A:Answer A video file contains roughly 24, 25 or 30 frames per second (FPS). Your HTPC has a video card which produces a signal to your TV or monitor. This signal in theory can be anything from 24, 25, 30, 50, 60, 75 or even 100Hz. i.e. 60Hz means the signal is refreshed 60 times a second. If there is a mismatch in the FPS from your media file and the Hz signal to your TV or monitor, this is most likely to be visible as judder in the video. Dynamic Refresh Rate Changer attempts to address this by synchronizing the output of the video with the rate of the TV.
https://www.team-mediaportal.com/wiki/display/MediaPortal1/Dynamic+Refresh+Rate.
