Virtual Midi Callback Procs never called

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Rick Hoiberg

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Jan 2, 2014, 1:40:42 PM1/2/14
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I have fixed a couple of PGMidi issues in this fork.

• VirtualMidiPorts are correctly enabled.
• MIDIDestinationCreate fails with a -10844, (kMIDINotPermitted) OSStatus unless you have the audio key set for UIBackgroundModes.

https://github.com/rhoiberg/PGMidi

Using TouchOSC, I see both the source and the destination. I know that MIDI Events are being sent, however the callback procs in MidiMonitor are never called.

Would love to solve this mystery, if anyone can help. I know this works, because I am using Bluetooth Midi and seeing it work. (Great product!)

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Rick Hoiberg

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Feb 2, 2014, 1:29:16 PM2/2/14
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Mikkel,

I have done more analysis.

• I forked PGMidi and modified it so that it correctly sets up the virtualDestinationSource.
https://github.com/rhoiberg/PGMidi
• Using TouchOSC, the PGMIDIVirtualDestinationReadProc never gets called, even though it shows up in the list of output ports.
• I have tried multiple other applications with the same result.
• Using the MidiMonitor the PGMIDIVirtualDestinationReadProc will get called by tapping the "Send Midi" button.
• I think that it is related to the fact the the MidiMonitor app is in the foreground.

My guess is that there is something about iOS7, that even though I have the audio UIBackgroundMode set, CoreMidi is not calling the static method PGMIDIVirtualDestinationReadProc.

Ring any bells?

Rick Hoiberg

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Feb 18, 2014, 9:04:56 PM2/18/14
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Thanks for all the feedback. I figured it out.

Thomas Stahl

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Feb 22, 2014, 12:43:40 PM2/22/14
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Hi Rick!

What did the trick? I am facing the same problem here...

Would be great if you could share your workaround.

Cheers,
-Thomas

Clément Vidal

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Jul 29, 2014, 10:17:04 AM7/29/14
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Hi Thomas and Rick.

I'm facing exactly the same problem.
Does any of you could give some hints about how to solve that problem ?

Thanks a lot !

Clément
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