Follow these steps before you attempt to compile your FFmpeg:
0. Compile/install '''[http://lame.sourceforge.net/ libmp3lame]'''
0. See '''[[How to quickly compile libaacplus]]'''
0. See '''[[How to quickly compile libx264]]'''

In order to quickly compile your FFmpeg with the support for libraries '''libmp3lame''', '''libaacplus''' and '''libx264''', you can type the following commands in your shell:
{{{
# cd /my/path/where/i/keep/compiled/stuff
# git clone git://source.ffmpeg.org/ffmpeg.git
# cd ffmpeg
# ./configure --enable-gpl --enable-libx264 --enable-libmp3lame --enable-nonfree --enable-libaacplus
# make
# make install
}}}

P.S. If you are using Ubuntu, you'll most probably have to use sudo for the last 2 commands, like:
{{{
# sudo make install
# sudo ldconfig
}}}