Cross-Platform Screen Recording in C# and .NET
Build a screen recorder in C# with one API for Windows, macOS, Linux, Android and iOS: the full screen, a window or a region, with sound, the cursor and click highlights, to MP4 or a live stream. Video Capture SDK .NET and Media Blocks SDK .NET use the native capture API of each platform.
From €250/year · Lifetime from €750
A screenshot loop is not a screen recorder
Graphics.CopyFromScreen gives you one bitmap on Windows. A recorder also needs a steady frame rate, the cursor, sound, an encoder and a file whose audio stays in sync with the video, and on every other operating system the capture API is different again: AVFoundation or ScreenCaptureKit on macOS, X11 on Linux, MediaProjection on Android, ReplayKit on iOS. In the VisioForge SDKs the screen is a video source like a webcam. ScreenSourceBlock uses the native API of the platform it runs on, and the encoder, the file and the stream are the same code everywhere.
Building a cross-platform screen recorder yourself vs. using the SDK
| Typical do-it-yourself stack | VisioForge Video Capture SDK .NET and Media Blocks SDK .NET | |
|---|---|---|
| Capturing the screen | A different native API on each OS, each behind your own interop: Desktop Duplication or Windows Graphics Capture on Windows, ScreenCaptureKit or AVFoundation on macOS, X11 or PipeWire on Linux, MediaProjection on Android, ReplayKit on iOS | ScreenSourceBlock with one settings class per platform; ScreenSourceBlock() without arguments takes the platform default |
| One window or a region | Window identifiers and crop code that differ per OS: HWND on Windows, an X11 window ID on Linux | WindowHandle on Windows or XID on Linux for one window, Rectangle for a region, MonitorIndex on Windows or Monitor on macOS for the monitor |
| Cursor and clicks | Composite the cursor and click marks onto each frame yourself | CaptureCursor on Windows, macOS and Linux; MouseHighlight draws an expanding circle at each click, taken from a global mouse hook on Windows and passed in by your code on other platforms |
| Sound | A separate audio API per OS for the microphone, plus WASAPI loopback for system sound on Windows, synchronized with the video by your code | SystemAudioSourceBlock for a microphone on every platform, LoopbackAudioCaptureDeviceSourceSettings for system sound on Windows, on the same timeline as the video |
| Encoding and the file | Media Foundation, VideoToolbox and MediaCodec wrapped one by one, or an FFmpeg build shipped with each app | H264EncoderBlock picks MediaCodec, VideoToolbox, or NVENC, AMF and Quick Sync with OpenH264 as fallback; MP4, WebM, MKV, MOV, AVI or MPEG-TS output |
| Code to maintain | Five platform implementations to write, test and keep in step | One C# pipeline; only the source settings differ per platform |
Screen capture on each platform
ScreenSourceBlock() with no arguments picks the default source for the platform. Pass a settings object to choose the API, the window or the region.
| Platform | Capture API | Settings class | Sound | Notes |
|---|---|---|---|---|
| Windows | Windows Graphics Capture, DXGI Desktop Duplication, DirectX 9, GDI | ScreenCaptureD3D11SourceSettings, ScreenCaptureDX9SourceSettings, ScreenCaptureGDISourceSettings | System sound (WASAPI loopback) or a microphone | Monitor, region or one window; click highlights |
| macOS | AVFoundation | ScreenCaptureMacOSSourceSettings | Microphone | Needs the Screen Recording permission: ScreenSourceBlock.AskPermissions() |
| Mac Catalyst (.NET MAUI) | ScreenCaptureKit | ScreenCaptureMacOSSourceSettings | Microphone | The same settings class as macOS |
| Linux | X11 | ScreenCaptureXDisplaySourceSettings | Microphone | Needs an X11 session; XID or XName selects one window |
| Android | MediaProjection | AndroidScreenCaptureSourceSettings | Microphone | The user accepts the system prompt; recording runs in a foreground service |
| iOS | ReplayKit | IOSScreenSourceSettings, IOSBroadcastSourceSettings | Microphone | Your own app, or the whole device through a Broadcast Upload Extension |
What the SDK does for a screen recorder
Screen and desktop recording is a video source in VideoCaptureCoreX (Video Capture SDK .NET) and a ScreenSourceBlock in Media Blocks SDK .NET. Everything after the source works as it does for a camera: preview, recording, streaming and video effects.
- Three capture modes: the full screen of any monitor, one application window by its handle, or a rectangle of the desktop
- Windows Graphics Capture is selected by default on Windows 10 version 1803 and later; DXGI Desktop Duplication, DirectX 9 and GDI sources are also available
- Sound from the PC through WASAPI loopback or from a microphone; in Media Blocks SDK .NET, AudioMixerBlock mixes both into one track
- Cursor capture and click highlights with configurable color, radius and duration, for tutorials and demos. On Windows the clicks come from a global mouse hook: when MouseHighlight is set, VideoCaptureCoreX installs it on start; in Media Blocks you call MouseHighlightSubscribe(). On other platforms your code passes each click to MouseHighlightAddClickEvent (MouseHighlight_AddClickEvent in VideoCaptureCoreX)
- Hardware H.264: MediaCodec on Android, VideoToolbox on Apple platforms; on Windows the SDK tries NVENC, AMF and Quick Sync and falls back to OpenH264
- Several outputs at once: record MP4 while streaming the same screen to YouTube over RTMP, SRT or NDI; pause and resume a recording or start a new file without stopping the preview
- One API on Windows, macOS, Linux, Android and iOS, from WinForms, WPF, .NET MAUI and native macOS, Android and iOS apps; a sample for each
Use cases
Tutorial and e-learning recorders
Record a window or the whole screen with narration and click highlights, and save the lesson to MP4.
Support and session recording
Record what a user did before a problem appeared and attach the video to the support ticket.
QA and test automation
Record each automated UI test run and keep the video of the failed ones as evidence.
Presentations and live streams
Stream the screen to YouTube or an NDI receiver and keep a local MP4 copy from the same capture.
Code examples
Condensed from the Screen Capture demos of Video Capture SDK .NET and Media Blocks SDK .NET. The first two run in a WinForms form, the third in a .NET MAUI page; each has a VisioForge VideoView named videoView1 or videoView.
Record the screen and system sound to MP4
C#Record one window with click highlights
C#One recorder for Windows, macOS, Android and iOS (.NET MAUI)
C#The pipeline
The window example and the .NET MAUI example use the same four blocks. ScreenSourceBlock captures the screen with the platform's API, TeeBlock splits the frames between the preview and the encoder, and MP4SinkBlock writes the file. Only the source settings change from platform to platform.
Frequently asked questions
How do I record the sound the PC is playing?▼
Can I record a window that is covered by other windows?▼
Does it work on macOS and Linux?▼
Can I record the screen on Android and iOS?▼
Why is the recording black?▼
Which SDK do I need?▼
Documentation and samples
Screen capture guide
Full screen, region and window capture with VideoCaptureCore and VideoCaptureCoreX, multi-monitor setups and troubleshooting.
Screen capture to MP4 tutorial
Step-by-step C# tutorial with a video walkthrough: console recorder, system audio and GPU encoders.
Screen Capture X Demo (WPF)
Video Capture SDK .NET sample: screen, region or window, microphone or loopback audio, MP4, WebM, AVI, MOV and MPEG-TS output.
Screen Capture MB Demo (WPF)
Media Blocks SDK .NET sample: screen or window capture with click highlights, preview and MP4 recording.
Screen source in Media Blocks
ScreenSourceBlock reference: the settings class for each platform and the capture technology behind it.
ScreenCaptureMB (.NET MAUI)
Media Blocks SDK .NET sample for Windows, Mac Catalyst, Android and iOS: screen preview and MP4 recording, with the MediaProjection prompt on Android.
Start recording the screen
Download the fully functional 30-day trial and run the Screen Capture demos. Depending on the engine and output, a watermark or an unregistered-version notice may appear.
SDKs with screen recording
Video Capture SDK .NET
Capture engine: screen, window or region with system sound or a microphone, recorded to a file or streamed, with preview.
Learn more →Media Blocks SDK .NET
Pipeline SDK: ScreenSourceBlock on Windows, macOS, Linux, Android and iOS, combined with your own processing, mixing and outputs.
Learn more →From €250/year · Lifetime from €750