Unicorn Digital Timepiece, Руководство пользователя, Страница: 55 / 101

S T R I P I N G T I M E C O D E
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11 To stop striping, press stop on your MMC
transport controls or in ClockWorks. Or stop your
external time code source. Or press the STRIPE
button on the Digital Timepiece front panel.
STRIPING FRAME-LOCKED LTC ONTO VIDEO
The Digital Timepiece can stripe SMPTE LTC onto
video while resolved to the video, ensuring that the
LTC is frame-locked (i.e. LTC won’t drift out of
sync with the video frames).
When you do this, you are recording SMPTE time
code onto one of the two audio tracks on the video
tape. If you have a video tape recorder (VTR) that
doesn’t allow you to dub audio separately from
video, you’ll have to dub video at the same time,
either through the Digital Timepiece or separately
via some form of video distribution amplifier.
Below is an example of a typical dubbing scenario:
Figure 7-1: To record SMPTE time code onto video, you need a video
deck that can dub audio onto an existing tape, or you need two video
decks as shown here.
STRIPING SMPTE ON A MULTITRACK TAPE
DECK
The goal when striping SMPTE time code is to
generate an error-free signal strong enough for
reliable lockup, but not so strong that the SMPTE
bleeds through to adjacent tracks.
There are several ways to handle this. One way is to
leave an empty track on your multi-track tape deck
as a buffer between the SMPTE and other tracks.
With a buffer track, SMPTE can be recorded at
very strong (“hot”) levels (above 0 VU) without
risk of bleed through.
If your tape deck has no tracks to spare, a good
level at which to record is around –3 VU. That is,
the VU meter for the SMPTE track on your tape
deck should read –3 when you stripe the SMPTE.
This records SMPTE that is hot enough for reliable
lockup and weak enough so that it will not bleed
into adjacent tracks. -3 VU is only a rule of thumb,
though, so don’t hesitate to use other levels if they
work better for you.
REGENERATING FRESH TIME CODE
SMPTE is a problem when you are copying tapes: it
degrades rapidly every time you try to copy it from
one tape to another. Often, the SMPTE signal
deteriorates so much that it will not be
recognizable by any SMPTE-to-MIDI converter,
including the Digital Timepiece, and you will no
longer be able to lock to it.
The solution to this problem is to use the Digital
Timepiece to regenerate fresh SMPTE time code
that matches the original time code while you are
copying the tape. Some people refer to this process
as
jam syncing . When the Digital Timepiece
receives a SMPTE signal on its SMPTE IN cable, it
always regenerates a fresh signal that exactly
matches the incoming signal and sends it out the
SMPTE OUT cable (except for drop-outs, which it
eliminates with freewheeling).
Digital Timepiece
in
Video/Internal mode or
Video/SMPTE (LTC) mode
PLAY REC
Source video
PLAY REC
Destination VTR
Video
OUT
Video
IN
Video
OUT
Video
IN
Video signal with optional SMPTE burn-
in from Digital Timepiece, plus other
optional video display features.
Video image
with optional
SMPTE burn-in