Reads input from multiple Midi input devices via plug&play and sends them to an Axoloti

README.md

Install

pip3 install python-rtmidi

Run

python3 chip_midi_delegate.py

chip_midi_delegate.py

#!/usr/bin/env python

import logging
import sys
import time
import rtmidi.midiutil
import os

os.system('sudo echo "Welcome!"')

class MidiHandler(object):
    def __init__(self, name, channel):
        self.name = name
        self.channel = channel

    def __call__(self, event, data=None):
        message, deltatime = event
        if target is None:
            return

        if 'Axoloti Core' in self.name or 'Audio Kontrol 1' in self.name:
            status = None
            data1 = message[1]
            data2 = message[2]
            if(message[0] >= 144 and message[0] <= 159): # note on
                status = 144
            if(message[0] >= 128 and message[0] <= 143): # note off
                status = 128
            if(message[0] >= 176 and message[0] <= 191): # cc
                status = 176

            if(status is not None):
                returnChannel = message[0]-status+1
                if(any(list(filter(lambda item: item['channel'] == returnChannel, controllers)))):
                    controller = list(filter(lambda item: item['channel'] == returnChannel, controllers))[0]

                    if(channelMap[0] in controller['name'] and status == 128): # for midi mix change note off to note on vel=0
                        status = 144
                        data2 = 0

                    controller['returnPort'].send_message([status, data1, data2])
            return


        alteredMessage = message[:]
        alteredMessage[0] += self.channel-1
        try:
            target.send_message(alteredMessage)
        except:
            print('MIDI SEND ERROR');

        print(self.name, message, alteredMessage)

# These lines introduce huge latency
#        if message[0] == 144:
#            os.system('sudo i2cset -f -y 0 0x34 0x93 0x1')
#        else:
#            os.system('sudo i2cset -f -y 0 0x34 0x93 0x0')

channelMap = [
    'MIDI Mix',            #1
    'LPD8',                #2
    'GarageKey mini',      #3
    'K-Mix MIDI 1',        #4
    'K-Mix MIDI 2',        #5
    'K-Mix MIDI 3'         #6
]

midiin = rtmidi.MidiIn()
midiout = rtmidi.MidiOut()
controllers = []
target = None

def updateOutputTarget():
    global target
    names = midiout.get_ports()

    existenceCheck = False
    for name in names:
        if 'Axoloti Core' in name or 'Audio Kontrol 1' in name:

            if 'RtMidiIn Client' in name:
                continue

            existenceCheck = True

            if target is not None:
                break;

            print ('+ Found Axoloti or AK1. Adding it as midi target')
            
            try:
                target, port_name = rtmidi.midiutil.open_midiport(name, "output")
            except (EOFError, KeyboardInterrupt):
                print('Failed to open midi port', name)

            break

    if target is not None and existenceCheck is False:
        print ('+ Removing Axo target')
        try:
            target.close_port()
        except ValueError:
            print('could not close target midi port')
            pass
        target = None

def updateControllerList():
    names = midiin.get_ports()
    returnPortNames = midiout.get_ports()
    cachedControllerNames = [tmp['name'] for tmp in controllers]

    for name in names:

        if not list(filter(lambda item: item['name'] == name, controllers)):

            blacklist = ['Midi Through', 'RtMidiOut Client', 'IAC Driver KASE']#, 'K-Mix Audio Control', 'K-Mix Expander']

            if any([s for s in blacklist if s in name]):
                continue

            port = None

            if not name:
                continue

            try:
                port, port_name = rtmidi.midiutil.open_midiport(name)
            except (EOFError, KeyboardInterrupt, ValueError):
                print('Failed to open midi port', name)

            if not port:
                continue

            try:
                returnPort, port_name = rtmidi.midiutil.open_midiport(name, "output")
            except (EOFError, KeyboardInterrupt):
                print('Failed to open RETURN midi port', name)

            channel = 3
            if any([s for s in channelMap if s in name]):
                channel = channelMap.index([s for s in channelMap if s in name][0]) +1
            port.set_callback(MidiHandler(name, channel))
            controllers.append(dict(port=port, name=name, channel=channel, returnPort=returnPort))
            print('> Adding controller', name)

        try:
            cachedControllerNames.remove(name)
        except ValueError:
            pass

    for removed in cachedControllerNames:

        removedController = [item for item in controllers if item['name'] == removed]

        if removedController:
            removedController = removedController[0]
            try:
                removedController['port'].close_port()
                removedController['returnPort'].close_port()
            except ValueError:
                print('could not close midi port', removedController)
                pass

            try:
                controllers.remove(removedController)
                print('> Removing controller', removedController['name'])
            except ValueError:
                print('could not remove from controllers', removedController['name'])
                pass
        else:
            print('problem: could not find controller to remove!')

try:
    # just wait for keyboard interrupt in main thread
    while True:
        updateOutputTarget()
        updateControllerList()
        time.sleep(3)

except KeyboardInterrupt:
    print('')
finally:
    print("Exit.")
    del midiin
    del midiout