Welcome to XSpectrum, a very simple but fast audio spectrum for Linux + X11. You will need Linux 2.0.1 or newer to run XSpectrum (prior to 2.0.1 was a bug in the sound driver which prevent the use of memory mapped input). You will also need a 16 bits sound-card. I use an old SB16 firmware 4.5.
It works well, it's stable on my box, but its quiet limited about functionality. You can change sampling rate on the fly and freeze the current spectrum on the screen. You can't change the size of the display window, zoom in a particular area or the frequency range or output a frozen spectrum to printer. Those features will be added with time.
Starting with release 1.1, I use the EZWGL widget library. You must have a working EZWGL if you want to recompile XSpectrum. You can find EZWGL at http://www.ma.utexas.edu/~mzou/EZWGL/
xspectrum.c and fftbench.c are licensed under the term of GPL2 (file included), libdsp.c is registered with LGPL2 (also included).
To build:
You may edit the Makefile and change setting in the top part.
make xspectrum
make P5fftbench # if you want to measure timings of FFT algorithm on your
# CPU/compiler combination. Work only on intel P5, since it
# use the pentium cycle counter.
About xspectrum:
XSpectrum does 30 fps for 1024 pts R4 FFT (P5 90MHz) under X11 with a good VRAM graphic card, using double-buffering for flicker-free animation, 43 fps on a P5 166MHz
About P5fftbench:
I can do approx 1.8ms for a 1024 pts floating point (32bits) complex/complex R4 decimation in frequency FFT on a intel Pentium 90 MHz using pentium gcc 2.7.2, 1.1ms on a P5 166MHz
Pentium GCC can be found on http://goof.com/pcg/index.html
Enjoy,
Philippe Strauss, <philippe.strauss@urbanet.ch>