FIR filter Plugin is a XMMS effect plugin that allows filtering of audio data through long FIR filters.
The plugin uses the fftw3 library to perform filtering using the overlap-and-add method. If fftw3 is not available, the plugin will perform filtering (convolution) in the time-domain, which is much less efficient for long filters.
To use the plugin, simply open the preferences in XMMS using CRTL-P and select the Effect Plugins tab. From there, enter the path to the filter coefficients file in the "Filter coefficients file" field and press "Apply" or "Ok" button. Additionally, there is a Filter Gain control for users to adjust the filter gain from 0.1 to 9.9.
Users should note that if the filter gain is too high, the audio signal may clip when the audio data is converted from floating-point to PCM data. It is recommended to analyze filters in tools like Octave or Matlab.
The plugin also offers code for users to examine their filters further. The filter file format is a text file with filter taps in floating point format, and it is assumed that the filter weights are stored column wise in a text file.
Unfortunately, the plugin can only read one filter at a time, and there is no error checking when reading the filter file. However, the FIR filter Plugin is an excellent tool for filtering audio data using long FIR filters. Overall, it offers a powerful solution for loudspeaker and room equalization.
Version 1.0.0: N/A