Computer Editing: Editing Approaches

The phrase "video editing" is a kind of misnomer; really, what video editors do is audio/video editing. How often, in the course of your video editing, have you found yourself spending more time on the audio than on the video? It's a common occurrence in the video-editing realm.
There are two main ways in which video and audio interact, from the video editor's perspective. There are times when the audio drives the edit, setting the aesthetic direction and pacing a music video, for example, or an interview. At other times, however, the pictures will drive the sound, forcing the music, sound effects, dialogue, narration etc. to take their cues from the visual aspects of the production.
As the title of this article suggests, we're going to look at the latter of these two approaches to video editing when pictures drive sound. This is probably the most common approach to video editing the approach generally used by documentarians and feature film editors. We'll be covering some specific practices that you can use the next time you edit some video.
Letting your pictures drive your edit may seem simple and obvious. It is. In fact, this approach to video editing is probably the most intuitive way to go about it.
Note that this approach doesn't have to and in fact shouldn't begin with editing. While you're in the pre-production planning stage of your video, you should certainly keep in mind how you're going to approach the edit. If, for example, you are beginning with a piece of music of a certain length, and you know you must use the entire piece, you will not be using this approach; instead, you'll want to shoot the video to fit the sound. (For more on that topic, take a look at next month's column, When Sound Drives Picture).
Now let's take a look at a few examples of videos where the images drive the edit.

Example One: Comedy

Suppose you are going shooting a comical scene, which involves one of the most time-honored tricks of the comedy trade - deception:
Character A (Tony) is in the kitchen, preparing to eat a rather large sandwich. As he begins to dig into the hero, he hears the sound of the front door beginning to open.
Character B (Sandi), his wife, yells, "Honey! I'm home!"
With a mouthful of sandwich, Tony looks panic-stricken, and begins to dart around the kitchen. Quickly hiding the unfinished portion of the sandwich in a cupboard, he begins chewing in earnest.
Sandi yells, "Did you stick to your diet today, dear?"
Tony mumbles "Mmm-hmmm," as he struggles to chew the sandwich enough for swallowing.
Sandi then begins to relate the details of her busy day as Tony laboriously chews the huge portion.
Just as he swallows, the kitchen door opens and Sandi enters.
There are five main audio elements to this shot: the on-screen audio from Tony, three snippets of dialogue from Sandi, and the sound effect of the front door opening and closing when Sandi arrives.
Like all comedy, this sequence will only work if the timing is perfect. You may think the easiest way to pull off a scene like this would be to mike Sandi's off-camera audio while you shoot, and capture the whole thing at once. And, in fact, you may wish to proceed in this way in your shoot.
In order to get the timing perfect, however, a little editing may be in order. Because the visual portion is one big shot with no cuts, the audio must be cut to match the video. It's a simple matter, with today's computer editing systems to record each of the off-screen audio snippets as separate clips, then place them in the appropriate spot on the timeline for the most comedic effect. Even if you recorded the off-screen audio as you shot the scene, you would still have the option available to cut it into pieces in the editing room and put it together in order to achieve the appropriate comedic effect.
Attempting to shoot a scene like this "in-camera" might require elaborate timing and blocking, and would certainly require an extra microphone and an audio mixer at the very least. By waiting to set up the timing in the edit, you can make your job much easier.<…