Jeremy Salwen has released a Linux LV2 version of St3pan0va's kn0ck0ut plug-in.

Kn0ck0ut-LV2 is an LV2 plugin to perform spectral subtraction. It can be used to achieve a wide variety of effects, most notably removing or extracting the center of a two channel audio file. As Kn0ck0ut is only a plugin, you will need a host for LV2 plugins in order to use it, such as Ardour, Qtractor, Igen, lv2_jack_host, or lv2file. It requires lv2-c++-tools, lv2core, and fftw3 to build.

kn0ck0ut-LV2 is released under the terms of the GPL version 3 (with the permission of st3pan0va).

In addition to the features of the original Kn0ck0ut, Kn0ck0ut-LV2 features:

• Improved performance through use of FFTW and more efficient buffering code.
• Completely variable FFT size and overlap amount controls.
• Experimental "Phase Compensation" option, which will perhaps preserve additional fidelity in certain cases.
• Restored Low-cut filter which was removed in later releases.