That OS-supplied high-level video player object can demux containers, decode, play audio, and copy uncompressed frames to D3D11 textures. Then, it’s relatively easy to use DXGI surface sharing API to share the resulting RGBA8 frames from D3D11 into D3D12.
When I wanted to play video and render them inside D3D12 scenes, I have used a higher-level one, IMFMediaEngine https://learn.microsoft.com/en-us/windows/win32/api/mfmediae...
That OS-supplied high-level video player object can demux containers, decode, play audio, and copy uncompressed frames to D3D11 textures. Then, it’s relatively easy to use DXGI surface sharing API to share the resulting RGBA8 frames from D3D11 into D3D12.