In most cases it's easier to use pre-built binaries, which are available for
Windows and for several major Linux distributions from the main download page:
http://mp3diags.sourceforge.net/010_getting_the_program.html
Build instructions for Windows are at:
http://mp3diags.sourceforge.net/unstable/010_getting_the_program.html#sourceWindows
Build instructions for Linux / others are at:
http://mp3diags.sourceforge.net/unstable/010_getting_the_program.html#sourceGeneric
Basically, you should run BuildMp3Diags.hta on Windows and Install.sh elsewhere.
Note that even if there is a CMakeLists.txt, CMake isn't officially supported.
If it works for you - fine. If it doesn't - you're on your own.