What it does and how to use it
The TCFXM Timecode Plugin provides Arithmetic and Conversion functions dealing with timing and length values in film and video post production to FileMaker Pro users. It is usable in both 32 and 64 bit.
The plugin takes parameters as timecode, decimal seconds, frame counts, as well as feet & frames.
The plugin can add, subtract, multiply and divide values in each of these formats. Formats can be mixed, e.g. you can add feet & frames to a timecode. Results will be formatted to match the first input parameter.
There are conversion functions to from any to all of the four formats. These conversions keep the number of frames constant, and thus can change running time.
For convenience, there is a function that converts from one timecode format to another timecode format, where the running time is kept constant. This function is likely to incur rounding errors.
There is a function to conveniently add the appropriate colons or semicolons to a value that has only numbers.
For timecodes at 24, 25, 48 and 50 fps only, there is a pair of functions that lets you simulate the effect of converting to and from dropframe timecode  which does not exist for these formats. This might be most useful for 24 fps timecode used for 23.98 fps.
The plugin expects frame rates, as well as frames per foot, entered according to industry standards.
(To find out how to get the plugin, go here.)
Number Formats / Counts
The four format types listed below are referred to as 'counts'. They are recognized automatically and can be used interchangeably. When counts are not entered to the specifications below, the calculation is aborted, resulting in a '?' in FileMaker.
Format  Description  Examples 

Timecode  11 digit text where 4 pairs of digits are separated by colons, semicolons or periods. See below for exceptions^{*}  01:23:12:13 10;18;45;12 00.11.22.11 1:18 9;34;09 12.01.22

Seconds  decimal number, using period or comma as decimal point  113.4 2288,0 
Frames  number, using only digits  22517 2288 
Footage  feet and frames, separated by either + or & The separating character has no effect of how the value is parsed. 
18+12 327&37 
^{*}Timecode can be entered with fewer than 8 numerical digits. So 1:18, 12;15 and 8.34.06 are all valid timecode entries. The plugin will add in the missing leading zeros. However, entries with a single decimal point, like 12.15, will be treated as seconds.
Functions
Arithmetic Functions  Conversion Functions  from and to any number format 

TCFXM_Add  TCFXM_To_Frames 
TCFXM_Subtract  TCFXM_To_TC 
TCFXM_Multiply  TCFXM_To_Seconds 
TCFXM_Divide  TCFXM_To_Footage 
All of these functions internally convert to and from frame counts. This means: 1:20
@ 30
fps added to 1:01
@ 24
fps is turned into 50 + 25 = 75 frames. That then gets converted to the format of the first count. Here, that would be 75 divided by 24 = 00:00:03:02
@ 24
fps.
Timecode Format Conversion 

TCFXM_TC_ConstantTime_Convert 
This function is strictly timebased, it does not convert to frames internally. So, 11:09:29
at 30n
converted to 24
becomes 11:09:23
. This function is likely to incur rounding errors.
'Literal' Conversion to Timecode 

TCFXM_NumericalText_To_TC 
This function takes a string of digits, treats them as a timecode and adds the missing colons or semicolons. For example, 23141520
becomes 23:14:15:20
. The result is always a full 11 digit timecode, as the input is 0padded.
Timecode Pull Down or Up 

TCFXM_TC_Pull_Down 
TCFXM_TC_Pull_Up 
These two functions only work with timecodes in 24, 25, 48 or 50 fps. They simulate the effect of conversion to and from dropframe timecodes  which don't exist for these rates. Primarily, these functions can help answer questions like how much real time has actually passed after playing 01:23:48:11
worth of footage at 23.98 fps?
Internally, the frame counts are multiplied by 1000 and divided by 1001, or vice versa. The subsequent rounding to whole frames incurs rounding errors.
Frame Rates
Count Type  Frames per Second 

Timecode
Seconds Frames 
24, 25, 30, 30n, 30d

n is for nondrop frame timecode, d is for drop frame timecode. If neither n or d is specified, n is assumed. Drop / nondrop timecode is determined solely by the rate parameter, the character used in the count (';', ':' or '.') is ignored.
Count Type  Frames per Foot 

Footage  16, 20, 40

The plugin will ignore the separating character between feet and frames (+ or &). The number of frames in each foot is solely determined by the frame rate.
Count and Rate Combinations
The count and the rate have to fit together, otherwise the calculation is aborted, resulting in a '?' in FileMaker. The possible combinations are listed in the two tables above.
For example, a count of 17+12
can't have a format of 24
. (17+12
is a footage, a compatible rate would be 16
. A rate of 24
would be acceptable for any of: 00:23:11:09, 12.8, 442816
.)
Function Syntax in FileMaker Pro
Most of the listed parameters are mandatory, only the ones in curly braces '{...}' can be omitted.
Arithmetic
TCFXM_Add( count; rate; count{; rate} )
TCFXM_Subtract( count; rate; count{; rate} )
TCFXM_Multiply( count; rate; factor )
TCFXM_Divide( count; rate; divisor )
Notes:
 The result is formatted to match the first input count.
 Any combination of the 4 count types is permitted.
 For addition and subtraction the fourth parameter is optional. If it is not entered the rate of the first count is applied to the second count.
 The factor / divisor is a positive or negative either decimal or whole number.
 Multiplication and Division both incur rounding errors.
Format Conversions
TCFXM_To_Frames( count; rate )
TCFXM_To_TC( count; in_rate; out_rate )
TCFXM_To_Seconds( count; rate )
TCFXM_To_Footage( count; in_rate; out_rate )
Notes:
 The result's count type (obviously) depends on the function used.
 Any of the 4 count types can be used with any of the these four functions.
Timecode Conversions
TCFXM_TC_ConstantTime_Convert( count; in_rate; out_rate )
Notes:
 This function only takes timecode as a count.
 Internally the timecode is converted into seconds. The subsequent rounding to whole frames incurs rounding errors.
TCFXM_TC_Pull_Up( count{; rate} )
Notes:
 This function only takes timecode as a count.
 Internally, the frame counts are multiplied by 1001 and divided by 1000. The subsequent rounding to whole frames incurs rounding errors.
 The rate has to be one of
24, 25, 48
or50
. Otherwise the function fails and yields '?'.  If the second, optional rate parameter is omitted the default of
24
is assumed.
TCFXM_TC_Pull_Down( count{; rate} )
Notes:
 This function only takes timecode as a count.
 Internally, the frame counts are multiplied by 1000 and divided by 1001. The subsequent rounding to whole frames incurs rounding errors.
 The rate has to be one of
24, 25, 48
or50
. Otherwise the function fails and yields '?'.  If the second, optional rate parameter is omitted the default of
24
is assumed.
Text to Timecode
TCFXM_NumericalText_To_TC( count; rate )
Notes:
 This function only takes positive numbers with 1 to 8 digits as a count, e.g.
01120023
, resulting in01:12:00:23
.  The frame rate has to be suitable for timecodes.
 If the count has fewer than 8 digits, zeros are added to the head of the number. Thus,
2312
becomes00:00:23:12
.
TCFXM_To_TC and TCFXM_TC_ConstantTime_Convert compared
The fundamental difference between TCFXM_To_TC and TCFXM_TC_ConstantTime_Convert is that the former preserves the frame count, and the latter preserves the running time.
With an input of count: 10:10
in_rate: 24
out_rate: 30
, here is what happens:
Function  Result  Methodology 

TCFXM_To_TC  00:00:08:10

10*24 frames + 10 => 250 frames
250 divided by 30 => 8 seconds, 10 frame remainder 
TCFXM_TC_ConstantTime_Convert  00:00:10:13

10 + 10/24 secs => 10.416667 secs
10.41667 * 30 fr => 10 secs 12.5 fr 12.5 fr rounded up to 13 
Value Overflows
Whenever timecodes are entered using impossible values, such as 00:80:00:00
, where 80 minutes are not strictly 'legal', the plugin converts to a proper output. In this case, that would be 01:20:00:00
.
For frames, seconds and minutes this behaviour produces results that are equivalent to the overflowing values. Above, 80 minutes are exactly the same as 1 hour and 20 minutes.
This also works for feet & frames, e.g. an entry of 150+48
at 16
is not strictly correct, because a foot only has 16 frames. The plugin turns the 48 frames into 3 feet, for a result of 153+00
.
Timecodes Beyond Midnight
When timecode hours flow over, the real value would be in the next day, so to speak: a timecode value of 29:00:00:00
could be thought of as 1 day and 5 hours. However, since there is no day count in timecode, the extra day is simply omitted. Thus, 29:00:00:00
simply becomes 05:00:00:00
.
When 'crossing midnight' in the other direction, e.g. by subtracting 12:00:00:00
from 08:00:00:00
, the result would be a negative timecode (here: 04:00:00:00
). The plugin instead converts to the corresponding value 'on the previous day'. Here that would be 20:00:00:00
, i.e. 4 hours before midnight.
Usage Hint
When you enter a calculation in FileMaker and you want to use a function from the TCFXM TimeCode Plugin, you can follow these steps to save some typing work:
 get to the window titled 'Specify Calculation'
 press the tab key until you reach the search field
 type 'TC' on the keyboard
 the function list now only shows the functions from the plugin, and it's easy to doubleclick the one you want to use.
Alternatively, you can just enter 'TC' in the calculation field, and use FileMaker's text completion feature. Use arrowup and arrowdown to select the function you want and press return.
Plugin Version Check
To check the version of TCFXM that is currently installed, open FileMaker's Preferences window. Under the 'PlugIns' tab, click the line 'TCFXM Timecode PlugIn' so that it is highlighted. The version number will be listed under the text field.