Fourier - Live Frequency Analysis of Sound Data

What Is It?

Fourier does a realtime frequency analysis of recorded sounds and displays it. The application is intended to run on the OpenMoko FreeRunner, but will also work for different Openembedded devices and different mobiles / PDAs or computers (if compiled from source).


You can download an .ipk package that runs at least in FDOM:
fourier_1.1_arm.ipk (24 KB)
Or compile it from source: fourier-1.1.tar.gz (4.6 KB)


Changes in version 1.1: fourier now automatically loads the (correct) mixer settings from /etc/fourier/fourier.state (and also restores the previous settings after quitting).

Needed Libraries

Fourier uses libsdl for graphics output and libfftw3 for the frequency analysis. You need to additionally install libfftw3 for FDOM, a suitable package can be downloaded here:
libfftw3-3_3.1.2-r1_armv4t.ipk (8.5 KB)
(obtained from


If you only get a black screen with the white update line running down, it is very likely that the mixer is not setup correctly to use the built-in microphone of the FreeRunner. In this case, you can try to load capturehandset.state via alsa (alsactl -f capturehandset.state restore). It is possible that you already have the file on your device.


Copyright (C) 2009 Christian Reitwießner
This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program; if not, see