/// <summary>
/// Updates the specified frame with the next retrieved frame.
/// </summary>
private void UpdateFrame(DesktopDuplicatorInternal ddupe, DesktopFrame frame)
{
// Try to get the latest frame;
if (ddupe.TryRetrieveFrame(out var frameInfo))
{
try
{
ddupe.RetrieveFrameMetadata(frame, frameInfo);
ddupe.RetrieveCursorMetadata(frame, frameInfo);
ddupe.ProcessFrame(frame);
}
finally
{
ddupe.ReleaseFrame(_logger);
}
}
}
/// <summary>
/// Duplicates the desktop yielding Desktop Frames until cancelled.
/// </summary>
/// <param name="token"></param>
/// <returns></returns>
public IEnumerable <DesktopFrame> DuplicateDesktop(CancellationToken token)
{
_logger.LogInformation($"Beginning Desktop Duplication");
using var duplicator = DesktopDuplicatorInternal.CreateDesktopDuplicator(_logger, _adapterIndex, _outputDeviceIndex);
while (token.IsCancellationRequested == false)
{
var desktopFrame = new DesktopFrame();
UpdateFrame(duplicator, desktopFrame);
if (token.IsCancellationRequested == false)
{
if (desktopFrame.IsDesktopImageBufferEmpty)
{
continue;
}
yield return(desktopFrame);
}
}
}
public static DesktopDuplicatorInternal CreateDesktopDuplicator(ILogger logger, int adapterIndex, int outputDeviceIndex)
{
var dd = new DesktopDuplicatorInternal
{
_outputDeviceIndex = outputDeviceIndex
};
var createFactoryResult = DXGI.CreateDXGIFactory1(out IDXGIFactory1 factory);
if (!createFactoryResult.Success)
{
throw new DesktopDuplicationException("Couldn't create a DXGI Factory.");
}
IDXGIAdapter1 adapter = null;
IDXGIOutput output = null;
try
{
var result = factory.EnumAdapters1(adapterIndex, out adapter);
if (result.Failure)
{
throw new DesktopDuplicationException($"An error occurred attempting to retrieve the adapter at the specified index ({adapterIndex}): {result}");
}
if (adapter == null)
{
throw new DesktopDuplicationException($"An adapter was not found at the specified index ({adapterIndex}).");
}
logger.LogInformation($"Using adapter at index {adapterIndex} - {adapter.Description.Description}");
var createD3dDeviceResult = D3D11.D3D11CreateDevice(adapter, DriverType.Unknown, DeviceCreationFlags.None, null, out dd._d3dDevice, out dd._immediateContext);
if (!createD3dDeviceResult.Success)
{
throw new DesktopDuplicationException("Couldn't create a D3D device from the specified adapter.");
}
using var device = dd._d3dDevice.QueryInterface <IDXGIDevice>();
var outputResult = adapter.EnumOutputs(outputDeviceIndex, out output);
if (outputResult.Failure)
{
throw new DesktopDuplicationException($"An error occurred attempting to retrieve the output device at the specified index ({outputDeviceIndex}): {outputResult}");
}
if (output == null)
{
throw new DesktopDuplicationException($"An output was not found at the specified index ({outputDeviceIndex}).");
}
logger.LogInformation($"Using output device on adapter {adapterIndex} at index {outputDeviceIndex}.");
var output6 = output.QueryInterface <IDXGIOutput6>();
try
{
// Copy the values to a new rect.
var rectTemp = output6.Description.DesktopCoordinates;
dd._desktopRect = new RawRect(rectTemp.Left, rectTemp.Top, rectTemp.Right, rectTemp.Bottom);
dd._outputDuplication = output6.DuplicateOutput(device);
var stagingTexture = new Texture2DDescription()
{
CpuAccessFlags = CpuAccessFlags.Read,
BindFlags = BindFlags.None,
Format = dd._outputDuplication.Description.ModeDescription.Format,
Width = Math.Abs(dd._desktopRect.Right - dd._desktopRect.Left),
Height = Math.Abs(dd._desktopRect.Bottom - dd._desktopRect.Top),
OptionFlags = ResourceOptionFlags.None,
MipLevels = 1,
ArraySize = 1,
SampleDescription = { Count = 1, Quality = 0 },
Usage = Usage.Staging // << can be read by CPU
};
// Initialize the Output Duplication -- If this isn't done occassionally an 'Unsupported' result will occur with DuplicationOutput1
dd._desktopImageTexture = dd._d3dDevice.CreateTexture2D(stagingTexture);
}
catch (SharpGenException ex)
{
if (ex.Descriptor.NativeApiCode == "DXGI_ERROR_UNSUPPORTED")
{
throw new DesktopDuplicationException("Unsupported desktop mode or scenario.");
}
else if (ex.Descriptor.NativeApiCode == "DXGI_ERROR_NOT_CURRENTLY_AVAILABLE")
{
throw new DesktopDuplicationException("There is already the maximum number of applications using the Desktop Duplication API running, please close one of the applications and try again.");
}
else
{
throw;
}
}
}
finally
{
if (output != null)
{
output.Dispose();
}
if (adapter != null)
{
adapter.Dispose();
}
if (factory != null)
{
factory.Dispose();
}
}
return(dd);
}
