Can i filter midi messages (clock , sysex) with pipes?

[GVCompu]

I want to pipe incoming midi from serial to usb or other serial , and meanwhile filter midi messages at the incoming port (or outgoing)
Is there way to do that?

Kind Regards

[tttapa]

Yes this is supported, see https://forum.arduino.cc/t/midi-filter-processor-sketch/1115459/4?u=pieterp for an example.

[rommil67]

A very helpful example. I used it to modify it a bit
By the way, I will ask if my code modification is good? is supposed to change all noteON/noteOff on channel 1 to channel 3 and work on uno / Nano.

//Arduino MIDI-filtr
#include <Control_Surface.h>

 // Instantiate a MIDI over USB interface.
//USBDebugMIDI_Interface midi;
//HardwareSerialMIDI_Interface midi;
HardwareSerialMIDI_Interface midi = Serial;
//HardwareSerialMIDI_Interface midiser = Serial;
//HairlessMIDI_Interface midi;
//USBDebugMIDI_Interface midi;
 
// A unidirectional pipe that connects a MIDI source to a MIDI sink.
// Messages coming from the source are handled by the `mapForwardMIDI()`
// function, where they can be modified or filtered out, and then sent
// to the MIDI sink by calling the `sourceMIDItoSink()` function.
struct MyMIDIFilter : MIDI_Pipe {
  // Pass on only Note On/Off messages, changing the channel to 5 and
  // transposing all notes an octave down.
  void mapForwardMIDI(ChannelMessage msg) override {
    switch (msg.getMessageType()) {
      case MIDIMessageType::NoteOff:  // fallthrough
      case MIDIMessageType::NoteOn:
      if (msg.getChannel() == (Channel_1))
        msg.setChannel(Channel_3);
        //if (msg.data1 >= 12) // zakomentowana transpozycja
        //  msg.data1 -= 12;
        sourceMIDItoSink(msg);
        break;
      default: break;
    }
  }
  // Do not pass on System Exclusive messages

[tttapa]

@rommil67 although the indentation is a bit misleading, and the behavior doesn't match the comments in the code, it does look okay. Note that it will not pass on any messages besides Note On/Off.

[rommil67]

thanx pon., 12 lut 2024 o 19:18 Pieter P ***@***.***> napisał(a):

…

@rommil67 <https://github.com/rommil67> although the indentation is a bit misleading, and the behavior doesn't match the comments in the code, it does look okay. Note that it will not pass on any messages besides Note On/Off. — Reply to this email directly, view it on GitHub <#964 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AV4MWEDT4CDY7XYGKXHU3W3YTJMHVAVCNFSM6AAAAAA55GRVB2VHI2DSMVQWIX3LMV43SRDJONRXK43TNFXW4Q3PNVWWK3TUHM4DINBVGE2TA> . You are receiving this because you were mentioned.Message ID: ***@***.***>