From the first film frame, two video fields are derived, the

Note:

The insertion of White Line flags is only done,

second film frame, three video fields are derived, from the

 

when timecode is actually recorded on film. If

next film frame, two video fields and so on.

 

there is no timecode recording, for example

 

 

because the camera is not running on a time-

The White Line flag works as follows:

 

code speed, no White Line flag is sent out.

Every time, the video field corresponds to a new film frame,

Note:

The White Line has priority over VITC lines. If

the letter will change either from A to B or B to A and the

 

the same line is selected for White Line as well

number will be set to 1. As long as no new film frame is

 

as for VITC, White Line will appear.

taken, the video fields are counted, beginning from 1.

 

 

Consequently A2 is the first repetition of A1. B2 would be

 

 

the first repetition of B1, B3 would be the second

 

 

repetition. On every A1 or B1, the selected video line will

 

 

get set to video signal white, indicating that only these

 

 

video frames correlate one-to-one to film frames. The

 

 

duplicated video fields are not marked.

 

 

In spite of the fact that the name Pull-Down comes from

 

 

the working practice in the NTSC systems, where on a

 

 

telecine the film is running on 23.976 fps and gets

 

 

converted to 29.97 fps, the definition of Pull-Down

 

 

information on the IVS can also be applied to PAL and to

 

 

film speeds other than 23.976 fps.

 

 

Video-Asssist-System

169