This is a simple console utility that takes audio from the default input and displays a bouncy PSD, in curses!
It requires pthreads, fftw3, portaudio and ncurses. And clang
To install:
    make
    sudo make install
And to uninstall:
    sudo make uninstall

On MacOS development was tested using the macports system.
On FreeBSD, use gmake, not the regular make.
On Windows 7 and 10 (8 untested) the MinGW64 system was used. This has 3 targets, 32bit, 64bit and msys.
32bit and 64bit work when the fftop binary is renamed fftop.exe and then run from a cmd.exe console.
Appears to compile on OpenBSD, but does nothing. I suspect I just haven't got recording enabled correctly...


KNOWN ISSUES
===== ======
gmake tar on *BSD probably broken - use gnutar
Using the lprintf logging reveals dropouts in the buffers. I suspect this is because the display thread is at
normal priority and overloads. The usleep() value could be better tuned.
Rapid resizing of the Xwindow fftop is running in can result in a mismatch between the buffer sizes and the
quantity of data inserted - resulting in a crash. So don't do that.


TODO
====
Add some command line configuration for sound input, fft size, update delay, sample rate, AGC, decay rate,
colors, raw or 10*log10 display and so on.


MISC
====
To make a portable binary on MacOS, use static libraries:
    /opt/local/lib/libncurses.a
    /opt/local/lib/libfftw3.a
    /opt/local/lib/libportaudio.a
And system frameworks:
    -framework CoreFoundation
    -framework AudioToolbox
    -framework CoreAudio
    -framework CoreServices