Native GPU video preview beneath a transparent embedded web view with zero-copy video memory decode

A desktop application architecture where a user interface in an embedded web view (WebView2) displays high-performance video through a native GPU surface instead of an HTML canvas element. A DirectX 12 / wgpu swapchain is created on the window beneath a transparent web view. The web page cuts a hole where the player is located using CSS clip-path with the even-odd fill rule. The video is rendered natively underneath while HTML menus, tooltips, and timeline controls draw seamlessly on top, solving the desktop airspace problem. For video playback, the system decoder (Media Foundation) outputs NV12 frames directly into video memory; a Direct3D 11 video processor converts them to shared BGRA textures opened via NT handles in Direct3D 12 without copying through system memory. Published as open prior art under Creative Commons Attribution 4.0 International (CC-BY 4.0).