Magazine: Government Video
By Sheldon Liebman
As computer-based tools continue to evolve, it’s often helpful to evaluate them in the context of the process they replace. For example, comparing a paint package with the process of taking brush to canvas instead of comparing it with other paint programs. This month, we’re going to look at software packages designed for non-linear editing compared with the process of using a traditional A/B Roll editing system.
Getting to the Source
When you set up an A/B Roll system, it isn’t a requirement that you shot the footage yourself. You just need to have a system capable of playing it back. Obviously, you can’t play a Betacam tape on a U-Matic machine, but if you get the source in a format you can use, then you can work with it. For the purpose of this story, we’re going to assume that you can get source material as digital files in a popular format such as an Apple QuickTime file or a Microsoft AVI file. We’re going to further assume that the ultimate deliverable you want to create is a similar digital file.
By making these assumptions, we don’t have to worry about capturing video onto a computer or creating a tape once our project is completed. If you need to start with tape or end up on tape, there are two options. The first is to purchase a hardware/software NLE system from a company like Accom, Avid or Media 100. These turnkey systems include the components necessary to import and export videotaped material. You can also build your own system by purchasing products from companies like Fast, Matrox or Pinnacle, just to name a few.
Ignoring the input/output issue, we can concentrate on the software only solutions. Packages in this area include Adobe Premiere, Apple’s Final Cut, EditDV from Digital Origin, in-sync’s Speed Razor and Ulead MediaStudioPro. These products just keep adding features and the latest versions were on display at the recent SIGGRAPH trade show in Los Angeles. One of the reasons they keep getting better so quickly is that most now support the use of “plug-in” technology. With plug-ins, you can add new capabilities without needing to purchase another version of the software. Dozens of companies exist today just to supply these plug-ins. Traditional editing systems just don’t have anything to compete with that.
The Editing Console
In a standard A/B Roll setup, the input and output machines are connected to an editing console, which is also connected to a video monitor. The console is designed to control all your machines and to let you specify the locations and order of the material you wish to put onto the finished tape. In a software-based editing environment, the computer, keyboard, and mouse replace the editing console and the computer display replaces the video monitor.
Now that we’ve looked at the physical setup, we can delve into the actual process of working with the source material and creating the program. This is the point where software-based editing and traditional editing go in completely different directions. The differences are based on two very unique aspects of computer-based editing compared to traditional methods.
The first is that you can have all the material available to you all the time. Instead of having a box (or shelf) full of videotapes that need to be shuffled around constantly, non-linear editing systems can utilize as many files as you need to access the source material. If you need material from Tape #1 in the beginning and the end of the project, you don’t have to load it twice.
The second big difference is that using editing software doesn’t limit you to two tracks of video. When this type of software was first introduced, it closely followed the concept of using only two “layers” of video. Today, most editing software allows dozens, or even hundreds of tracks of video that can be used for editing as well as compositing.
Since it’s all done in software, you can create a project today that uses two layers and a project tomorrow with ten. No additional hardware is required and you don’t have to change any wires. You also have access to more than just “cuts-only” editing. All non-linear editing software packages provide dozens of transitions and effects that can be used for simple effects like wipes and dissolves to complex effects like page turns, mosaics and more.
Bin There, Spun That
The key to using NLE software effectively is the concept of bins. In most systems, virtually everything is organized into bins. Usually, bins are displayed on the upper left side of the computer screen and can provide a lot of information. If you click on a bin that has video, it can tell you the name, date and size of the file, but it might also offer a description of the contents, the video format it’s in and the starting time code.
Bins are also used to show libraries of transition effects. Many packages actually provide very small previews of the effects when this bin is open using the letters “A” and “B” to easily convey how the transition is applied to the foreground and background video channels. Since all of the previews typically have additional settings, this information can usually be accessed and adjusted by clicking on the effect. For example, you might specify how quickly a page turn occurs or how many times the video spins as it travels in or out of the frame.
When you want to add a video clip or an effect to your project, you can usually just select it with the mouse and drag it down to the spot on your timeline in which you want it to occur.
Timing is Everything
The timeline mentioned above is another key area of editing software and virtually all packages place this in the lower half of the display screen. Early packages had five “channels” in the timeline representing Video A, Video B, Transition, Audio A and Audio B.
Time starts at 0:00:00 at the left edge of the screen and progresses toward the right. In most packages, you can zoom in or out to adjust exactly how much time is displayed across your screen. This is crucial when it’s necessary to adjust the timing of events to a single frame.
Audio and video items are added to the timeline by selecting them from the bins and dragging them onto one of the available channels. When an item is positioned in this way, it’s automatically set up to start at the beginning and continue for its entire length. Placing another item on the same channel creates a cut from the end of one to the start of the next. When items are placed on different channels, transitions can be specified to occur between them, usually corresponding to the time period in which they overlap. As with video and audio, transition effects are usually selected from a bin and dragged onto the transition channel.
The Ins and Outs of Software Editing
If you only wanted to use complete clips, this might be enough to finish your project. However, it’s rarely that easy. Instead, you need the ability to set your in and out points to the exact frame you need. With editing software, this can usually be done either visually or from the keyboard. Visually, you can move your mouse to the start or end of a clip and just drag it in or out. Numerically, you can bring up the details for a clip and type in the time code for the in and out points to whatever you need.
In some packages, you may even find an option to compress or expand the time of a clip so that you can pick the footage you want and fit it exactly into the time frame you need. You can also slide clips around so that they occur earlier or later in your project.
As we’ve been describing the layout of editing software screens, we’ve covered the bins and the timeline, but we haven’t mentioned anything about the video and audio themselves. That’s usually located in upper right hand portion of the screen. This area can be used to play a low-resolution version of the video project as it stands, either in full or in part. Playing part of the project simply involves setting in and out points for the preview (instead of in and out points for specific clips).
When it’s time to actually generate the final video, all of these packages have a “Record” or “Publish” function that automatically creates every frame of the project, video and audio, with appropriate transition effects, and saves it to one of the digital file formats supported by the product. At that point, you can just stick it on a disk and deliver it to your client.
But Wait, There’s More
One of the nice things about using software is that it can offer more capabilities than traditional hardware editing systems. For instance, many of these packages have expanded beyond just editing and provide compositing functions as well. In this mode, you can create as many “channels” of video as you want and each new channel is placed on top of the ones before. If all the channels are displayed on the full screen, you only see the top layer. But, by keying out backgrounds or using 3D-style effects, you can actually view many layers of video at once and produce amazingly complex projects.
With all these layers and special effects, your simple software-based non-linear system can appear to be a multi-channel compositing and digital effects system. It can also be used to combine still images or graphics with video for other applications like titling. In fact, at least one of the software companies indicated that a titling module is under development for a future release. There really is no limit to what these systems can do as long as programmers keep improving them and third parties continue to develop plug-ins. If you’re ready to move into software editing, you’ll never want to do A/B Roll again.