Manipulating video footage, especially by looping and reversing scenes to achieve an effect or to follow the beat of a song.
Just as scratching and sampling has forever changed music, video scratching is starting to revolutionize musical performances.
The process is remarkably similar. Using a pair of Titanium G4 PowerBooks and Apple's Final Cut Pro 3 video editing software, the Video DJs (VJs) can match the rhythm of any video footage to the tempo of the music.
Using a standard video-mixing desk, the VJs blend and cross fade between two feeds, one from each PowerBook. A video-editing jog-shuttle allows them to scratch the video; so Fred Astaire is made to go through the same graceful twirl back and forth to the rhythm of a drum and bass track.
Leander Kahney, "Video scratching on M-M-Macs," Wired News, July 12, 2002
One product set to reach the consumer market in 1995 is VuJak, a non-linear video editing and realtime performance tool from L.A.-based D/Zone that allows the user to manipulate video, text, graphics, audio, music, and special effects using any MIDI input device. . . . Club-based VJs now can follow in their audio counterparts' footsteps, with the potential to popularize a new form of entertainment known as "video scratching," Petit says.
Deborah Russell, "VuJak Heralds Era Of Video Sampling," Billboard, January 14, 1995
EBN's O'Donnell, meanwhile, is responsible for searching the video archives for recorded material to integrate into the group's live shows using traditional DJ techniques of cutting, scratching, and transforming.
Deborah Russell, "EBN's Not-So-Mindless Entertainment," Billboard, March 20, 1993
As hinted in the example citation, the original form of scratching was the musical kind, which is called album scratching or vinyl scratching and dates to the early 1980s. This turntablism (1997) involves moving a small segment of a vinyl record back and forth under the needle, timing the movement to the beat or rhythm of a song.
Video scratching uses powerful computer hardware and software to achieve a similar effect using video footage. According to the above Wired News article, the technique was created the Emergency Broadcast Network (who called themselves a "guerrilla media group") in the late 1980s. References to video scratching appear as early as 1993 in Usenet newsgroups.