A .NET wrapper library for FFmpeg, built on top of FFmpeg.AutoGen. It provides a managed, object-oriented interface to FFmpeg's C API, making it easier and safer to use FFmpeg from .NET applications, without giving up direct access to the underlying API when you need it.
📚 API Documentation 🧪 Sample Projects
FFmpeg is a powerful open-source multimedia framework for handling video, audio, and streams. FFmpeg.AutoGen exposes FFmpeg's native C API to .NET, but using it directly means working with raw pointers and unsafe memory operations.
FFmpeg (.NET Wrapper) builds a high-level, managed abstraction on top of FFmpeg.AutoGen, so you can access FFmpeg's encoding, decoding, transcoding, and streaming capabilities safely from C#, with automatic resource cleanup and idiomatic .NET types.
- A .NET Standard 2.1–compatible runtime (.NET Core 3.1+, .NET 5+, .NET 6+, Mono, etc.)
- FFmpeg binaries available on your system path (or bundled via NuGet — see Installation)
FFmpeg 9.0+ ("Lei")
| Library | Version |
|---|---|
| avcodec | 63 |
| avdevice | 63 |
| avfilter | 12 |
| avformat | 63 |
| avutil | 61 |
| swresample | 7 |
| swscale | 10 |
Install the wrapper from NuGet:
dotnet add package FFmpegDotNetIf you don't already have FFmpeg installed on your system, the 
dotnet add package FFmpegDotNet.bin.winx64The FFmpeg namespace includes a static helper class, FFmpegLoader, responsible for locating and initializing the native FFmpeg libraries before use. If Initialize() is not called manually, the library automatically attempts to locate the FFmpeg binaries using the default search order below.
Default search order:
- Current directory (
./) ./ffmpeg/- Platform-specific subdirectories (e.g.
./ffmpeg/win-x64,./ffmpeg/linux-arm64) - The system
PATHenvironment variable
If no suitable library is found, initialization fails and FFmpeg functions become unavailable. You can also point Initialize() at a specific directory if your binaries live somewhere non-standard:
FFmpegLoader.Initialize(@"C:\tools\ffmpeg\bin");A minimal example using the high-level API to remux a file (copy streams into a new container without re-encoding):
using FFmpeg;
using FFmpeg.Formats;
using FFmpeg.Utils;
FFmpegLoader.Initialize();
using MediaSource src = MediaSource.Open("input.mp4");
using MediaSink dst = MediaSink.Create("output.mkv")!;
// Copy all streams as-is (no decoding/encoding involved).
foreach (var stream in src.Streams)
dst.AddStream(stream);
using AVPacket packet = AVPacket.Allocate();
AVResult32 result;
while (!(result = src.ReadPacket(packet)).IsError)
{
dst.WritePacket(packet).ThrowIfError();
}
if (result != AVResult32.EndOfFile)
result.ThrowIfError();
dst.WriteTrailer().ThrowIfError();Note: Real transcoding — decoding, re-encoding with a specific codec, and optionally running frames through a
FilterGraph— is significantly more involved than a stream copy, since you're responsible for driving the decode/filter/encode loop yourself (see the Filters example for a full walkthrough usingCodecContext,FilterGraph, andMediaSink). If you just need a straightforward file-to-file transcode with no custom filtering or frame-level access, it's often simpler and more robust to shell out toffmpeg.exedirectly (e.g. viaSystem.Diagnostics.Process) and reserveMediaSource/MediaSinkfor scenarios where you need in-process control.
For finer control over decoding, filtering, or encoding, see the high-level abstractions below or browse the example projects.
The FFmpeg namespace provides managed wrapper classes around FFmpeg's core C structs and APIs. These classes simplify interacting with FFmpeg by handling resource management, initialization, and data conversion automatically.
These classes map directly to FFmpeg's internal structures and are typically used when building advanced or custom media pipelines.
| Class | Description |
|---|---|
FFmpeg.Formats.FormatContext |
Wraps AVFormatContext. Handles input/output container formats, stream information, and demuxing/muxing. |
FFmpeg.Codecs.CodecContext |
Wraps AVCodecContext. Manages codecs for encoding and decoding audio/video streams. |
FFmpeg.Utils.AVPacket |
Wraps AVPacket. Represents encoded data (compressed frames or packets). |
FFmpeg.Utils.AVFrame |
Wraps AVFrame. Represents decoded, uncompressed media frames in memory. |
FFmpeg.Filters.FilterGraph |
Wraps AVFilterGraph. Provides access to FFmpeg's filter system (resizing, color correction, etc.). |
FFmpeg.Images.SwsContext |
Wraps SwsContext. Handles image scaling and pixel format conversion via libswscale. |
FFmpeg.Audio.SwrContext |
Wraps SwrContext. Handles audio resampling, format conversion, and channel layout adjustments via libswresample. |
Note: These classes closely follow FFmpeg's internal lifecycle patterns and implement
IDisposable. Always dispose them (or wrap them in ausingstatement) when no longer needed to avoid leaking native resources.
If your goal is simply to read, decode, encode, or transcode media, use these instead of managing FormatContext and CodecContext directly.
| Class | Description |
|---|---|
MediaSource |
Simplifies reading and decoding frames from a file or stream. Handles demuxing and decoding internally. |
MediaSink |
Simplifies encoding and writing frames to a file or stream. Handles muxing and encoding internally. |
Transcoder |
Reads from one source and writes to another, performing full media transcoding in a few lines of code. For simple file-to-file transcodes, consider calling ffmpeg.exe directly instead — see the note in Quick Start. |
These abstractions are ideal for typical scenarios such as:
- Extracting frames from a video
- Re-encoding media to a different format
- Streaming or piping decoded frames to other components
Complete sample applications are available in the FFmpeg.Examples repository, ranging from low-level API usage to the higher-level abstractions provided by FFmpegDotNet. Each project is intentionally small and focused, demonstrating a single feature or workflow:
- Opening media files with
DemuxerContext - Decoding audio and video streams
- Reading and writing media containers
- Audio resampling with
SwrContext - Image scaling and pixel format conversion with
SwsContext - Using
MediaSourcefor simplified decoding - Encoding
- Filters
- A simple video player
Contributions, bug reports, and feature requests are welcome. Please open an issue or pull request on GitHub.
This project is licensed under the LGPL-2.1 License. FFmpeg itself is licensed separately under the LGPL/GPL — see the FFmpeg legal page for details on which license applies to your build.