I don't think there is a dependency on libfaac. Here is what I got when I
typed dpkg --info avidemux_2.5.2-0ubuntu3_amd64.deb (I downloaded the Debian
package from Ubuntu's website in the Lucid section as I'm using Trisquel
Taranis):
Depends: libatk1.0-0 (>= 1.29.3), libavidemux0 (>= 1:2.5.2), libc6 (>= 2.4),
libcairo2 (>= 1.2.4), libfontconfig1 (>= 2.8.0), libfreetype6 (>= 2.2.1),
libgcc1 (>= 1:4.1.1), libglib2.0-0 (>= 2.14.0), libgtk2.0-0 (>= 2.18.0),
libpango1.0-0 (>= 1.14.0), libsdl1.2debian (>= 1.2.10-1), libstdc++6 (>=
4.4.0), libx11-6 (>= 0), libxext6 (>= 0), libxml2 (>= 2.7.4), libxv1,
avidemux-common
Avidemux-common doesn't depend on any other package (I also downloaded the
pacakge avidemux-common_2.5.2-0ubuntu3_all.deb), so you should be able to
install both of these packages without libfaac.
I also requested this package in the past. Let's hope it gets added to the
repositories.