Tool to produce A5 booklet from A4 pages PS / PDF

[Polytropon]

In order NOT to try to reinvent the wheel, I'd like to ask
if anyone knows a tool that does helps to produce a printable
and foldable booklet from A4 pages.

I'm searching for a tool that scales down and reorders A4
pages (from a document, usually PS or PDF) in a way that
the result can be printed with a duplex printer (content
on both sides of the paper sheet) and then be folded in
the middle in order to get a "book" (or let's better call
it a booklet) in A5 format. Additionally, the booklet
can be stapled where it has been folded (using the proper
mechanical tool).

Of course, this just seems useful for standard A paper
formats (A4 / A5) which keep the aspect ratio sqrt(2)
(or nearly 1.414:1) even after folding or combining:

	       A4
	+------++------+
	|      ||      |
	|  A5  ||  A5  |
	|      ||      |
	+------++------+

Illustration here:
http://upload.wikimedia.org/wikipedia/commons/8/8a/A_size_illustration.svg

Depending on the "real" page number, it would require to
completely re-order and rotate (90 or 270 degree) the
contained pages, depending where they will appear on the
result paper.

For example, page 1 needs to be placed on page 1, top,
rotated 270 degrees, while the lase page also has to be
placed on page 1, bottom, rotated 270 degrees. Page 2
will be on page 2 (which is the rear side of page 1),
top, rotated 90 degrees... and now my imaginary force
is failing. :-) All pages have to be scaled down to
50% of their original size, of course.

In ideal case, the number of pages to be processed this
way is modulo 4, because 4 pages go to one sheet (two
per side).

So basically, I'm searching for a program that does the
renumbering and rotation magic, provided PS or PDF files
as input, and also as output.

What tool can you suggest to do so?



Sidenote: Since my system crashed in July 2008, I can't
access my home directory anymore (inode missing, content
still on disk). I wrote a program that does all this for
image files as input - creates a LaTeX document that
includes the properly rotated and scaled images so you
can print from a stack of images and result in a happy
little booklet - jpg2tex, pdflatex, lpr. I don't want
to do this again... :-(



-- 
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...