FFMediaToolkit is a .NET library for creating and reading video files. It uses native FFmpeg libraries by the FFmpeg.Autogen bindings.

• Decoding/encoding videos in many formats supported by FFmpeg.
• Access to any video frame by frame index² or timestamp.
• Creating videos from images with metadata, pixel format, bitrate, CRF, FPS, GoP, dimensions and other codec settings.
• Supports reading multimedia chapters and metadata.
• Cross-platform - works on Linux, Windows and MacOS - with .NET Core or .NET Framework projects.

1 The time it takes to obtain a frame depends on the number of keyframes in the video stream(see https://en.wikipedia.org/wiki/Key_frame#Video_compression)
2 Access to frame by index is not supported in Variable Frame Rate videos.

• Extract all video frames as PNG files

  int i = 0;
  var file = MediaFile.Open(@"C:\videos\movie.mp4");
  while(file.Video.TryReadNextFrame(out var imageData))
  {
      imageData.ToBitmap().Save($@"C:\images\frame_{i++}.png");
      // See the #Usage details for example .ToBitmap() implementation
      // The .Save() method may be different depending on your graphics library
  }

• Video decoding

  // Opens a multimedia file.
  // You can use the MediaOptions properties to set decoder options.
  var file = MediaFile.Open(@"C:\videos\movie.mp4");
  
  // Print informations about the video stream.
  Console.WriteLine($"Bitrate: {file.Info.Bitrate / 1000.0} kb/s");
  var info = file.Video.Info;
  Console.WriteLine($"Duration: {info.Duration}");
  Console.WriteLine($"Frames count: {info.NumberOfFrames ?? "N/A"}");
  var frameRateInfo = info.IsVariableFrameRate ? "average" : "constant";
  Console.WriteLine($"Frame rate: {info.AvgFrameRate} fps ({frameRateInfo})");
  Console.WriteLine($"Frame size: {info.FrameSize}");
  Console.WriteLine($"Pixel format: {info.PixelFormat}");
  Console.WriteLine($"Codec: {info.CodecName}");
  Console.WriteLine($"Is interlaced: {info.IsInterlaced}");
  
  // Gets a frame by its number.
  var frame102 = file.Video.ReadFrame(frameNumber: 102);
  
  // Gets the frame at 5th second of the video.
  var frame5s = file.Video.ReadFrame(TimeSpan.FromSeconds(5));

• Encode video from images.

  // You can set there codec, bitrate, frame rate and many other options.
  var settings = new VideoEncoderSettings(width: 1920, height: 1080, framerate: 30, codec: VideoCodec.H264);
  settings.EncoderPreset = EncoderPreset.Fast;
  settings.CRF = 17;
  using(var file = MediaBuilder.CreateContainer(@"C:\videos\example.mp4").WithVideo(settings).Create())
  {
      while(file.Video.FramesCount < 300)
      {
          file.Video.AddFrame(/*Your code*/);
      }
  }

Install the FFMediaToolkit package from NuGet.

dotnet add package FFMediaToolkit

PM> Install-Package FFMediaToolkit

FFmpeg libraries are not included with the package. To use FFMediaToolkit, you need the FFmpeg shared build binaries: avcodec, avformat, avutil, swresample, swscale.

• Windows - You can download it from the BtbN/FFmpeg-Builds or gyan.dev. You only need *.dll files from the .\bin directory (not .\lib) of the ZIP package. Place the binaries in the .\ffmpeg\x86_64\(64bit) in the application output directory or set FFmpegLoader.FFmpegPath.
• Linux - Download FFmpeg using your package manager.
• MacOS - Install FFmpeg via Homebrew.`

You need to set FFmpegLoader.FFmpegPath with full path to FFmpeg libraries.

If you want to use 64-bit FFmpeg, you must disable the Build -> Prefer 32-bit option in Visual Studio project properties.

FFMediaToolkit uses the ref struct ImageData for bitmap images. The .Data property contains pixels data in a Span<byte>.

If you want to process or save the ImageData, you should convert it to another graphics object, using one of the following methods.

These methods are not included in the program to avoid additional dependencies and provide compatibility with many graphics libraries.

• For ImageSharp library (.NET Standard/Core - cross-platform):

  using SixLabors.ImageSharp;
  using SixLabors.ImageSharp.PixelFormats;
  ...
  public static Image<Bgr24> ToBitmap(this ImageData imageData)
  {
      return Image.LoadPixelData<Bgr24>(imageData.Data, imageData.ImageSize.Width, imageData.ImageSize.Height);
  }

• For .NET Framework System.Drawing.Bitmap (Windows only):

  // ImageData -> Bitmap (unsafe)
  public static unsafe Bitmap ToBitmap(this ImageData bitmap)
  {
      fixed(byte* = bitmap.Data)
      {
          return new Bitmap(bitmap.ImageSize.Width, bitmap.ImageSize.Height, bitmap.Stride, PixelFormat.Format24bppRgb, new IntPtr(bitmap.Data));
      }
  }
  
  // Bitmap -> ImageData (safe)
  public static ImageData ToImageData(this Bitmap bitmap)
  {
      var rect = new Rectangle(Point.Empty, bitmap.Size);
      var bitLock = bitmap.LockBits(rect, ImageLockMode.ReadOnly, PixelFormat.Format24bppRgb);
  
      var bitmapData = ImageData.FromPointer(bitLock.Scan0, bitmap.Size, ImagePixelFormat.Bgr24);
      bitmap.UnlockBits(bitLock);
      return bitmapData;
  }

• For .NET Framework/Core desktop apps with WPF UI. (Windows only):

  using System.Windows.Media.Imaging;
  ...
  // ImageData -> BitmapSource (unsafe)
  public static unsafe BitmapSource ToBitmap(this ImageData bitmapData)
  {
      fixed(byte* ptr = bitmapData.Data)
      {
          return BitmapSource.Create(bitmapData.ImageSize.Width, bitmapData.ImageSize.Height, 96, 96, PixelFormats.Bgr32, null, new IntPtr(ptr), bitmapData.Data.Length, bitmapData.Stride);
      }
  }
  
  // BitmapSource -> ImageData (safe)
  public static ImageData ToImageData(this BitmapSource bitmap)
  {
      var wb = new WriteableBitmap(bitmap);
      return ImageData.FromPointer(wb.BackBuffer, ImagePixelFormat.Bgra32, wb.PixelWidth, wb.PixelHeight);
  }

• FFMediaToolkit will also work with any other graphics library that supports creating images from Span<byte>, byte array or memory pointer

This project is licensed under the MIT license.