How can I use the fxlab effects code on a stereo buffer?

[Gilianp]

I am adapting the fxlab code to apply effects to pre-recorded audio clips instead of microphone input (similar to Drumthumper sample). It works well for mono audio. The problem arises when I need to use stereo audio since the fxlab effects code handles mono input. How can I modify the effects code to support stereo audio? I believe one solution is to instantiate two effects and apply them to each channel independently, but that would add overhead.