Grass Valley MRC v.1.2 - Manual (Page 155)

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Miranda Router Configurator
User’s Guide
A router must have at least one level defined. If no level is defined, the router’s control card will
be in an error state (red LED illuminated).
Mono and Stereo Switching
Mono and Stereo in the NV8500 Hybrid Routers
The NV8500 series routers supports two forms of audio:
• Asynchronous AES. This is discrete AES available through the router’s AES input and output
cards.
• Synchronous AES. This is AES embedded in standard video and hybrid video I/O and multi-
plexed in MADI I/O.
Asynchronous AES is always stereo and is switched the same way that video signals are
switched.
Synchronous AES is always mono and can be recombined in any way as long as the router has
disembedder and embedder cards or MADI cards. If you want to create stereo pairs, it is a simple
matter to create devices in NV9000-SE Utilities that have two mono levels.
Mono and Stereo in Other Routers
Caution: although MRC can open, save, and upload configurations for routers other than
NV8500 hybrid routers, it does not officially support any routers other than NV8500 hybrid
routers.
UniConfig must be used for a successful configuration of routers other than the NV8500 hybrid
routers.
Mono audio partitions in the NV7256, NV7512 and NV5128 are a case in point. At this time, MRC
does not properly configure mono audio partitions.
Video Fields and Frames
For interlaced video, a frame comprises two fields, field 1 and field 2. Progressive video does not
have fields.
For NTSC interlaced video, there are 30 frames (60 fields) per second. For NTSC progressive
video, there are 60 frames per second.
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Note: If you are configuring an NV8256 or NV8256-Plus, MRC’s ‘Output Attributes’ page lets you
configure outputs to switch on a frame or a field basis.
About Vertical Timing
A “switch point” is a point in time in which an output is switched from its current source to a new
input. Different video and audio formats require different switch points to prevent switching
artifacts (noise or disturbances).
SMPTE standards specify the video lines where the switch should occur. The line number and
position within the video line vary by signal format and line rate. A router’s control card uses the