Libfilth - (c) 2004 Anders Johansson


Libfilth is a library for designing, analysing, transforming and executing digital FIR and IIR filters. Several examples of how to use the library are found in the manual. The library is available under the GPL, except for the file qld.c, see COPYING.

For installation see INSTALL.

The filter design methods include:


Reference manual
API Reference


Remove dependency on other libraries (work begun) and find GPL compatible implementation of quadratic programming solver.


Version 0.1 released 2004-04-10

The first 13 design methods were written by Anders Johansson in 2003-2004 as part of course in advanced digital filter design at the Blekinge Institute of Technology in Sweden.

DFT Filterbanks were added for fun, at the release date it was the only properly debugged part of the library.

Version 0.2 released 2004-04-26

IIR Filter design debugged, problems with passband gain errors for Elliptic and Chebyshev fixed. A new design method for analog Bessel-Thomson filter added.

Version 0.3 released 2004-05-13

IIR Filter transformation added and analog filter representation reworked. Allpass realisation of IIR filter debugged.

Version 0.4 released 2004-05-23

Doxygen generated API documentation added. Major cleanup of unused functions and spell check of all source files.

Submitting patches and complaints

diff -Naur > patch.diff mail it to me