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Kara7 Kara7 is offline
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Default How do I subtract time where hh:mm:ss:ff (frames = 30 frames/sec)

Follow-up to my previous problem, since I forgot to think about the issue of
drop-frame vs. non-drop frame timecode.

Drop-frame time code (primarily used in film projects shot at 24fps)
actually drops 2 frames per second every minute except on minutes ending in
zero (in order to remain in sync). So - it actually ends up being 23.97 fps.

Anyone out there got the math for Excel 2003 to help me out with that?

Here's where I'm at so far: I've got a cell (C13)marked DROP FRAME validated
to be True/false, and H13 is Frame Rate in fps(ex: 24, 30, etc) and G21 is
the TC in ... so I'm hoping that I can set something up where

=if(C13,(text(G21,"hh:mm:ss")&":"&TEXT((G21)*24*60 *60-INT(G21*24*60*60))*H13",00))), (--INSERT DFTC FORMULA HERE --))

Hidden Columns B&D- starting @ row 21: where Columns A & C are TC In & Out:
=LEFT(A21,2)/24+MID(A21,4,2)/(24*60)+MID(A21,7,2)/(24*60*60)+RIGHT(A21,2)/(H13*60*60*24)
=LEFT(C21,2)/24+MID(C21,4,2)/(24*60)+MID(C21,7,2)/(24*60*60)+RIGHT(C21,2)/(H13*60*60*24)

Hidden Column G - starting @ Row 21:
=D21-B21

Thanks Again!!
Best ~
KJ7


"KJ7" wrote:

I've got a template I'm using (in Excel 2003) where I need to subtract two
time-based fields from one another. (Seems simple enough). However... this is
for use @ a small post production co., where the smallest unit of measure is
not actually the more commonly referenced 'second', but rather - the 'frame'
(generally at the rate of 24 or 30 frames per second).

What I'd like to accomplish is this: a formula that takes the two timecodes
and subtracts in from out... leaving me with a duration:

EX: 01:11:27.03 - 01:11:23.20 = 00:00:03.13 (or 3 sec & 13 frames)
thanks for your help.
~kj