Enable/disable specific midi ports on Windows

[BN701]

The current Windows 10 class compliant driver for USB/Midi is not sharable between Windows apps. (Many custom drivers can be shared, but a lot of USB/midi hardware being released at the moment does not have a custom driver and relies on the class compliant driver instead.)

Looking at Sonic Pi version 3.2.2 on Windows 10, it opens all available midi ports regardless whether you intend to use them in your code. This means that other software - in my case I also use Ableton, Reaper, and VCV Rack - cannot open them for themselves even when Sonic Pi isn't using them. Imagine a situation with several outboard synths. I want to use Sonic Pi to sequence some of them and Ableton to sequence others ... but I can't use Ableton for this when Sonic Pi has grabbed all the midi ports on the PC.

Both Reaper and Ableton have configuration UIs which allow specific midi ports to be enabled/disabled for use within the app. Any disabled ports are free for use by other software. It would greatly improve flexibility and interoperability on Windows if the Midi Ports panel in Prefs/IO had this functionality, too.

[samaaron]

Hi @BN701 - thanks for this.

I hadn't realised that Windows class compliant drivers had some sort of concurrency restrictions and only allowed one app to connect at any one time. Thanks so much for letting me know about this.

Unfortunately as it currently stands, the MIDI driver binding behaviour is hard-coded into the native library we use (developed by @Lloret). However, we are currently in the process of reworking our entire MIDI architecture.

We are currently looking into the work required to support the ability to opt in/out of connecting to certain MIDI ports.

I'll get back to you here when we have more understanding of the situation and the possibilities we have to improve things. It would be great to discuss them here to make sure that if we are able to offer something like this it works for you :-)

[BN701]

Always happy to discuss or help. I'm also a C/C++ coder with a several decades worth of intermittent experience, most of it on Windows, though nothing current. I would be happy to roll up my sleeves, if needed.

[samaaron]

Hey @BN701 - is this still an issue with v4?

https://github.com/sonic-pi-net/sonic-pi/release

[BN701]

Hi Sam, thanks for following this up and I'm sorry for taking a while to respond. I've just installed v4.0.3 on Windows and yes this is still an issue. Certainly, the state of class compliant USB midi drivers not being sharable on Windows won't have changed, and isn't going to change unless Microsoft withdraws support for the old legacy APIs - I can't remember which ones without looking them up - and forces everyone to rebuild apps that use new APIs (which do support sharing). So, I looked again to see if Sonic Pi now has an option for enabling/disabling specific drivers in the way that Reaper/Ableton/Etc can do, but I couldn't find anything. Certianly, looking at the Preferences/IO page, I can't select individual interfaces there. I am puzzled by the IO option in the Main Menu, though. This lists all the Midi ins and outs, but what's supposed to happen when you select them? It looks like you might be able to turn them on or off, but I don't see any check marks appearing. What it this feature actually supposed to do?