Switching audio output device (esp. for VR)

[godatplay]

We’re having problems with fmod using the correct audio output device with VR. A lot of times the headset connects after the start of the application, including in the editor.

fmod seems to not handle this at all, unlike the rest of the Unity audio, which works fine.

Is this as designed? I ask because it’s a big pain for VR, and it’d really be nice if it auto-switched like Unity.

What’s the suggested way to handle switching output devices?

[godatplay]

After some more testing, I’ve concluded that it doesn’t matter if you start the Oculus app and connect the headset first, before running the Unity editor. It seems like there’s some device hand-off that happens later anyway.

Any suggestions on how to set up an output device switch? Or is this a bug?

[cameron-fmod]

By default FMOD will use the system default output device.

The best way to change the output device that FMOD uses is:

• Find out how many devices there are (FMOD::System::getNumDrivers).
• For each driver get name (FMOD::System::getDriverInfo).
• Use the name to determine the index of the wanted device.
• Set the new driver (FMOD::System::setDriver).

[godatplay]

Thanks for the info! If the system default output device switches while the app is running, does it update? If so, there seems to be a bug because it doesn’t update when the device switches.

[cameron-fmod]

This is currently the way FMOD works, only if the device list has changed (eg. device removed or added) will FMOD update it’s device list.

See this thread for more information:

[Windows] Possible bug with setDriver and getDriverInfo

Hello!, I am trying to change the current driver after detect a default device change on Windows, however every time I call in the main thread [setDriver] with the right driver somehow the drivers get changed, so when I call getDriver and getDriverInfo to know if changed to the right driver the device selected is wrong. After hours debugging, it gives me these values, lets say we have 3 output devices detected by Fmod, after I change the default device to another, lets say it becomes the driver…

We are planning to add this behavior in the next major release, as it requires internal behavior changes.

[Richieva64]

Hello, is there any news regarding this issue? I am also working on a VR proyect and it’s something really important for VR, both Oculus and SteamVR change the windows audio output to the headset when launching the game, and currently if you launch the game directly from Steam before opening SteamVR for example, the windows audio output is changed after the game finished launching so fmod ends up with the last output windows had.

[cameron-fmod]

This has been added in version 2.01.00:
https://fmod.com/resources/documentation-api?version=2.1&page=welcome-revision-history.html

• Core API - Win - FMOD_OUTPUT_DEVICELISTCHANGED_CALLBACK now responds to default device changes.