ListAudioRenderingDevices.cpp

#include <windows.h>
#include <MMDeviceAPI.h>
#include <functiondiscoverykeys.h>
#include <atlstr.h>

#define EXIT_ON_ERROR(hres) if (FAILED(hres)) { goto Exit; }
#define SAFE_RELEASE(punk) if ((punk) != NULL) { (punk)->Release(); (punk) = NULL; }

const CLSID CLSID_MMDeviceEnumerator = __uuidof(MMDeviceEnumerator);
const IID IID_IMMDeviceEnumerator = __uuidof(IMMDeviceEnumerator);

// This function enumerates all active (plugged in) audio rendering endpoint devices. It prints the friendly name and endpoint ID string of each endpoint device.
//In short :
//Create an IMMDeviceEnumerator
//Call EnumAudioEndpoints specifying render to enumerate into an IMMDeviceCollection
//Obtain individual IMMDevice instances from IMMDeviceCollection
//Device name and description are queried from IMMDevice using OpenPropertyStore

void PrintEndpointNames()
{
    HRESULT hr = S_OK;
    IMMDeviceEnumerator *pEnumerator = NULL;
    IMMDeviceCollection *pCollection = NULL;
    IMMDevice *pEndpoint = NULL;
    IPropertyStore *pProps = NULL;
    LPWSTR pwszID = 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");
    }


    for (ULONG i = 0; i < count; i++) {
        hr = pCollection->Item(i, &pEndpoint);
        EXIT_ON_ERROR(hr)

        hr = pEndpoint->GetId(&pwszID);
        EXIT_ON_ERROR(hr)

        hr = pEndpoint->OpenPropertyStore(STGM_READ, &pProps);
        EXIT_ON_ERROR(hr)

        PROPVARIANT varName;
        PropVariantInit(&varName);

        hr = pProps->GetValue(PKEY_Device_FriendlyName, &varName);
        EXIT_ON_ERROR(hr)

        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)
    return;

Exit:
    printf("Error!\n");
    CoTaskMemFree(pwszID);
    SAFE_RELEASE(pEnumerator)
    SAFE_RELEASE(pCollection)
    SAFE_RELEASE(pEndpoint)
    SAFE_RELEASE(pProps)
}

int main(void) {
    HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED); //Mandatory setup,  use COINIT_APARTMENTTHREADED for GUI app
    PrintEndpointNames();
    system("pause");
}