NAME

basicdsp —

DSP demonstration program

SYNOPSIS

A program for experimenting with simple audio DSP algorithms.

DESCRIPTION

BasicDSP is a program to apply simple Digital Signal Processing algorithms to audio signals. The input can either be taken from the sound card, or be a locally generated sine wave, white noise or impulse signal. The output is fed to the sound card, as well as to a virtual oscilloscope and spectrum analyzer.

The DSP algorithm itself is specified in a very straightforward programming language which has only assignment statements (and on unix 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', 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.

Note: the program was originally written to accompany a series of articles on Software-Defined Radio appearing in the Dutch amateur radio journal ´Electron´. Another tutorial appeared in the December 2007 issue of SPRAT.

PROJECT WEBSITE, DOCUMENTATION

http://wwwhome.cs.utwente.nl/~ptdeboer/ham/basicdsp/

AUTHORS

Pieter-Tjerk de Boer, Niels A. Moseley