evertz 4025TR Instruction Manual page 27

OVERVIEW
PREFIX: The edge numbers are usually composed of a group of digits that
remain constant throughout the length of the roll, and a count
number, which increments every foot or half foot. The constant
numbers, are referred to as the prefix. The count numbers are
referred to as the footage number.
INK NUMBER: An identifying number is stamped along the edge of the
work print and the associated magnetic audio stock. These
numbers, also known as INK NUMBERS or ACMADE
NUMBERS, occur at one foot intervals, hence they have also
become known as footage numbers. The film frames between
the edge numbers are identified by interpolation from one edge
number to the next.
These Ink Numbers are typically used to keep the picture and
sound in sync throughout the work print conforming process.
2/3 PULLDOWN: Film is typically viewed at 24 frames per second (fps)
while NTSC video is viewed at 30 fps. To compensate for this
difference in the frame rates, telecines use a 2/3 pulldown.
Since each video frame is comprised of two video fields, video
is viewed at 60 fields per second. Telecines can transfer 24 film
frames to 60 video fields (30 video frames). The resulting ratio
is 24:60 or 2:5, which means 2 film frames every 5 video fields.
The 2/3 implies that one of the film frames is transferred to 2
video fields, the following film frame is transferred to 3 video
fields, and so on.
GEN LOCK: In order to ensure that the timecode to video relationship is
fixed, according to SMPTE/EBU specifications, a video
reference must be supplied to the 4025TR Film Footage
Encoder. Normally, the gen lock signal is the program video out
from the telecine, onto which the vertical interval time code
(VITC) is being applied. When VITC is not being used, the gen
lock signal is usually the colour black system reference to which
the telecine is itself genlocked.
necessary, even if vertical interval time code is not being used.
WHITE FLAG:
vertical interval on the first video field of a new picture. This
pulse is normally used on 24 frame per second transfers to
NTSC video that will end up on video disc recorders. This pulse
allows the disc recorder to match the disc frames to the 2/3
pulldown automatically, ensuring jitter free playback when the
recorder is parked on a single frame.
SMPTE: Refers to the Society of Motion Picture and Television
Engineers.
EBU: Refers to the European Broadcasting Union
Model 4025TR Film Footage Encoder Manual
A white pulse recorded on one or more lines in the
The gen lock reference is
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