Somewhat minimum specs for 1080p:
CPU: Intel i5 or i7 Quad-Core or AMD FX 8xxx or 9xxx 6-Cores or 8-cores.
RAM: 4GB
GPU: Intel HD 2000 Graphics/Radeon R7 (on-board) or newer or any cheap DirectX 10 compatible GPU (e.g. Nvidia GTX 7xx or newer, AMD Radeon 5xxx or newer)
Compatible capture card of course (we recommend intenal PCI-E cards or USB 3.0 boxes)