.NET Window Capture Samples

NOTE: This is an experimental project. Please use it at your own risk.

Captures a window or desktop screen and renders it in WPF or DirectX.

System Requirements

• Windows 10 (64-bit, April 2018 Update)
• DirectX 11
• .NET Framework 4.7.2
• Visual Studio 2019

Capture Methods

Project Name	Minimal Windows Version	Render To	Platform
Win32.BitBlt	Windows 95	DirectX	Win32
Win32.DesktopDuplication	Windows 8	DirectX	Win32
Win32.DwmSharedSurface	Windows 7	DirectX	Win32
Win32.DwmThumbnail	Windows 7	WPF	Win32
WinRT.GraphicsCapture	Windows 10 1803	DirectX	WinRT

Comparison

Compare with capture target

Capture Method	Window Capture	Desktop Capture	Outside of Desktop	HW Acceleration	DirectX Games
Win32.BitBlt	Yes	Yes	Yes	No	Yes
Win32.DesktopDuplication	No	Yes	No	Yes	Yes
Win32.DwmSharedSurface	Yes	No	Yes	No	Yes
Win32.DwmThumbnail	Yes	No	Yes	Yes	Yes
WinRT.GraphicsCapture	Yes	Yes	Yes	Yes	Yes

• Games is checked using Märchen Forest.

Compare with capture source

Capture Method	Window Handle	Monitor Handle	Another
Win32.BitBlt	Yes	No	-
Win32.DesktopDuplication	No	No	Device (Monitor)
Win32.DwmSharedSurface	Yes	No	-
Win32.DwmThumbnail	Yes	No	-
WinRT.GraphicsCapture	Yes *	Yes *	Embedded Picker

• *: Require Windows 10 1903 or greater.

Compare with delay

Capture Method	Delay (ms)
Win32.BitBlt	~ 20ms
Win32.DesktopDuplication	N/A
Win32.DwmSharedSurface	~ 20ms
Win32.DwmThumbnail	0ms
WinRT.GraphicsCapture	~ 40ms

• I used this video to investigate the delay.
• It is just a reference value, but it is certain that the delay of Win32.DwmThumbnail is 0 ms.
  • This is because it uses a drawing method that is entirely common to other windows.

License

This project is licensed under the MIT license.

Third-Party Notices

Dependencies

• Microsoft.Windows.SDK.Contracts
• SharpDX

Code Includes

• SharpDX Samples (MIT)
• Windows Universal Samples (MIT)
• Windows.UI.Composition Win32 Samples (MIT)