Detect that audio interface is external

Windows
1

Does anyone know how to detect if an audio device is on an external interface (USB, firewire) in Windows?

2

See here, from Microsofts’ Core Audio API documents:

Basically, you:

  • Enumerate audio devices using IMMDeviceEnumerator.
  • For each device, open its IPropertyStore to access properties.
  • Check the DEVPKEY_Device_Interface or DEVPKEY_Device_BusTypeGuid to determine if the device is on a USB or FireWire interface.

See the code in $JUCE/modules/juce_audio_devices/native/juce_WASAPI_windows.cpp for more clues .. and one or two places you could extend things to add USB/Firewire detection. (JUCE v7.0.13)

3

Thanks for this. I’d actually gone down this path and was reading out any device property I could find, but the BusTypeGuid never popped up.

4

Yeah, this is a bit thorny, alas .. see also this note from Microsoft about using this key in older versions of Windows:

It would be cool to see the “Bus Type” exposed in JUCE somehow … for some cases its quite useful to differentiate between whether the user is accessing built-in audio or usb/firewire/whatever-based audio ..

5

For reasons which will remain eternally mysterious, I couldn’t get this working - mainly because I couldn’t find DEVPKEY_Device_Interface anywhere. Eventually I got a working solution using the SetupDI interface, particularly SetupDiGetDeviceRegistryProperty with parameter SPDRP_DEVICEDESC, and then scanning the result for “USB” or “Firewire”. Absolutely awful compared to the way you do this on MacOS.

6

Alas, there are two approaches that need to be taken to be able to use this, depending on Windows version.

Did you see the docs here?

I looked at whether I could share my code for this, but alas I cannot .. however, similar code can be found if you search GitHub for the key ..