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Finding Your NLE Settings
using CPC Calibration Black Movie
Closed
Caption data sits on Line 21 of the VBI in NTSC (525 line) video. In a
720x486 digital video file, captions sit somewhere on Row 0 through Row 2,
and Column 19 through Column 35 depending on the
NLE system. When you transfer the 720x486 video file to video tape, you must use an NLE
system which can map the caption data from Row 0, 1 or 2 of the 720x486 video
file to VBI
Line 21 of NTSC video. CPC
found the exact locations for the closed caption data for several
NLE systems. For example, the caption data sits on Row 1 and Column
26 for Avid Symphony. Click here
for a list of known compatible NLE systems. If your NLE system is
not listed there or the preset values listed there do not work for
your NLE system, you need to do the following test to find the row
and starting column for your NLE system.
CPC created a calibration video (7:30 minutes). The closed caption
content of the first 5 seconds of the calibration movie is "Row 0, Col 14" and
it is generated with the Row set to 0 and starting Column set to
14; the next 5 seconds of the movie has the CC content of "Row 0,
Col 15" and is generated with Row 0 Column 25, etc. This shifting continues through Row 0 and Column 40 at
which time it shifts to Row 1 Column 15. The last movie segment is
Row 4 Column 40.
Please download and play one of
the following
caption encoded calibration videos (created with different codecs) on your NLE system
and print the video through your NLE hardware (not Firewire), so you can determine the preset values (row/column) for your NLE system.
Avid Meridian
Codec (Adrenaline, Symphony)
Uncompressed
8 bit 422 (AJA, Blackmagic, Premiere, Final Cut)
QuickTime Animation (Generic
Codec)
Apple ProRes 422 (Final Cut Studio 2)
Finding row/column for your
NLE system using CPC caption
calibration movie:
Step 1.
Download and
unzip the Caption Encoded Calibration QuickTime movie that corresponds with
your NLE sequence codec settings. (A matching codec can cut down or avoid
render time)

Fig. 1: This is a screenshot of the caption encoded calibration movie
Step 2.
Import the caption encoded calibration movie into your NLE system.
(Avid users: You import
720x486/Non-Squared with "ITU601" Effect Aperture and "1:1" resolution;
use the correct field order as usual.) Step 3. Make a new
timeline or sequence in your NLE system. Make sure that your timeline or sequence settings are
720x486, non-squared, with the correct field order (upper or lower as
needed). Below is an example of what your NLE sequence should be set to in Final Cut
Pro.

Fig. 2:
Sequence settings from Final Cut Pro
Blackmagic
DeckLink users: You must optimize your settings in order to caption with our
software solution. For a complete list of
BlackMagic settings in a Final Cut Pro system click here.
Step 4.
Place the caption encoded
calibration QuickTime movie into your new timeline.
Step 5.
Connect the
video output of your NLE capture card to a NTSC television set. (Use the
Composite video input for this test) Avid users: Enable "VBI Preserve" in
the Video Output Tool.
Step 6.
Turn on your
caption decoder to CC1 on your NTSC television set. (consumer grade TVs may require a remote control
to turn on the caption CC1 decoder)
Step 7.
Play the caption encoded
calibration QuickTime movie from your timeline out to your
television.
For a while you may not see anything on the TV other than a black screen. When the video reaches a point where the
caption setting matches your NLE video editing
system, you will see on your TV screen the captions with those settings. You may have to watch the TV screen for up
to 7:30 minutes until you see a few captions like this come on
the screen.

Fig. 3: This is what
will appear on your TV set
If do not see any
captions at all, your NLE system is not caption compatible. And if
you do see captions, you need to pick a row and column value pair
from the numbers you see. To avoid errors, you pick the mid-value of
all visible column numbers. In this example it is Col 23. So the
preset NLE values for your NLE system is Primary Row: 0 and Column: 23.
Once you have
determined these values, you can use these values in the CPC
software settings to caption your videos using your NLE system.
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