I find the alembik transcode server a cool piece of software, but I found lots of caveats when started to use it.

The most difficult part is that alembik supports only two versions of libavcodec for ffmpeg, so you must compile it from the sources, since they are quite old.
That happens because ffmpeg changes the parameters from version to version and the alembik team had choosen both 51.40.4 and 51.48.0 to be supported. I think that in the future it will be possible to have an external “.properties” file, so I hope that it will not be necessary to compile ffmpeg by hand, every time.

I’ve used this references:
http://sourceforge.net/mailarchive/message.php?msg_name=48A176CC.8080300%40kimiasol.com (here i’ve found the rpm of a ffmpeg with libavcodec version 51.40.4 to download)
http://juliensimon.blogspot.com/2008/12/howto-compiling-ffmpeg-x264-mp3-xvid.html (this post teach how to install libamr from mediubuntu repository)

install both amr, you can install also from mediubuntu repo.

wget http://ftp.penguin.cz/pub/users/utx/amr/amrnb-6.1.0.4.tar.bz2
wget http://ftp.penguin.cz/pub/users/utx/amr/amrwb-7.0.0.1.tar.bz2
# apt-get install g++ nasm zlib1g-dev libx264-dev libfaad-dev faad liba52-0.7.4-dev libgsm1-dev libmp3lame-dev \
libtheora-dev libvorbis-dev libxvidcore4-dev libfaac-dev libimlib2-dev libfreetype6-dev

Use an aplication to convert the rpm to tar and decompress it (with alien or something else):

# wget http://dag.wieers.com/rpm/packages/ffmpeg/ffmpeg-0.4.9-0.9.20070530.rf.src.rpm

# ./configure --enable-libmp3lame --enable-libogg --enable-libvorbis --enable-libamr-nb --enable-libfaad --enable-libfaac \
--enable-libgsm --enable-xvid --enable-x264 --enable-liba52 --enable-liba52bin --enable-pp --enable-shared --enable-pthreads \
--enable-libtheora --enable-gpl --disable-strip --enable-libfaadbin --prefix=/usr/local --enable-swscaler --enable-libamr-wb

Install it as a package or with “make && make install” and settup alembik with “ffmpeg.version=51.40.4″