Three Channel (or N Channel) support

[bitlab]

Trifield in CamillaDSP could be possible, could look something like:

   

The input gains of the mixer DIV are the equivalent of the original potentiometers and the image width control. 
Also prob need an all pass filter between mixer MS and mixer DIV on the S signal as mentioned in the original article about the Trifield conversion.

You can try it out with CamillaDsp on the command line. Use raw 2 channel audio input file and generate a raw 3 channel output file.