Video conversion

Use Avalonia.HeadlessTestingFramework.Recording and configure Skia rendering before recording. Run capture operations on the Avalonia UI thread.

The VideoConverter converts PNG sequences to video files using FFmpeg.

Basic Usage

var converter = new VideoConverter();

// Check FFmpeg availability
if (converter.IsFfmpegAvailable())
{
    Console.WriteLine($"FFmpeg version: {converter.GetFfmpegVersion()}");

    // Convert PNG sequence to video
    var result = converter.ConvertPngSequenceToVideo(
        inputDirectory: "/path/to/frames",
        outputPath: "/path/to/output.mp4",
        options: new VideoConversionOptions
        {
            Format = VideoFormat.Mp4,
            FrameRate = 30,
            Quality = 23
        });

    if (result.Success)
    {
        Console.WriteLine($"Video created: {result.OutputPath}");
        Console.WriteLine($"Frames processed: {result.FrameCount}");
        Console.WriteLine($"Duration: {result.Duration}");
    }
    else
    {
        Console.WriteLine($"Error: {result.ErrorMessage}");
    }
}

Video Formats

Format	Codec	Description
Mp4	H.264	Most compatible, good quality
WebM	VP9	Web-optimized, open format
Gif	GIF	Animated GIF (limited colors)
Avi	MJPEG	Legacy format

Conversion Options

var options = new VideoConversionOptions
{
    Format = VideoFormat.Mp4,
    FrameRate = 30,              // Output frame rate
    Quality = 23,                // H.264 CRF (0-51, lower = better)
    Scale = 1.0,                 // Output scale (0.5 = half size)
    OverwriteExisting = true,
    DeleteSourceFiles = false,   // Keep PNG files after conversion
    Timeout = TimeSpan.FromMinutes(5),
    LoopCount = 0,               // GIF loop count (0 = infinite)
    FfmpegPath = null,           // Custom FFmpeg path (null = auto-detect)
    CustomArguments = null       // Additional FFmpeg arguments
};

Async Conversion

var result = await converter.ConvertPngSequenceToVideoAsync(
    inputDirectory: "/path/to/frames",
    options: options,
    cancellationToken: cts.Token);

Convert Multiple Directories

var results = await converter.ConvertMultipleAsync(
    directories: new[] { "/dir1", "/dir2", "/dir3" },
    options: options);

foreach (var (dir, result) in results)
{
    Console.WriteLine($"{dir}: {(result.Success ? "Success" : result.ErrorMessage)}");
}

Extension Methods

// Convert a recording session directly
var session = recorder.CurrentSession;
var result = await session.ToVideoAsync(
    outputPath: "/output.mp4",
    options: new VideoConversionOptions { Format = VideoFormat.Mp4 });

// Synchronous version
var result = session.ToVideo();