pyrtmidi

pyrtmidi is a Python interface to RtMidi?. It provides real-time midi input and output.

import rtmidi
midiin = rtmidi.RtMidiIn()

ports = range(midiin.getPortCount())
if ports:
    for i in ports:
        print midiin.getPortName(i)
    midiin.openPort(1, True)
    while True:
        print 'MESSAGE:',midiin.getMessage()
else:
    print 'NO MIDI INPUT PORTS!'

Documentation

The API is copied near verbatim from the C++ code. Refer to the RtMidi tutorial, and take into account the following caveats:

RtMidiIn?

openPort(port, blocking=False)

• The port argument is required, and cannot be 0 (this locked my system, not sure why).
• An optional blocking argument causes getMessage() to block and wait for a message instead of its default behavior, which is to not block and return a blank message.

getMessage()

• The message argument has been removed.
• The call will always return (byte1, byte2, byte3, timestamp) - or an empty tuple if no data was available.
• getMessage() will block if openPort() was called with blocking enabled.
• If openPort() was called with blocking disabled, the return value will be an empty tuple.

setCallback

• Callback support is not available yet.
• Use openPort(port, blocking=True).

Recipes

QObject interface

The pksampler implements a QObject wrapper for rtmidi.RtMidiIn? that emits a 'message()' signal. The original source can be found at /pk/sampler/midi.py. The essential code is follows:

class MidiInput(QThread):
    def __init__(self, devid, parent=None):
        QThread.__init__(self, parent)
        self.device = rtmidi.RtMidiIn()
        self.device.openPort(devid, True)
        self.running = False

    def run(self):
        self.running = True
        while self.running:
            msg = self.device.getMessage()
            if msg:
                self.msg = msg
                self.emit(SIGNAL('message(PyObject *)'), self.msg)
                self.emit(SIGNAL('message()')

midi = MidiInput(1)
def slotMessage(msg):
   print msg
QObject.connect(midi, SIGNAL('message(PyObject *)'), slotMessage)