debdiff for v3 source packages with multiple tarballs?

[Matthias Klose <doko@ubuntu.com>]

I was looking at http://patches.ubuntu.com/o/openoffice.org/, a 133MB "patch" 
for OOo. Afaiu the diff is cause by updating the ooo-build tarball from
openoffice.org_3.2.1.orig-ooo-build-3-2-1-2.tar.gz
to openoffice.org_3.2.1.orig-ooo-build-3-2-1-3.tar.gz. The tarballs are unpacked 
into two different directories
 ooo-build-3-2-1-2
 ooo-build-3-2-1-3
and debdiff isn't able anymore to show a meaningful diff.  Is there any way to 
decouple the name of the tarball and the directory name where the tarball is 
unpacked? Or is there a way to create a more meaningful diff?

thanks, Matthias