OK, I tried to follow this guide very thoroughly, and after 15 seconds of using it the computer freezes, my explanation was that somehow since this shuttle model has 2 PCI-E x16 slots, this video card may be seen as a video graphics card and not as a video capture card.
Since the author of this post never answers questions regarding technical problem, and not Shuttle nor Blackmagic has a solution for this, don’t waste your money on this config!