我正在开发一个通过桌面复制API（使用DirectX 11）捕获屏幕的应用程序（只有前一个屏幕更新的差异）并在另一个窗口上呈现它（查看器可能正在另一个窗口上运行）机器通过LAN连接）。该代码是MSDN中提供的sample的改进版本。一切正常，除了设备没有给出任何屏幕更新，虽然在中间有一次，大约10％的时间在一些机器上发生（大多数在Windows 8 / 8.1机器上，很少在Windows 10机器上）。我尝试了所有可能的方法来解决这个问题。减少了设备重置的次数，这为我提供了一些可靠的输出，但并不总能正常工作100％。
设备无法提供初始屏幕（全屏）（在支持桌面复制的所有Windows操作系统上，这种情况发生的时间占60％），我想出了一个重新开始的工作从设备更新，直到它提供一个，但这也导致了多个问题，设备可能甚至没有给出初始屏幕。
我已经投入了数周的时间来解决这个问题，但没有找到合适的解决方案，而且我所知道的论坛没有讨论这些问题。任何帮助将不胜感激。
下面是我的代码，用于将屏幕差异化为前一个，启动设备，填充适配器和监视器。
请耐心等待一段很长的代码段，提前致谢。
要获取屏幕更新：
INT getChangedRegions(int timeout, rectangles &dirtyRects, std::vector <MOVE_RECT> &moveRects, UINT &rect_count, RECT ScreenRect)
{
UINT diffArea = 0;
FRAME_DATA currentFrameData;
bool isTimeOut = false;
TRY
{
m_LastErrorCode = m_DuplicationManager.GetFrame(¤tFrameData, timeout, &isTimeOut);
if(SUCCEEDED(m_LastErrorCode) && (!isTimeOut))
{
if(currentFrameData.FrameInfo.TotalMetadataBufferSize)
{
m_CurrentFrameTexture = currentFrameData.Frame;
if(currentFrameData.MoveCount)
{
DXGI_OUTDUPL_MOVE_RECT* moveRectArray = reinterpret_cast<DXGI_OUTDUPL_MOVE_RECT*> (currentFrameData.MetaData);
if (moveRectArray)
{
for(UINT index = 0; index < currentFrameData.MoveCount; index++)
{
//WebRTC
// DirectX capturer API may randomly return unmoved move_rects, which should
// be skipped to avoid unnecessary wasting of differing and encoding
// resources.
// By using testing application it2me_standalone_host_main, this check
// reduces average capture time by 0.375% (4.07 -> 4.055), and average
// encode time by 0.313% (8.042 -> 8.016) without other impacts.
if (moveRectArray[index].SourcePoint.x != moveRectArray[index].DestinationRect.left || moveRectArray[index].SourcePoint.y != moveRectArray[index].DestinationRect.top)
{
if(m_UseD3D11BitmapConversion)
{
MOVE_RECT moveRect;
moveRect.SourcePoint.x = moveRectArray[index].SourcePoint.x * m_ImageScalingFactor;
moveRect.SourcePoint.y = moveRectArray[index].SourcePoint.y * m_ImageScalingFactor;
moveRect.DestinationRect.left = moveRectArray[index].DestinationRect.left * m_ImageScalingFactor;
moveRect.DestinationRect.top = moveRectArray[index].DestinationRect.top * m_ImageScalingFactor;
moveRect.DestinationRect.bottom = moveRectArray[index].DestinationRect.bottom * m_ImageScalingFactor;
moveRect.DestinationRect.right = moveRectArray[index].DestinationRect.right * m_ImageScalingFactor;
moveRects.push_back(moveRect);
diffArea += abs((moveRect.DestinationRect.right - moveRect.DestinationRect.left) *
(moveRect.DestinationRect.bottom - moveRect.DestinationRect.top));
}
else
{
moveRects.push_back(moveRectArray[index]);
diffArea += abs((moveRectArray[index].DestinationRect.right - moveRectArray[index].DestinationRect.left) *
(moveRectArray[index].DestinationRect.bottom - moveRectArray[index].DestinationRect.top));
}
}
}
}
else
{
return -1;
}
}
if(currentFrameData.DirtyCount)
{
RECT* dirtyRectArray = reinterpret_cast<RECT*> (currentFrameData.MetaData + (currentFrameData.MoveCount * sizeof(DXGI_OUTDUPL_MOVE_RECT)));
if (!dirtyRectArray)
{
return -1;
}
rect_count = currentFrameData.DirtyCount;
for(UINT index = 0; index < rect_count; index ++)
{
if(m_UseD3D11BitmapConversion)
{
RECT dirtyRect;
dirtyRect.bottom = dirtyRectArray[index].bottom * m_ImageScalingFactor;
dirtyRect.top = dirtyRectArray[index].top * m_ImageScalingFactor;
dirtyRect.left = dirtyRectArray[index].left * m_ImageScalingFactor;
dirtyRect.right = dirtyRectArray[index].right * m_ImageScalingFactor;
diffArea += abs((dirtyRect.right - dirtyRect.left) *
(dirtyRect.bottom - dirtyRect.top));
dirtyRects.push_back(dirtyRect);
}
else
{
diffArea += abs((dirtyRectArray[index].right - dirtyRectArray[index].left) *
(dirtyRectArray[index].bottom - dirtyRectArray[index].top));
dirtyRects.push_back(dirtyRectArray[index]);
}
}
}
}
return diffArea;
}
CATCH_ALL(e)
{
LOG(CRITICAL) << _T("Exception in getChangedRegions");
}
END_CATCH_ALL
return -1;
}
以下是初始化设备的代码
//
// Initialize duplication interfaces
//
HRESULT cDuplicationManager::InitDupl(_In_ ID3D11Device* Device, _In_ IDXGIAdapter *_pAdapter, _In_ IDXGIOutput *_pOutput, _In_ UINT Output)
{
HRESULT hr = E_FAIL;
if(!_pOutput || !_pAdapter || !Device)
{
return hr;
}
m_OutputNumber = Output;
// Take a reference on the device
m_Device = Device;
m_Device->AddRef();
/*
// Get DXGI device
IDXGIDevice* DxgiDevice = nullptr;
HRESULT hr = m_Device->QueryInterface(__uuidof(IDXGIDevice), reinterpret_cast<void**>(&DxgiDevice));
if (FAILED(hr))
{
return ProcessFailure(nullptr, _T("Failed to QI for DXGI Device"), _T("Error"), hr);
}
// Get DXGI adapter
IDXGIAdapter* DxgiAdapter = nullptr;
hr = DxgiDevice->GetParent(__uuidof(IDXGIAdapter), reinterpret_cast<void**>(&DxgiAdapter));
DxgiDevice->Release();
DxgiDevice = nullptr;
if (FAILED(hr))
{
return ProcessFailure(m_Device, _T("Failed to get parent DXGI Adapter"), _T("Error"), hr);//, SystemTransitionsExpectedErrors);
}
// Get output
IDXGIOutput* DxgiOutput = nullptr;
hr = DxgiAdapter->EnumOutputs(Output, &DxgiOutput);
DxgiAdapter->Release();
DxgiAdapter = nullptr;
if (FAILED(hr))
{
return ProcessFailure(m_Device, _T("Failed to get specified output in DUPLICATIONMANAGER"), _T("Error"), hr);//, EnumOutputsExpectedErrors);
}
DxgiOutput->GetDesc(&m_OutputDesc);
IDXGIOutput1* DxgiOutput1 = nullptr;
hr = DxgiOutput->QueryInterface(__uuidof(DxgiOutput1), reinterpret_cast<void**>(&DxgiOutput1));
*/
_pOutput->GetDesc(&m_OutputDesc);
// QI for Output 1
IDXGIOutput1* DxgiOutput1 = nullptr;
hr = _pOutput->QueryInterface(__uuidof(DxgiOutput1), reinterpret_cast<void**>(&DxgiOutput1));
if (FAILED(hr))
{
return ProcessFailure(nullptr, _T("Failed to QI for DxgiOutput1 in DUPLICATIONMANAGER"), _T("Error"), hr);
}
// Create desktop duplication
hr = DxgiOutput1->DuplicateOutput(m_Device, &m_DeskDupl);
DxgiOutput1->Release();
DxgiOutput1 = nullptr;
if (FAILED(hr) || !m_DeskDupl)
{
if (hr == DXGI_ERROR_NOT_CURRENTLY_AVAILABLE)
{
return ProcessFailure(nullptr, _T("Maximum number of applications using Desktop Duplication API"), _T("Error"), hr);
}
return ProcessFailure(m_Device, _T("Failed to get duplicate output in DUPLICATIONMANAGER"), _T("Error"), hr);//, CreateDuplicationExpectedErrors);
}
return S_OK;
}
最后获取当前帧和前一帧的差异：
//
// Get next frame and write it into Data
//
_Success_(*Timeout == false && return == DUPL_RETURN_SUCCESS)
HRESULT cDuplicationManager::GetFrame(_Out_ FRAME_DATA* Data, int timeout, _Out_ bool* Timeout)
{
IDXGIResource* DesktopResource = nullptr;
DXGI_OUTDUPL_FRAME_INFO FrameInfo;
try
{
// Get new frame
HRESULT hr = m_DeskDupl->AcquireNextFrame(timeout, &FrameInfo, &DesktopResource);
if (hr == DXGI_ERROR_WAIT_TIMEOUT)
{
*Timeout = true;
return S_OK;
}
*Timeout = false;
if (FAILED(hr))
{
return ProcessFailure(m_Device, _T("Failed to acquire next frame in DUPLICATIONMANAGER"), _T("Error"), hr);//, FrameInfoExpectedErrors);
}
// If still holding old frame, destroy it
if (m_AcquiredDesktopImage)
{
m_AcquiredDesktopImage->Release();
m_AcquiredDesktopImage = nullptr;
}
if (DesktopResource)
{
// QI for IDXGIResource
hr = DesktopResource->QueryInterface(__uuidof(ID3D11Texture2D), reinterpret_cast<void **>(&m_AcquiredDesktopImage));
DesktopResource->Release();
DesktopResource = nullptr;
}
if (FAILED(hr))
{
return ProcessFailure(nullptr, _T("Failed to QI for ID3D11Texture2D from acquired IDXGIResource in DUPLICATIONMANAGER"), _T("Error"), hr);
}
// Get metadata
if (FrameInfo.TotalMetadataBufferSize)
{
// Old buffer too small
if (FrameInfo.TotalMetadataBufferSize > m_MetaDataSize)
{
if (m_MetaDataBuffer)
{
delete [] m_MetaDataBuffer;
m_MetaDataBuffer = nullptr;
}
m_MetaDataBuffer = new (std::nothrow) BYTE[FrameInfo.TotalMetadataBufferSize];
if (!m_MetaDataBuffer)
{
m_MetaDataSize = 0;
Data->MoveCount = 0;
Data->DirtyCount = 0;
return ProcessFailure(nullptr, _T("Failed to allocate memory for metadata in DUPLICATIONMANAGER"), _T("Error"), E_OUTOFMEMORY);
}
m_MetaDataSize = FrameInfo.TotalMetadataBufferSize;
}
UINT BufSize = FrameInfo.TotalMetadataBufferSize;
// Get move rectangles
hr = m_DeskDupl->GetFrameMoveRects(BufSize, reinterpret_cast<DXGI_OUTDUPL_MOVE_RECT*>(m_MetaDataBuffer), &BufSize);
if (FAILED(hr))
{
Data->MoveCount = 0;
Data->DirtyCount = 0;
return ProcessFailure(nullptr, L"Failed to get frame move rects in DUPLICATIONMANAGER", L"Error", hr);//, FrameInfoExpectedErrors);
}
Data->MoveCount = BufSize / sizeof(DXGI_OUTDUPL_MOVE_RECT);
BYTE* DirtyRects = m_MetaDataBuffer + BufSize;
BufSize = FrameInfo.TotalMetadataBufferSize - BufSize;
// Get dirty rectangles
hr = m_DeskDupl->GetFrameDirtyRects(BufSize, reinterpret_cast<RECT*>(DirtyRects), &BufSize);
if (FAILED(hr))
{
Data->MoveCount = 0;
Data->DirtyCount = 0;
return ProcessFailure(nullptr, _T("Failed to get frame dirty rects in DUPLICATIONMANAGER"), _T("Error"), hr);//, FrameInfoExpectedErrors);
}
Data->DirtyCount = BufSize / sizeof(RECT);
Data->MetaData = m_MetaDataBuffer;
}
Data->Frame = m_AcquiredDesktopImage;
Data->FrameInfo = FrameInfo;
}
catch (...)
{
return S_FALSE;
}
return S_OK;
}
更新：
无法在DUPLICATIONMANAGER中获取下一帧，只要设备挂起就会被打印（这是在流媒体屏幕中间，例如：连续捕获视频并将其发送到另一端）
// Get new frame
HRESULT hr = m_DeskDupl->AcquireNextFrame(timeout, &FrameInfo, &DesktopResource);
if (hr == DXGI_ERROR_WAIT_TIMEOUT)
{
*Timeout = true;
return S_OK;
}
*Timeout = false;
if (FAILED(hr))
{
return ProcessFailure(m_Device, _T("Failed to acquire next frame in DUPLICATIONMANAGER"), _T("Error"), hr);//, FrameInfoExpectedErrors);
}
这是详细的错误信息：
Id3d11DuplicationManager :: ProcessFailure - 错误：无法在DUPLICATIONMANAGER中获取下一帧，详细信息：键控的互斥锁已被放弃。
更新2： 每当设备无法永久提供屏幕更新时，我都会收到错误代码，这里也是相同的
Id3d11DuplicationManager :: ProcessFailure - 错误：在DUPLICATIONMANAGER中无法获得重复输出，详细信息：访问被拒绝。
错误代码为E_ACCESSDENIED。
我不明白为什么我收到此错误，因为我已经在SYSTEM模式下运行并且SetThreadDesktop已执行两次（一次在init期间，另一次在检测到故障后）
这就是MSDN上的错误说明：如果应用程序没有当前桌面映像的访问权限，则为E_ACCESSDENIED。例如，只有在LOCAL_SYSTEM上运行的应用程序才能访问安全桌面。
还有什么会导致这类问题吗？
答案 0 :(得分：0)
检查返回码并立即退回到GDI或任何其他可用的屏幕捕获方法，以防出现不可恢复的错误，这总是好事。对于某些硬件错误（例如已达到最大限制，内存不足，设备已移除等），大多数情况下，重试大部分时间都无效，但我还是很难学到。此外，在极少数情况下，DirectX设备在生成初始帧之前需要进行几次迭代。重试10次以上并没有什么用，您可以安全地回退或尝试重新初始化设备，以检查一次再回退一次。
以下是一些基本检查：
处理DXGI_ERROR_NOT_CURRENTLY_AVAILABLE错误：
_pOutput->GetDesc(&m_OutputDesc);
// QI for Output 1
IDXGIOutput1* DxgiOutput1 = nullptr;
hr = _pOutput->QueryInterface(__uuidof(DxgiOutput1), reinterpret_cast<void**>(&DxgiOutput1));
if (FAILED(hr))
{
return ProcessFailure(nullptr, _T("Failed to QI for DxgiOutput1 in DUPLICATIONMANAGER"), _T("Error"), hr);
}
// Create desktop duplication
hr = DxgiOutput1->DuplicateOutput(m_Device, &m_DeskDupl);
DxgiOutput1->Release();
DxgiOutput1 = nullptr;
if (FAILED(hr) || !m_DeskDupl)
{
if (hr == DXGI_ERROR_NOT_CURRENTLY_AVAILABLE)
{
return ProcessFailure(nullptr, _T("Maximum number of applications using Desktop Duplication API"), _T("Error"), hr);
}
return ProcessFailure(m_Device, _T("Failed to get duplicate output in DUPLICATIONMANAGER"), _T("Error"), hr);//, CreateDuplicationExpectedErrors);
}
检查设备是否已删除（DXGI_ERROR_DEVICE_REMOVED）或设备重置（DXGI_ERROR_DEVICE_RESET）和内存不足（E_OUTOFMEMORY）错误代码（有时我收到E_OUTOFMEMORY，尽管不常见）：
HRESULT ProcessFailure(_In_opt_ ID3D11Device* Device, _In_ LPCWSTR Str, _In_ LPCWSTR Title, HRESULT hr)//, _In_opt_z_ HRESULT* ExpectedErrors = NULL)
{
HRESULT TranslatedHr;
// On an error check if the DX device is lost
if (Device)
{
HRESULT DeviceRemovedReason = Device->GetDeviceRemovedReason();
switch (DeviceRemovedReason)
{
case DXGI_ERROR_DEVICE_REMOVED:
case DXGI_ERROR_DEVICE_RESET:
case static_cast<HRESULT>(E_OUTOFMEMORY) :
{
// Our device has been stopped due to an external event on the GPU so map them all to
// device removed and continue processing the condition
TranslatedHr = DXGI_ERROR_DEVICE_REMOVED;
break;
}
case S_OK:
{
// Device is not removed so use original error
TranslatedHr = hr;
break;
}
default:
{
// Device is removed but not a error we want to remap
TranslatedHr = DeviceRemovedReason;
}
}
}
else
{
TranslatedHr = hr;
}
_com_error err(TranslatedHr);
LPCTSTR errMsg = err.ErrorMessage();
return TranslatedHr;
}
此外，桌面复制需要激活真实的图形设备才能正常工作。否则，您可能会得到E_ACCESSDENIED。
在其他情况下，您也可能会遇到此错误，例如桌面开关盒，废弃的键互斥锁。在这种情况下，您可以尝试重新初始化设备。
我还上传了示例项目here。