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Linear Editing Primer

How linear deck-to-deck editing works.

a primer by Eric Adler

This is a basic primer in linear editing, meant for people who already understand the basic concepts of videography.  Check back to this site for more video how-tos and other information. 

Make sure all your footage has continuous track and, if using a time code capable system, continuous time code (or at least pre- and post-roll of 5 seconds on every shot)

First you log your raw footage, or at least have a very good idea where everything is on your source tapes. 
If you have any footage that you want to do an effect between it and another piece of footage on the same tape, make a dub of that footage, remembering to allow for continous timecode or pre- and post-roll. 

Take a new tape and insert it into your editing recorder.  Fast forward it to the end then rewind it to the beginning, this will stretch and properly tension the tape. 

Diagram of a blank tape

At the beginning of the tape, record a SMPTE header.  60 seconds of SMPTE bars with 1 KHz or 440 Hz tone.  10 seconds black, 10 seconds slate, 10 seconds countdown (10 to 2, with chirps on the second but a double chirp on 2, then black), then either let the remainder of the tape record black (known as "blacking out" the tape) so that you have continuous time code or procede in assemble mode. 

Diagram of a tape with a leader
Diagram of a tape with a leader and black track

In assemble mode, you will be adding video at a particular point on the record tape and continuing from there.  Where you assemble will continue with unbroken timecode, but this will (most likely) leave a glitch at the end of the assemble operation.  Many VTRs that support edit controllers but do not have one built in will attempt to assemble when put into record mode. 

In insert mode, you will be recording on top of a track with continuous timecode, inserting on the tracks of your choice:  V, A1, A2, (and possibly A3, A4, and A5-A8).  This will replace the selected tracks with the same tracks from the source deck selected.  If you have your sources running through a mixer and a switcher (Vision Mixer for those of you in the UK), you can use multiple sources and/or play things from one audio track and mix them to another.

Once you have decided which of these best suits your needs, you can continue on. 

To make your first edit, select the mode(s) on your edit controller that you will be using.  Select your record deck with the edit controller and use the shuttle/jog and other controls to go to the point after your countdown where the video should start.  Mark your in point on the recorder and then select a source deck, find the first piece you want, mark an in point and an out point.  Now, since your edited piece should go from black to black, you should run the video output of your source to a switcher and fade it up from black, either via a GPI trigger or RS422 control from your edit controller or by timing it and fading in manually. 
Press "auto edit" or "record now" to apply this edit.  Your decks will go into motion, going a bit before the edit in point, starting playback, and if synchronized, the recorder will begin recording at the in point.  If not synchronized, the controller will either report an error state or try again.  If in a rush, you can set only in points, and the controller will continue until you press the "all stop" button or the "auto edit" button again. 

If in insert mode, at the end of the edit, your recorder will stop recording but continue to move the tape for a bit, this will prevent the deck from slowing down prior to the end of the piece and not matching with the sync on the tape.  You can insert just video, just audio, or video and audio, allowing for editing video to match audio such as music and adding voice overs to match the video shown.
Diagram of tape with leader, black track, and video inserted on

In assemble mode, the recorder will continue recording for a bit, this will allow your next edit to start without destroying part of the current edit, as there needs to be sync at the beginning of the newly laid track. 
Diagram of tape with leader and video assembled after

Your next edit will be the same as your first, except your edit system will usually automatically mark your new in point on the recorder to the out point of the previous edit.  You can continue on from this point to make a finished piece.

If you try to assemble over preexisting video or audio, you will end up with broken track at the end of the edit.  this yields a visible glitch due to a break in sync track
Diagram of tape with an assemble edit in the middle of footage
Inserting video instead of assembling video in the middle of a preexisting piece will not destroy sync and will result in a clean edit.
Diagram of tape with a video insert edit in the middle of footage

Note, the functions listed here are a primer and should work as stated for most edit controllers.  The controls used may vary.  Please read your controller's manual to check for the right functions.