Dolby Laboratories DP564 - Manual (Page 86)

DP564 Multichannel Audio Decoder Appendix A: Metadata
A-16
Surround Downmix
Level Setting
Definition
0.707 (–3 dB) default The left and right surround channels are each
attenuated 3 dB and sent to the left and right
front channels, respectively.
0.5 (–6 dB) Same as above, but the signal is attenuated 6 dB.
0 (–999 dB) The surround channel(s) are discarded.
Dolby Surround Mode
This parameter indicates to a Dolby Digital decoding product that also contains a
Dolby Pro Logic decoder (for example a 5.1-channel amplifier) whether the two-
channel encoded bitstream contains a Dolby Surround (Lt/Rt) program that requires
Pro Logic decoding. Decoders can use this flag to automatically switch on Pro Logic
decoding as required.
Dolby Surround Mode
Setting
Definition
Not Dolby Surround The bitstream contains information that was not
Dolby Surround encoded.
Dolby Surround The bitstream contains information that was
Dolby Surround encoded. After Dolby Digital
decoding, the bitstream is Pro Logic decoded.
Not Indicated There is no indication either way
Audio Production Information
This parameter indicates whether the mixing level and room type values are valid. If
Yes, then a receiver or amplifier could use these values as described below. If No,
then the values in these fields are invalid. In practice only high-end consumer
equipment implements these features.
Audio Production
Information Setting
Definition
Yes Mixing Level and Room Type
parameters are valid.
No Mixing Level and Room Type
parameters are invalid and should
be ignored.
Mixing Level
The Mixing Level parameter describes the peak sound pressure level (SPL) as
experienced during the final mixing session at the studio or on the dubbing stage. The
parameter allows an amplifier to set its volume control such that the SPL in the replay