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October 1997, Week 3


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Wayne Holmes <[log in to unmask]>
Reply To:
Film and TV Studies Discussion List <[log in to unmask]>
Wed, 15 Oct 1997 23:42:55 -0700
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Jayna Neagle wrote:
> I have a simple question, maybe too simple for this group.  However, I
> will ask it anyway because this has been on my mind for quite
> sometime--what is linear and non-linear editing?  what is off-line,
> on-line editing?
In LINEAR EDITING the programme is assembled by the editor shot by shot,
starting with the first shot, then the second and so on. This is
typically the process used in editing videotape. It requires considerable
forethought before each shot is edited onto the end of the existing
sequence. If you decide to alter the duration of a shot that occurs early
in your programme, you will have to re-lay (in one way or another) every
subsequent shot too.
In NON-LINEAR editing you can construct a sequence of shots in any order
you choose, and later alter the duration of any shot in any position in
the programme without affecting subsequent shots. This is true both of
film editing and of digital random access editing systems (such as Avid
or Lightworks). With film editing, however, you do still have to consider
each edit very carefully before you make it - simply because it is
awkward to change an edit later (cutting off or replacing single frames
which can then sometimes be difficult to play). What most people mean
today when they say non-linear is the non-linear digital random access
computer based systems. Here, to be honest, you don't need to pay too
much attention to each cut as you make it because each cut can be
instantly altered. I'm not arguing that as a working method, it is
probably still a good idea to carefully consider each cut before you make
it - the point is that if your decision is wrong it is easily and quickly
changeable. These systems also allow you to try relatively quickly
alternative cuts, without losing your original version. In short, these
so called non-linear systems might more usefully be referred to as random
access systems.
OFF-LINE and ON-LINE editing refer to the two principal stages of
videotape editing. They roughly correspond to EDITING (off-line) and
OPTICAL PRINTING/NEG CUTTING (on-line) in film. The terms themselves come
from the computer industry.
OFF-LINE editing usually refers to the stage during which relatively
inexpensive equipment is used by the editor to construct the essential
story of the film - what shots go where and for how long. An off-line
edit can be made using linear or non-linear or random access systems.
Usually the output of the off-line edit is a list of edit decisions (most
often in the form of a computer readable edit decision list, EDL). Often
people refer to the off-line edit as the rough cut, but this is wrong. To
be effective - ie to save you lots of money in the on-line - it must be
very accurate, identifying each shot (by tape number and timecode), its
position and duration. The only way in which it is rough is in the
technical quality of the images - depending on the system you use, the
off-line pictures can be of poor visual quality.
The EDL is used in the ON-LINE to re-conform or re-constitute the
programme using the original source footage in high quality (and hence
expensive) equipment. The first part of the process is fairly automatic,
the edit controller calls for the tapes to be inserted in turn into a
particular player. It then spools to the correct point and edits the shot
onto the record tape. Here the on-line editor's main job is technical,
ensuring that the edits are all of the highest technical quality. Once
this auto-conform process is complete, the director and on-line editor
typically will go through the programme again, adding effects,
multi-layering and titles etc. This part of the on-line editor's job can
be very creative. On-line edits can take place in tape based on-line
suites (usually consisting of two players, one recorder, an edit
controller, a mixer, a digital effects computer, a caption generator, an
audio mixer, various meters and so on) or in a random access non linear
computer based system (consisting of a single player/recorder and a
computer system such as Avid).
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