evertz 4025 Instruction Manual page 111

Model 4025 Film Footage Encoder Manual
The 4025 Film Footage Encoder encodes the latent film edge numbers
(also known as footage numbers or key numbers), with the frame offset
from the edge number and an optional numeric prefix, into the user bits of
the generator in one of several formats.
Using normal BCD encoding, (GENERIC mode) there is only room to
encode a maximum of 6 digits of film feet plus 2 digits of frames into the
user bits. The maximum footage number is programmed using the Format
menu. The number of prefix digits permitted is dependent on the maximum
footage number that is selected. (See section 3.10.7.)
By utilizing a compressed binary format, (EVERTZ mode) up to 7 digits of
feet plus frames can be encoded, along with the pulldown information,
however, special decoding routines in the time code readers will be
required to recover this information and display it as decimal digits. These
modes are sufficient to record all of the numeric edge number information
from the older edge number styles.
When used with KeyKode numbers, only part of the edge number can be
encoded into the user bits in the EDGE modes. The full KeyKode number
with frame offset can be encoded by using the secondary VITC lines ( the
+ KEYKODE modes) while leaving room for auxiliary timecode information
( e.g. production sound time code) in the user bits of the LTC and the
primary VITC generators.
In the + KEYKODE modes, the Key Info data consisting of the
manufacturer code, the emulsion code and the first four digits of the prefix
are stored in the time bits of the secondary VITC generator. The user bits
contain the same information as would go into the primary VITC in the
EDGE modes as determined by the EDGE STYLE and EDGE FORMAT
menu settings (See sections 3.10.6 and 3.10.7 for further information
about edge numbering modes.)
In the 3 Line VITC STD, the film type, film gauge and transfer rate are
encoded along with the keykode number, film frame & pulldown information
in the second line of the 3 Line block.
In any of the EDGE user bit modes, the user bits of the primary VITC
generator follow the actual film frame numbers on a field by field basis,
accurately tracking the pulldown of the telecine. However, because the
LTC is only a frame rate code, the film edge numbers in the LTC user bits
are only accurate to the closest frame. In the + KEYKODE modes, the
secondary VITC generator follows the actual film pulldown on a field by
field basis, and the LTC output follows the primary VITC output.
The KKODE key is used to display the film edge number and frames.
When used with an external KeyKode reader, the complete film edge
number may be displayed on the front panel and in the character inserter.
Selection of the desired format for the film edge numbering is performed
using the FILM drop down menu on the Format menu displayed on the
character generator.
OPERATION Page 45