alcReopenDeviceSOFT with ALC_SOFT_loopback

[SuperDevbot]

I've got a rather unusual situation where possible targets for my audio stream include WASAPI devices as well as custom APIs and even a case where I need to get those samples out to HIDs.
For this case I am looking for a way to do something like alcReopenDeviceSOFT but with the additional ability to turn the device into a loopback device and back.

alcReopenDeviceSOFT explicitly does not support DeviceType::Loopback but closing and opening a new device is not an option, as I can't reload any of the resources. Is there an alternative to that?

[kcat]

Currently there isn't, unfortunately. Since the loopback device doesn't technically have a name, and unsupported format attributes would create difficulties with error handling, it's not too straight forward to support changing an open device from outputting to a real device to on-demand rendering to a user buffer. It is something to consider though, and probably isn't an insurmountable problem.

The only alternative in the mean time that I can think of right now is to always use a loopback device for rendering, and manually play that yourself with WASAPI or other APIs. Then you're in control over which device(s) are getting the audio at any given time. Not the best solution since OpenAL Soft won't be able to auto-configure itself to the output and various user/config options won't be honored, but it should work.

[SuperDevbot]

I should be able to use a loopback device at all times for rendering, before routing the samples to whatever API I might need on my end. But the point you raise about the auto-configuration might actually be a problem here. Most devices just take a mono stream so I'd be fine on that end, but sample rates might be different and there is at least one known target that can actually do 4 channel setups. Whether it would benefit from actually rendering 4 channels remains to be seen when I get to test it as that particular setup mostly plays back lower bass, which isn't particularly directional to begin with.
I don't think I'll go for manual channel configuration even if that were possible.
There isn't at least some way to reconfigure the output sample rate of a loopback device, is there?
On some devices I might even have to go as low as 400Hz so I might have to unclamp this a little, given that the current min is 8000Hz. Is there any reason to avoid going that low?