Screen recording

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

The HeadlessScreenRecorder captures frames during UI interactions for visual testing.

Basic Recording

using var recorder = new HeadlessScreenRecorder();

// Start recording
var session = recorder.StartRecording(
    window,
    options: new RecordingOptions
    {
        FrameRate = 60,
        Format = RecordingFormat.PngSequence,
        Quality = 90
    },
    outputPath: "/path/to/output"
);

// Manual frame capture
recorder.CaptureFrame();

// Stop recording
RecordingStatistics stats = recorder.StopRecording();

Console.WriteLine($"Frames captured: {stats.FramesCaptured}");
Console.WriteLine($"Duration: {stats.Duration}");

Recording Options

// High quality preset
var options = RecordingOptions.HighQuality;

// Performance preset (lower quality, smaller files)
var options = RecordingOptions.Performance;

// Custom options
var options = new RecordingOptions
{
    FrameRate = 30,
    Format = RecordingFormat.PngSequence,
    Quality = 100,
    ScaleFactor = 1.0,
    AutoCapture = false,           // Manual capture mode
    WriteImmediately = true,       // Write frames to disk immediately
    MaxBufferedFrames = 1000,
    CaptureOnChangeOnly = false,   // Capture every frame
    IncludeTimestamp = false,
    IncludeFrameNumber = false,
    MaxDuration = TimeSpan.FromMinutes(5),
    OutputDirectory = "/custom/path"
};

Recording Formats

Format	Description
PngSequence	Sequence of PNG images (lossless)
JpegSequence	Sequence of JPEG images (lossy, smaller)
Gif	Animated GIF (limited colors)
RawFrames	Raw frame data for custom processing

Recording behavior

ScaleFactor resizes captured pixels with nearest-neighbor sampling. MaxDuration stops a session when the next submitted frame exceeds that duration; it is not an independent timer.

IncludeTimestamp and IncludeFrameNumber must remain false: overlay rendering is not implemented and enabling either option throws NotSupportedException. Use recorded timeline events and markers for those diagnostics.

The built-in GIF encoder writes an animated GIF with a fixed 256-color palette and an infinite loop. It uses opaque output, flattens premultiplied alpha against black, and has a minimum frame delay of 10 milliseconds. Use PNG sequences for lossless frame storage or FFmpeg conversion when another encoding policy is required.

Events

recorder.RecordingStarted += (s, e) => Console.WriteLine("Recording started");
recorder.RecordingStopped += (s, e) => Console.WriteLine("Recording stopped");
recorder.FrameCaptured += (s, e) => Console.WriteLine($"Frame {e.FrameNumber} captured");
recorder.RecordingError += (s, e) => Console.WriteLine($"Error: {e.Exception.Message}");

Async Recording

// Record an async action
await recorder.RecordActionAsync(async () =>
{
    await someAnimationTask;
}, frameInterval: 16);

// Record for a duration
await recorder.RecordDurationAsync(TimeSpan.FromSeconds(2), frameInterval: 16);