Xabe.FFmpeg.Conversion is the main class to handle FFmpeg conversions. User can manipulate audio, video and subtitle through this class.

Sample below shows basic conversion video file from mkv to mp4 format:

string output = Path.Combine(Path.GetTempPath(), Guid.NewGuid() + ".mp4");
var snippet = await FFmpeg.Conversions.FromSnippet.Convert(Resources.MkvWithAudio, output);
IConversionResult result = await snippet.Start();

This could be done also by:

string outputPath = Path.ChangeExtension(Path.GetTempFileName(), ".mp4");
IMediaInfo mediaInfo = await FFmpeg.GetMediaInfo(Resources.MkvWithAudio);

IStream videoStream = mediaInfo.VideoStreams.FirstOrDefault()
    ?.SetCodec(VideoCodec.H264);
IStream audioStream = mediaInfo.AudioStreams.FirstOrDefault()
    ?.SetCodec(AudioCodec.Aac);

FFmpeg.Conversions.New()
    .AddStream(audioStream, videoStream)
    .SetOutput(outputPath)
    .Start();

Almost all methods in streams return specific stream (IAudioStream, IVideoStream etc.). It allows to create chain of methods. Stream object could be use more than once.

string outputPath = Path.ChangeExtension(Path.GetTempFileName(), ".mp4");
IMediaInfo mediaInfo = await FFmpeg.GetMediaInfo(Resources.MkvWithAudio);

IStream videoStream = mediaInfo.VideoStreams.FirstOrDefault()
    ?.SetCodec(VideoCodec.H264)
    ?.Reverse()
    ?.SetSize(VideoSize.Hd480);

FFmpeg.Conversions.New()
    .AddStream(videoStream)
    .SetOutput(outputPath)
    .Start();

Method IConversions.Clear() sets IConversion to untouched state. All parameters passed to it are overrided by default values.

IConversion provides events to handle FFmpeg output. OnDataReceived and OnProgress events allow redirect FFmpeg output to user and inform him about progress.

conversion.OnProgress += (sender, args) =>
{
var percent = (int)(Math.Round(args.Duration.TotalSeconds / args.TotalLength.TotalSeconds, 2) * 100);
Debug.WriteLine($"[{args.Duration} / {args.TotalLength}] {percent}%");
};
await conversion.Start();

OnDataReceived:

conversion.OnDataReceived += (sender, args) =>
{
Debug.WriteLine($"{args.Data}{Environment.NewLine}") ;
};
await conversion.Start();