Non-destructive editing
Encyclopedia
Non-destructive editing is a form of editing signals where the original content is not modified in the course of editing—instead the edits themselves are edited by video editing software
on a non-linear editing system
(NLE).
A pointer-based playlist—effectively an edit decision list
(EDL)—is used to keep track of edits. Each time the edited audio or video is played back or accessed, it is reconstructed from the original source and the EDL. Although this process is more computationally intensive than rendering each edit, changing the edits themselves can be almost instantaneous, and it prevents further generation loss
as the audio or video is edited.
When videotape
was first developed in 1956 by Ampex Corporation
, the only way to edit was to physically cut the tape with a razor blade and splice segments together. While the footage excised in this process was not technically "destroyed", continuity was lost and the footage was generally discarded.
In 1963 with the introduction of the Ampex
Editec, video tape could be edited electronically with a process known as linear video editing
by selectively copying (or dubbing) the original footage to another tape called a "master". The original recordings are not destroyed or altered in this process.
Non-linear editing, originally developed in 1971 by CMX
and now the most prevalent form of editing video and film, is also non-destructive: Un-edited original footage is digitized into electronic files stored digitally on a computerized disk-based system. The edited end-product (often referred to as a "sequence" or "playlist") is simply a series of digital files played back out of the editing computer. In this case, neither the original footage nor the digitized source files are destroyed in the editing process.
Video editing software
Video editing software, is application software which handles the post-production video editing of digital video sequences on a computer non-linear editing systems...
on a non-linear editing system
Non-linear editing system
In video, a non-linear editing system is a video editing or audio editing digital audio workstation system which can perform random access non-destructive editing on the source material...
(NLE).
A pointer-based playlist—effectively an edit decision list
Edit decision list
An edit decision list or EDL used in the post-production process of film editing and video editing. The list contains an ordered list of reel and timecode data representing where each video clip can be obtained in order to conform the final cut....
(EDL)—is used to keep track of edits. Each time the edited audio or video is played back or accessed, it is reconstructed from the original source and the EDL. Although this process is more computationally intensive than rendering each edit, changing the edits themselves can be almost instantaneous, and it prevents further generation loss
Generation loss
Generation loss refers to the loss of quality between subsequent copies or transcodes of data. Anything that reduces the quality of the representation when copying, and would cause further reduction in quality on making a copy of the copy, can be considered a form of generation loss...
as the audio or video is edited.
When videotape
Videotape
A videotape is a recording of images and sounds on to magnetic tape as opposed to film stock or random access digital media. Videotapes are also used for storing scientific or medical data, such as the data produced by an electrocardiogram...
was first developed in 1956 by Ampex Corporation
Ampex
Ampex is an American electronics company founded in 1944 by Alexander M. Poniatoff. The name AMPEX is an acronym, created by its founder, which stands for Alexander M. Poniatoff Excellence...
, the only way to edit was to physically cut the tape with a razor blade and splice segments together. While the footage excised in this process was not technically "destroyed", continuity was lost and the footage was generally discarded.
In 1963 with the introduction of the Ampex
Ampex
Ampex is an American electronics company founded in 1944 by Alexander M. Poniatoff. The name AMPEX is an acronym, created by its founder, which stands for Alexander M. Poniatoff Excellence...
Editec, video tape could be edited electronically with a process known as linear video editing
Linear video editing
Linear video editing is a video editing post-production process of selecting, arranging and modifying images and sound in a predetermined, ordered sequence. Regardless whether captured by a video camera, tapeless camcorder, recorded in a television studio on a video tape recorder the content must...
by selectively copying (or dubbing) the original footage to another tape called a "master". The original recordings are not destroyed or altered in this process.
Non-linear editing, originally developed in 1971 by CMX
CMX Systems
CMX Editing Systems was a company founded jointly by CBS and Memorex, that developed some of the very first computerized systems for linear and non-linear editing of videotape for post production...
and now the most prevalent form of editing video and film, is also non-destructive: Un-edited original footage is digitized into electronic files stored digitally on a computerized disk-based system. The edited end-product (often referred to as a "sequence" or "playlist") is simply a series of digital files played back out of the editing computer. In this case, neither the original footage nor the digitized source files are destroyed in the editing process.