Ruffle not switching audio

[ActionWavele]

Describe the bug

when I open ruffle and then plug in my headphones, ruffle does not switch audio to my headphones, while everthing else does

Expected behavior

pretty sure this never used to be an issue

Affected platform

Desktop app

Operating system

Windows 10

Browser

No response

Additional information

No response

[n0samu]

I just tried it and I cannot reproduce the issue. Maybe it's an issue with your PC's audio drivers.

[ActionWavele]

I don't really update my drivers mich, so I'm not sure

[torokati44]

This might very well be a driver problem indeed: https://answers.microsoft.com/en-us/windows/forum/all/windows-10-not-switching-between-headphones-and/6241f6ae-bfb1-4658-894a-89315dec33c6

[ActionWavele]

maybe, if I was having this problem 5 years ago

[ActionWavele]

No, its definitely Ruffle desktop
I tried NG player, with headphones in, wait till music plays, then unplugged, and it swapped to my speakers (which I forgot were max volume) then plug back headphones, and it switched to headphones as normal. then I tried web demo Ruffle, and same thing, no prob.

Desktop still has the issue where unplugging headphones just kills audio, no matter how many time I switch, or mess with volume mixer

I have no idea what kind of driver would only make Ruffle desktop not work, and everything else work just fine.

[n0samu]

Okay, I finally managed to reproduce the issue. It happens on my Windows laptop when I unplug USB-C headphones, which use a separate driver from the Realtek driver for the built-in speakers and headphone jack. Here is the error that occurs:
ERROR ruffle_desktop::audio: Audio stream error: The requested device is no longer available. For example, it has been unplugged.

[n0samu]

Related to RustAudio/cpal#373, RustAudio/cpal#740, RustAudio/cpal#754

[ActionWavele]

I don't even use USB C headphones
I just have one with a 3.5mm jack

I do get the same error when using ruffle from the command line

[sidit77]

The problem is that querying the current default output with WASAPI returns the specific device (i.e. Realtek(R) Speakers) that is the current default rather than a "proxy value" that always points to the default audio device. This means that the program itself has to change its output device whenever the default output device changes (for example by registering a IMMNotificationClient) . If you don't do this the audio will keep playing on the speakers even if you plug in headphones.

You can easily reproduce this using just the cpal example synth_tones:

1. Set the default output to speakers
   
2. Start the example
3. Switch to another output while the example is playing
4. The example should continue to play over the speaker

However, by using a ActivateAudioInterfaceAsync you can actually get a "proxy value" that always points to current default output. This is what I implemented in RustAudio/cpal#754.

[n0samu]

Thank you for the explanation and for rebasing your PR! Looking forward to seeing it merged in the future 👍