rtmidi2 0.5.4

Python wrapper for RtMidi written in Cython. Allows sending raw messages, multi-port input and sending multiple messages in one call.

Python wrapper for RtMidi, the lightweight, cross-platform MIDI I/O library. For Linux, Mac OS X and Windows.

Based on rtmidi-python

Setup

The wrapper is written in Cython. Cython should be installed for this module to be installed. RtMidi is included in the source tree, so you only need to do:

python setup.py install

Python 2 & 3

Thanks to Cython, this module is both compatible with Python 2 and Python 3. The only visible difference is that under python 3, all strings are byte strings. If you pass a unicode string to any function taking a string (open_virtual_port), an attempt will be made to encode the string as ASCII, through .encode(“ASCII”, errors=”ignore”).

Usage Examples

rtmidi2 uses a very similar API as RtMidi

Print all in and out ports

import rtmidi2
print(rtmidi2.get_in_ports())
print(rtmidi2.get_out_ports())

Send messages

import rtmidi2

midi_out = rtmidi2.MidiOut()
# open the first available port
midi_out.open_port(0)
# send C3 with vel. 100 on channel 1
midi_out.send_noteon(0, 48, 100)

Get incoming messages - blocking interface

midi_in = rtmidi.MidiIn()
midi_in.open_port(0)

while True:
    message, delta_time = midi_in.get_message()  # will block until a message is available
    if message:
         print(message, delta_time)

Get incoming messages using a callback – non blocking

def callback(message, time_stamp):
    print(message, time_stamp)

midi_in = rtmidi2.MidiIn()
midi_in.callback = callback
midi_in.open_port(0)

Note that the signature of the callback differs from the original RtMidi API: message is now the first parameter, like in the tuple returned by get_message().

Open multiple ports at once

# get messages from all available ports
midi_in = MidiInMulti().open_ports("*")

def callback(msg, timestamp):
    msgtype, channel = splitchannel(msg[0])
    print(msgtype2str(msgtype), msg[1], msg[2])

midi_in.callback = callback

You can also get the device which generated the event by changing your callback to:

def callback(src, msg, timestamp):
    # src will hold the name of the device
    print("got message from", src)

Send multiple notes at once

The usecase for this is limited to a few niche-cases, but was the reason why this fork was initiated in the first place. I needed a fast way to send multiple notes at once for an application transcribing the spectrum of a voice to midi messages to be played by an automated piano.

# send a cluster of ALL notes with a duration of 1 second
midi_out = MidiOut().open_port()
notes = range(127)
velocities = [90] * len(notes)
midi_out.send_noteon_many(0, notes, velocities)
time.sleep(1)
midi_out.send_noteon_many(0, notes, [0] * len(notes))

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License

rtmidi2 is licensed under the MIT License, see LICENSE.

It uses RtMidi, licensed under a modified MIT License, see RtMidi/RtMidi.h.