Install build & documentation dependencies: autopoint, autoconf, libtool, gettext, doxygen, graphviz. And needed libraries: libmad, libogg, libvorbis, libid3tag, libflac. Example on a Debian-like system:

sudo apt-get install autopoint autoconf libtool gettext doxygen graphviz libmad0-dev libogg-dev libvorbis-dev libid3tag0-dev libflac-dev

To compile libmp3splt, go inside the libmp3splt directory and type the following commands:

mkdir target
./autogen.sh
./configure --prefix=`pwd`/target
make
make install

Once libmp3splt is compiled, go inside the newmp3splt directory and type the following commands:

export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:`pwd`/../libmp3splt/target/lib/pkgconfig/
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:`pwd`/../libmp3splt/target/lib/ # needed for running the final executable
./autogen.sh
./configure
make

mp3splt executable can be found in newmp3splt/src/mp3splt.

Install needed development files for audacious, gstreamer, gtk-3, libaudclient & libdbus-glib Example on a Debian-like system:

sudo apt-get install audacious-dev libgstreamer1.0-dev libgtk-3-dev libaudclient-dev libdbus-glib-1-dev

Make sure to compile libmp3splt before this step. Once libmp3splt has been compiled, go inside the mp3splt-gtk directory and type the following commands:

export PKG_CONFIG_PATH=$PKG_CONFIG_PATH:`pwd`/../libmp3splt/target/lib/pkgconfig/
export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:`pwd`/../libmp3splt/target/lib/ # needed for running the final executable
./autogen.sh
./configure
make

mp3splt-gtk executable can be found in mp3splt-gtk/src/mp3splt-gtk.