(E-Mail Removed) (Aaron) wrote in message news:<(E-Mail Removed). com>...

> (E-Mail Removed) (Doublehp) wrote in message news:<(E-Mail Removed). com>...

> > I have to build an ISO with only two specs:

> > - I have to know where is a given file, I mean, I have to know how far

> > from the center of the CD is a particular file

> > - the file has to be alone in that zone.

> >

> > I can choose what ever I want to do that: ISO, Joliet, or what ever.

> >

> > Since I expect a CD to have interlaced sectors like a HDD, I think

> > that the easiest way is to declare two white 50M files, one before and

> > one after, and build the raw image using the UNIX tool mkisofs.

> >

> > Then remain two questions :

> > - how to know where will be located the given file (on which circle it

> > will be burnt - how far from the center will it be )

> > - how to make sure no file will overlap that zone (how to make sure

> > only the two white files will be wixed in the same circles than the

> > given file)

> >

> > Thanks for help.

>

> You could just use a simple ratio to do the job. For example, if you

> want the file half-way out from the middle, then you figure out the

> ratio of the area of a circle to the area of a circle with half that

> diameter. Then you will know how much "white file" to put on each

> side of your real file, and it should go in the correct place.

>

> Aaron
Whoa, looks like you (doublehp) accidently cross posted. Here is your

quote:

> that does not look possible because the spread of a file is not linear:

> the middle of the disk do not contain the middle of the ISO ... I know

> that it is a very complex equation ... the middle of the ISO is near the

> outside border ...

>

> doublehp
Well, I don't think that it is so complex. It should be fairly

similar (in fact, derived from) the formula for the area of a circle:

(pi)(r)^2=(area)

So, let's do an example: You want a track burned 1/3 out from the

middle (measuring from where the data starts). Use a ruler, and find

out how far from center of CD that is. Find the area using that

radius, and then subtract the area of the middle of the CD (the

"hole"). Thus, after subtracting the two, you have the "area" of data

that you will need before your track. We will call this area1.

Next you need to figure out the area of the data you need after your

track. This is similar to the above. First, find out the total area

of the disk, and then subtract from that the area of the "hole". Also

subtract the area of the data before your track, and then you will

have the second of your two numbers. We will call this area2.

Now we want those in ratio. So put it like this area1:area2

For 1/3, I guessing maybe...well, I don't know, and I don't have the

correct tools here with me at school to try it out, so you're on your

own.

Anyway, with your ratio, just make two of your "white files" with

proper lengths so as to fill the CD (that's important--CD must be

filled for track to be in proper location), keeping in mind that they

have to be in ratio also. That should about do it.

Hope it's understandable,

Aaron