multiple coreMIDI Network Sessions (rtpMIDI) possible ?

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Joined: Tue Jun 16, 2020 3:56 pm

multiple coreMIDI Network Sessions (rtpMIDI) possible ?

Post by sounda »

Hi there,
I am about to buy Midiflow for a specific usage – hence I want to ensure its possible beforehand to avoid refund stuff.

I am looking for a way to access and route multiple (at least 3, maybe more) MIDI Network Sessions, which I setup on a Windows 10 PC with rtpMidi, inside of iOS on an iPad Pro (1st Generation).

My aim is to route at least 3 virtual MIDI out ports of the Touchscaper app to one MIDI Network Session each – so that there is 1:1 mapping.
The reason for this is MPE – Touchscaper MIDI out feature creates for some of its internal instruments notes & channel aftertouch MIDI messages compliant to MPE, which means e.g. if you play a 3-finger/note chord, main-instrument A MIDI out port will put out 3 notes each on a different MIDI channel on that specific instrument Port and the touch-movements you perform after the “touch down” will create “channel aftertouch” MIDI messages for each note … I hope this makes it clear, why I need for each MPE enabled Instrument an entire MIDI Port and its not sufficient to map 1 Instrument on 1 Channel to the preexisting Network Session 1.

I already tried a setup with AudioBus 3 – but it failed and I am not sure if this to a limitation of iOS itself, that it only allows an iOS (iPad) device to participate in 1 MIDI Network Session / rtpMIDI session.

I am curious about this, because AudioBus3 sees the different MIDI Network Sessions I created on the PC (musicHost and musicHost2 are the Bonjour names) with the rtpMidi Software ( – they are listed under Network Midi, see the attached image “AudioBus available Midi Ports.jpg” – but the routing does not work.

There different buggy scenarios, but the easiest way to understand why it may be iOS itself, merging the data together under the hood, and hence Midiflow will fail as well is the following.

As you see in the attached image “AudioBus Midi Routing.jpg” I setup 2 MIDI lanes in AudioBus3, each outputting to another of the 2 “PC side created” rtpMIDI sessions (and yes the iPad is connected over there and I see Latency information, so the connection is established), but only 1 MIDI lane receives MIDI / MPE data input from Touchscaper main-instrument A.

If I now play the Touchscaper main-instrument with 1 finger and move it around (hence 1 note-on and several aftertouch messages are created and a note-off when I lift the finger), I receive the correct MIDI data, but on BOTH rtpMIDI sessions respectively MIDI-Ports: see attached image “Protokol Snapshot.png” (monitored with this free software: - developer of touchOSC by the way)
In other word, there should be NO DATA arriving on PC side for “musicHost2” … and I am not sure “who put it there”.

I hope this is not too much and confusing information, but instead gives enough context to understand my question.

It would be great to hear that Midiflow can route any virtual MIDI Port (created by itself or other apps like Touchscaper) to “any amount” of MIDI Network Sessions the iOS device (iPad Pro – if its resource bound) … but I got a doubt that only 1 MIDI Network Session is supported.

AudioBus Midi Routing.jpg
AudioBus Midi Routing.jpg (75.61 KiB) Viewed 1228 times
AudioBus available Midi Ports.jpg
AudioBus available Midi Ports.jpg (127.6 KiB) Viewed 1228 times
Protokol Snapshot.png
Protokol Snapshot.png (214.29 KiB) Viewed 1228 times