Translating the arcane language of CoreMIDI into one natural to iOS.
Note: This framework is still not feature complete. Most notably, MIDI Receive operations have no effect at this time.
- High level semantics for MIDI operations, e.g.
sendPitchbend - Normalises the API for Network, Hardware/App, and Virtual connections
- Network MIDI scanning made easy(er)
- Audiobus Support (in progress)
- UserDefaults stores and restores manual network connections
- Arbitrary number of virtual source/destinations
- API Simplicity with optional granularity,
- Public exposure of CoreMIDI objects for digging deeper
_midiSession = [MFMIDISession sessionWithName:@"Your App Name"];
_midiSession.networkEnabled = YES;
_midiSession.restorePreviousConnectionStates = YES;
_midiSession.autoEnableDestinations = YES;
_midiSession.midiChannel = 0;
// Create the Virtual Source to expose to other apps
[_midiSession createVirtualSourceWithName:_midiSession.name]; // disabled by default
// ...some time later...
[_midiSession sendNoteOn:64 velocity:127];
[_midiSession sendPitchbend:0x3FFF];
// etc
For more, see the MFMIDISession.h.
Connection: A source or destination for MIDI Messages
Message: NoteOn, NoteOff, CC, Pitchbend, Program Change, Channel Aftertouch, Poly Aftertouch, Sysex
Virtual Source/Destination: Connections which we create in the app with a specified name which show up in other apps. Keep in mind that when the app is a VirtualSource it means it is a MIDISource for other apps. Locally it appears as a MIDIDestination because we output to it
"Connect" vs "Enable": "Connect" refers to discovering the existence of a physical/virtual/wifi connection. All devices are auto-connected so-to-speak in that they are discovered by the system scan. "Enable" indicates whether they send/receive midi messages when you send them through MIDISession. This is slightly confusing in the code as "en/disabling" a Network Connection does indeed "connect/disconnect" the host from the MIDINetworkSession (see notes above). This is one example of the abnormal lingo in CoreMIDI that MIDIFish seeks to normalise.
Setting restorePreviousConnectionStates causes previous connections, when re-discovered, to be enabled/disabled based on their value from a previous run of the app. Currently, it does NOT restore Virtual Connections or IP based network ones which were discovered
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Network Connections have their Sources and Destinations coupled such that enabling/disabling one enables/disables the other.
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MIDINetworkHost's created with NSNetService's discovered by Bonjour are currently unreliable. I believe this is due to an IPv6 address being interpreted as IPv4 (0.0.0.0:5004) the actual IPv4 address (NSNetService::resolve results in 2 address) is ignored. In the client, we manually resolve the NSNetService and then connect with a MIDINetworkHost instantiated with IP/Port. (See https://developer.apple.com/library/mac/qa/qa1298/_index.html)