Grass Valley CRSC v.3.2 - Manual (Page 143)

131
CRSC
User’s Guide
Figure A-20 shows a simplified view of the CQX digital video router:
Fig. A-21: Block Diagram of the CQX Digital Video Router
The video routers perform input equalization and perform reclocking of outputs. Router
outputs are switched in sync with an external video reference if it is present. The video reference
also provides sync for embedded audio.
All CQX video routers accept bi-level or tri-level video references (sync) and switch according to
SMPTE RP168-2002.
The CQX video routers also provide a bypass path for non-synchronous input signals. If the two
sources chosen for a clean and quiet switch are not of the same format, are off-rate, are not at
the same frame rate as the video reference, or do not meet the timing window (± 3 lines), the
video processor enters non-sync bypass mode where the source signal bypasses the video
processor and goes straight to the outputs. Thus, the clean and quiet output behaves like an aux
output in which there is no video or audio processing
— with no transition processing. Switches
still occur at the specified switchpoint for the video reference, but they will not be “clean and
quiet.”
However, if there is no video reference present, the CQX does the cut to the new source as soon
as it receives the command from the control panel and does not wait for the switchpoint.
Where one or both of the sources is off-rate or at a frame rate different from that of the video
reference, the output will bypass the video processor.
If a clean and quiet output is in a non-sync state but conditions change so that a clean switch is
possible, the processor waits for one frame of video before switching to processed video to
ensure that the processed video has enough time to pass through the video processing path.
The CQX video routers have a removable fan unit. The fan unit is not visible when a CQX panel is
mounted on the router.
Fig. A-22: Front View of the CQX Video Router
non-sync
bypass
clean 2
clean 1
Reclock
Em. Bypass 2
CQX 2
6
6
μP Logic
Inputs
(Equalized)
Aux Outputs
Control
Panel
Video Reference
Automation
Ethernet
(optional)
16
Mix 1
Mix 2
Reclock
Em. Bypass 1
CQX 1
Reclock
GPIO
2
Recessed Fan unit 16-pos Mode Switch
16-pos Frame ID Switch