[Question] Handling device disconnects

[JamesMoreau]

So I have a music player application and I would like for the user to be able to select the audio output device.

The user could switch devices or unplug it in the middle of a track. So, I need to be able to rebuild the stream at any point.

However, I noticed, at least on macOS, that upon disconnecting a device (in this case my headphones), the audio gets automatically rerouted to another device all on its own. This is nice but now I no longer know what the current device actually is. Which means that my application state, which display the current device, is now out of sync.

Is there a way to turn off this feature, or is it something the OS does? Otherwise, is it possible to listen for a particular stream event? Or maybe just even be able to query the current output device given a particular stream?

Thanks.

[roderickvd]

It's currently hardcoded:

cpal/src/host/coreaudio/macos/mod.rs

Line 673 in 1c9c642

add_disconnect_listener(&stream, error_callback_disconnect)?;

Could be knob to add in #1010.

[sandreas]

@roderickvd
I would also appreciate this due to the nature of USB-C Audio adapters that could be plugged out (accidentally or intentionally) in the middle of audio playback / Streaming.

I think a "DeviceChange" enum containing the device that changed and the nature of the change could be enough for a first implementation

• DeviceChange::Disconnect(cpal::Device)
• DeviceChange::Connect(cpal::Device)

along with cpal::on_device_change(callback)...

[roderickvd]

I see now that this is a bug. Let's continue over at #1175.

[roderickvd]

Please give PR #1178 a shot and report back there.