MetalDuck is an experimental macOS real-time scaler inspired by Lossless Scaling, built with ScreenCaptureKit + Metal + MetalFX.

It captures a window or display, applies GPU processing (upscaling and optional frame generation), and presents the processed result in a dedicated output window.

• Real-time capture with ScreenCaptureKit.
• Metal render pipeline for low-latency presentation.
• MetalFX spatial upscaling (MTLFXSpatialScaler).
• Optional frame generation (2x / 3x) with GPU optical-flow estimation + warping.
• Runtime controls for capture FPS, target FPS, scaling, sharpness, dynamic resolution, and FG.
• Live output HUD with SOURCE / CAP / GEN / OUT FPS.

• This is not a native game renderer injection path.
• Quality can still differ from Lossless Scaling, especially in fast occlusion scenes.
• Highest FG quality still requires true game motion vectors/depth from engine integration.
• DRM-protected content may not be capturable by macOS APIs.

• Apple Silicon Mac
• macOS 15+
• Swift 6.2 toolchain (or compatible)
• Xcode Command Line Tools

SDKROOT=/Library/Developer/CommandLineTools/SDKs/MacOSX15.4.sdk swift build

SDKROOT=/Library/Developer/CommandLineTools/SDKs/MacOSX15.4.sdk swift build -c release

SDKROOT=/Library/Developer/CommandLineTools/SDKs/MacOSX15.4.sdk swift run

./.build/release/MetalDuck

bash scripts/create_release.sh

Output:

• dist/MetalDuck-macos-arm64.dmg

1. Open MetalDuck-macos-arm64.dmg.
2. Drag MetalDuck.app to Applications.
3. Open MetalDuck from Launchpad or /Applications.

1. Open a true 30 FPS video in your browser.
2. In MetalDuck:
   • Capture mode: Window
   • Source: browser window
   • Capture FPS: 30
   • Frame Generation: On
   • FG mode: 2x
   • Target FPS: 60
3. Click Scale.
4. Keep source window visible (browser may throttle hidden tabs/windows).
5. Confirm in output HUD:
   • SOURCE around 30
   • CAP around 30
   • GEN > 0
   • OUT around 60

• Capture FPS: input cadence.
• Target FPS: output cadence cap.
• Frame Generation: inserts generated frames.
• Scale + Match Output: controls final processed resolution.
• Dynamic Resolution: trades detail for frame stability.

• Sources/MetalDuck/App app lifecycle, control UI, output window.
• Sources/MetalDuck/Capture ScreenCaptureKit integration.
• Sources/MetalDuck/Rendering main render loop and presentation.
• Sources/MetalDuck/Upscaling MetalFX spatial upscaler wrapper.
• Sources/MetalDuck/FrameGeneration optical-flow FG engine.
• docs/ architecture, usage, troubleshooting.

• docs/ARCHITECTURE.md
• docs/USAGE.md
• docs/FRAME_GENERATION.md
• docs/TROUBLESHOOTING.md
• docs/ROADMAP.md
• docs/RELEASE.md

MIT (LICENSE).