +4 dB (20:1 ratio)
The details of the dynamic range characteristics for each preset are shown for
reference only and are not adjustable, and, as mentioned previously, the dialogue
normalization value determines the placement of the null band. Upon decoding,
however, a customer has the option of scaling the amount of boost or cut, depending
on the feature set available in their home decoder. Once again, the ability to scale
only applies to Line mode.