The purpose of ReClock is to definitely get rid of jerky playback of AVI and MPEG material on a PC (or a HTPC driving a TV, a flat panel, or a video-projector). It's a DirectShow filter which is loaded in place of the default directsound audio renderer. It provides a new reference clock that is locked to the video card hardware clock, in order to ensure that frames are played at the exact speed of what is expected by the video card vertical sync. It also provides a frame rate adaptator for media files that do not match a multiple of the video card refresh rate (ex: playback of 23,976fps IVTC NTSC on a PAL TV). The combination of the two will give you the true experience of smooth playback with your PC