问题
I'm writing a program that converts OSC into MIDI, allowing OSC enabled applications (like touchOSC on my iPhone) to control MIDI enabled applications (Sibelius, Ableton Live and so on).
I'm using Python to create an OSC server and convert from OSC to MIDI. To get MIDI to the application in question, I'm outputting MIDI to the Apple IAC driver, which is then enabled as an input within the program in question.
Does anyone know of a means to programmatically configure Mac MIDI devices programmatically? In particular, I need to enable the IAC driver, which is disabled by default.
Using FileMon, I have observed that Audio Midi Setup.app modifies this file when enabling/disabling the IAC driver:
~/Preferences/ByHost/com.apple.MIDI.0017f2cxxxxx.plist
The number 0017f2cxxxxx is my system IOPlatformUUID. It's a simple XML property list, but I'm wary of writing to it directly. Even if I did, presumably I would need to cajole the midi server process into re-reading it somehow?
Finally, I'm becoming more and more aware that using the IAC driver at all is a pretty naff solution - for a start it only works on Mac! Ideally, I would write a loopback MIDI driver and all my problems would be solved...
回答1:
Your hunch about writing directly to the plist is correct -- you probably shouldn't do it. I'm not 100% sure about this, but I have a feeling that the plist reflects the state of the MIDI device, but altering it will not open or close that MIDI device as you need.
To actually open the MIDI device, you could use something like pygame. I have used it for some audio-related projects, and the SDK is very straightforward and easy to work with. As python doesn't have great support for MIDI directly, this is probably your best bet (short of writing the python C module yourself, which would be rather painful).
As for IAC, it's a shame that other OS's don't come with virtual MIDI devices like this. IAC is very useful and good at what it does. So while relying on IAC for something like this would not be cross-platform, you could write an abstraction layer for manipulating the loopback device. For Windows users, you could recommend a free MIDI loopback device to be used with your software.
回答2:
If you want to send OSC to MIDI then you're best off creating a Virtual Midi port in software rather trying to remotely configure an IAC. This virtual port will show up in Ableton etc so you can then have it control things programmatically.
You can do this using the rtmidi-python library (or older and slightly different pyrtmidi) - both based on the cross-platform rtmidi lib which provides for straightforward sending of MIDI Control and Notes:
import rtmidi_python as rtmidi
vmidi_out = rtmidi.MidiOut()
vmidi_out.open_virtual_port('My Virtual MIDI Output Port')
vmidi_out.send_message([0x90, 48, 100]) # Note on
vmidi_out.send_message([176, 7, 100]) # Control Change - Volume
回答3:
PyGame itself uses PortMidi under the hood. If you don't need all PyGame library, maybe this can be useful for you.
来源：https://stackoverflow.com/questions/5872858/configure-mac-os-x-midi-programmatically