Lucas film's EditDroid
In this article, we take our first look at non-linear editing, how it all began and the current situation in the market. Due to the amount of material to be covered, this article will be serialised.

The ‘Free Dictionary’ notes that  Edit - is to assemble the components of (a film or soundtrack, for example), as by cutting and splicing.

We all know that this is the basic principal, so what exactly does non-linear editing mean? Non-linear editing for film and television postproduction is a modern editing method which involves being able to access any frame in a video clip with the same ease as any other.

This method is similar in concept to the ‘cut and paste‘ technique used in film editing from the beginning.

However, when working with film, it is a destructive process, as the actual film negative must be cut. Non-linear, non-destructive methods began to appear with the introduction of digital video technology. It can also be viewed as the audio/video equivalent of word processing, which is why it is called desktop editing in the consumer space.

Video and audio data are first captured to hard disks or other digital storage devices. The data is either recorded directly to the storage device or is imported from another source. Once imported, they can be edited on a computer using any of a wide range of software. In non-linear editing, the original source files are not lost or modified during editing. Professional editing software records the decisions of the editor in an edit decision list (EDL) which can be interchanged with other editing tools.

Many generations and variations of the original source files can exist without needing to store different copies, allowing for very flexible editing. It also makes it easy to change cuts and undo previous decisions simply by editing the EDL (without having to have the actual film data duplicated). Loss of quality is also avoided due to not having to repeatedly re-encode the data when different effects are applied.

Compared to the linear method of tape-to-tape editing, non-linear editing offers the flexibility of film editing, with random access and easy project organisation. With the EDLs, the editor can work on low-resolution copies of the video. This makes it possible to edit both standard-definition broadcast quality and high definition broadcast quality very quickly on normal PCs, which don’thave the power to do the full processing of the huge full-quality high-resolution data in real-time.

The costs of editing systems have dropped such that non-linear editing tools are now within the reach of home users. Some editing software can now be accessed free as web applications.  Certain ones, like Cinelerra (focused on the professional market) and Blender3D, can be downloaded free of charge while others, like Microsoft's Windows Movie Maker or Apple Computer's iMovie, come included with the appropriate operating system.

A computer for non-linear editing of video will usually have a video capture card to capture analogue video and/or a FireWire connection to capture digital video from a DV camera, with its video editing software. Modern web based editing systems can take video directly from a camera phone over a GPRS or 3G mobile connection, and editing can take place through a web browser interface, so strictly speaking a computer for video editing does not require any installed hardware or software beyond a web browser and an internet connection. Various editing tasks can then be performed on the imported video before it is exported to another medium, or MPEG encoded for transfer to a DVD.

So that’s the short story but what about the history, how did it all begin, and how long has non-linear editing actually been around?

The first truly non-linear editor, the CMX 600, was introduced in 1971 by CMX Systems, a joint venture between CBS and Memorex. It recorded and played back black-and-white analogy video recorded in ‘skip-field‘ mode on modified disk pack drives the size of washing machines. These were commonly used to store data digitally on mainframe computers. The 600 had a console with 2 monitors built in. The right monitor, which played the preview video, was used by the editor to make cuts and edit decisions using a light pen. The editor selected from options which were superimposed as text over the preview video. The left monitor was used to display the edited video. A Digital PDP-11 computer served as a controller for the whole system. As the video edited on the 600 was in black and white and in low-resolution ‘skip-field‘ mode, the 600 was suitable only for offline editing.

Various approximations of non-linear editing systems were built in the '80s using computers coordinating multiple laser discs, or banks of VCRs. One example of these tape and disc-based systems was Lucasfilm's EditDroid, which used several laserdiscs of the same raw footage to simulate random-access editing (a compatible system was developed for sound post production by Lucasfilm called SoundDroid (one of the earliest digital audio workstations).

The term ‘nonlinear editing was formalised in 1991 with the publication of Michael Rubin's Nonlinear: A Guide to Digital Film and Video Editing, which popularised this terminology over other language common at the time, including ‘real time‘ editing, ‘random-access‘ or ‘RA‘ editing, ‘virtual‘ editing, ‘electronic film‘ editing, and so on. The handbook has remained in print and is currently in its 4th edition. Computer processing advanced sufficiently by the end of the '80s to enable true digital imagery, and has progressed today to provide this capability in personal desktop computers.

An example of computing power progressing to make non-linear editing possible was demonstrated in the first all-digital non-linear editing system to be released, the ‘Harry‘ effects compositing system manufactured by Quantel in 1985. Although it was more of a video effects system, it had some non-linear editing capabilities. Most importantly, it could record (and apply effects to) 80 seconds (due to hard disk space limitations) of broadcast-quality uncompressed digital video encoded in 8-bit CCIR 601 format on its built-in hard disk array.

In the next newsletter, we’ll look at the introduction of non-linear editing as we know it today by Editing Machines Corp (EMC) and how things progressed from there.

If you have any comments or queries on this article, or would like us to cover any other topic, please let us know.