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Re: Forcing A Frames.



Randy Coonfield wrote:
>Obviously, making these A frames occur on designated frames is a
function of the edit controller >and only edit controllers which
control the telecine as well as the tape recorders
>will work. However,the need to do so is greatly mis-understood, even among 
>telecine professionals. Avid does not require such alignment, nor does 
>Lightworks. In fact, all any of the popular editing systems need is an
accurate
>'pull-in' for each take. In other words, the editing systems need to be told 
>where the A frame is.

That's a good explanation Randy.  What the Edit systems really need is
an unambiguous KeyKode/Timecode relationship for each shot. The easiest
way to determine that is on the A frame where there is a 1;1
correspondence between the film and video.  As you mentioned, the Evertz
Key_Log software only logs A frames.

One way to check the accuracy of your system is to use the Kodak KeyKode
verification film, which Kodak developed with input from Evertz and
several other manufacturers and users.  There are check symbols along
the film that repeat every four frames. If you do random pickups or
forced A frame pickups you can determine the accuracy of the system. 
Evertz recommends that periodic checks be made for system accuracy. 
This is necessary to check that delays in the system such as noise
reducers or encoders are properly compensated for.  An ounce of
prevention...

Alan Lambshead
Evertz Microsystems Ltd.
alan at evertz.com

Alan Lambshead
V.P., Director of Engineering
Evertz Microsystems Ltd.
Burlington, Ontario
alan at evertz.com