Need a MIDI router that does this...

Hi wdmcm,

A short history first! Before Audiobus there was OMAC which was a loose collaboration of iOS music developers. Under OMAC I developed an open protocol for switching between apps from other apps' UI's and also via MIDI command. There is a freely available SDK for implementing fast-switching (here). During Audiobus' initial development I conversed with the Audiobus people (Audiobus was conceived initially in the OMAC auspices but then made closed for commercial purposes) and tried to convince them to absorb the OMAC stuff into Audiobus (I offered to assist with this) so that any Audiobus app could be sent a message to switch to another app. Unfortunately I was not able to convince them to do this an they told me they would be just doing it themselves. That was, what, 3 years ago and this was never important enough for them to implement despite a number of requests from their users. Once Audiobus was established, OMAC essentially withered on the vine although I continue to support it to this day.

The technicality behind switching apps remotely is that only the foreground app can switch to another app, so that foreground app needs to be sent a message to 'switch to app X'.

So, yes, MidiBridge can be configured to bind a MIDI command to 'switch to app X' but this is only effective if the current foreground app is OMAC aware. These days the OMAC code has been incorporated into the MidiBus MIDI library but the number of apps that are using that (or OMAC directly) is fairly small comparatively. A list of OMAC aware apps is at the MidiBus site

My understanding is that Audiobus may add MIDI bindings to Audiobus Remote which will do what you need. Because of Audiobus' penetration with developers they are really the only ones that can implement this so it becomes useful (apart from Apple, of course). Whether they will add this feature or not will depend upon if they perceive this as something they should do, but if they do add MIDI bindings then they would open up the ability for any app (local or remote!) to issue MIDI commands to switch apps which may not be what they would like. If they do add that feature, then one could program MidiBridge to issue program changes and switch apps via it's 'Scenes' facility in one go.

Regards, Nic.

Hi wdmcm,

I guess I could have spared you the history and said, yes it works but with just a handful of apps. :-)

MidiBridge runs in the background so you can swap to other apps using the home button no problem.

You could go one step further and switch scenes in MidiBridge by sending a program change from your controller for hands-off scene switches.

Many of those apps you mention have controllable parameters via Continuous Controller (CC). You could have per app mappings of your hardware controller and when an app is actively routed use the knobs on the controller to adjust without touching the iPad. You could map common things (eg. resonance which is present on just about every synth) to the same knob on your controller in a 'wdmcm' standard fashion. You could then do everything from the controller (switch scenes/routings and make adjustments to 1 (or more) of your running apps).

Regards, Nic.