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Re: 3 line Vitc



>>Its great that a new standard is being established. It would also be =
great 
>>if the group was polled for suggestions.
>> Kevin Shaw (Freelance Colorist, Consultant and Instructor)

>The "three line VITC" standard was developed by Aaton & Evertz. This would
>be an excellent time for the specifications to be published on the web.
>Listening, Allan, JP?
>--David Tosh (Video Engineer, Complete Post, Hollywood)

Hello David,
Yes I'am listening, and here is the document you asked for.
--jp 


(Open in monospaced font such as 'Courrier' or 'Monaco' for =
tabulation)
_______________________________________________________________________=
__
3Line VITC FORMAT                                               =
August-94 
                        As generated by Aaton Keylink 
                          and read by Aaton Sorter

The 3LineVITC is meant to occupy the vertical interval with more 
efficient data recording than the standard VITC.
It fills the empty space between the standard 2Line VITC (e.g. 19-21) 
with another line (i.e 20); it doesn't repeat the same message twice, 
hence each line has a different content. 
The first line carries the standard Video-TC, the second carries 
the Keycode, and the third the AudioTC either read on the film or =
entered 
from an audio recorder.
The 3Line Vitc proposition (Aaton, Avid, Evertz, Lightworks) should 
become the safest way to transport film data into the Non Linear =
Editing 
world.  The three consecutive lines are inserted from line 13 to 20 
in NTSC and from line 14 to 23 in Pal:

        Time Bits             User Bits                   CRC
Line1   Video-TC              Tape Reel or AatonTags      Normal
Line2   KC Prefix, Pulldown   KC count & Frame            Inverted
Line3   Audio-TC              Time, Date, Cam.ID*         Nibble Inv.

* AatonCode or ArriFIS.

The first line is encoded with the normal SMPTE 12M CRC, so that =
existing
VITC readers can access Video TC and AatonTags.  Each of the other =
two 
lines are encoded with their own CRC so that there will not be any
confusion for existing VITC readers which can=B9t 'see' them. 

_____________________________
1  VIDEO TAPE TC - FIRST LINE
The Video tape TC is encoded into the first line of the group =
according 
to the specifications of SMPTE 12M - 1992.  The CRC is the normal 
SMPTE 12M CRC encoding.  The frame rate of this time code is 25 fps 
in PAL and 30 fps Drop Frame or Non Drop Frame in NTSC.
The user bits are encoded as 8 hexadecimal digits, and carry the 
AATON Tags (address of the field in the Aaton transfer database), 
or the VTR user bits, or the Video Reel ID, or any arbitrary HEX =
value.

________________________
2  KEYCODE - SECOND LINE
The Keycode Information and pulldown flags are encoded into the =
second 
line of the group.  The CRC is the inverse of the SMPTE 12M CRC, i.e. =
the 
regular CRC being =8C01010101=B9(hi to low), the Keycode CRC will be =
10101010.

 ____________
 2a TIME BITS of the keycode line are used to store the pulldown 
 flags, film manufacturer ID, film gauge, emulsion type and part of 
 the prefix of the Key code number.  Encoding is as follows:

TIME BIT NIBBLES      BIT #     CONTENT
Hour tens            75        Field flag 0=3Dfld1, 1=3Dfld2
                     72-74     Pldwn flag [see tables 1 to 4]
Hour units           62-65     Film Mftr + Gauge [see table 5]
Minute tens          52-55     Emulsion type, MS digit 
Minute units         42-45     Emulsion type, LS digit 
Second tens          32-35     Prefix 1, MS digit
Second units         22-25     Prefix 2
Frame tens           12-15     Prefix 3
Frame units          02-05     Prefix 4
Note: The film manufacturer, gauge and emulsion type data correspond =
to 
the encoded values recovered from the machine readable barcode, and =
not 
to the letter codes on the human readable part of the edge number. 

 ____________
 2b USER BITS of the keycode line contain the rest of the prefix, 
 the counting part of the key code number, (sometimes referred to as 
 footage), the maximum frame count, and the frame offset from the last
 keycode number. Encoding is as follows:

USER BIT NIBLES      BIT #     CONTENT
Group 8, Hrs tens    76-79     Prefix 5 
Group 7, Hrs units   66-69     Prefix 6, LS digit
Group 6, Min tens    56-59     Footage 1, MS digit
Group 5, Min units   46-49     Footage 2
Group 4, Sec tens    36-39     Footage 3 
Group 3, Sec units   26-29     Footage 4, LS digit
Group 2, Frm tens    18-19     Max Frame Count [see table5]
                     16-17     Frame 2 MSB, binary encoded
Group 1, Frm units   06-09     Frame 4 LSB, binary encoded

                                _______
                                Table 1 
           Pulldown Flags  at  24 fps/NTSC (w. 3&2 compensation).

FILM     VIDEO FIELD  PD3     PD2    PD1      NIBBLE       Video frame
FRAME    B75          B74     B73    B72      VALUE        example
A        0            1       0      0        4            0:00
         1            1       0      0        C
B        0            1       0      1        5            0:01
         1            1       0      1        D
         0            0       1      1        3            0:02
C        1            0       1      1        B
         0            0       1      0        2            0:03
D        1            0       1      0        A
         0            0       0      0        0            0:04
         1            0       0      0        8
A        0            1       0      0        4            0:05
         1            1       0      0        C

                                _______
                                Table 2
            Pulldown Flags  at  24 fps/PAL (w. 24&1 compensation).  
  24 film images converted into 25 video images with L3 & X3 extra =
fields.

FILM   VID.FLD  PD3 PD2 PD1  NIBBLE    FILM   VID.FLD  PD3 PD2 PD1  =
NIBBLE
FRAME  B75      B74 B73 B72  VALUE     FRAME  B75      B74 B73 B72  =
VALUE
A1     0        1   0   0    4         A2     1        1   0   0    C
B1     0        1   0   0    4         B2     1        1   0   0    C
C1     0        1   0   0    4         C2     1        1   0   0    C
D1     0        1   0   0    4         D2     1        1   0   0    C
E1     0        1   0   0    4         E2     1        1   0   0    C
F1     0        1   0   0    4         F2     1        1   0   0    C
G1     0        1   0   0    4         G2     1        1   0   0    C
H1     0        1   0   0    4         H2     1        1   0   0    C
I1     0        1   0   0    4         I2     1        1   0   0    C
J1     0        1   0   0    4         J2     1        1   0   0    C
K1     0        1   0   0    4         K2     1        1   0   0    C
L1     0        1   0   1    5         L2     1        1   0   1    D
L3     0        0   1   1    3         M1     1        0   1   1    B
M2     0        1   1   0    6         N1     1        1   1   0    E
N2     0        1   1   0    6         O1     1        1   1   0    E
O2     0        1   1   0    6         P1     1        1   1   0    E
P2     0        1   1   0    6         Q1     1        1   1   0    E
Q2     0        1   1   0    6         R1     1        1   1   0    E
R2     0        1   1   0    6         S1     1        1   1   0    E
S2     0        1   1   0    6         T1     1        1   1   0    E
T2     0        1   1   0    6         U1     1        1   1   0    E
U2     0        1   1   0    6         V1     1        1   1   0    E
V2     0        1   1   0    6         W1     1        1   1   0    E
W2     0        0   1   0    2         X1     1        0   1   0    A
X2     0        0   0   0    0         X3     1        0   0   0    8

                                  _______
                                  Table 3
         Pulldown Flags  at  25fps/PAL & 30fps/NTSC.  Field 1 dominance

FILM     VIDEO FIELD  PD3     PD2    PD1      NIBBLE       Video frame
FRAME    B75          B74     B73    B72      VALUE        example
A        0            0       0      1        1            0:01
         1            0       0      1        9
A        0            0       0      1        1            0:02
         1            0       0      1        9  

                                  _______
                                  Table 4
          Pulldown Flags  at  25fps/PAL & 30fps/NTSC.  Field 2 dominance

FILM     VIDEO FIELD  PD3     PD2    PD1      NIBBLE       Video frame
FRAME    B75          B74     B73    B72      VALUE        example
A        0            1       1      1        7            0:01
B        1            1       1      1        F   
         0            1       1      1        7            0:02
C        1            1       1      1        F  

                                  _______
                                  Table 5
                      Film Gauge & Maximum Frame Count  
  The frame number is binary encoded in the least significant byte of =
the 
   user bits along with two flags identifying the MFC of the key =
numbers. 
     This MFC is encoded as two bits (18-19) and is interpreted based 
              on the Film Mftr + Gauge nibble (bits 62-65).

Film Mftr ID       Gauge        Max Frame count               B19   =
B18
0    Ink           35 mm (4P)   16                            0     0
                   16 mm        20                            1     0
                   16 mm        40                            0     1
                                reserved                      1     1
1    Agfa          35 mm        16 (4P Keycode/Ft & fr)       0     0
2    Kodak                      21 (3P head dot - perf 1)     1     0
3    Fuji                       21 (3P center dot - perf 2)   0     1
                                22 (3P tail dot - perf 3)     1     1
4    Agfa          Special      35 mm 8P (Vistavision)        0     0
5    Kodak                      65 mm 5P 60 Fps               1     0
6    Fuji                       reserved                      0     1
                                reserved                      1     1
7    Agfa          65/70 mm     24 (5 perf)                   0     0
8    Kodak        (12P Key#     15 (8 perf)                   1     0
9    Fuji            cycle)     10 (10 perf)                  0     1
                                8 (15 perf)                   1     1
A    n.u.
B    Agfa           16 mm       n.u.                          0     0
C    Kodak                      20 (Key # & frames)           1     0
D    Fuji                       40 (Foot & frames)            0     1
                                reserved.                     1     1
E    n.u. 
F    n.u. 

 __________
 2c EXAMPLE
 35mm 4P, Keycode KJ12 3456 7890+12

Mfg's code      02          letter K for Kodak 35mm gauge
Film type       96          letter J for 5296
Prefix          12 3456
Footage         7890
Frames          C           binary # for frame 12
Pldwn & Field   4          =8CA=B9 frame, field 1

KJ12 3456 7890+12 is encoded as follows:
time bits              user bits
hh  mm  ss  ff         b12  b34  b66  b78
42  96  12  34         56   78   90   0C


_______________________
3 AUDIO TC - THIRD LINE
The Audio TC (AatonCode) is encoded in the third line of the group.
The CRC is calculated the same way as the normal SMPTE 12M CRC, but =
shows
an inverted high order nibble, i.e. the regular CRC being  =
=8C01010101=B9 
(hi to low), the Audio TC CRC will be 10100101.
The time bits of the AatonCode line contain the Audio TC and frame =
count.

The default frame rate of the production time code is 25 fps in PAL 
systems, and  30 fps df or ndf in NTSC.  This frame rate can be =
recorded 
under any other user selectable frame rate such as the camera frame =
rate.

 _______________
 3a CAMERA SPEED: encoded into Bits 74-75 as shown below:
B 75    B 74     FPS
0       0        24
1       0        25
0       1        30 [29.97]
1       1        other

 ____________
 3b USER BITS: they normally contain the same data as the Audio LTC 
 user bits. Bits 55 & 35 indicate the type of encoding:
B 55    B 35     TYPE
0       0        not encoded (8 hexadecimal digits)
0       1        date & camera ID (see under: AATON FORMAT)
1       0        reserved
1       1        reserved

 _______________
 3c AATON FORMAT: Year [00-99] is 7 bit encoded; Month [01-12] is 4 =
bit 
 encoded; Day [01-31] is 5 bit encoded; Camera ID digits are =
hexadecimal 
 containing values 0 to F.  The full camera ID is 4 hex digit.

USER BIT NIBLES      BIT #     CONTENT
Group 8, Hrs tens    76-79     Year 4MSB
Group 7, Hrs units   67-69     Year 3LSB.
                     66        Month MSB
Group 6, Min tens    57-59     Month 3LSB
                     56        Day MSB
Group 5, Min units   46-49     Day 4LSB
Group 4, Sec tens    36-39     Camera id 1 [MS digit]
Group 3, Sec units   26-29     Camera id 2
Group 2, Frm tens    16-19     Camera id 3
Group 1, Frm units   06-09     Camera id 4 [LS digit].
_________________  end


_______________________________________________________________________=
___
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