Cisco D9054 Installation And Operation Manual page 138

Setting Up the Dolby Digital Audio Input,
4. If relevant, enable Passthrough of Dolby Digital/Dolby Digital Plus.
Important: Passthrough of Dolby Digital or Dolby Digital Plus requires that
Dolby Digital Encoding be enabled.
For Passthrough of Dolby Digital or Dolby Digital Plus, you can set the Input
Type to Digital or Embedded.
Note: The Sample Rate must be set to 48 kHz if Passthrough of Dolby Digital is
enabled.
5. Select the Audio Coding Mode of the input signal.
Stereo 2/0
Dual Mono 1+1
Mono (Center) 1/0
3/2 (L,R,C,Ls,Rs)
Use this field to select the number of channels and the channel format within the
encoded bit stream.
The four available audio encoding modes are Stereo 2/0, Dual Mono 1+1, Mono
(Center) 1/0, and 3/2 (L,R,C,Ls,Rs). The mode definition uses two numbers (
), with
n
of rear (surround) channels.
The default setting is Stereo
Note: LFE is only available if LFE is enabled in the Processing page. For more
information, see Setting Up Dolby Digital Processing, page 5-59.
If the mode is set to Dual Mono (1+1), then two completely independent
program channels, referenced as Mono Channel 1 and Mono Channel 2, are
encoded into the bit stream. Dual-mono mode is primarily intended for
professional applications. Dual-mono cannot be expected to work with
consumer Dolby Digital decoders. Dual Mono mode is recommended if
simultaneous output of unrelated, independent audio signals is required.
Dual Mono mode gives the greatest degree of audio separation, but requires
more complex coding, and, consequently, higher operating bit rates.
If the mode is set to 3/2 (L, R, C, Ls, Rs), the C, LFE and Ls, Rs settings for the
digital, embedded, and Dolby-E decoder inputs are enabled.
Note: The 3/2 (L,R,C,Ls,Rs) mode is only available for encoders equipped with
a Multiple Channel Audio (MCA) card.
Note: The 3/2 (L,R,C,Ls,Rs) mode is only available for Ch 1 and Ch 4.
5-54
Mode
Left, Right
Left – Channel 1, Right – Channel 2
Center (uses the left channel of the physical
input)
Left, Right, Center, Left surround, Right surround
indicating the number of front channels, and
m
2/0
D9054 HDTV Encoder Intstallation and Operation Guide
Continued
Channel Format
.
indicating the number
n
4038938 Rev A
/
m