ObsKit.NET 0.0.11

ObsKit.NET

A modern .NET 9 wrapper for OBS Studio, providing a fluent C# API for video recording, streaming, and replay buffer functionality.

Features

• Cross-Platform - Windows, Linux, and macOS support
• Fluent API - Clean, chainable configuration
• Recording - Record video to MP4, MKV, FLV, and more
• Replay Buffer - Keep a rolling buffer of the last N seconds
• Sources - Monitor capture, window capture, game capture, images, media files
• Encoders - x264, NVENC (H.264/HEVC), AAC audio
• Headless Operation - Run without GUI dependencies

Requirements

• .NET 9.0 or later
• OBS Studio runtime (see OBS Runtime Setup)

Quick Start

using ObsKit.NET;
using ObsKit.NET.Outputs;
using ObsKit.NET.Sources;

var obsPath = AppContext.BaseDirectory;

// Initialize OBS
using var obs = Obs.Initialize(config => config
    .WithDataPath(Path.Combine(obsPath, "data", "libobs"))
    .WithModulePath(
        Path.Combine(obsPath, "obs-plugins", "64bit"),
        Path.Combine(obsPath, "data", "obs-plugins", "%module%"))
    .ForHeadlessOperation()
    .WithVideo(v => v.Resolution(1920, 1080).Fps(60))
    .WithAudio(a => a.WithSampleRate(48000)));

Console.WriteLine($"OBS {Obs.Version} initialized");

// Create a scene with monitor capture
using var scene = Obs.Scenes.Create("My Scene");
using var monitor = MonitorCapture.FromPrimary();
scene.AddSource(monitor);
scene.SetAsProgram();

// Set up and start recording
using var recording = new RecordingOutput("My Recording")
    .SetPath("output.mp4")
    .SetFormat(RecordingFormat.Mp4)
    .WithDefaultEncoders(videoBitrate: 6000, audioBitrate: 192);

recording.Start();
Console.WriteLine("Recording... Press any key to stop.");
Console.ReadKey();

recording.Stop();
Console.WriteLine($"Recorded {recording.TotalFrames} frames");

OBS Runtime Setup

ObsKit.NET requires OBS Studio binaries. Use the setup script to download them:

./tools/setup-obs-runtime.sh

The script will prompt you for version and platform. For manual setup, download OBS from GitHub Releases.

Windows Structure

YourApp/
├── YourApp.exe
├── obs.dll, obs-ffmpeg-mux.exe, *.dll  # From OBS bin/64bit/
├── data/
│   ├── libobs/                          # Shader files
│   └── obs-plugins/                     # Plugin data
└── obs-plugins/64bit/                   # Plugin DLLs

Linux Structure

YourApp/
├── YourApp
├── lib/libobs.so.0                      # OBS libraries
├── obs-plugins/                         # Plugin .so files
└── data/libobs/, obs-plugins/           # Data files

Run with: LD_LIBRARY_PATH="$PWD/lib" ./YourApp

macOS Structure

YourApp/
├── YourApp
└── OBS.app/Contents/
    ├── Frameworks/                      # OBS libraries
    ├── PlugIns/                         # Plugin .so files
    └── Resources/data/                  # Data files

Run with: DYLD_LIBRARY_PATH="$PWD/OBS.app/Contents/Frameworks" ./YourApp

Source Types

// Monitor capture
using var monitor = MonitorCapture.FromPrimary();
using var monitor = MonitorCapture.FromMonitor(1);

// Window capture
using var window = WindowCapture.FromWindow(WindowCapture.AvailableWindows[0]);

// Game capture (Windows only)
using var game = new GameCapture("Game", GameCapture.CaptureMode.AnyFullscreen);

// Image and media
using var image = ImageSource.FromFile("logo.png");
using var media = new MediaSource("Video", "video.mp4").SetLooping(true);

Encoders

// Video - x264 (CPU)
var encoder = VideoEncoder.CreateX264("Video", bitrate: 6000);

// Video - NVENC (NVIDIA GPU)
var encoder = VideoEncoder.CreateNvencH264("Video", bitrate: 6000);
var encoder = VideoEncoder.CreateNvencHevc("Video", bitrate: 6000);

// Audio - AAC
var encoder = AudioEncoder.CreateAac("Audio", bitrate: 192);

DPI Awareness (Windows)

When using DXGI Desktop Duplication for monitor capture on Windows, your application must be configured as per-monitor DPI aware.

For Windows Forms / WPF apps, add to your .csproj:

<PropertyGroup>
  <ApplicationHighDpiMode>PerMonitorV2</ApplicationHighDpiMode>
</PropertyGroup>

For console apps, add an app.manifest file:

<?xml version="1.0" encoding="utf-8"?>
<assembly manifestVersion="1.0" xmlns="urn:schemas-microsoft-com:asm.v1">
  <application xmlns="urn:schemas-microsoft-com:asm.v3">
    <windowsSettings>
      <dpiAwareness xmlns="http://schemas.microsoft.com/SMI/2016/WindowsSettings">PerMonitorV2</dpiAwareness>
      <dpiAware xmlns="http://schemas.microsoft.com/SMI/2005/WindowsSettings">true/pm</dpiAware>
    </windowsSettings>
  </application>
</assembly>

And reference it in your .csproj:

<PropertyGroup>
  <ApplicationManifest>app.manifest</ApplicationManifest>
</PropertyGroup>

Alternatively, use MonitorCaptureMethod.WindowsGraphicsCapture which doesn't require DPI awareness.

Troubleshooting

License

This project wraps OBS Studio which is licensed under GPLv2. See the OBS Studio license for details.