Avid Technology Digidesign USD User Manual page 53

To regenerate VITC based on an external
positional reference using USD Setup:
Ensure that the USD is connected in-line
1
with a video source and video destination.
Ensure that VITC Insertion Enabled is
2
checked in the USD Setup window, and
that you have selected the appropriate for-
mat (NTSC or PAL).
Use the VITC Generate Lines menu to
3
configure the line pair, if necessary.
Select the appropriate clock reference, us-
4
ing USD Setup's Clock Reference menu.
Select either LTC or Bi-Phase/Tach from
5
the USD Setup Positional Reference pop-up
window:
The USD will now regenerate VITC and in-
sert it onto the video signal (as soon as it re-
ceives a valid clock reference signal and po-
sitional reference signal).
Internal VITC Generation
The USD can also generate VITC internally,
using its integral time code generating fea-
ture. In this mode (Positional Reference
switch = Generate) you can use either an
external clock reference, or the USD's inter-
nal crystal as a clock reference with a vari-
able start time.
When generating VITC internally, if the in-
sertion is not timed based upon an up-
stream video reference you may encounter
repeated or skipped VITC frames. Be sure to
check "VITC Timing Rule" on page 50 and
"VITC Video Source Rule" on page 47.
To generate VITC internally using the front
panel controls:
Ensure that the USD is connected in-line
1
with a video source and video destination.
Select VITC Insertion (VI7C In5), using
2
the Set, Down, and Up switches. For de-
tailed instructions, see "VITC Insertion" on
page 56.
Use the Down and Up switches to display
3
VITC Insertion on/off.
When on is selected, press Set.
4
Select VITC Generate Lines (6En LInE),
5
using the Set, Down, and Up switches.
Press the Set switch again. The default
6
line pair is 14/16, which is also the SMPTE-
recommended setting.
Use the Down and Up switches to scroll
7
through the parameter values. When the
desired line pair value is displayed, press
Set.
Using the Positional Reference switch, se-
8
lect Generate.
Set the time code start time. See "Gener-
9
ator Start Time" on page 46 for instruc-
tions.
Arm the destination VTR to record
10
video, so that VITC can be inserted into the
video signal, and be recorded on the desti-
nation videotape.
Make sure that your chosen clock refer-
11
ence is actually present and running, then
press the USD Run switch.
The time code addresses will begin to incre-
ment.
Chapter 4: Using the USD 49