vgmrips

Hi all,
I am working on reducing the channels' polyphony of some MIDIs (e.g. from 4-note to 2-note) and was trying out the Nokia Sound Converter program from the 2004 Nokia PC Suite. Despite using the program's advanced mode to select the polyphony limit per channel, the channels in the resultant output MIDI file always retained their original polyphony limit.
Is there another MIDI utility or editor that can check and limit channel polyphony? Thanks in advance.