hey, for real-time live performance you really have to get a pedal that sends the MIDI CC#64 as standard; or you can have it assigned to some other button or knob in a physical MIDI controller.
in either case you must also reckon that it is actually the instrument or sound generator (eg. a synth) that must recognize and react to MIDI CC#64 properly--it actually depends on its own MIDI implementation and not quite dependant on qtractor which just conveys the MIDI event.
hey, for real-time live performance you really have to get a pedal that sends the MIDI CC#64 as standard; or you can have it assigned to some other button or knob in a physical MIDI controller.
in either case you must also reckon that it is actually the instrument or sound generator (eg. a synth) that must recognize and react to MIDI CC#64 properly--it actually depends on its own MIDI implementation and not quite dependant on qtractor which just conveys the MIDI event.
hth.
byee