I'm heared you , and yet , but I do tested this in OpenMPT RETRO (x86) 32 bit Version 1.33.00.06-r23542 RETRO TEST , and if I open MIDI file in this tracker and play opened file , I recive music on Microsoft GS Wavetable Synth or generated sounds of GM.dls thus I understand that core OpenMPT can read and play MIDI files , but this core can not select output MIDI device , that's why I again ofer you add this option in LibOpenMPT as option MIDI output , as this make with samplerate , channels , interpolation , repeat , volume , the only thing this must be different , this two feature :
1) request list MIDI devices in system as this does in OpenMPT in Options -> MIDI -> MIDI Recording -> MIDI input device :
only in my offer need in libOpenMPT -> MIDI -> MIDI playing -> MIDI output device in xmp-openmpt.dll and openmpt-mpg123.dll , but for correct play MIDI with transmite MIDI stream to external MIDI devices or Virtual system port for example LoopMIDI for VSTi hosts , need
2) generate feedback silence stream for XMPlay with 48000 hz / 32 bit then user recive function play MIDI files via LibOpenMPT with function select transmit MIDI stream to external or virtual device , and also user recive functions rewind , pause and stop MIDI files in XMPlay and other players in whitch not support MIDI format or this does not fully or not correct

Please , not angry to me , I want help improve functions and in LibOpenMPT plugin , and solve with XMPlay via improved LibOpenMPT plugin

Unfortunately, I cannot go here https://forum.openmpt.org/ that’s why I'm writing through the bug tracker

Somehow I was able , please excusme , now duplicate topic on forum https://forum.openmpt.org/index.php?topic=7457.0