So thats a mess, ok. I found out that the stable versions require more modern FFMPEG as Ubuntu 9.10 provides. The solution is to use an older package then.
you need to download a version not younger than aegisub-2.1.6-dev-r2740.tar.gz (Revision 2740) from February 18th 2009 from
http://www.mahou.org/~verm/aegisub/archives/
and can confirm that this can include newest FFMPEG. For those who still dont know: There is no ffmpeg-dev, but you have to install different libraries -dev packages(most start with libav, I think essential should be: libavformat-dev and libavcode-dev) and also libhunspell-dev (HUNSPELL) for spell checking.
So my recommendation for Ubuntu to date is NOT to use the SVN version. I dont know why the require such new version of FFMPEG. It makes building unnecessary hard in my opinion.
I also installed these packages: ruby1.8-dev (otherwise you get “auto4_ruby.h:48:18: error: ruby.h: No such file or directory“), libperl-dev,…
Then you can enter directory and type
./configure ./make
And if that works ok:
sudo make install
That worked for me. If I missed soemthing ot you have questions pleas comment. And sorry I am not up to package building, yet. If a newer version works I will update this page, also.