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

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Guest

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
 
This is based upon 30 frames per second (Digital video)

In A1 and A2 we enter as text:

01:11:27:03
01:11:23:20

In B1 and B2 we enter:

=LEFT(A1,2)/24+MID(A1,4,2)/(24*60)+MID(A1,7,2)/(24*60*60)+RIGHT(A1,2)/(30*60*60*24)
=LEFT(A2,2)/24+MID(A2,4,2)/(24*60)+MID(A2,7,2)/(24*60*60)+RIGHT(A2,2)/(30*60*60*24)

and format as Custom hh:mm:ss.00 to display:

01:11:27.10
01:11:23.67

the tenth of a second because 3 frames is a tenth of a second. In B3 enter:

=B1-B2 to display 00:00:03.43 in the same format. Finally to convert the
..43 seconds into frames, in B4 enter:

=TEXT(B3,"hh:mm:ss") &":" & TEXT((B3*24*60*60-INT(B3*24*60*60))*30,"00")
to display:
00:00:03:13
 
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
 
hi! please convert this to > 25 frames per second (pal video) ty

Gary''s Student said:
This is based upon 30 frames per second (Digital video)

In A1 and A2 we enter as text:

01:11:27:03
01:11:23:20

In B1 and B2 we enter:

=LEFT(A1,2)/24+MID(A1,4,2)/(24*60)+MID(A1,7,2)/(24*60*60)+RIGHT(A1,2)/(30*60*60*24)
=LEFT(A2,2)/24+MID(A2,4,2)/(24*60)+MID(A2,7,2)/(24*60*60)+RIGHT(A2,2)/(30*60*60*24)

and format as Custom hh:mm:ss.00 to display:

01:11:27.10
01:11:23.67

the tenth of a second because 3 frames is a tenth of a second. In B3 enter:

=B1-B2 to display 00:00:03.43 in the same format. Finally to convert the
.43 seconds into frames, in B4 enter:

=TEXT(B3,"hh:mm:ss") &":" & TEXT((B3*24*60*60-INT(B3*24*60*60))*30,"00")
to display:
00:00:03:13
Click to expand...
[/QUOTE]
 
Well you could look at the formula and work out what it is doing (as all the
functions arte standard Excel functions which are clearly explained in Excel
help), or at the very least you could look at where 30 appears in the
formula and wonder whether you could sensibly replace the 30 by 25 to meet
your needs. And of course you'll test it, as you would with any other
formula which is suggested to you.
--
David Biddulph

Gervin Callo said:
hi! please convert this to > 25 frames per second (pal video) ty
Click to expand...
[/QUOTE]
 
This works great!

I found one little glitch. Not sure how to fix it.

When the duration of a clip is an even second, for example a clip that is
exactly two seconds long, the results are displayed as: 00:00:01:30

Which is equivalent to two seconds, just like writing two halves equals one.
But it would be more clear if it was displayed as: 00:00:02:00.

Again not sure what the best way to fix that is, just thought I'd raise it.
 
I used these formuls to create another type of form. What I call a rundown.
What it is, is a sheet to help you calculate segment lengths for a video or
film project of a specific length. So you enter the duration of parts of the
program and it keeps a running total of how long the project is and how much
remains to fill.

Example, you want to produce a 30 minute magazine style show. Segment 1 is
one story, Segment 2 is an interview etc etc...

What I've done is used these formulas to convert the hh:mm:ss:ff timecode
values into seconds and convert them back once I've added or subtracted the
values as needed to tell me how much time has been used up and how much time
is left.

What I noticed is that when I enter the length of the first segment, if the
timecode has a frame value of 15 or higher, the formula seems to add a second
to the time. Ex: My title sequence for a show might be 00:00:45:22 but when
it gets converted into hh:mm:ss.00 and then back into hh:mm:ss:ff the time
becomes 00:00:46:22

This seems to happen even if I don;t do any other operations to the values
other than the conversion. Any ideas?
 
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