midi transpose

MidiTranspose

#example #midi #simple

MIDI note transposition utility.

Module Name	midi transpose
Type	mtSimple
Color	clMIDIModuleColor
Source	examples/MidiTranspose/

Description

Transposes incoming MIDI note messages by a specified number of semitones. Demonstrates MIDI event processing using TUsineMidiCode and array-based MIDI access.

Parameters

#	Name	Type	I/O	Range	Details
0	in	ptMidi	Input	—	MIDI input stream
1	out	ptMidi	Output	—	Transposed MIDI output
2	pitch	ptDataFader	Input	-127 – +127 ht	Transposition amount (IsStoredInPreset)

How It Works

In onProcess:

1. Copies MIDI input to output
2. Iterates through each MIDI message in the event
3. For NOTEON and NOTEOFF messages, adds the pitch offset to Data1 (note number)
4. Clamps the result to 0–127

for (int i = 0; i < size; i++)
{
    TUsineMidiCode code = midiOut.getArrayMidi(i);
    if (code.Msg == MIDI_NOTEON || code.Msg == MIDI_NOTEOFF)
    {
        int note = code.Data1 + (int)pitch;
        code.Data1 = std::clamp(note, 0, 127);
        midiOut.setArrayMidi(i, code);
    }
}

Key Concepts Demonstrated

• ptMidi parameter type for MIDI streams
• TUsineMidiCode structure: Channel, Msg, Data1, Data2
• getArrayMidi / setArrayMidi for MIDI event access
• MIDI constants: MIDI_NOTEON, MIDI_NOTEOFF
• Process-driven module (no callbacks needed for the main logic)
• IsStoredInPreset for pitch offset persistence

SDK Callbacks Used

onGetModuleInfo · onGetParamInfo · onProcess

Related Examples

• DataMultiply — Simple data processing
• AudioVolume — Audio stream processing

SDK Reference

• UserModuleBase Class