 Most digital turntables, whether CD or DVD, have a fader-start capability, in which the cross-fader of the audio or video mixer can tell a player to pause or play.By using these types of switchers (the Pioneer A/V switcher is a very common example), scratching video effects can show the typical back-and-forth motion heard on audio.More-advanced video mixers also have a chroma-key capability, known by most as "green screen" compositing.