obs-studio/plugins/win-wasapi/enum-wasapi.cpp

#include "enum-wasapi.hpp"

#include <util/base.h>
#include <util/platform.h>
#include <util/windows/HRError.hpp>
#include <util/windows/ComPtr.hpp>
#include <util/windows/CoTaskMemPtr.hpp>

using namespace std;

string GetDeviceName(IMMDevice *device)
{
	string device_name;
	ComPtr<IPropertyStore> store;
	HRESULT res;

	if (SUCCEEDED(device->OpenPropertyStore(STGM_READ, store.Assign()))) {
		PROPVARIANT nameVar;

		PropVariantInit(&nameVar);
		res = store->GetValue(PKEY_Device_FriendlyName, &nameVar);

		if (SUCCEEDED(res)) {
			size_t size;

			size = os_wcs_to_utf8(nameVar.pwszVal, 0, nullptr);
			if (size) {
				device_name.resize(size);
				os_wcs_to_utf8(nameVar.pwszVal, size,
						&device_name[0]);
			}
		}
	}

	return device_name;
}

void GetWASAPIAudioDevices_(vector<AudioDeviceInfo> &devices, bool input)
{
	ComPtr<IMMDeviceEnumerator> enumerator;
	ComPtr<IMMDeviceCollection> collection;
	UINT count;
	HRESULT res;

	res = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL, CLSCTX_ALL,
			__uuidof(IMMDeviceEnumerator),
			(void**)enumerator.Assign());
	if (!res)
		throw HRError("Failed to create enumerator", res);

	res = enumerator->EnumAudioEndpoints(input ? eCapture : eRender,
			DEVICE_STATE_ACTIVE, collection.Assign());
	if (!res)
		throw HRError("Failed to enumerate devices", res);

	res = collection->GetCount(&count);
	if (FAILED(res))
		throw HRError("Failed to get device count", res);

	for (UINT i = 0; i < count; i++) {
		ComPtr<IMMDevice>   device;
		CoTaskMemPtr<WCHAR> w_id;
		AudioDeviceInfo     info;
		size_t              size;

		res = collection->Item(i, device.Assign());
		if (FAILED(res))
			continue;

		res = device->GetId(&w_id);
		if (FAILED(res) || !w_id || !*w_id)
			continue;

		info.name = GetDeviceName(device);

		size = os_wcs_to_utf8(w_id, 0, nullptr);
		info.id.resize(size);
		os_wcs_to_utf8(w_id, size, &info.id[0]);
	}
}

void GetWASAPIAudioDevices(vector<AudioDeviceInfo> &devices, bool input)
{
	devices.clear();

	try {
		GetWASAPIAudioDevices_(devices, input);

	} catch (HRError error) {
		blog(LOG_ERROR, "[GetWASAPIAudioDevices] %s: %lX",
				error.str, error.hr);
	}
}