$ cd ~/ffmpeg_sources
$ wget http://www.tortall.net/projects/yasm/releases/yasm-1.3.0.tar.gz
$ tar xzvf yasm-1.3.0.tar.gz
$ cd yasm-1.3.0
$ ./configure --prefix="$HOME/ffmpeg_build" --bindir="$HOME/bin"
$ make
$ make install
$ make distclean
$ export "PATH=$PATH:$HOME/bin"