This is by no measure an authoritative guide to building ffmpeg for OSX (including XServes) but it was how I got it done. I could not use the binary that is floating around because (although it says it does) it does not support 3gpp.
You must have subversion installed, a good SubVersion installer for OS X is at codingmonkeys.
Building ffmpeg
Prerequisites
curl -O http://download.videolan.org/pub/videolan/libdca/0.0.2/libdca-0.0.2.tar.gz
tar zxvf ./libdca-0.0.2.tar.gz
cd libdts-0.0.2/
./configure
make
sudo make install
cd ..
curl -O http://kbs.cs.tu-berlin.de/~jutta/gsm/gsm-1.0.12.tar.gz?
tar zxvf ./gsm-1.0.12.tar.gz
cd gsm-1.0-pl12/
vi Makefile
sudo make install
curl -O http://downloads.xiph.org/releases/ogg/libogg-1.1.3.tar.gz?
tar zxvf libogg-1.1.3.tar.gz
cd libogg-1.1.3
./configure
make
sudo make install
cd ..
curl -O http://downloads.xiph.org/releases/vorbis/libvorbis-1.1.2.tar.gz?
tar zxvf ./libvorbis-1.1.2.tar.gz
cd libvorbis-1.1.2
./configure
make
sudo make install
cd ..
#curl -O http://downloads.xvid.org/downloads/xvidcore-1.1.2.tar.gz?
#tar zxvf xvidcore-1.1.2.tar.gz
#cd ./xvidcore-1.1.2/build/generic
#./configure
#make
#sudo make install
#cd ../../..
/usr/local/bin/svn co svn://svn.videolan.org/x264/trunk x264
cd x264/
./configure
make
sudo make install
cd ..
#(NOTE the tar file below has a broken configure file. Hopefully by the time this needs to be done again it will be fixed. If it is not – you will need to edit the ./configure file once it is built – just after the autoconf command. Open .configure with vi and find the line that starts with ac_config_files= you will see some misrepresented line feeds – fix them and you are set.)
curl -O http://nchc.dl.sourceforge.net/sourceforge/faac/faac-1.25.tar.gz?
tar zxvf ./faac-1.25.tar.gz
aclocal -I .
autoheader
glibtoolize –automake
automake –add-missing
autoconf
./configure –with-mp4v2
make
sudo make install
cd ..
#(NOTE way to make my life difficult – this installer is broken too)
curl -O http://nchc.dl.sourceforge.net/sourceforge/faac/faad_src_20020104.tar.gz?
mkdir faad
cd faad
tar zxvf ../faad_src_20020104.tar.gz
aclocal -I .
autoheader
glibtoolize –automake
automake –add-missing
autoconf
./configure
make -j2
sudo make install
cd ..
#Download from SVN
/usr/local/bin/svn checkout svn://svn.mplayerhq.hu/ffmpeg/trunk ffmpeg
cd ffmpeg/
#Install the stuff for 3gpp transcoding to work
curl -O http://www.3gpp.org/ftp/Specs/archive/26_series/26.073/26073-510.zip?
unzip ./26073-510.zip
rm -f 26073-510.doc
mkdir libavcodec/amr
cd libavcodec/amr
unzip ../../26073-510_ANSI-C_source_code.zip
cd ../..
rm -f ./26073-510.zip ./26073-510_ANSI-C_source_code.zip
curl -O http://www.3gpp.org/ftp/Specs/archive/26_series/26.104/26104-510.zip?
unzip 26104-510.zip
rm -f 26104-510.doc
mkdir libavcodec/amr_float
cd libavcodec/amr_float
unzip ../../26104-510_ANSI_C_source_code.zip
cd ../..
rm -f ./26104-510.zip ./26104-510_ANSI_C_source_code.zip
curl -O http://www.3gpp.org/ftp/Specs/archive/26_series/26.204/26204-510.zip?
unzip ./26204-510.zip
rm -f ./26204-510.doc
mkdir libavcodec/amrwb_float
cd libavcodec/amrwb_float
unzip ../../26204-510_ANSI-C_source_code.zip
cd ../..
rm -f ./26204-510.zip ./26204-510_ANSI-C_source_code.zip
#configure
./configure –enable-pp –enable-swscaler –enable-a52 –enable-dts –enable-faac –enable-faadbin –enable-libgsm –enable-mp3lame –enable-libogg –enable-vorbis –enable-x264 –enable-amr_nb-fixed –enable-amr_nb –enable-amr_wb –enable-amr_if2 –enable-gpl
#and then install
make
sudo make install

Thank you soooo much! I was tearing my hair out trying to get FFmpeg to compile! You are a godsend!
I’m trying to run this command with ffmpeg extracted from FFmpegX:
ffmpeg -threads 6 -i “32775808.avi” -y -s 480×360 -aspect 4:3 -r 30000/1001 -vcodec libx264 -b 1200k -maxrate 4096k -level 21 -qmin 10 -qmax 51 -acodec libfaac -ar 48000 -ac 2 -ab 128k -title “Titulo” -flags +loop -cmp +chroma -me_range 16 -g 300 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -rc_eq “blurCplx^(1-qComp)” -qcomp 0.6 -qdiff 4 -coder 0 -refs 1 -bufsize 4M -partitions +parti4×4+partp8×8+partb8×8 -subq 5 -f mp4 “output.mp4″
But for some reason don’t work, I try to build my own FFmpeg with this guide but I get many issues.
I have OS X 10.5.5 Leopard and want to build a full FFmpeg binary, a standalone that don’t need external libraries, like FFmpegX.
I have ben able to build in linux with this guide:
http://code.google.com/p/vs4p/wiki/BackEndApps
but again, this guide makes many files and I want to make just one single FFmpeg file, in Linux or Mac (unix)
thanks a lot for your help.