Finding if the end point is default end point in windows 8 - windows

Question

I have a code where I can enumerate all the audio-endpoints on my system, but I don't know how to find which end point is the default end point.
int _tmain(int argc, _TCHAR* argv[])
{
HRESULT hr = S_OK;
IMMDeviceEnumerator *pEnumerator = NULL;
IMMDeviceCollection *pCollection = NULL;
IMMDevice *pEndpoint = NULL;
IPropertyStore *pProps = NULL;
LPWSTR pwszID = NULL;
system("pause");
CoInitialize(NULL);
hr = CoCreateInstance(
CLSID_MMDeviceEnumerator, NULL,
CLSCTX_ALL, IID_IMMDeviceEnumerator,
(void**) &pEnumerator);
EXIT_ON_ERROR(hr)
hr = pEnumerator->EnumAudioEndpoints(
eRender, DEVICE_STATE_ACTIVE,
&pCollection);
EXIT_ON_ERROR(hr)
UINT count;
hr = pCollection->GetCount(&count);
EXIT_ON_ERROR(hr)
if (count == 0)
{
printf("No endpoints found.\n");
}
// Each loop prints the name of an endpoint device.
for (ULONG i = 0; i < count; i++)
{
// Get pointer to endpoint number i.
hr = pCollection->Item(i, &pEndpoint);
EXIT_ON_ERROR(hr)
// Get the endpoint ID string.
hr = pEndpoint->GetId(&pwszID);
EXIT_ON_ERROR(hr)
hr = pEndpoint->OpenPropertyStore(
STGM_READ, &pProps);
EXIT_ON_ERROR(hr)
PROPVARIANT varName;
// Initialize container for property value.
PropVariantInit(&varName);
// Get the endpoint's friendly-name property.
hr = pProps->GetValue(
PKEY_Device_FriendlyName, &varName);
EXIT_ON_ERROR(hr)
hr = pProps->GetValue(PKEY_Device_DeviceDesc, &varName );
EXIT_ON_ERROR(hr)
// Print endpoint friendly name and endpoint ID.
printf("Endpoint %d: \"%S\" (%S)\n",i, varName.pwszVal, pwszID);
//printf("Endpoint %d: \"%S\" (%S)\n",i, varName.pwszVal, pwszID);
CoTaskMemFree(pwszID);
pwszID = NULL;
PropVariantClear(&varName);
SAFE_RELEASE(pProps)
SAFE_RELEASE(pEndpoint)
}
SAFE_RELEASE(pEnumerator)
SAFE_RELEASE(pCollection)
system("pause");
return 0;
Exit:
printf("Error!\n");
CoTaskMemFree(pwszID);
SAFE_RELEASE(pEnumerator)
SAFE_RELEASE(pCollection)
SAFE_RELEASE(pEndpoint)
SAFE_RELEASE(pProps)
}

Answer 1

First of all, you should get the default driver:
using C#
const uint DRVM_MAPPER_PREFERRED_GET = 0x2015;
const uint DRVM_MAPPER_PREFERRED_SET = 0x2016;
uint ret = waveOutMessage(
WAVE_MAPPER,
DRVM_MAPPER_PREFERRED_GET,
ref defaultDeviceId,
ref param1);
So the defaultDeviceId variable will contain the correct index, and then you should query the defaultdriverName with waveOutGetDevCaps from system. The LPWAVEOUTCAPS will contain a valid szPname member.
And finally, you should compare this string(szPname) with value of PKEY_Device_FriendlyName property:
using C++
PROPVARIANT friendlyName;
PropVariantInit(&friendlyName);
hr = propertyStore->GetValue(PKEY_Device_FriendlyName, &friendlyName);
bstr_friendlyName = ::SysAllocString(friendlyName.pwszVal);
if (NULL != wcsstr(friendlyName.pwszVal, woc.szPname))//WAVEOUTCAPS szPname
//def device

Answer 2

uint ret = waveOutMessage(WAVE_MAPPER, DRVM_MAPPER_PREFERRED_GET, ref defaultDeviceId, ref param1);
if (ret == MMSYSERR_NOERROR)
{
int waveOutDevicesCount = waveOutGetNumDevs(); //get total
if (waveOutDevicesCount > defaultDeviceId)
{
WaveOutCaps waveOutCaps = new WaveOutCaps();
waveOutGetDevCapsA((int)defaultDeviceId, ref waveOutCaps,
Marshal.SizeOf(typeof(WaveOutCaps)));
string defaultDeviceName = (new string(waveOutCaps.szPname).Remove(
new string(waveOutCaps.szPname).IndexOf('\0')).Trim());