Module 56

Updated: 04/05/2010

Video Editing,  Part VII

Dedicated and

Software-Based Editors

A dedicated editor is designed to do only one thing: video editing.

Dedicated editing equipment was the norm until desktop computer software started to become available in the late 1980s.

Software-based editors use desktop and laptop computers as a base. Video editing is just one of the tasks they can perform; it all depends on the software you load.

It was in the early 1990s that sophisticated video editing hardware and software became available for desktop computers. By 2000, the best laptop computers had become  powerful enough to handle sophisticated editing programs.

Historically, the Video Toaster system for the Amiga computer was the first widely used system. The basic screen for that system is shown here. The Toaster was both a video switcher and an editing system.

Thereafter, several software companies introduced computer-based editing systems for the Apple and Windows operating systems. Today's desktop and laptop computers can rival the capabilities of  dedicated editing systems. 

Simple, Free Editing Systems

Mac and Windows machines come with simple video editors. Although they aren't capable of  sophisticated effects, for assembling audio and video clips with basic transition effects (such as those typically found on YouTube) they are quite adequate.

Although some people prefer the Mac editor, the Windows Live Movie Maker shown here is simplicity in itself and it's potentially available to more computer users.

You only have to drag the video clips (either stills or movie clips) from anywhere on your computer to the area on the right.  You can trim segments as needed, add filter effects, and create special effect transitions between video segments.  If you wish, the program can automatically space the timing of the video segments to correspond with selected music or audio. The result can be output in the .WMV file format.

These simple editors can be used to create a quick "blueprint" of a production to get an idea of how shots will flow together. Later, if you need more elaborate special effect filters or color correction, the original footage can be put trough a more sophisticated video editor.

The illustration below shows a basic representation of how scenes, transitions, and audio sources can be represented on the timeline of a more sophisticated editing system.  A mouse is used to drag the elements into different positions.

Note that one sequence of video segments is represented in the dark blue area at the top of the illustration and another in dark blue below that.  In between, transition effects, filters, and visual effects are represented.

At the bottom the audio elements (music, narration, and special effect tracks) are shown in light blue. Relative levels and transitions are controlled by a mouse and drop-down menu selections.

Compositing

The question arises, what happens if you select two video sources for display at the same time -- for example, in the above illustration Scene 1 and Scene 2 without the transition effect?

Answer: As you might expect, you simply end up with one scene on top of the other -- which may result in a mess, or (if you know what you are doing) a crafted effect in compositing or layering.

In it's most basic form you get a superimposition ("super") or a key effect, which we illustrate in Module 60 through the use of a video switcher.  However, with an editing system such as the one shown below it's possible to combine multiple video sources and create much more sophisticated effects.

For example, you can place at least two video clips on your editor timeline, one directly above the other and by adjusting the individual layers -- turning down the opacity, cropping, or keying out parts of each one as needed -- you'll see the combined effect. Using this technique you can add titles over video, substitute elements in a scene (such a adding a new background) or create a variety of visual effects.

The Avid editing screen shown below more accurately depicts how timelines actually look on an editing system.  This particular system allows you to mix standard-definition and high-definition video in the same project -- an important consideration during this period of analog-to-digital transition.

Although you can edit audio on a machine like the one above (note the two tracks of audio on the time-line at the bottom of the screen) for more demanding audio editing you will want to consider a sophisticated audio editing system like this one.

With sophisticate editing systems there are a variety of video filters and plug-ins (software additions that add various effect options to the original editing program). 

Examples are various types of blur, color corrections, cropping, sharpening, fog effects, geometric distortions, and even image stabilization.

The latter attempts to lock onto a central element in a scene and keep it from moving, thus canceling moderate camera shake. More on that later.

Although it's not possible to create detail that isn't in video to start with, with some plug-ins it's possible to rather convincingly convert standard definition video (SDTV) to HDTV. 

As we've noted, there are both dedicated and software based laptop editing systems.

An example of a rugged dedicated system is this Panasonic field editing unit, primarily used in news work. Note that the controls designed exclusively for video and audio editing.

However, with computer-based systems you have the advantage of a wide variety of "off the shelf" laptop computers, plus the software can be readily switched and upgraded.

In addition to editing, computer-based systems can accommodate other computer programs, such as those used to write news scripts.

Computer-based editing used to be confined to especially modified ("souped up") desktop computers.  However, in recent years high end laptop computers can do most anything desktop systems can.

These computers typically use a FireWire, IEEE 1394, USB-2, or i.Link cable connection to download the video from the camcorder to the computer's hard drive.

Because video information takes up a lot of digital space, these computers need a high-capacity hard-drive. (One minute of uncompressed video requires about one gigabyte (GB) of disk space.)

One of the best ways to learn how a nonlinear editor works is simply to play with one for several hours. One popular nonlinear editing program, Adobe Premiere, is available on the Internet for download. This demo version—if it's still available when you read this—does everything but save files. If you are interested, click on Premiere.

The professional editing programs tend to be quite expensive, so if you want to postpone that kind of an investment, you can check out Avidemux. This free editing program runs on all the major computer operating systems.  It supports many file types, including AVI, DVD compatible MPEG files, MP4 and ASF, using a variety of codecs. There's an associated forum on the site.

Even though most computer-based editing systems today are non-linear, at this point we need to point out the difference between linear and non-linear systems.

Linear and Non-Linear Editing Systems

Working on a non-linear editing system is like working with a sophisticated word processor. Using a computer screen and a mouse you can randomly cut and past segments and move them around until you are satisfied with the result. Working on a linear editing system is a bit like using a typewriter to type a term paper; you need to assemble everything in the proper sequence as you go along. After it's all on paper (or in this case recorded), adding, deleting or rearranging things can be a major problem.

With nonlinear editing the video and audio segments are not permanently recorded as you go along as they are in linear editing. The edit decisions exist in computer memory as a series of internal digital markers that tell the computer where to look for segments on the hard disk.

This means that at any point you can instantly check your work and make adjustments. It also means that you can easily (and seemingly endlessly!) experiment with audio and video possibilities.

Sony's complete high-definition NLE (non-linear editing, or random access editing) system is shown below. This editing system compliments Sony's line of XDCAM cameras.

Although a sophisticated nonlinear (random access) editing system such as the one above may take a while to learn, once you figure one out, you can  transfer the basic skills to other editing programs.

After you finalize your edit decisions most editing systems allow you to save your EDL (edit decision list) — preferable on some removable media that you can take with you in case you need it again. This will save you from having to start from scratch if you later want to come back to the original footage to make revisions.

The final edited video and audio output can be handled in two ways.

It can be "printed" (transferred) in final, linear form to videotape or a DVD or it can remain on a computer drive to be recalled and modified as needed. The latter approach, which is often used for segments in newscasts, requires high-capacity storage devices such as... 

File Servers

Video and audio segments—especially HDTV—take up a great amount of hard disk storage space.

Instead of trying to replicate the needed storage in each desktop computer, many  facilities use a centralized mass storage device called a file server, sometimes called a media server or video server (shown here.)

These were introduced in an earlier module.  Even editing programs  can be run from a server.

A centralized video server not only gives all of the computer editing stations the advantage of having access to large amounts of storage, but it means that segments can be reviewed, edited, or played back from any of the editing workstations (desktop or laptop computers equipped with a network connection) within the facility.

As high-speed, Internet connections become commonplace, you will be able to link to a media server from any location — even your home — and edit and re-edit pieces. In fact, many professionals are doing that now.