问如何从音频回放设备中获取频道数？

EN

IMMDeviceEnumerator *enumerator = nullptr;
IMMDevice *device = nullptr;

hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), nullptr, CLSCTX_ALL, __uuidof(IMMDeviceEnumerator), (void**)&enumerator);
if (FAILED(hr))
       ...

// Get the default renderer
hr = enumerator->GetDefaultAudioEndpoint(eRender, eConsole, &device);
if (FAILED(hr))
       ...

    hr = pEndpoint->OpenPropertyStore(
                      STGM_READ, &pProps);
if (FAILED(hr))
       ...

    PROPVARIANT varName;
    // Initialize container for property value.
    PropVariantInit(&varName);

    // Get the endpoint's physical speaker property.
    hr = pProps->GetValue(
                   PKEY_AudioEndpoint_PhysicalSpeakers, &varName);
if (FAILED(hr))
       …

    // See https://learn.microsoft.com/en-us/windows/win32/coreaudio/pkey-audioendpoint-physicalspeakers

    PropVariantClear(&varName);