Custom (S)VCD XML Editing

[Amey]

Hi Guys!
I need some help with XML descriptor file understanding & editing.
I created a VCD image with NeroVision Express 2 and then created a XML file of it with VCDImager Tools GUI so as to learn & be able to create customised VCDs. But I'm facing a problem with the "selection" part under the "pbc" section.
I'm giving a sample XML file as an attachment:
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If you observe the part under "pbc" you will see that it contains "x1, y1, x2 & y2" variables at many places. I have an idea that these variables probably are representing certain co-ordinates for "Hotspots" on the chapter selection menu/s. I need to know what exactly they stand for and how are their values determined there? So that I maybe able to create my custom/additional menus similarly.

What I know:
NeroVision Exoress 2 uses the background images(*.jpeg) of size 768 X 576(for 4:3 aspect ratio menu) originally. But according to my calculations, the values in the XML file probably point to co-ordinates on an image roughly of size 256 X 255 so as to locate (the area of) a supposed "hotspot". But I cannot be sure about it as yet.

What I need to know:
If my idea is correct then what exact size of background image must I consider (according to which the values for x1, y1, x2 & y2 are determined for any menu for direct/final entry in the XML file)?
And if my idea is incorrect then what exactly do the above mentioned variables signify and how are their values determined?

Thanx for your time in advance.

regards

[Amey]

Found the way!

Good Day!
I'm having found an answer replying to my own post for the sake of those who might be interested in making their own customized (S)VCDs with a good looking menu structure.

Indeed the XML decriptor file considers and points/locates the area of Hotspots on an image of size 255 X 255 regarless of the original size of the still menu image(which may be 704 X 480 & so on as prescribed at http://users3.ev1.net/~CavemanLawyer/).
So all those who like to watch their (S)VCDs on the PC using PowerDVD or WinDVD can now make use of these hotspots to make the necessary selections almost comparable to those in DVDs.
I'm attaching a reference XML descriptor file to help you understand how it goes.
So finally using NeroVision Express 2, VCDEasy and GNU VCDImager Tools GUI and of course partially following the guide at http://users3.ev1.net/~CavemanLawyer/ one can get a good menu structure.
It may be not as good looking as that created with "VideoPack" (which by the way I haven't tried yet). But possibly worth it for those who don't have VideoPack or equivalent menu making software.