C++ (Cpp) IAudioEndpointVolume::SetMasterVolumeLevel示例

示例#1

文件： 소스.cpp 项目： rollrat/old-library

bool ChangeVolume(double nVolume,bool bScalar)
{
 
    HRESULT hr=NULL;
    bool decibels = false;
    bool scalar = false;
    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 currentVolume = 0;
		endpointVolume->GetMasterVolumeLevel(&currentVolume);
		//printf("Current volume in dB is: %f\n", currentVolume);

		hr = endpointVolume->GetMasterVolumeLevelScalar(&currentVolume);
		//CString strCur=L"";
		//strCur.Format(L"%f",currentVolume);
		//AfxMessageBox(strCur);

		// printf("Current volume as a scalar is: %f\n", currentVolume);
		if (bScalar==false)
		{
		    hr = endpointVolume->SetMasterVolumeLevel((float)newVolume, NULL);
		}
		else if (bScalar==true)
		{
		    hr = endpointVolume->SetMasterVolumeLevelScalar((float)newVolume, NULL);
		}
		endpointVolume->Release();
 
    CoUninitialize();
 
    return FALSE;
}

示例#2

文件： volctrl.cpp 项目： shubham-theway/Codes-here-there

void modifyVolume(char ch)
{
	HRESULT hr;
	bool decibels = false;
	bool scalar = true;
	double newVolume = 10;
	// -------------------------
	CoInitialize(NULL);
	IMMDeviceEnumerator *deviceEnumerator = NULL;
	hr = CoCreateInstance(__uuidof(MMDeviceEnumerator), NULL, CLSCTX_INPROC_SERVER, __uuidof(IMMDeviceEnumerator), (LPVOID *)&deviceEnumerator);
	IMMDevice *defaultDevice = NULL;

	hr = deviceEnumerator->GetDefaultAudioEndpoint(eRender, eMultimedia, &defaultDevice);
	deviceEnumerator->Release();
	deviceEnumerator = NULL;

	IAudioEndpointVolume *endpointVolume = NULL;
	hr = defaultDevice->Activate(__uuidof(IAudioEndpointVolume), CLSCTX_INPROC_SERVER, NULL, (LPVOID *)&endpointVolume);
	defaultDevice->Release();
	defaultDevice = NULL;

	// -------------------------
	float currentVolume = 0;
	endpointVolume->GetMasterVolumeLevel(&currentVolume);
	//printf("Current volume in dB is: %f\n", currentVolume);

	hr = endpointVolume->GetMasterVolumeLevelScalar(&currentVolume);

	float min, max, inc;
	endpointVolume->GetVolumeRange(&min, &max, &inc);
	//printf("Current volume as a scalar is: %f\n", currentVolume);

	if (ch == 'u')
		newVolume = currentVolume + 0.1;
	else if (ch == 'd')
		newVolume = currentVolume - 0.1;

	if (ch == 'm')
	{
		endpointVolume->SetMute(TRUE, NULL);
	}
	else if (ch == 'n')
	{
		endpointVolume->SetMute(FALSE, NULL);
	}
	else
	{
		if (decibels)
		{
			hr = endpointVolume->SetMasterVolumeLevel((float)newVolume, NULL);
			//endpointVolume->VolumeStepUp(NULL);
		}
		else if (scalar)
		{
			hr = endpointVolume->SetMasterVolumeLevelScalar((float)newVolume, NULL);
			//endpointVolume->VolumeStepUp(NULL);
		}
	}


	endpointVolume->Release();

	CoUninitialize();
}