MFC win7 channel volume setting

BOOL CAudioHelper::SetWin7AudioLeftMute(void)

{

    HRESULT hr=NULL;

 

    double nVolume = (double)0;

    double newVolume=nVolume;

 

    CoInitialize(NULL);

    IMMDeviceEnumerator *deviceEnumerator = NULL;

    hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL, CLSCTX_INPROC_SERVER,

        __uuidof(IMMDeviceEnumerator), (LPVOID *)&deviceEnumerator);

    IMMDevice *defaultDevice = NULL;

 

    hr = deviceEnumerator->GetDefaultAudioEndpoint(eRender, eConsole, &defaultDevice);

    deviceEnumerator->Release();

    deviceEnumerator = NULL;

 

    IAudioEndpointVolume *endpointVolume = NULL;

    hr = defaultDevice->Activate(__uuidof(IAudioEndpointVolume),

        CLSCTX_INPROC_SERVER, NULL, (LPVOID *)&endpointVolume);

    defaultDevice->Release();

    defaultDevice = NULL;

 

    float fVolumeMin, fVolumeMax, fVolumeInc;

    endpointVolume->GetVolumeRange(&fVolumeMin, &fVolumeMax, &fVolumeInc);

 

    UINT uiChannelCount;

    endpointVolume->GetChannelCount(&uiChannelCount);

    for (UINT i=0; i<uiChannelCount; i++ )

    {

        if ( i == 1 )

            continue;

        endpointVolume->SetChannelVolumeLevel(i, fVolumeMin, NULL);

    }

 

    endpointVolume->Release();

 

    CoUninitialize();

 

    return TRUE;

}