Fx Video Capture (also known as Fx VidCap) is a multimedia tool, totally for free, that lets you make captures directly from your video or audio devices, and even from a TV signal.
The whole process in Fx Video Capture is very simple. It automatically detects and obtains the signal, and the user just indicates the start and end of the fragment they wish to capture. The resulting video is saved in AVI format.
For Fx Video Capture to work correctly you need to previously install DirectX 9.0 or later