How can I switch device in ma_engine

[m1maker]

Hello
Can I make ma_engine reinitialize device to another device? I have the code, but it doesn't work. Is it possible?

bool set_output_audio_device(asUINT id) {
	if (!g_SoundInitialized)soundsystem_init();
	if (devs.size() == 0)devs = GetOutputAudioDevices();
	mixer_stop();// Need to reset and uninitialize audio_device
	ma_device_uninit(sound_default_mixer.pDevice);
	sound_default_mixer.pDevice = nullptr;
	sound_default_mixer.pDevice = (ma_device*)ma_malloc(sizeof(*sound_default_mixer.pDevice), &sound_default_mixer.allocationCallbacks);
	ma_device_config devConfig = ma_device_config_init(ma_device_type_playback);;
	devConfig.playback.pDeviceID = &devs[id].id;
	devConfig.periodSizeInFrames = period_size;
	devConfig.playback.channels = CHANNELS;
	devConfig.sampleRate = SAMPLE_RATE;
	if (ma_device_init(nullptr, &devConfig, sound_default_mixer.pDevice) != MA_SUCCESS)return false;
	mixer_start();
	return true;
}

Thank you!

[day-garwood]

It doesn't look like you are using ma_engine in that code, unless sound_default_mixer is a global ma_engine instance.
I would be interested to know myself though. As you rightly noted, trying to directly change the engine's device context doesn't work, so what I'm doing in my code right now is initialising a new ma_engine object with the new device in a very roundabout, low-level way.
Error checks removed for brevity.

int ko_audio_set_device(int id)
{
ma_device* dev=ma_engine_get_device(engine);
ma_context* ctx=ma_device_get_context(dev);
ma_device_info* devinfo;
ma_context_get_devices(ctx, &devinfo, NULL, NULL, NULL);
ma_device_id target_device_id=devinfo[id].id;
ma_engine_uninit(engine);
ma_engine_config config=ma_engine_config_init();
config.pPlaybackDeviceID=&target_device_id;
ma_engine_init(&config, engine);
ma_engine_start(engine);
return 1;
}

I'm sure there must be a much easier way of doing this...

[mackron]

I somehow missed this one. You don't change the internal device when using ma_engine. What you can do instead is use the ma_device API directly and initialize your ma_engine object to not use it's own self-managed ma_device. To do this, you configure the engine's config:

engineConfig.noDevice = MA_TRUE; // <-- This tells miniaudio to not use an internal `ma_device` with the `ma_engine` object.
engineConfig.channels = YOUR_CHANNEL_COUNT; // <-- This and `sampleRate` *must* be specified when `noDevice` is set.
engineConfig.sampleRate = YOUR_SAMPLE_RATE;

Then you need to manually call ma_engine_read_pcm_frames() in your ma_device data callback. With this technique you are using both the low-level and the high-level APIs together which is fully supported, and you have full control over how you manage your ma_device object, including switching it out for another.

The alternative is to do a full teardown and reinitialization of a new ma_engine object. If you have sounds loaded in the resource manager which you'd rather avoid having to reload, you can use a self-managed ma_resource_manager object.