DirectX11 DXGI Capture Screen when in full screen - c++

Question

I'm currently trying to develop a personal project where I will light up LEDs according to what's happening on the screen of my computer.
I've tried several solutions to capture my screen, and DirectX11 with DXGI is the fastest way I found to have a good FPS Rate.
My only issue is the following: When in full screen (for example, watching Netflix trogh Win10 App or playing any game in fullscreen), it seems that nothing is captured. I have two functions (one to set up and another one to capture a frame:
Setup Up Function:
bool DXGIScreenCapturer::Init() {
int lresult(-1);
D3D_FEATURE_LEVEL lFeatureLevel;
HRESULT hr(E_FAIL);
hr = D3D11CreateDevice(
nullptr,
D3D_DRIVER_TYPE_HARDWARE,
nullptr,
0,
gFeatureLevels,
gNumFeatureLevels,
D3D11_SDK_VERSION,
&_lDevice,
&lFeatureLevel,
&_lImmediateContext);
if (FAILED(hr))
return false;
if (!_lDevice)
return false;
// Get DXGI device
ComPtr<IDXGIDevice> lDxgiDevice;
hr = _lDevice.As(&lDxgiDevice);
if (FAILED(hr))
return false;
// Get DXGI adapter
ComPtr<IDXGIAdapter> lDxgiAdapter;
hr = lDxgiDevice->GetParent(__uuidof(IDXGIAdapter), &lDxgiAdapter);
if (FAILED(hr))
return false;
lDxgiDevice.Reset();
UINT Output = 0;
// Get output
ComPtr<IDXGIOutput> lDxgiOutput;
hr = lDxgiAdapter->EnumOutputs(Output, &lDxgiOutput);
if (FAILED(hr))
return false;
lDxgiAdapter.Reset();
hr = lDxgiOutput->GetDesc(&_lOutputDesc);
if (FAILED(hr))
return false;
// QI for Output 1
ComPtr<IDXGIOutput1> lDxgiOutput1;
hr = lDxgiOutput.As(&lDxgiOutput1);
if (FAILED(hr))
return false;
lDxgiOutput.Reset();
// Create desktop duplication
hr = lDxgiOutput1->DuplicateOutput(_lDevice.Get(), &_lDeskDupl);
if (FAILED(hr))
return false;
lDxgiOutput1.Reset();
// Create GUI drawing texture
_lDeskDupl->GetDesc(&_lOutputDuplDesc);
// Create CPU access texture
_desc.Width = _lOutputDuplDesc.ModeDesc.Width;
_desc.Height = _lOutputDuplDesc.ModeDesc.Height;
_desc.Format = _lOutputDuplDesc.ModeDesc.Format;
std::cout << _desc.Width << "x" << _desc.Height << "\n\n\n";
_desc.ArraySize = 1;
_desc.BindFlags = 0;
_desc.MiscFlags = 0;
_desc.SampleDesc.Count = 1;
_desc.SampleDesc.Quality = 0;
_desc.MipLevels = 1;
_desc.CPUAccessFlags = D3D11_CPU_ACCESS_FLAG::D3D11_CPU_ACCESS_READ;
_desc.Usage = D3D11_USAGE::D3D11_USAGE_STAGING;
while (!CaptureScreen(_result));
_result = cv::Mat(_desc.Height, _desc.Width, CV_8UC4, _resource.pData);
return true;
}
And the capture function:
bool DXGIScreenCapturer::CaptureScreen(cv::Mat& output)
{
HRESULT hr(E_FAIL);
ComPtr<IDXGIResource> lDesktopResource = nullptr;
DXGI_OUTDUPL_FRAME_INFO lFrameInfo;
ID3D11Texture2D* currTexture = NULL;
hr = _lDeskDupl->AcquireNextFrame(999, &lFrameInfo, &lDesktopResource);
if (FAILED(hr))
return false;
if (lFrameInfo.LastPresentTime.HighPart == 0) // not interested in just mouse updates, which can happen much faster than 60fps if you really shake the mouse
{
hr = _lDeskDupl->ReleaseFrame();
return false;
}
//int accum_frames = lFrameInfo.AccumulatedFrames;
//if (accum_frames > 1) {// && current_frame != 1) {
// // TOO MANY OF THESE is the problem
// // especially after having to wait >17ms in AcquireNextFrame()
//}
// QI for ID3D11Texture2D
hr = lDesktopResource.As(&_lAcquiredDesktopImage);
// Copy image into a newly created CPU access texture
hr = _lDevice->CreateTexture2D(&_desc, NULL, &currTexture);
if (FAILED(hr))
{
hr = _lDeskDupl->ReleaseFrame();
return false;
}
if (!currTexture)
{
hr = _lDeskDupl->ReleaseFrame();
return false;
}
_lImmediateContext->CopyResource(currTexture, _lAcquiredDesktopImage.Get());
UINT subresource = D3D11CalcSubresource(0, 0, 0);
_lImmediateContext->Map(currTexture, subresource, D3D11_MAP_READ, 0, &_resource);
_lImmediateContext->Unmap(currTexture, 0);
currTexture->Release();
hr = _lDeskDupl->ReleaseFrame();
output = _result;
return true;
}