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NeroLINUX Advanced functions •

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the filename replaced by '$file'. Do not forget to include the quotation marks as

well. These are required in case the filename of your file contains spaces.

You must then parse the output of your program. Apart from a few mathematical

functions like abs, int, sqrt, sin, cos, tan and C-Style boolean operators,

NeroLINUX supports two powerful ways of retrieving your command line tool's

output:

 getpos(y,x)

 regexp('regular expression').

As the latter will always produce strings as its function result, you have to use the

strval('string') function to convert a string to a number. The basic idea of this

whole concept is that you can assemble the track length in Bytes from the output

generated by your external program using some mathematical function. For

example, if your command line tool will generate the following output if called with

tracksizetool -filename '$file':

Playing time of file '/home/ghost/something.ext' is

00 Hours, 2 Minutes, 23 Seconds, 43 Frames

You can use the getpos() function to calculate the track size. To understand what

this function does,, imagine the output generated by tracksizetool as a grid of

numbers: getpos(3,1) will return '00' in our example. getpos(3,2) will return '2' and

getpos(3,3) will return '23'. Generally, getpos(y,x) will return the x-th number in

the y-th line of output. Consequently, we can get the number of frames with

getpos(3,4).

One frame is 1/75th of a second and 2354 Bytes of audio data. So if you know all

you need to know about our file now: the following function will resolve to our

track size in Bytes (for the 44.1kHz,16 Bit, Stereo stream required by

NeroLINUX):

((getpos(3,1)*3600+getpos(3,2)*60+getpos(3,3))*75+getpos(3,4))*2354

Enter this line into the last field of your file type registry entry and the process is

complete. On the other hand, not all command line tools will create output

parseable by the getpos(y,x) function. In this case, you need to use the regexp()

function. Suppose our output will look something like:

Playing time of file '/home/ghost/some08minuteslongfile.ext' is 00:08:03.23

This is an example of a particularly awkard filename as it contains numbers as

well and will confuse getpos() when retrieving the different parts of our playing

time. So you use a regular expression for this. The result of the regexp('exp')

function is always the first part of the expression put into brackets, e.g.

regexp('.*:([0-9]*):.*') will return the minutes part of our playing time for the output

above as a string. Pass this through the strval() function and you have what you

want. For the example above, the track size calculation function will read

something like this:

((strval(regexp('.* is ([0-9]*):[0-9]*:[0-9]*.[0-9]*$'))*3600+strval(regexp('.* is [0-

9]*:([0-9]*):[0-9]*.[0-9]*$'))*60+strval(regexp('.* is [0-9]*:[0-9]*:([0-9]*).[0-

9]*$')))*75+strval(regexp('.* is [0-9]*:[0-9]*:[0-9]*.([0-9]*)$')))*2354