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The two time code
types can
be in
one
of four formats
,
European Broadcasting
Union ( EBU )
,
SMPTE
Non -
Drop
Frame
( NDF )
,
SMPTE
Drop
Frame ( DF )
,
or
FILM
.
Each format is
designed
for use in
a specific application
,
to
wit
:
O
EBU is used for
videotapes
made at
a rate
of 25 frames
per
second ( Fr /
s
)
,
in accordance with
European broadcasting
standards
;
SMPTE NDF is used for monochrome
videotapes
made at
a rate
of
30 Fr
/ s
,
in accordance with National Television
Standards Committee ( NTSC ) standards
;
SMPTE DF is used for color
videotapes
made at a rate of
29.97
Fr /
s
,
in accordance with NTSC
standards
;
color television
FILM is used for motion
pictures
made
at a rate
of 24
Fr / s
.
C
.
1.2
SMPTE DF
The
APR
-
5003
V records SMPTE
NDF
and SMPTE DF time code
at a
frequency
of
2400 bits
per
second ( 80 bits LTC x 30 Fr /
s
)
.
However
,
in order
to
accommodate the
slightly less than
30
Fr /
s
color
videotape
frame rate of 29.97
,
two frames are
dropped
from the SMPTE
DF data
stream each minute
(
with the
exception
of
every
tenth minute ) to
correct the offset
that occurs because of the frame rate differential
,
short term time error experienced
by
this format is
illustrated in
Figure
C
-
l
.
n
error
The
+ 60
+
40
.
5
co
+ 20
s
o
QJ
< D
—
20
E
-
40
-
60
0
1
2
3
4
5
6
7
8
9
10 11
12 13
14
15
30
20
50
40
Time in Minutes
Short Term Error in
Drop
Frame Mode
Figure
C
-
l
*
n
C
-
2
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