To provide structure for the discussion, I'll refer to a recent project of mine that's fairly typical of the event video work that I do. The performer was Taimo Toomast, an opera singer from Estonia, and the event was his performance in a neighboring town last December. I shot the concert with two cameras and delivered finished DVDs to Toomast and the concert promoter.
The concert had two sets, each about 45 minutes long. I changed tapes during the intermission, so before editing, I had to capture three hours of video from four separate tapes.
As with many concerts, the actual editing was fairly minimal; I used Liquid Edition's Multicam interface Figure 1 to synchronize Cameras A and B, and cut from camera to camera, consolidating each set into one 45-minute clip. I had to color-correct both clips to make the colors appear consistent, add some titles and credits, and I was ready to start authoring.
Recognizing that the type of effects used to produce the concert is not representative of most wedding and other projects, I built a three-minute test project from the same footage to compare the performance of the RAM and processor configurations presented below. This test project included chromakey, color correction, still-image pan and zoom, picture-in-picture, 2D motion within the video file, and slow motion. I ran the test project through three programs—Adobe Premiere 1.5, Pinnacle Edition 6, and Sony Vegas 5— for a broader assessment of the benefits of upgrading CPU and RAM.
With all programs, I rendered this project twice to test RAM and CPU performance: first, into DV format, representing the time it would take to preview the project; and second, into MPEG-2, which of course indicates the time to render for DVD production. Then I multiplied the results by 30 to scale rendering times up to the actual 90-minute project.
To analyze the savings produced by a faster DVD recorder, I assumed that I would have to burn the final project five times, one to keep and four to give to the artist and promoter. I burned the project to DVD using Adobe Encore 1.5.
Since the advent of DV, capture has been a real-time procedure, so capturing my 180 minutes of source video would take 180 minutes, plus setup time. The only way to shorten this is by using a digital disk recorder (DDR)—essentially a hard drive attached to your camcorder—while shooting. Then, instead of capturing the video traditionally from tape, you connect the DDR to your computer via FireWire, where it looks like another hard disk, and drag the video files from the DDR to your main editing drive. For more information on DDR operation and products, check out Stephen F. Nathans' http://www.eventdv.net/Articles/ReadArticle.aspx?ArticleID=8681 and David Doering's http://www.eventdv.net/Articles/ReadArticle.aspx?ArticleID=8950.
To test the time savings produced by DDRs, we captured one hour of video with nNovia's QuickCapture A2D Figure 2 which, as the name suggests, can capture video from both analog and DV camcorders. Then we dragged the video from the DDR to our main capture drive, which took 11 minutes, a savings of 49 minutes over real-time capture, or 147 minutes for three hours of video.
Though the savings-per-hour-saved yielded by the DDR (as shown in Table 1) come with high up-front costs, consider that the QuickCapture unit and others like it also provide a backup copy of your video in the event of tape failure. During shooting, you can access your captured video on a DDR much more quickly than you can from tape, so in certain situations you can check your shots while you still have time to reshoot.
In addition, these units save wear and tear on your camcorder during capture since you're no longer using the camcorder to play the video. (You could also use a dedicated capture deck, but of course there's an equipment investment involved with that approach as well.) In a pinch, you can edit directly from the DDR when attached to your computer, eliminating the transfer time totally, though most users will likely prefer to drag the video to their main drives and edit from there. Note that less expensive DDRs are coming, though most without QuickCapture's high-quality analog-to-digital capture capability.
Central Processing Unit (CPU)
Once the video is captured to disk, it's time to start editing, where the speed of your computer's central processing unit, or CPU, becomes paramount. When considering a new system, note that upgrading your CPU can deliver three potentially complementary mechanisms to accelerate project preview and rendering.
First is CPU speed, which is represented in Gigahertz or GHz, or millions of operations per second. Simply stated, a 3.6GHz processor can perform twice as many operations per second as a 1.8GHz processor. All other things being equal, this generally translates to twice the performance, so your rendering times should drop by roughly 50%. (Of course, the real-life comparison never adds up so cleanly, which is why you have to test it.)
The next way to boost performance is to purchase a processor with Hyperthreading (HT) Technology. At a high level, processors with HT Technology can perform two logical operations simultaneously, but still can perform only one execution operation at a time. To explain, assume that a processor is a widget stamper on an assembly line. The widget stamper itself can stamp X widgets per hour—this is the execution engine. Feeding the widgets into the stamper is an assembly-line worker, which is the logical operation. If the assembly-line worker takes a break to scratch his nose or chat with his neighbor, having an extra assembly-line worker to feed widgets to the stamper boosts overall production. Even adding the extra worker, however, you'll still never produce more than X widgets per hour. Similarly, adding the additional logical operation makes the processor more efficient, but not truly faster.
In addition, programs must be rewritten to benefit from HT Technology. If the original program was highly efficient, HT Technology may provide little benefit. Like any other coding, some rewrites for HT Technology are done better than others, so may produce variable benefits. The bottom line is that you can't expect HT Technology to double your performance, and in some instances, performance boosts may be quite modest.
The third way to increase performance is by installing two processors, each of which can have HT Technology, which together look like four processors to Windows. Here you've installed an additional stamping machine, which theoretically should double performance. Again, however, application developers must modify their programs to benefit from dual processors, and performance gains vary widely by program.
To test the benefit of HT Technology and dual pro- cessors, we used a dual 3.6GHz Xeon Dell Precision 670 workstation Figure 3. In the system setup, we configured and tested the system in three different ways: as a single processor without HT Technology, as a single processor with HT Technology, and as a dual-processor system with HT Technology. We ran all configurations with 1GB of system RAM.