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);

Troubleshooting

Problem	Solution
"OBS runtime not found"	Ensure obs.dll / libobs.so.0 / libobs.0.dylib is in the correct location
"Failed to find 'default.effect'"	The data/libobs/ folder is missing
"Source ID 'xxx' not found"	Required plugin not loaded
Recording fails	Ensure obs-ffmpeg-mux.exe exists (Windows) and output path is writable
Module loading hangs	Use .ForHeadlessOperation() to exclude GUI modules

License

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