A macOS menu-bar app that captures any game window or display via ScreenCaptureKit and applies real-time frame interpolation (e.g. 30 fps → 60+ fps) using Apple's on-device VideoToolbox ML models (VTLowLatencyFrameInterpolation). The output is rendered as a transparent, click-through overlay that sits precisely on top of the original window — no game modifications required.

• Frame interpolation — doubles (or triples/quadruples) the frame rate of any window using Apple's VideoToolbox neural interpolation model
• Transparent overlay — borderless, click-through window rendered with AVSampleBufferDisplayLayer so the game remains fully interactive underneath
• Auto-fallback — if a chosen processing resolution is unsupported on the current device, MetalDuck automatically steps down to the next lower resolution
• Device diagnostics — built-in diagnostics runner that tests model capabilities on your specific chip and generates a markdown report for GitHub issues
• Menu bar app — lives in the menu bar; no Dock icon, no interference with your workflow
• Content picker — uses SCContentSharingPicker to visually select any window or display

Frame interpolation uses VTLowLatencyFrameInterpolation, available on Apple Silicon. On M1 Pro, only up to 720p processing resolution is supported by the model; higher resolutions fall back automatically.

cd MetalDuck
xcodebuild build -scheme MetalDuck -destination 'platform=macOS'

Or open MetalDuck/MetalDuck.xcodeproj in Xcode and press Run.

On first launch MetalDuck will request Screen Recording permission. Grant it in System Settings → Privacy & Security → Screen Recording.

1. Launch MetalDuck — a videogame controller icon appears in the menu bar.
2. Click the icon → Preferences.
3. Select a Capture Type (Window or Display) and pick your target.
4. Set Mode to Frame Interpolation and choose a Processing Resolution (720p is currently the most tested).
5. Click Start in the menu — the overlay appears on top of your window.
6. To stop, click the menu bar icon → Stop.

If the model fails to produce a frame within 5 seconds at the selected resolution, MetalDuck automatically falls back to the next lower resolution.

SCStream
  └─ AsyncThrowingStream<CapturedFrame>   (CaptureSession)
       └─ AppCoordinator
            └─ RealTimeFrameInterpolation  (actor, optional)
                 └─ OverlayManager.enqueueBuffer()
                      └─ AVSampleBufferDisplayLayer  (timed via CMTimebase)

Key components:

MetalDuck includes a diagnostics tool to map which processing resolutions work on your chip. Run it via Preferences → Debug → Run Device Diagnostics. It will:

1. Detect your chip, CPU cores, RAM, and macOS version
2. Test each ProcessingResolution with the VideoToolbox interpolation model
3. Query super-resolution scaler capabilities
4. Generate a markdown report you can paste into a GitHub issue

This helps build the community compatibility database (Resources/DeviceCapabilities.json).

If you run the diagnostics on a chip that isn't in the database yet, please open a GitHub issue and paste the generated report. This data improves the resolution recommendations shown in Preferences for all users.

• Capture is fixed at 1920×1080 regardless of the target window size — some system APIs return incorrect dimensions for game windows.
• SCStream's capture buffer contains ~3% black padding on the right edge; MetalDuck clips this automatically using the content-width ratio computed on the first frame.
• Super-resolution (VTLowLatencySuperResolutionScaler) on M1 Pro only supports 2× upscale at inputs ≤ 960×540.
• Multipliers above 2× may introduce latency or quality artifacts; 2× is recommended.