Cobalt Digital COMPASS 9081 HD_SD Frame Sync - Manual (Page 13)

9081-OM (V4.6) 9081 PRODUCT MANUAL 1-9
Introduction
9081 Functional Description
Audio Processor Description
The audio processor operates as an internal audio router. The router function
chooses from the following inputs:
• 16 channels of embedded audio from the SDI video
• Four independent internal tone generators (described below)
• Digital silence (mute) setting
• Internal Down Mix and Mono Mixer outputs (described below)
• ( +DEC only ) Decoded Dolby ® channels
The router function provides 16 channels of embedded audio on the SDI OUT
outputs. The router acts as an audio cross point. Each of the 16 embedded
output channels can receive signal from any one of 16 embedded audio input
channels, four internal tone generators, or several mixer outputs. Unused
output channels can be mapped to a “Silence” source. Each output also
provides gain adjustment and selectable polarity inversion. Output audio rates
are always 48 kHz locked to the selected reference.
( +DEC only ) In addition to the audio sources described above, the up to 10
decoded Dolby ® channels are available as input sources.
As set with the default settings, the routing between embedded input channels
and output channels is basic 1-to-1 (embedded input channel 1 input is routed
to embedded output channel 1, and so on). Other sources (described below)
for each channel are selected using the card edge controls or a remote control
system.
Audio Down Mix and Mono Mix Function
(See Figure 1-3.) The Audio Down Mixer function provides for the selection
of any five embedded audio sources serving as Left (
L ), Right ( R ), Center ( C ),
Left Surround ( Ls ), and Right Surround ( Rs ) individual signals to be
multiplexed into stereo pair Down Mix Left ( DM-L ) and Down Mix Right
( DM-R ). The resulting stereo pair DM-L and DM-R can in turn be routed and
processed just like any of the other audio sources described earlier.
Figure 1-3 Audio Down Mix Functional Block Diagram with Example Sources
The Mono Mixer function generates an additional mono-mixed channel from
two selected embedded input channels serving as left and right inputs. The
resulting mono mix channel is available as an audio source for any of the 16
destination embedded output channels.
DM-L
L
R
C
Ls
Rs
DM-R
Emb Ch 3
Emb Ch 5
Emb Ch 6
Emb Ch 9
Emb Ch 11
Embed Ch 1 - Ch 16