BasicDSP is a program to apply simple Digital Signal Processing algorithms to audio signals. The input can either be taken from the sound card, read from a .WAV file, or be a locally generated sine wave or white noise. The output is fed to the sound card, and its spectrum can be displayed.

The DSP program is written in a very straightforward language which has only assignment statements (and on Linux a print statement). Each line contains one statement, and all lines are executed once for each incoming sample. The input sample is available in variables named 'in', 'inl' (left channel) and 'inr' (right channel). The program should write the output into variables named 'out', 'outl' and/or 'outr'.
Here's a simple example program:
a = a + slider1 * (in - a)
outl = a
outr = fir(in, 0.1, 0.3, 0.3, 0.1)

This illustrates defining new variables ('a' in the example), the use of the sliders, and the use of a built-in function like fir(). The help-menu gives access to a complete list of built-in variables and functions.