MIDI support in IPlug AU

[Stu Kennedy]

Is sending MIDI messages supported for AU? there's some comment in the AU code that seems to suggest that you're just passing the MIDI through:-


bool IPlugAU::SendMidiMsg(IMidiMsg* pMsg)
{
// I believe AU passes midi messages through automatically.
// For the case where we're generating midi messages, we'll use
AUMIDIOutputCallback.
// See AudioUnitProperties.h.
if (mMidiCallback.midiOutputCallback) {
// Todo.
}
return false;
}


Can I send CC messages like I can in the VST code?

[schwa]

No, there's no support in iplug for generating MIDI from an AU yet. If you are interested, it should be straightforward to implement (using AUMIDIOutputCallback as noted).

[cc_]

I implemented it, but I can't find any AU hosts that support it, so it's no use.

I asked on the AudioUnits mailing list and nobody knew of one either.

Also, if you look at the example of how to send MIDI in the AudioUnits SDK it's actually broken, so I think it has never been run.

[Stu Kennedy]

eh?

So are you saying you can't produce MIDI out in AU plugins period?

Or is there another method?

Stu

[Stu Kennedy]

CC_,

could you post the code you wrote for the AU MIDI implementation just for completeness?

Cheers

Stu

[schwa]

The OSX MIDI implementation is a lot better and easier to use than Windows MIDI. It may be that MIDI AU plugins send output directly to MIDI ports, rather than passing the MIDI back to the host the way a VST can.

At least now I don't feel too lame for never implementing AU MIDI :)

[cc_]

Yeah, I'm sure deep down you sensed it wasn't host supported :)

I think maybe it's a chicken and egg thing: no host support it, so no plugs use it so no hosts need to support it. Some hosts that support MIDI out from VSTs (like Ableton Live) don't support it from AUs, maybe because they have no plugs to test it with?

I'm not really an expert, but I thought if you used the OSX midi stuff you would not be able to get accurate timing?

I could post my code up, but I'm a bit hesitant as it has never been run! It does compile though. If you really want it though...

[Stu Kennedy]

Hmm ... if it's easy to send MIDI from an AU straight to the MIDI ports, then that may work!

Any ideas where to look to accomplish that? (I'm really not a native OS X user and this is all new territory for me)
I guess it's not in the AU SDK :-)

[cc_]

Take a look at:
/Developer/Examples/CoreAudio/MIDI/SampleTools/Echo.cpp

[Stu Kennedy]

which website is that from ;-)

[cc_]

Oh, sorry I should have explained. It guess it's part of the mac developer tools, once you've installed them on your mac there's a top level /Developer directory and it's under there.

Or you can probably find it somewhere at developer.apple.com .