a pointer filled in with the number of devices returned, may be NULL.
a 0 terminated array of device instance IDs or NULL on error; call SDL_GetError() for more information. This should be freed with SDL_free() when it is no longer needed.
Threadsafety: It is safe to call this function from any thread.
Get a list of currently-connected audio playback devices.
This returns of list of available devices that play sound, perhaps to speakers or headphones ("playback" devices). If you want devices that record audio, like a microphone ("recording" devices), use SDL_GetAudioRecordingDevices() instead.
This only returns a list of physical devices; it will not have any device IDs returned by SDL_OpenAudioDevice().
If this function returns NULL, to signify an error, *count will be set to zero.