GUIDE TO INSTALLATION AND OPERATION
HCO-1822 |
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3.4.8 The Miranda ALC panel
Minimizing loudness differences between segments in a playout channel is an important issue in a world where
multiple programs originating in different formats from different sources must be integrated seamlessly. The Automatic
Loudness Control (ALC) option is the solution to this need. It uses Grass Valley’s proprietary
wideband
ALC
algorithm.
•
Identified as HCO-1822-OPT-ALC-X, where X can be 2, 6, 8 or 16 input channels. The table shows the ALC
models available :
Model
Description
Output Channel Config.
PGM 1
PGM2
PGM3
PGM4
HCO-1822-OPT-ALC-2
2-Channel ALC, up to 2 programs
Up to 2.0
Up to 2.0
N/A
N/A
HCO-1822-OPT-ALC-6
6-Channel ALC, up to 4 programs
Up to 5.1 Up to 5.1
Up to 5.1
Up to 5.1
HCO-1822-OPT-ALC-8
8-Channel ALC, up to 4 programs
Up to 7.1 Up to 7.1 Up to 7.1 Up to 7.1
HCO-1822-OPT-ALC-16
16-Channel ALC, up to 4 programs Up to 7.1 Up to 7.1 Up to 7.1 Up to 7.1
Depending on the model, different channel configurations are possible as listed in the table above. The 2-channel
ALC supports only two independent programs (either one 2.0 program, or 2 mono programs). All other ALC models
supports up to 4 independent programs (mono channel, 2.0 channels, 3.0 channels, 4.0 channels, 5.1 channels and
7.1 channels).
Note: The ALC works with PCM audio. If non-PCM audio like Dolby-E or AC-3 is fed to the module, it will be ignored
and all the program channels will be bypassed to prevent interference with the other PCM audio channel
3.4.8.1 Config tab
Channels per program
Pull-downs are available to select the number of channels
per program. Depending on the ALC model, you may have
different possible selections, from 1 to 8 channels per
program.
Input channels selection
An input shuffler allows any combination of the available
channels to be used as inputs to each ALC program.
Note: An input channel cannot be assigned to more than
one (1) program.
ALC filter
This pull-down selects which type of filtering is applied to the
audio content for all programs:
•
None
•
RLB filtering as per recommendation ITU-R BS.1770.
Enable Loudness Monitoring
turns ON the ALC input and
output loudness monitoring for all programs.
Figure 3.24 Grass Valley ALC – Config tab
