ISO 9642:1993

INTERNATIONAL ISO
STANDARD 9642
First edition
1993-08-15
Time and control code
Cinematography -
for 24,25 and 30 frames per second
motion-picture Systems - Specifications
- Code de chronombtrage et de commande pour /es
Cinbma tographie
systemes cinematographiques a 24, 25 et 30 images par seconde -
Spkifica tions
Reference number
ISO 9642:1993(E)

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ISO 9642:1993(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide
federation of national Standards bodies (ISO member bodies). The work
of preparing International Standards is normally carried out through ISO
technical committees. Esch member body interested in a subject for
which a technical committee has been established has the right to be
represented on that committee. International organizations, governmental
and non-governmental, in liaison with ISO, also take part in the work. ISO
collaborates closely with the International Electrotechnical Commission
(1 EC) on all matters of electrotechnical standardization.
Draft International Standards adopted by the technical committees are
circulated to the member bodies for voting. Publication as an International
Standard requires approval by at least 75 % of the member bodies casting
a vote.
International Standard ISO 9642 was prepared by Technical Committee
lSO/TC 36, Cinematography.
Annex A of this International Standard is for information only.
0 ISO 1993
All rights reserved. No part of this publication may be reproduced or utilized in any form or
by any means, electronie or mechanical, including photocopying and microfilm, without per-
mission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-l 211 Geneve 20 l Switzerland
Printed in Switzerland

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ISO 9642:1993(E)
INTERNATIONAL STANDARD
Cinematography - Time and control code for 24,25
and 30 frames per second motion-picture Systems -
Specifications
ISO 4241:1987, Cinematography - Leaders and run-
1 Scope
out trailers for 35 mm and 16 mm release prints -
Specifica tions.
This International Standard specifies digital code for-
mats and modulation methods for motion-picture film
ISO 8758:1992, Cinematography - Photographit
to be used for timing, control, editing and synchron-
control and data records on 16 mm and 35 mm
ization purposes. This International Standard also
motion-picture film and prints - Dimensions and lo-
specifies the relationship of the Codes to the motion-
ca tion.
picture frame.
Two types of code are described in this International
3 Modulation method
Standard. The first type, Type C, is a continuous code
which is very similar to the continuous code specified
The modulation method shall be such that a transition
in IEC 461[1]. This type of code tan be used in situ-
occurs at the beginning of every bit period. “One” is
ations where the film is moving continuously at the
represented by a second transition half a bit period
time of both recording and reproduction.
after the Start of the bit. “Zero” is represented when
The second type of Code, Type 5, is a non-continuous,
there is no transition within the bit period.
block-type Code, composed of blocks of data, each
complete in itself, with gaps between the blocks. lt is
designed so that the code may be recorded and
4 Code formats
played back on equipment with intermittent film mo-
tion but still be decoded with the same type of elec-
Two code formats are described: Type C and Type
tronic equipment used to read the Type C or
B. The unique characteristics of the two code types
continuous time Code.
are described in 4.1 and 4.2 respectively. Information
which applies to both code types is given in 4.3 and
44 . ,
2 Normative references
4.1 Type C code format
The following Standards contain provisions which,
4.1.1 Esch motion-picture frame shall be defined by
through reference in this text, constitute provisions
a unique and complete address.
of this International Standard. At the time of publi-
cation, the editions indicated were valid. All Standards
are subject to revision, and Parties to agreements
4.1.2 The frames shall be numbered successively 0
based on this International Standard are encouraged
to 23, 24 or 29 inclusive, corresponding to the frame
to investigate the possibility of applying the most re-
rate being used.
cent editions of the Standards indicated below.
Members of IEC and ISO maintain registers of cur-
4.1.3 Esch address shall consist of 80 bits num-
rently valid International Standards.
bered 0 to 79 inclusive.
ISO 2022:1986, Information processing - ISO 7-bit
and 8-bit coded Character sets - Code extension 4.1.4 The bits shall be assigned as shown in the
techniques. appropriate columns of figure 1 and table 1.

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4.1.6 The Start of the address, i.e. the clock edge
4.15 The address shall Start at the clock edge be-
fore the first address bit (bit Zero). The bits shall be before the first bit, shall coincide with the frameline
at the beginning of the image to which the address
evenly spaced throughout the address period and
they shall fully occupy the address period, which is refers. The tolerante of this location is + 0 % (in the
one frame. Consequently, the bit rate shall be 80 direction of film travel) and - 50 % of a frame length
times the frame rate in frames per second. (in the other direction). Thus, the Start of the address
tan lie anywhere in the top half of the frame with the
preferred Position at the frameline. See figure2.
Table 1
Bit number
Bit description
Type C code Type B code
*
o-7 Alternating Zero, one Pattern
*
8-23 Synchronizing word
*
8-9 Fixed zero
*
IO-21 Fixed one
*
22 Fixed zero
*
23 Fixed one
24-27 Units of frame
o-3
First binary group
4-7 28-3 1
Tens of frames
8-9 32-33
IO 34 Drop frame flag (see 4.4)
4.4)
11 35 Colour frame flag (see
12-15 36-39 Second binary group
16-19 40-43 Units of seconds
20-23 44-47 Third binary group
24-26 48-50 Tens of seconds
51 Bi-Phase mark Phase correction bit (see 4.4)
27
Fourth binary group
28-31 52-55
Units of minutes
32-35 56-59
group
36-39 60-63 Fifth binary
40-42 64-66 Tens of minutes
43 67 Binary group flag bit (see 4.4)
44-47 68-71 Sixth binary group
48-51 72-75 Units of hours
group
52-55 76-79 Seventh binary
80-81 Tens of hours
56-57
82 Unassigned address bit (Zero until assigned by ISO/TC 36)
58
83 Binary group flag bit (see 4.4)
59
Eighth binary group
60-63 84-87
Synchronizing word
64-79 88-103
Fixed zero
64-65 88-89
Fixed one
66-77 90-101
Fixed zero
78 102
79 103 Fixed one
*
104-111 Alternating one, zero Pattern
* These bits do not exist in the type C Code.

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ISO 9642:1993(E)
BIT NUMBER BIT
TYPE C TYPE B VALUE DESCRIPTION Notes
0 0 TIMING BITS START FOR TYPE B
1 1 IS CLOCK EDGE
2 0 BETWEEN BIT 111
3 1 AND BIT 0
4 0
5 1
6 0
7 1
8 0 SYNC WORD
9 0
10 1
11 1
12 1
13 1
14 1
15 1
16 1
17 1
18 1
1
19
1 START FOR TYPE C
20
IS CLOCK EDGE
21 1
BETWEEN BIT 79
22 0
AND BIT 0
23 1
0 24 1 FRAMES UNITS
1 25 2
2 26 4
3 27 8
4 28 IST BINARY GROUP
5 29
6 30
7 31
8 32 10 FRAMES TENS
9 33 20
10 34 DROP FRAME FLAG
11 35 COLOUR FRAME FLAG
12 36 2ND BINARY GROUP
13 37
14 38
15 39

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BIT NUMBER BIT
TYPE C TYPE B VALUE DESCRIPTION Notes
16 40 1 SECONDS UNITS
17 41 2
18 42 4
19 43 8
20 44 3RD BINARY GROUP
21 45
22 46
23 47
24 48 10 SECONDS TENS
25 49 20
26 50 40
27 51 BI-PHASE MARK PHASE CORRECTION BIT
28 . 52 4TH BINARY GROUP
29 53
30 54
31 55
32 56 1 MINUTES UNITS
33 57 2
34 58 4
35 59 8
36 60 5TH BINARY GROUP
37 61
38 62
39 63
40 64 10 MINUTES TENS
41 65 20
42 66 40
43 67 BINARY GROUP FLAG BIT
44 68 6TH BINARY GROUP
45 69
46 70
47 71
48 72 1 HOURS UNITS
49 73 2
50 74 4
51 75 8
52 76 7TH BINARY GROUP
53 77
54 78
55 79

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ISO 9642:1993(E)
BIT NUMBER BIT
TYPE C TYPE B VALUE DESCRIPTION Notes
56 80 10 HOURS TENS
57 81 20
58 82 UNASSIGNED ADDRESS BIT
59 83 BINARY GROUP FLAG BIT
60 84 8TH BINARY GROUP
61 85
62 86
63 87
64 88 0 SYNC WORD
0
65 89
1
66 90
1
67 91
68 92 1
69 93 1
70 94 1
71 95 1
72 96 1
73 97 1
74 98 1
75 99 1
76 100 1
77 101 1
102 0
78
103 1
79
104 1 TIMING BITS
105 0
106 1
107 0
108 1
109 0
110 1
111 0
TYPE C TIME CODE TYPE B TIME CODE
80 BITS PER FRAME 112 BITS PER FRAME
32 USER BINARY
32 USER BINARY
SPARE BITS
SPARE BITS
16 SYNC 48 SYNC
31 ASSIGNED ADDRESS
31 ASSIGNED ADDRESS
1 UNASSIGNED ADDRESS
1 UNASSIGNED ADDRESS
UNASSIGNED BIT IS
UNASSIGNED BIT IS
ZERO
ZERO
- Bit assignment
Figure 1

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ISO 9642:1993(E)
TRAVEL
l
FRAME LINE
NOTE - Figure2 illustrates the preferred longitudinal placement of a frame of time code relative to the picture frame. The
figure applies to all film formats, even though 35 mm film is shown.
Figure 2 - Type C code
4.2.6 The length of any one bit shall not differ by
4.2 Type B code format
more than 5 % from the length of either adjacent bit.
In addition, the length of no bit shall be so short as to
make the recording and reproduction of that data, us-
4.2.1 Esch motion-picture frame shall be identified
ing practical equipment, unrelia
...