Grass Valley MRC v.1.2 User Manual
Page 54
44
Configuring Routers
Router Levels Page
Regions of the Special Audio Section
The title of this section is ‘Audio Settings for Level’:
Fig. 3-2: Special Audio Section
The section has 3 parts that allow you to define the following items:
•
The null audio source.
•
The basic pass-through audio source.
•
Sixteen audio sources for extended pass-through.
The port numbers in this section must all be unique. You may not have duplicates.
Null Audio Source
When used (by a control panel operator), a “null audio source” lets the router control card know
that null audio is required for an audio output (in an embedder or disembedder/embedder
output card).
The port you specify as the null audio source is not a source of audio. This “null audio source”
tells the router to use, instead, silence from an internal silence generator.
Null audio is generated silence, but is more than just silence because when all the channels
of an audio group are null, the group is omitted from the output altogether.
See
on page 151 for more in
formation.
How to Specify a Null Audio Source
1 Check the ‘Null Audio Source’ check box. If this box is not checked, the null audio source field
is greyed out.
2 Enter one of the audio input ports of the hybrid router in the null audio source field. The field
actually accepts values in the range [0–65,535] but only valid audio port numbers will work
properly. Specify one of the unused audio ports of the router’s disembedder cards (or MADI
cards). Otherwise, if you specify a normal port, that port cannot be used for any real input.
Always choose an unused audio port number that is greater than the number of video
input ports of the router. Unused port number between 1152 and 2304 will work well for
any NV8500 router.
Uncheck the ‘Null Audio Source’ check box if you do not want to use null audio.
3 Perform other changes in the ‘Router Level’ page as required and click the ‘Update Control
Card’ button at the bottom of the page.
To be usable, the null audio source must also be configured in NV9000-SE Utilities.