Table d-7 – Dolby Laboratories DP570 User Manual
Page 108
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Dolby
®
DP570 Multichannel Audio Tool User’s Manual
A Guide to Dolby Metadata
Parameter Definitions
Line Mode Compression Profile and RF Mode Compression Profile
For details of the available profiles, see
Dynamic Range Control Profiles
RF Overmodulation Protection
This parameter is designed to protect against overmodulation when a decoded Dolby
Digital bitstream is RF modulated. When enabled, the Dolby Digital encoder includes
pre‐emphasis in its calculations for RF Mode compression. The parameter has no effect
when decoding using Line mode compression. Except in rare cases, this parameter should
be disabled.
Center Downmix Level
When the encoded audio has three front channels (L, C, R), but the consumer has only two
front speakers (left and right), this parameter indicates the nominal downmix level for the
Center channel with respect to the Left and Right channels. Dolby Digital decoders use this
Assc. Commentary (C)
This is typically a single‐channel program intended to convey
additional commentary that can be optionally decoded along with
the main audio service. This service differs from a dialogue service
because it contains an optional, rather than a required, dialogue
channel. The C service may also be a complete mix of all program
channels, comprising up to six channels.
Assc. Emergency (E)
This is a single‐channel service that is given priority in
reproduction. When the E service appears in the bitstream, it is
given priority in the decoder and the main service is muted.
Assc. Voice Over (VO)
This is a single‐channel service intended to be decoded and mixed
to the Center channel (requires special decoders).
Main Sv Karaoke (K)
The bitstream is a special service for karaoke playback. In this case,
the Left and Right channels contain music, the Center channel has a
guide melody, and the Left and Right Surround channels carry
optional backing vocals.
Table D-7 RF Overmodulation Protection Setting
RF Overmodulation
Protection Setting
Enabled
Disabled
Table D-6 itstream Mode Options
Bitstream Mode
Setting
Definition